Clean up our Objective-C usage

- Move ivars into @implementation
- Use instancetype where applicable
- Use dot notation for property access
- Use subscript operator for dictionaries and arrays
- Format selectors consistently
- Use proper style for init methods
- Use generics instead of void pointers where possible
- Use "range for" loops instead of indexing
- Replace or replace IBAction/IBOutlet with void

Change-Id: I1667812a51d4dfe44ae80fe337cb1f4bc9699d92
Reviewed-by: Jake Petroules <jake.petroules@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

62 files changed, 598 insertions, 687 deletions

diff --git a/src/corelib/io/qfilesystemwatcher_fsevents.mm b/src/corelib/io/qfilesystemwatcher_fsevents.mm
index 792ea387ac..844aa9daa7 100644
--- a/src/corelib/io/qfilesystemwatcher_fsevents.mm
+++ b/src/corelib/io/qfilesystemwatcher_fsevents.mm
@@ -499,7 +499,7 @@ bool QFseventsFileSystemWatcherEngine::startStream()
 
     DEBUG() << "Starting stream with paths" << watchingState.watchedPaths.keys();
 
-    NSMutableArray *pathsToWatch = [NSMutableArray arrayWithCapacity:watchingState.watchedPaths.size()];
+    NSMutableArray<NSString *> *pathsToWatch = [NSMutableArray<NSString *> arrayWithCapacity:watchingState.watchedPaths.size()];
     for (PathRefCounts::const_iterator i = watchingState.watchedPaths.begin(), ei = watchingState.watchedPaths.end(); i != ei; ++i)
         [pathsToWatch addObject:i.key().toNSString()];
 
diff --git a/src/corelib/kernel/qcore_mac_objc.mm b/src/corelib/kernel/qcore_mac_objc.mm
index 24d73fa8be..b91b5e76be 100644
--- a/src/corelib/kernel/qcore_mac_objc.mm
+++ b/src/corelib/kernel/qcore_mac_objc.mm
@@ -87,19 +87,20 @@ QT_FOR_EACH_MUTABLE_CORE_GRAPHICS_TYPE(QT_DECLARE_WEAK_QDEBUG_OPERATOR_FOR_CF_TY
 QT_END_NAMESPACE
 QT_USE_NAMESPACE
 @interface QT_MANGLE_NAMESPACE(QMacAutoReleasePoolTracker) : NSObject
-{
+@end
+
+@implementation QT_MANGLE_NAMESPACE(QMacAutoReleasePoolTracker) {
     NSAutoreleasePool **m_pool;
 }
--(id)initWithPool:(NSAutoreleasePool**)pool;
-@end
-@implementation QT_MANGLE_NAMESPACE(QMacAutoReleasePoolTracker)
--(id)initWithPool:(NSAutoreleasePool**)pool
+
+- (instancetype)initWithPool:(NSAutoreleasePool **)pool
 {
-    if (self = [super init])
+    if ((self = [self init]))
         m_pool = pool;
     return self;
 }
--(void)dealloc
+
+- (void)dealloc
 {
     if (*m_pool) {
         // The pool is still valid, which means we're not being drained from
diff --git a/src/corelib/kernel/qeventdispatcher_cf.mm b/src/corelib/kernel/qeventdispatcher_cf.mm
index 8499b3fd57..35b2390c6d 100644
--- a/src/corelib/kernel/qeventdispatcher_cf.mm
+++ b/src/corelib/kernel/qeventdispatcher_cf.mm
@@ -58,18 +58,18 @@
 
 QT_USE_NAMESPACE
 
-@interface QT_MANGLE_NAMESPACE(RunLoopModeTracker) : NSObject {
-    QStack<CFStringRef> m_runLoopModes;
-}
+@interface QT_MANGLE_NAMESPACE(RunLoopModeTracker) : NSObject
 @end
 
 QT_NAMESPACE_ALIAS_OBJC_CLASS(RunLoopModeTracker);
 
-@implementation RunLoopModeTracker
+@implementation RunLoopModeTracker {
+    QStack<CFStringRef> m_runLoopModes;
+}
 
-- (id) init
+- (instancetype)init
 {
-    if (self = [super init]) {
+    if ((self = [super init])) {
         m_runLoopModes.push(kCFRunLoopDefaultMode);
 
         [[NSNotificationCenter defaultCenter]
@@ -77,21 +77,21 @@ QT_NAMESPACE_ALIAS_OBJC_CLASS(RunLoopModeTracker);
             selector:@selector(receivedNotification:)
             name:nil
 #ifdef Q_OS_OSX
-            object:[NSApplication sharedApplication]];
+            object:NSApplication.sharedApplication];
 #elif defined(Q_OS_WATCHOS)
-            object:[WKExtension sharedExtension]];
+            object:WKExtension.sharedExtension];
 #else
             // Use performSelector so this can work in an App Extension
-            object:[[UIApplication class] performSelector:@selector(sharedApplication)]];
+            object:[UIApplication.class performSelector:@selector(sharedApplication)]];
 #endif
     }
 
     return self;
 }
 
-- (void) dealloc
+- (void)dealloc
 {
-    [[NSNotificationCenter defaultCenter] removeObserver:self];
+    [NSNotificationCenter.defaultCenter removeObserver:self];
 
     [super dealloc];
 }
@@ -100,13 +100,13 @@ static CFStringRef runLoopMode(NSDictionary *dictionary)
 {
     for (NSString *key in dictionary) {
         if (CFStringHasSuffix((CFStringRef)key, CFSTR("RunLoopMode")))
-            return (CFStringRef)[dictionary objectForKey: key];
+            return (CFStringRef)dictionary[key];
     }
 
     return nil;
 }
 
-- (void) receivedNotification:(NSNotification *) notification
+- (void)receivedNotification:(NSNotification *)notification
 {
      if (CFStringHasSuffix((CFStringRef)notification.name, CFSTR("RunLoopModePushNotification"))) {
         if (CFStringRef mode = runLoopMode(notification.userInfo))
@@ -116,7 +116,7 @@ static CFStringRef runLoopMode(NSDictionary *dictionary)
 
      } else if (CFStringHasSuffix((CFStringRef)notification.name, CFSTR("RunLoopModePopNotification"))) {
         CFStringRef mode = runLoopMode(notification.userInfo);
-        if (CFStringCompare(mode, [self currentMode], 0) == kCFCompareEqualTo)
+        if (CFStringCompare(mode, self.currentMode, 0) == kCFCompareEqualTo)
             m_runLoopModes.pop();
         else
             qCWarning(lcEventDispatcher) << "Tried to pop run loop mode"
@@ -126,7 +126,7 @@ static CFStringRef runLoopMode(NSDictionary *dictionary)
      }
 }
 
-- (CFStringRef) currentMode
+- (CFStringRef)currentMode
 {
     return m_runLoopModes.top();
 }
diff --git a/src/platformsupport/clipboard/qmacmime.mm b/src/platformsupport/clipboard/qmacmime.mm
index 09901ba0a5..caa2ccc6e5 100644
--- a/src/platformsupport/clipboard/qmacmime.mm
+++ b/src/platformsupport/clipboard/qmacmime.mm
@@ -536,13 +536,13 @@ QVariant QMacPasteboardMimeRtfText::convertToMime(const QString &mimeType, QList
 
     // Read RTF into to NSAttributedString, then convert the string to HTML
     NSAttributedString *string = [[NSAttributedString alloc] initWithData:data.at(0).toNSData()
-            options:[NSDictionary dictionaryWithObject:NSRTFTextDocumentType forKey:NSDocumentTypeDocumentAttribute]
+            options:@{NSDocumentTypeDocumentAttribute: NSRTFTextDocumentType}
             documentAttributes:nil
             error:nil];
 
     NSError *error;
     NSRange range = NSMakeRange(0, [string length]);
-    NSDictionary *dict = [NSDictionary dictionaryWithObject:NSHTMLTextDocumentType forKey:NSDocumentTypeDocumentAttribute];
+    NSDictionary *dict = @{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType};
     NSData *htmlData = [string dataFromRange:range documentAttributes:dict error:&error];
     return QByteArray::fromNSData(htmlData);
 }
@@ -554,13 +554,13 @@ QList<QByteArray> QMacPasteboardMimeRtfText::convertFromMime(const QString &mime
         return ret;
 
     NSAttributedString *string = [[NSAttributedString alloc] initWithData:data.toByteArray().toNSData()
-            options:[NSDictionary dictionaryWithObject:NSHTMLTextDocumentType forKey:NSDocumentTypeDocumentAttribute]
+            options:@{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType}
             documentAttributes:nil
             error:nil];
 
     NSError *error;
     NSRange range = NSMakeRange(0, [string length]);
-    NSDictionary *dict = [NSDictionary dictionaryWithObject:NSRTFTextDocumentType forKey:NSDocumentTypeDocumentAttribute];
+    NSDictionary *dict = @{NSDocumentTypeDocumentAttribute: NSRTFTextDocumentType};
     NSData *rtfData = [string dataFromRange:range documentAttributes:dict error:&error];
     ret << QByteArray::fromNSData(rtfData);
     return ret;
@@ -853,8 +853,8 @@ QList<QByteArray> QMacPasteboardMimeTiff::convertFromMime(const QString &mime, Q
 
     QImage img = qvariant_cast<QImage>(variant);
     NSDictionary *props = @{
-        static_cast<NSString *>(kCGImagePropertyPixelWidth) : [NSNumber numberWithInt:img.width()],
-        static_cast<NSString *>(kCGImagePropertyPixelHeight) : [NSNumber numberWithInt:img.height()]
+        static_cast<NSString *>(kCGImagePropertyPixelWidth): @(img.width()),
+        static_cast<NSString *>(kCGImagePropertyPixelHeight): @(img.height())
     };
 
     CGImageDestinationAddImage(imageDestination, qt_mac_toCGImage(img), static_cast<CFDictionaryRef>(props));
diff --git a/src/platformsupport/fontdatabases/mac/qcoretextfontdatabase.mm b/src/platformsupport/fontdatabases/mac/qcoretextfontdatabase.mm
index 5eb5cd8a30..85d213ad46 100644
--- a/src/platformsupport/fontdatabases/mac/qcoretextfontdatabase.mm
+++ b/src/platformsupport/fontdatabases/mac/qcoretextfontdatabase.mm
@@ -101,14 +101,14 @@ enum { LanguageCount = sizeof(languageForWritingSystem) / sizeof(const char *) }
 #ifdef Q_OS_OSX
 static NSInteger languageMapSort(id obj1, id obj2, void *context)
 {
-    NSArray *map1 = (NSArray *) obj1;
-    NSArray *map2 = (NSArray *) obj2;
-    NSArray *languages = (NSArray *) context;
+    NSArray<NSString *> *map1 = reinterpret_cast<NSArray<NSString *> *>(obj1);
+    NSArray<NSString *> *map2 = reinterpret_cast<NSArray<NSString *> *>(obj2);
+    NSArray<NSString *> *languages = reinterpret_cast<NSArray<NSString *> *>(context);
 
-    NSString *lang1 = [map1 objectAtIndex: 0];
-    NSString *lang2 = [map2 objectAtIndex: 0];
+    NSString *lang1 = [map1 objectAtIndex:0];
+    NSString *lang2 = [map2 objectAtIndex:0];
 
-    return [languages indexOfObject: lang1] - [languages indexOfObject: lang2];
+    return [languages indexOfObject:lang1] - [languages indexOfObject:lang2];
 }
 #endif
 
@@ -184,23 +184,9 @@ QCoreTextFontDatabase::~QCoreTextFontDatabase()
         CFRelease(ref);
 }
 
-static CFArrayRef availableFamilyNames()
-{
-#if QT_DARWIN_PLATFORM_SDK_EQUAL_OR_ABOVE(1060, 100000, 100000, 30000)
-    if (&CTFontManagerCopyAvailableFontFamilyNames)
-        return CTFontManagerCopyAvailableFontFamilyNames();
-#endif
-#if defined(QT_PLATFORM_UIKIT)
-    CFMutableArrayRef familyNames = CFArrayCreateMutableCopy(kCFAllocatorDefault, 0, (CFArrayRef)[UIFont familyNames]);
-    CFArrayAppendValue(familyNames, CFSTR(".PhoneFallback"));
-    return familyNames;
-#endif
-    Q_UNREACHABLE();
-}
-
 void QCoreTextFontDatabase::populateFontDatabase()
 {
-    QCFType<CFArrayRef> familyNames = availableFamilyNames();
+    QCFType<CFArrayRef> familyNames = CTFontManagerCopyAvailableFontFamilyNames();
     for (NSString *familyName in familyNames.as<const NSArray *>())
         QPlatformFontDatabase::registerFontFamily(QString::fromNSString(familyName));
 
@@ -220,7 +206,7 @@ bool QCoreTextFontDatabase::populateFamilyAliases()
     if (m_hasPopulatedAliases)
         return false;
 
-    QCFType<CFArrayRef> familyNames = availableFamilyNames();
+    QCFType<CFArrayRef> familyNames = CTFontManagerCopyAvailableFontFamilyNames();
     for (NSString *familyName in familyNames.as<const NSArray *>()) {
         NSFontManager *fontManager = [NSFontManager sharedFontManager];
         NSString *localizedFamilyName = [fontManager localizedNameForFamily:familyName face:nil];
@@ -570,21 +556,21 @@ QStringList QCoreTextFontDatabase::fallbacksForFamily(const QString &family, QFo
     if (!didPopulateStyleFallbacks) {
 #if defined(Q_OS_MACX)
         NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
-        NSArray *languages = [defaults stringArrayForKey: @"AppleLanguages"];
+        NSArray<NSString *> *languages = [defaults stringArrayForKey:@"AppleLanguages"];
 
-        NSDictionary *fallbackDict = [NSDictionary dictionaryWithContentsOfFile: @"/System/Library/Frameworks/ApplicationServices.framework/Frameworks/CoreText.framework/Resources/DefaultFontFallbacks.plist"];
+        NSDictionary<NSString *, id> *fallbackDict = [NSDictionary<NSString *, id> dictionaryWithContentsOfFile:@"/System/Library/Frameworks/ApplicationServices.framework/Frameworks/CoreText.framework/Resources/DefaultFontFallbacks.plist"];
 
         for (NSString *style in [fallbackDict allKeys]) {
-            NSArray *list = [fallbackDict valueForKey: style];
+            NSArray *list = [fallbackDict valueForKey:style];
             QFont::StyleHint fallbackStyleHint = styleHintFromNSString(style);
             QStringList fallbackList;
             for (id item in list) {
                 // sort the array based on system language preferences
-                if ([item isKindOfClass: [NSArray class]]) {
-                    NSArray *langs = [(NSArray *) item sortedArrayUsingFunction: languageMapSort
-                                                                        context: languages];
-                    for (NSArray *map in langs)
-                        fallbackList.append(familyNameFromPostScriptName([map objectAtIndex: 1]));
+                if ([item isKindOfClass:[NSArray class]]) {
+                    NSArray *langs = [reinterpret_cast<NSArray *>(item)
+                        sortedArrayUsingFunction:languageMapSort context:languages];
+                    for (NSArray<NSString *> *map in langs)
+                        fallbackList.append(familyNameFromPostScriptName([map objectAtIndex:1]));
                 }
                 else if ([item isKindOfClass: [NSString class]])
                     fallbackList.append(familyNameFromPostScriptName(item));
diff --git a/src/plugins/bearer/corewlan/qcorewlanengine.mm b/src/plugins/bearer/corewlan/qcorewlanengine.mm
index 341d3bccf2..c3dd49ff3e 100644
--- a/src/plugins/bearer/corewlan/qcorewlanengine.mm
+++ b/src/plugins/bearer/corewlan/qcorewlanengine.mm
@@ -62,33 +62,29 @@ extern "C" { // Otherwise it won't find CWKeychain* symbols at link time
 #include <ifaddrs.h>
 
 @interface QT_MANGLE_NAMESPACE(QNSListener) : NSObject <CWEventDelegate>
-{
-    NSNotificationCenter *notificationCenter;
-    CWWiFiClient *client;
-    QCoreWlanEngine *engine;
-    NSLock *locker;
-}
-- (void)powerStateDidChangeForWiFiInterfaceWithName:(NSString *)interfaceName;
-- (void)remove;
-- (void)setEngine:(QCoreWlanEngine *)coreEngine;
-- (QCoreWlanEngine *)engine;
-- (void)dealloc;
 
 @property (assign) QCoreWlanEngine* engine;
 
 @end
 
-@implementation QT_MANGLE_NAMESPACE(QNSListener)
+@implementation QT_MANGLE_NAMESPACE(QNSListener) {
+    NSNotificationCenter *notificationCenter;
+    CWWiFiClient *client;
+    QCoreWlanEngine *engine;
+    NSLock *locker;
+}
 
-- (id) init
+- (instancetype)init
 {
-    [locker lock];
-    QMacAutoReleasePool pool;
-    notificationCenter = [NSNotificationCenter defaultCenter];
-    client = [CWWiFiClient sharedWiFiClient];
-    client.delegate = self;
-    [client startMonitoringEventWithType:CWEventTypePowerDidChange error:nil];
-    [locker unlock];
+    if ((self = [super init])) {
+        [locker lock];
+        QMacAutoReleasePool pool;
+        notificationCenter = [NSNotificationCenter defaultCenter];
+        client = [CWWiFiClient sharedWiFiClient];
+        client.delegate = self;
+        [client startMonitoringEventWithType:CWEventTypePowerDidChange error:nil];
+        [locker unlock];
+    }
     return self;
 }
 
@@ -300,7 +296,7 @@ void QScanThread::getUserConfigurations()
         if(airportPlist != nil) {
             NSDictionary *prefNetDict = [airportPlist objectForKey:@"PreferredNetworks"];
 
-            NSArray *thisSsidarray = [prefNetDict valueForKey:@"SSID_STR"];
+            NSArray<NSString *> *thisSsidarray = [prefNetDict valueForKey:@"SSID_STR"];
             for (NSString *ssidkey in thisSsidarray) {
                 QString thisSsid = QString::fromNSString(ssidkey);
                 if(!userProfiles.contains(thisSsid)) {
diff --git a/src/plugins/platforms/cocoa/qcocoaaccessibility.h b/src/plugins/platforms/cocoa/qcocoaaccessibility.h
index e456364555..457c158ddc 100644
--- a/src/plugins/platforms/cocoa/qcocoaaccessibility.h
+++ b/src/plugins/platforms/cocoa/qcocoaaccessibility.h
@@ -46,6 +46,8 @@
 
 #ifndef QT_NO_ACCESSIBILITY
 
+@class QT_MANGLE_NAMESPACE(QMacAccessibilityElement);
+
 QT_BEGIN_NAMESPACE
 
 class QCocoaAccessibility : public QPlatformAccessibility
@@ -82,9 +84,8 @@ namespace QCocoaAccessible {
 NSString *macRole(QAccessibleInterface *interface);
 NSString *macSubrole(QAccessibleInterface *interface);
 bool shouldBeIgnored(QAccessibleInterface *interface);
-NSArray *unignoredChildren(QAccessibleInterface *interface);
+NSArray<QT_MANGLE_NAMESPACE(QMacAccessibilityElement) *> *unignoredChildren(QAccessibleInterface *interface);
 NSString *getTranslatedAction(const QString &qtAction);
-NSMutableArray *createTranslatedActionsList(const QStringList &qtActions);
 QString translateAction(NSString *nsAction, QAccessibleInterface *interface);
 bool hasValueAttribute(QAccessibleInterface *interface);
 id getValueAttribute(QAccessibleInterface *interface);
diff --git a/src/plugins/platforms/cocoa/qcocoaaccessibility.mm b/src/plugins/platforms/cocoa/qcocoaaccessibility.mm
index 8b6dcb35a6..0a773ced29 100644
--- a/src/plugins/platforms/cocoa/qcocoaaccessibility.mm
+++ b/src/plugins/platforms/cocoa/qcocoaaccessibility.mm
@@ -257,12 +257,12 @@ bool shouldBeIgnored(QAccessibleInterface *interface)
     return false;
 }
 
-NSArray *unignoredChildren(QAccessibleInterface *interface)
+NSArray<QMacAccessibilityElement *> *unignoredChildren(QAccessibleInterface *interface)
 {
     int numKids = interface->childCount();
     // qDebug() << "Children for: " << axid << iface << " are: " << numKids;
 
-    NSMutableArray *kids = [NSMutableArray arrayWithCapacity:numKids];
+    NSMutableArray<QMacAccessibilityElement *> *kids = [NSMutableArray<QMacAccessibilityElement *> arrayWithCapacity:numKids];
     for (int i = 0; i < numKids; ++i) {
         QAccessibleInterface *child = interface->child(i);
         if (!child || !child->isValid() || child->state().invalid || child->state().invisible)
@@ -387,7 +387,7 @@ id getValueAttribute(QAccessibleInterface *interface)
     }
 
     if (interface->state().checkable) {
-        return [NSNumber numberWithInt: (interface->state().checked ? 1 : 0)];
+        return interface->state().checked ? @(1) : @(0);
     }
 
     return nil;
diff --git a/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.h b/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.h
index 07f3f3a99e..914aaa2b1b 100644
--- a/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.h
+++ b/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.h
@@ -52,13 +52,10 @@
 
 @class QT_MANGLE_NAMESPACE(QMacAccessibilityElement);
 
-@interface QT_MANGLE_NAMESPACE(QMacAccessibilityElement) : NSObject {
-    NSString *role;
-    QAccessible::Id axid;
-}
+@interface QT_MANGLE_NAMESPACE(QMacAccessibilityElement) : NSObject
 
-- (id)initWithId:(QAccessible::Id)anId;
-+ (QT_MANGLE_NAMESPACE(QMacAccessibilityElement) *)elementWithId:(QAccessible::Id)anId;
+- (instancetype)initWithId:(QAccessible::Id)anId;
++ (instancetype)elementWithId:(QAccessible::Id)anId;
 
 @end
 
diff --git a/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm b/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm
index df2336d08b..ad251a6a44 100644
--- a/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm
+++ b/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm
@@ -99,9 +99,12 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
         *end = curEnd;
 }
 
-@implementation QMacAccessibilityElement
+@implementation QMacAccessibilityElement {
+    NSString *role;
+    QAccessible::Id axid;
+}
 
-- (id)initWithId:(QAccessible::Id)anId
+- (instancetype)initWithId:(QAccessible::Id)anId
 {
     Q_ASSERT((int)anId < 0);
     self = [super init];
@@ -115,7 +118,7 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
     return self;
 }
 
-+ (id)elementWithId:(QAccessible::Id)anId
++ (instancetype)elementWithId:(QAccessible::Id)anId
 {
     Q_ASSERT(anId);
     if (!anId)
@@ -168,22 +171,15 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
 {
     QStringRef textBefore = QStringRef(&text, 0, index);
     int newlines = textBefore.count(QLatin1Char('\n'));
-    return [NSNumber numberWithInt: newlines];
+    return @(newlines);
 }
 
 - (BOOL) accessibilityNotifiesWhenDestroyed {
     return YES;
 }
 
-- (NSArray *)accessibilityAttributeNames {
-    static NSArray *defaultAttributes = nil;
-
-    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
-    if (!iface || !iface->isValid())
-        return defaultAttributes;
-
-    if (defaultAttributes == nil) {
-        defaultAttributes = [[NSArray alloc] initWithObjects:
+- (NSArray<NSString *> *)accessibilityAttributeNames {
+    static NSArray<NSString *> *defaultAttributes = [@[
         NSAccessibilityRoleAttribute,
         NSAccessibilityRoleDescriptionAttribute,
         NSAccessibilitySubroleAttribute,
@@ -196,35 +192,36 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
         NSAccessibilitySizeAttribute,
         NSAccessibilityTitleAttribute,
         NSAccessibilityDescriptionAttribute,
-        NSAccessibilityEnabledAttribute,
-        nil];
-    }
+        NSAccessibilityEnabledAttribute
+    ] retain];
+
+    QAccessibleInterface *iface = QAccessible::accessibleInterface(axid);
+    if (!iface || !iface->isValid())
+        return defaultAttributes;
 
-    NSMutableArray *attributes = [[NSMutableArray alloc] initWithCapacity : [defaultAttributes count]];
-    [attributes addObjectsFromArray : defaultAttributes];
+    NSMutableArray<NSString *> *attributes = [[NSMutableArray<NSString *> alloc] initWithCapacity:defaultAttributes.count];
+    [attributes addObjectsFromArray:defaultAttributes];
 
     if (QCocoaAccessible::hasValueAttribute(iface)) {
-        [attributes addObject : NSAccessibilityValueAttribute];
+        [attributes addObject:NSAccessibilityValueAttribute];
     }
 
     if (iface->textInterface()) {
-        [attributes addObjectsFromArray: [[NSArray alloc] initWithObjects:
+        [attributes addObjectsFromArray:@[
             NSAccessibilityNumberOfCharactersAttribute,
             NSAccessibilitySelectedTextAttribute,
             NSAccessibilitySelectedTextRangeAttribute,
             NSAccessibilityVisibleCharacterRangeAttribute,
-            NSAccessibilityInsertionPointLineNumberAttribute,
-            nil
+            NSAccessibilityInsertionPointLineNumberAttribute
         ]];
 
 // TODO: multi-selection: NSAccessibilitySelectedTextRangesAttribute,
     }
 
     if (iface->valueInterface()) {
-        [attributes addObjectsFromArray: [[NSArray alloc] initWithObjects:
+        [attributes addObjectsFromArray:@[
             NSAccessibilityMinValueAttribute,
-            NSAccessibilityMaxValueAttribute,
-            nil
+            NSAccessibilityMaxValueAttribute
         ]];
     }
 
@@ -261,13 +258,13 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
 
 - (id) minValueAttribute:(QAccessibleInterface*)iface {
     if (QAccessibleValueInterface *val = iface->valueInterface())
-        return [NSNumber numberWithDouble: val->minimumValue().toDouble()];
+        return @(val->minimumValue().toDouble());
     return nil;
 }
 
 - (id) maxValueAttribute:(QAccessibleInterface*)iface {
     if (QAccessibleValueInterface *val = iface->valueInterface())
-        return [NSNumber numberWithDouble: val->maximumValue().toDouble()];
+        return @(val->maximumValue().toDouble());
     return nil;
 }
 
@@ -289,7 +286,7 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
     } else if ([attribute isEqualToString:NSAccessibilityFocusedAttribute]) {
         // Just check if the app thinks we're focused.
         id focusedElement = [NSApp accessibilityAttributeValue:NSAccessibilityFocusedUIElementAttribute];
-        return [NSNumber numberWithBool:[focusedElement isEqual:self]];
+        return @([focusedElement isEqual:self]);
     } else if ([attribute isEqualToString:NSAccessibilityParentAttribute]) {
         return NSAccessibilityUnignoredAncestor([self parentElement]);
     } else if ([attribute isEqualToString:NSAccessibilityWindowAttribute]) {
@@ -312,7 +309,7 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
     } else if ([attribute isEqualToString:NSAccessibilityDescriptionAttribute]) {
         return iface->text(QAccessible::Description).toNSString();
     } else if ([attribute isEqualToString:NSAccessibilityEnabledAttribute]) {
-        return [NSNumber numberWithBool:!iface->state().disabled];
+        return @(!iface->state().disabled);
     } else if ([attribute isEqualToString:NSAccessibilityValueAttribute]) {
         // VoiceOver asks for the value attribute for all elements. Return nil
         // if we don't want the element to have a value attribute.
@@ -323,7 +320,7 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
 
     } else if ([attribute isEqualToString:NSAccessibilityNumberOfCharactersAttribute]) {
         if (QAccessibleTextInterface *text = iface->textInterface())
-            return [NSNumber numberWithInt: text->characterCount()];
+            return @(text->characterCount());
         return nil;
     } else if ([attribute isEqualToString:NSAccessibilitySelectedTextAttribute]) {
         if (QAccessibleTextInterface *text = iface->textInterface()) {
@@ -357,7 +354,7 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
                 int position = text->cursorPosition();
                 convertLineOffset(text, &line, &position);
             }
-            return [NSNumber numberWithInt: line];
+            return @(line);
         }
         return nil;
     } else if ([attribute isEqualToString:NSAccessibilityMinValueAttribute]) {
@@ -378,18 +375,17 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
     }
 
     if (iface->textInterface()) {
-            return [[NSArray alloc] initWithObjects:
-                    NSAccessibilityStringForRangeParameterizedAttribute,
-                    NSAccessibilityLineForIndexParameterizedAttribute,
-                    NSAccessibilityRangeForLineParameterizedAttribute,
-                    NSAccessibilityRangeForPositionParameterizedAttribute,
-//                    NSAccessibilityRangeForIndexParameterizedAttribute,
-                    NSAccessibilityBoundsForRangeParameterizedAttribute,
-//                    NSAccessibilityRTFForRangeParameterizedAttribute,
-                    NSAccessibilityStyleRangeForIndexParameterizedAttribute,
-                    NSAccessibilityAttributedStringForRangeParameterizedAttribute,
-                    nil
-                ];
+        return @[
+            NSAccessibilityStringForRangeParameterizedAttribute,
+            NSAccessibilityLineForIndexParameterizedAttribute,
+            NSAccessibilityRangeForLineParameterizedAttribute,
+            NSAccessibilityRangeForPositionParameterizedAttribute,
+//          NSAccessibilityRangeForIndexParameterizedAttribute,
+            NSAccessibilityBoundsForRangeParameterizedAttribute,
+//          NSAccessibilityRTFForRangeParameterizedAttribute,
+            NSAccessibilityStyleRangeForIndexParameterizedAttribute,
+            NSAccessibilityAttributedStringForRangeParameterizedAttribute
+        ];
     }
 
     return nil;
@@ -416,7 +412,7 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
             return nil;
         int line = -1;
         convertLineOffset(iface->textInterface(), &line, &index);
-        return [NSNumber numberWithInt:line];
+        return @(line);
     }
     if ([attribute isEqualToString: NSAccessibilityRangeForLineParameterizedAttribute]) {
         int line = [parameter intValue];
diff --git a/src/plugins/platforms/cocoa/qcocoaapplication.h b/src/plugins/platforms/cocoa/qcocoaapplication.h
index 66a92686bc..15530d8281 100644
--- a/src/plugins/platforms/cocoa/qcocoaapplication.h
+++ b/src/plugins/platforms/cocoa/qcocoaapplication.h
@@ -89,8 +89,7 @@
 #import <AppKit/AppKit.h>
 
 
-@interface QT_MANGLE_NAMESPACE(QNSApplication) : NSApplication {
-}
+@interface QT_MANGLE_NAMESPACE(QNSApplication) : NSApplication
 @end
 
 QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSApplication);
diff --git a/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.h b/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.h
index 59c71017e3..3073cb6b44 100644
--- a/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.h
+++ b/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.h
@@ -92,18 +92,12 @@
 
 @class QT_MANGLE_NAMESPACE(QCocoaMenuLoader);
 
-@interface QT_MANGLE_NAMESPACE(QCocoaApplicationDelegate) : NSObject <NSApplicationDelegate> {
-    bool startedQuit;
-    NSMenu *dockMenu;
-    NSObject <NSApplicationDelegate> *reflectionDelegate;
-    bool inLaunch;
-}
-+ (QT_MANGLE_NAMESPACE(QCocoaApplicationDelegate)*)sharedDelegate;
+@interface QT_MANGLE_NAMESPACE(QCocoaApplicationDelegate) : NSObject <NSApplicationDelegate>
++ (instancetype)sharedDelegate;
 - (void)setDockMenu:(NSMenu *)newMenu;
-- (void)setReflectionDelegate:(NSObject <NSApplicationDelegate> *)oldDelegate;
-- (void)getUrl:(NSAppleEventDescriptor *)event withReplyEvent:(NSAppleEventDescriptor *)replyEvent;
-- (void) removeAppleEventHandlers;
-- (bool) inLaunch;
+- (void)setReflectionDelegate:(NSObject<NSApplicationDelegate> *)oldDelegate;
+- (void)removeAppleEventHandlers;
+- (bool)inLaunch;
 @end
 
 QT_NAMESPACE_ALIAS_OBJC_CLASS(QCocoaApplicationDelegate);
diff --git a/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.mm b/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.mm
index a94e0dc517..53407d8b62 100644
--- a/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.mm
+++ b/src/plugins/platforms/cocoa/qcocoaapplicationdelegate.mm
@@ -73,7 +73,6 @@
 
 
 #import "qcocoaapplicationdelegate.h"
-#import "qnswindowdelegate.h"
 #import "qcocoamenuloader.h"
 #include "qcocoaintegration.h"
 #include <qevent.h>
@@ -86,7 +85,12 @@
 
 QT_USE_NAMESPACE
 
-@implementation QCocoaApplicationDelegate
+@implementation QCocoaApplicationDelegate {
+    bool startedQuit;
+    NSMenu *dockMenu;
+    NSObject <NSApplicationDelegate> *reflectionDelegate;
+    bool inLaunch;
+}
 
 + (instancetype)sharedDelegate
 {
@@ -102,7 +106,7 @@ QT_USE_NAMESPACE
     return shared;
 }
 
-- (id)init
+- (instancetype)init
 {
     self = [super init];
     if (self) {
@@ -151,7 +155,7 @@ QT_USE_NAMESPACE
     return [[dockMenu retain] autorelease];
 }
 
-- (BOOL) canQuit
+- (BOOL)canQuit
 {
     [[NSApp mainMenu] cancelTracking];
 
@@ -219,7 +223,7 @@ QT_USE_NAMESPACE
     return NSTerminateCancel;
 }
 
-- (void) applicationWillFinishLaunching:(NSNotification *)notification
+- (void)applicationWillFinishLaunching:(NSNotification *)notification
 {
     Q_UNUSED(notification);
 
@@ -249,14 +253,14 @@ QT_USE_NAMESPACE
 }
 
 // called by QCocoaIntegration's destructor before resetting the application delegate to nil
-- (void) removeAppleEventHandlers
+- (void)removeAppleEventHandlers
 {
     NSAppleEventManager *eventManager = [NSAppleEventManager sharedAppleEventManager];
     [eventManager removeEventHandlerForEventClass:kCoreEventClass andEventID:kAEQuitApplication];
     [eventManager removeEventHandlerForEventClass:kInternetEventClass andEventID:kAEGetURL];
 }
 
-- (bool) inLaunch
+- (bool)inLaunch
 {
     return inLaunch;
 }
diff --git a/src/plugins/platforms/cocoa/qcocoacolordialoghelper.mm b/src/plugins/platforms/cocoa/qcocoacolordialoghelper.mm
index aa6124507d..0e127902ae 100644
--- a/src/plugins/platforms/cocoa/qcocoacolordialoghelper.mm
+++ b/src/plugins/platforms/cocoa/qcocoacolordialoghelper.mm
@@ -50,7 +50,14 @@
 QT_USE_NAMESPACE
 
 @interface QT_MANGLE_NAMESPACE(QNSColorPanelDelegate) : NSObject<NSWindowDelegate, QNSPanelDelegate>
-{
+- (void)restoreOriginalContentView;
+- (void)updateQtColor;
+- (void)finishOffWithCode:(NSInteger)code;
+@end
+
+QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSColorPanelDelegate);
+
+@implementation QNSColorPanelDelegate {
     @public
     NSColorPanel *mColorPanel;
     QCocoaColorDialogHelper *mHelper;
@@ -61,17 +68,9 @@ QT_USE_NAMESPACE
     BOOL mDialogIsExecuting;
     BOOL mResultSet;
     BOOL mClosingDueToKnownButton;
-};
-- (void)restoreOriginalContentView;
-- (void)updateQtColor;
-- (void)finishOffWithCode:(NSInteger)code;
-@end
-
-QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSColorPanelDelegate);
-
-@implementation QNSColorPanelDelegate
+}
 
-- (id)init
+- (instancetype)init
 {
     self = [super init];
     mColorPanel = [NSColorPanel sharedColorPanel];
diff --git a/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm b/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm
index 94f2125bad..55c4e51242 100644
--- a/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm
+++ b/src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm
@@ -81,23 +81,6 @@ typedef QSharedPointer<QFileDialogOptions> SharedPointerFileDialogOptions;
 
 @interface QT_MANGLE_NAMESPACE(QNSOpenSavePanelDelegate)
     : NSObject<NSOpenSavePanelDelegate>
-{
-    @public
-    NSOpenPanel *mOpenPanel;
-    NSSavePanel *mSavePanel;
-    NSView *mAccessoryView;
-    NSPopUpButton *mPopUpButton;
-    NSTextField *mTextField;
-    QCocoaFileDialogHelper *mHelper;
-    NSString *mCurrentDir;
-
-    int mReturnCode;
-
-    SharedPointerFileDialogOptions mOptions;
-    QString *mCurrentSelection;
-    QStringList *mNameFilterDropDownList;
-    QStringList *mSelectedNameFilter;
-}
 
 - (NSString *)strip:(const QString &)label;
 - (BOOL)panel:(id)sender shouldEnableURL:(NSURL *)url;
@@ -117,12 +100,27 @@ typedef QSharedPointer<QFileDialogOptions> SharedPointerFileDialogOptions;
 
 QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSOpenSavePanelDelegate);
 
-@implementation QNSOpenSavePanelDelegate
+@implementation QNSOpenSavePanelDelegate {
+    @public
+    NSOpenPanel *mOpenPanel;
+    NSSavePanel *mSavePanel;
+    NSView *mAccessoryView;
+    NSPopUpButton *mPopUpButton;
+    NSTextField *mTextField;
+    QCocoaFileDialogHelper *mHelper;
+    NSString *mCurrentDir;
+
+    int mReturnCode;
+
+    SharedPointerFileDialogOptions mOptions;
+    QString *mCurrentSelection;
+    QStringList *mNameFilterDropDownList;
+    QStringList *mSelectedNameFilter;
+}
 
-- (id)initWithAcceptMode:
-    (const QString &)selectFile
-    options:(SharedPointerFileDialogOptions)options
-    helper:(QCocoaFileDialogHelper *)helper
+- (instancetype)initWithAcceptMode:(const QString &)selectFile
+                           options:(SharedPointerFileDialogOptions)options
+                            helper:(QCocoaFileDialogHelper *)helper
 {
     self = [super init];
     mOptions = options;
@@ -406,9 +404,9 @@ static QString strippedText(QString s)
 {
     if (mOpenPanel) {
         QList<QUrl> result;
-        NSArray* array = [mOpenPanel URLs];
-        for (NSUInteger i=0; i<[array count]; ++i) {
-            QString path = QString::fromNSString([[array objectAtIndex:i] path]).normalized(QString::NormalizationForm_C);
+        NSArray<NSURL *> *array = [mOpenPanel URLs];
+        for (NSURL *url in array) {
+            QString path = QString::fromNSString(url.path).normalized(QString::NormalizationForm_C);
             result << QUrl::fromLocalFile(path);
         }
         return result;
diff --git a/src/plugins/platforms/cocoa/qcocoafontdialoghelper.mm b/src/plugins/platforms/cocoa/qcocoafontdialoghelper.mm
index 9a96895d07..3010aa0870 100644
--- a/src/plugins/platforms/cocoa/qcocoafontdialoghelper.mm
+++ b/src/plugins/platforms/cocoa/qcocoafontdialoghelper.mm
@@ -76,7 +76,15 @@ static QFont qfontForCocoaFont(NSFont *cocoaFont, const QFont &resolveFont)
 @class QT_MANGLE_NAMESPACE(QNSFontPanelDelegate);
 
 @interface QT_MANGLE_NAMESPACE(QNSFontPanelDelegate) : NSObject<NSWindowDelegate, QNSPanelDelegate>
-{
+- (void)restoreOriginalContentView;
+- (void)updateQtFont;
+- (void)changeFont:(id)sender;
+- (void)finishOffWithCode:(NSInteger)code;
+@end
+
+QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSFontPanelDelegate);
+
+@implementation QNSFontPanelDelegate {
     @public
     NSFontPanel *mFontPanel;
     QCocoaFontDialogHelper *mHelper;
@@ -86,33 +94,25 @@ static QFont qfontForCocoaFont(NSFont *cocoaFont, const QFont &resolveFont)
     NSInteger mResultCode;
     BOOL mDialogIsExecuting;
     BOOL mResultSet;
-};
-- (void)restoreOriginalContentView;
-- (void)updateQtFont;
-- (void)changeFont:(id)sender;
-- (void)finishOffWithCode:(NSInteger)code;
-@end
-
-QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSFontPanelDelegate);
-
-@implementation QNSFontPanelDelegate
+}
 
-- (id)init
+- (instancetype)init
 {
-    self = [super init];
-    mFontPanel = [NSFontPanel sharedFontPanel];
-    mHelper = 0;
-    mStolenContentView = 0;
-    mPanelButtons = 0;
-    mResultCode = NSModalResponseCancel;
-    mDialogIsExecuting = false;
-    mResultSet = false;
+    if ((self = [super init])) {
+        mFontPanel = [NSFontPanel sharedFontPanel];
+        mHelper = 0;
+        mStolenContentView = 0;
+        mPanelButtons = 0;
+        mResultCode = NSModalResponseCancel;
+        mDialogIsExecuting = false;
+        mResultSet = false;
 
-    [mFontPanel setRestorable:NO];
-    [mFontPanel setDelegate:self];
-    [[NSFontManager sharedFontManager] setDelegate:self];
+        [mFontPanel setRestorable:NO];
+        [mFontPanel setDelegate:self];
+        [[NSFontManager sharedFontManager] setDelegate:self];
 
-    [mFontPanel retain];
+        [mFontPanel retain];
+    }
     return self;
 }
 
diff --git a/src/plugins/platforms/cocoa/qcocoahelpers.h b/src/plugins/platforms/cocoa/qcocoahelpers.h
index 84632c1487..7fd8715277 100644
--- a/src/plugins/platforms/cocoa/qcocoahelpers.h
+++ b/src/plugins/platforms/cocoa/qcocoahelpers.h
@@ -70,11 +70,8 @@ class QPixmap;
 class QString;
 
 // Conversion functions
-QStringList qt_mac_NSArrayToQStringList(void *nsarray);
-void *qt_mac_QStringListToNSMutableArrayVoid(const QStringList &list);
-
-inline NSMutableArray *qt_mac_QStringListToNSMutableArray(const QStringList &qstrlist)
-{ return reinterpret_cast<NSMutableArray *>(qt_mac_QStringListToNSMutableArrayVoid(qstrlist)); }
+QStringList qt_mac_NSArrayToQStringList(NSArray<NSString *> *nsarray);
+NSMutableArray<NSString *> *qt_mac_QStringListToNSMutableArray(const QStringList &list);
 
 NSDragOperation qt_mac_mapDropAction(Qt::DropAction action);
 NSDragOperation qt_mac_mapDropActions(Qt::DropActions actions);
@@ -170,12 +167,7 @@ QT_END_NAMESPACE
 - (void)onCancelClicked;
 @end
 
-@interface QT_MANGLE_NAMESPACE(QNSPanelContentsWrapper) : NSView {
-    NSButton *_okButton;
-    NSButton *_cancelButton;
-    NSView *_panelContents;
-    NSEdgeInsets _panelContentsMargins;
-}
+@interface QT_MANGLE_NAMESPACE(QNSPanelContentsWrapper) : NSView
 
 @property (nonatomic, readonly) NSButton *okButton;
 @property (nonatomic, readonly) NSButton *cancelButton;
@@ -187,6 +179,7 @@ QT_END_NAMESPACE
 
 - (NSButton *)createButtonWithTitle:(const char *)title;
 - (void)layout;
+
 @end
 
 QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSPanelContentsWrapper);
diff --git a/src/plugins/platforms/cocoa/qcocoahelpers.mm b/src/plugins/platforms/cocoa/qcocoahelpers.mm
index 3b45793944..632053b0c4 100644
--- a/src/plugins/platforms/cocoa/qcocoahelpers.mm
+++ b/src/plugins/platforms/cocoa/qcocoahelpers.mm
@@ -65,21 +65,19 @@ Q_LOGGING_CATEGORY(lcQpaCocoaMouse, "qt.qpa.cocoa.mouse");
 // Conversion Functions
 //
 
-QStringList qt_mac_NSArrayToQStringList(void *nsarray)
+QStringList qt_mac_NSArrayToQStringList(NSArray<NSString *> *array)
 {
     QStringList result;
-    NSArray *array = static_cast<NSArray *>(nsarray);
-    for (NSUInteger i=0; i<[array count]; ++i)
-        result << QString::fromNSString([array objectAtIndex:i]);
+    for (NSString *string in array)
+        result << QString::fromNSString(string);
     return result;
 }
 
-void *qt_mac_QStringListToNSMutableArrayVoid(const QStringList &list)
+NSMutableArray<NSString *> *qt_mac_QStringListToNSMutableArray(const QStringList &list)
 {
-    NSMutableArray *result = [NSMutableArray arrayWithCapacity:list.size()];
-    for (int i=0; i<list.size(); ++i){
-        [result addObject:list[i].toNSString()];
-    }
+    NSMutableArray<NSString *> *result = [NSMutableArray<NSString *> arrayWithCapacity:list.size()];
+    for (const QString &string : list)
+        [result addObject:string.toNSString()];
     return result;
 }
 
@@ -289,7 +287,12 @@ QT_END_NAMESPACE
     the target-action for the OK/Cancel buttons and making
     sure the layout is consistent.
  */
-@implementation QNSPanelContentsWrapper
+@implementation QNSPanelContentsWrapper {
+    NSButton *_okButton;
+    NSButton *_cancelButton;
+    NSView *_panelContents;
+    NSEdgeInsets _panelContentsMargins;
+}
 
 @synthesize okButton = _okButton;
 @synthesize cancelButton = _cancelButton;
diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index 55b3805df3..60541c32d9 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -196,7 +196,7 @@ QCocoaIntegration::~QCocoaIntegration()
         QCocoaApplicationDelegate *delegate = [QCocoaApplicationDelegate sharedDelegate];
         [delegate removeAppleEventHandlers];
         // reset the application delegate
-        [[NSApplication sharedApplication] setDelegate: 0];
+        [[NSApplication sharedApplication] setDelegate:nil];
     }
 
 #ifndef QT_NO_CLIPBOARD
@@ -232,8 +232,8 @@ Q_LOGGING_CATEGORY(lcCocoaScreen, "qt.qpa.cocoa.screens");
 */
 void QCocoaIntegration::updateScreens()
 {
-    NSArray *scrs = [NSScreen screens];
-    NSMutableArray *screens = [NSMutableArray arrayWithArray:scrs];
+    NSArray<NSScreen *> *scrs = [NSScreen screens];
+    NSMutableArray<NSScreen *> *screens = [NSMutableArray<NSScreen *> arrayWithArray:scrs];
     if ([screens count] == 0)
         if ([NSScreen mainScreen])
            [screens addObject:[NSScreen mainScreen]];
diff --git a/src/plugins/platforms/cocoa/qcocoamenu.mm b/src/plugins/platforms/cocoa/qcocoamenu.mm
index b3c2d5ae90..148dad5d6c 100644
--- a/src/plugins/platforms/cocoa/qcocoamenu.mm
+++ b/src/plugins/platforms/cocoa/qcocoamenu.mm
@@ -279,9 +279,7 @@ void QCocoaMenu::syncSeparatorsCollapsible(bool enable)
         bool previousIsSeparator = true; // setting to true kills all the separators placed at the top.
         NSMenuItem *previousItem = nil;
 
-        NSArray *itemArray = [m_nativeMenu itemArray];
-        for (unsigned int i = 0; i < [itemArray count]; ++i) {
-            NSMenuItem *item = reinterpret_cast<NSMenuItem *>([itemArray objectAtIndex:i]);
+        for (NSMenuItem *item in [m_nativeMenu itemArray]) {
             if ([item isSeparatorItem]) {
                 QCocoaMenuItem *cocoaItem = reinterpret_cast<QCocoaMenuItem *>([item tag]);
                 if (cocoaItem)
diff --git a/src/plugins/platforms/cocoa/qcocoamenuitem.mm b/src/plugins/platforms/cocoa/qcocoamenuitem.mm
index f8f9648822..59e0150168 100644
--- a/src/plugins/platforms/cocoa/qcocoamenuitem.mm
+++ b/src/plugins/platforms/cocoa/qcocoamenuitem.mm
@@ -331,12 +331,9 @@ NSMenuItem *QCocoaMenuItem::sync()
         NSFont *customMenuFont = [NSFont fontWithName:m_font.family().toNSString()
                                   size:m_font.pointSize()];
         if (customMenuFont) {
-            NSArray *keys = [NSArray arrayWithObjects:NSFontAttributeName, nil];
-            NSArray *objects = [NSArray arrayWithObjects:customMenuFont, nil];
-            NSDictionary *attributes = [NSDictionary dictionaryWithObjects:objects forKeys:keys];
             NSAttributedString *str = [[[NSAttributedString alloc] initWithString:finalString.toNSString()
-                                     attributes:attributes] autorelease];
-            [m_native setAttributedTitle: str];
+                                     attributes:@{NSFontAttributeName: customMenuFont}] autorelease];
+            [m_native setAttributedTitle:str];
             useAttributedTitle = true;
         }
     }
diff --git a/src/plugins/platforms/cocoa/qcocoamenuloader.h b/src/plugins/platforms/cocoa/qcocoamenuloader.h
index 95f347646c..3d040efa84 100644
--- a/src/plugins/platforms/cocoa/qcocoamenuloader.h
+++ b/src/plugins/platforms/cocoa/qcocoamenuloader.h
@@ -55,19 +55,6 @@
 #include <QtCore/private/qcore_mac_p.h>
 
 @interface QT_MANGLE_NAMESPACE(QCocoaMenuLoader) : NSResponder
-{
-    IBOutlet NSMenu *theMenu;
-    IBOutlet NSMenu *appMenu;
-    IBOutlet NSMenuItem *quitItem;
-    IBOutlet NSMenuItem *preferencesItem;
-    IBOutlet NSMenuItem *aboutItem;
-    IBOutlet NSMenuItem *aboutQtItem;
-    IBOutlet NSMenuItem *hideItem;
-    NSMenuItem *lastAppSpecificItem;
-    NSMenuItem *servicesItem;
-    NSMenuItem *hideAllOthersItem;
-    NSMenuItem *showAllItem;
-}
 + (instancetype)sharedMenuLoader;
 - (instancetype)init;
 - (void)ensureAppMenuInMenu:(NSMenu *)menu;
@@ -80,16 +67,16 @@
 - (NSMenuItem *)aboutQtMenuItem;
 - (NSMenuItem *)hideMenuItem;
 - (NSMenuItem *)appSpecificMenuItem:(NSInteger)tag;
-- (IBAction)terminate:(id)sender;
-- (IBAction)orderFrontStandardAboutPanel:(id)sender;
-- (IBAction)hideOtherApplications:(id)sender;
-- (IBAction)unhideAllApplications:(id)sender;
-- (IBAction)hide:(id)sender;
-- (IBAction)qtDispatcherToQPAMenuItem:(id)sender;
+- (void)terminate:(id)sender;
+- (void)orderFrontStandardAboutPanel:(id)sender;
+- (void)hideOtherApplications:(id)sender;
+- (void)unhideAllApplications:(id)sender;
+- (void)hide:(id)sender;
+- (void)qtDispatcherToQPAMenuItem:(id)sender;
 - (void)orderFrontCharacterPalette:(id)sender;
 - (BOOL)validateMenuItem:(NSMenuItem*)menuItem;
 - (void)qtTranslateApplicationMenu;
-- (NSArray *)mergeable;
+- (NSArray<NSMenuItem *> *)mergeable;
 @end
 
 QT_NAMESPACE_ALIAS_OBJC_CLASS(QCocoaMenuLoader);
diff --git a/src/plugins/platforms/cocoa/qcocoamenuloader.mm b/src/plugins/platforms/cocoa/qcocoamenuloader.mm
index cd597da71c..d4d7bc1d7a 100644
--- a/src/plugins/platforms/cocoa/qcocoamenuloader.mm
+++ b/src/plugins/platforms/cocoa/qcocoamenuloader.mm
@@ -50,7 +50,19 @@
 #include <QtCore/qcoreapplication.h>
 #include <QtGui/private/qguiapplication_p.h>
 
-@implementation QCocoaMenuLoader
+@implementation QCocoaMenuLoader {
+    NSMenu *theMenu;
+    NSMenu *appMenu;
+    NSMenuItem *quitItem;
+    NSMenuItem *preferencesItem;
+    NSMenuItem *aboutItem;
+    NSMenuItem *aboutQtItem;
+    NSMenuItem *hideItem;
+    NSMenuItem *lastAppSpecificItem;
+    NSMenuItem *servicesItem;
+    NSMenuItem *hideAllOthersItem;
+    NSMenuItem *showAllItem;
+}
 
 + (instancetype)sharedMenuLoader
 {
@@ -323,7 +335,7 @@
 #endif
 }
 
-- (IBAction)qtDispatcherToQPAMenuItem:(id)sender
+- (void)qtDispatcherToQPAMenuItem:(id)sender
 {
     NSMenuItem *item = static_cast<NSMenuItem *>(sender);
     if (item == quitItem) {
@@ -363,9 +375,10 @@
     }
 }
 
-- (NSArray*) mergeable
+- (NSArray<NSMenuItem *> *)mergeable
 {
-    // don't include the quitItem here, since we want it always visible and enabled regardless
+    // Don't include the quitItem here, since we want it always visible and enabled regardless
+    // Note that lastAppSpecificItem may be nil, so we can't use @[] here.
     return [NSArray arrayWithObjects:preferencesItem, aboutItem, aboutQtItem, lastAppSpecificItem, nil];
 }
 
diff --git a/src/plugins/platforms/cocoa/qcocoascreen.mm b/src/plugins/platforms/cocoa/qcocoascreen.mm
index ed1b19cd53..049cecff54 100644
--- a/src/plugins/platforms/cocoa/qcocoascreen.mm
+++ b/src/plugins/platforms/cocoa/qcocoascreen.mm
@@ -66,7 +66,7 @@ QCocoaScreen::~QCocoaScreen()
 
 NSScreen *QCocoaScreen::nativeScreen() const
 {
-    NSArray *screens = [NSScreen screens];
+    NSArray<NSScreen *> *screens = [NSScreen screens];
 
     // Stale reference, screen configuration has changed
     if (m_screenIndex < 0 || (NSUInteger)m_screenIndex >= [screens count])
diff --git a/src/plugins/platforms/cocoa/qcocoasystemtrayicon.mm b/src/plugins/platforms/cocoa/qcocoasystemtrayicon.mm
index f4c968ab57..0b1e186bce 100644
--- a/src/plugins/platforms/cocoa/qcocoasystemtrayicon.mm
+++ b/src/plugins/platforms/cocoa/qcocoasystemtrayicon.mm
@@ -93,31 +93,16 @@ QT_USE_NAMESPACE
 @class QT_MANGLE_NAMESPACE(QNSImageView);
 
 @interface QT_MANGLE_NAMESPACE(QNSStatusItem) : NSObject <NSUserNotificationCenterDelegate>
-{
-@public
-    QCocoaSystemTrayIcon *systray;
-    NSStatusItem *item;
-    QCocoaMenu *menu;
-    QIcon icon;
-    QT_MANGLE_NAMESPACE(QNSImageView) *imageCell;
-}
--(id)initWithSysTray:(QCocoaSystemTrayIcon *)systray;
--(void)dealloc;
--(NSStatusItem*)item;
--(QRectF)geometry;
+@property (nonatomic, assign) QCocoaMenu *menu;
+@property (nonatomic, assign) QIcon icon;
+@property (nonatomic, readonly) NSStatusItem *item;
+@property (nonatomic, readonly) QRectF geometry;
+- (instancetype)initWithSysTray:(QCocoaSystemTrayIcon *)systray;
 - (void)triggerSelector:(id)sender button:(Qt::MouseButton)mouseButton;
 - (void)doubleClickSelector:(id)sender;
-- (BOOL)userNotificationCenter:(NSUserNotificationCenter *)center shouldPresentNotification:(NSUserNotification *)notification;
-- (void)userNotificationCenter:(NSUserNotificationCenter *)center didActivateNotification:(NSUserNotification *)notification;
 @end
 
-@interface QT_MANGLE_NAMESPACE(QNSImageView) : NSImageView {
-    BOOL down;
-    QT_MANGLE_NAMESPACE(QNSStatusItem) *parent;
-}
--(id)initWithParent:(QT_MANGLE_NAMESPACE(QNSStatusItem)*)myParent;
--(void)menuTrackingDone:(NSNotification*)notification;
--(void)mousePressed:(NSEvent *)mouseEvent button:(Qt::MouseButton)mouseButton;
+@interface QT_MANGLE_NAMESPACE(QNSImageView) : NSImageView
 @end
 
 QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSStatusItem);
@@ -176,7 +161,7 @@ void QCocoaSystemTrayIcon::updateIcon(const QIcon &icon)
     if (!m_sys)
         return;
 
-    m_sys->item->icon = icon;
+    m_sys->item.icon = icon;
 
     // The reccomended maximum title bar icon height is 18 points
     // (device independent pixels). The menu height on past and
@@ -247,8 +232,8 @@ void QCocoaSystemTrayIcon::updateMenu(QPlatformMenu *menu)
     if (!m_sys)
         return;
 
-    m_sys->item->menu = static_cast<QCocoaMenu *>(menu);
-    if (menu && [m_sys->item->menu->nsMenu() numberOfItems] > 0) {
+    m_sys->item.menu = static_cast<QCocoaMenu *>(menu);
+    if (menu && [m_sys->item.menu->nsMenu() numberOfItems] > 0) {
         [[m_sys->item item] setHighlightMode:YES];
     } else {
         [[m_sys->item item] setHighlightMode:NO];
@@ -287,23 +272,29 @@ void QCocoaSystemTrayIcon::showMessage(const QString &title, const QString &mess
 }
 QT_END_NAMESPACE
 
-@implementation QNSImageView
--(id)initWithParent:(QNSStatusItem*)myParent {
+@implementation NSStatusItem (Qt)
+@end
+
+@implementation QNSImageView {
+    BOOL down;
+    QT_MANGLE_NAMESPACE(QNSStatusItem) *parent;
+}
+
+- (instancetype)initWithParent:(QNSStatusItem *)myParent {
     self = [super init];
     parent = myParent;
     down = NO;
     return self;
 }
 
--(void)menuTrackingDone:(NSNotification*)notification
+- (void)menuTrackingDone:(NSNotification *)__unused notification
 {
-    Q_UNUSED(notification);
     down = NO;
 
     [self setNeedsDisplay:YES];
 }
 
--(void)mousePressed:(NSEvent *)mouseEvent button:(Qt::MouseButton)mouseButton
+- (void)mousePressed:(NSEvent *)mouseEvent button:(Qt::MouseButton)mouseButton
 {
     down = YES;
     int clickCount = [mouseEvent clickCount];
@@ -317,12 +308,12 @@ QT_END_NAMESPACE
     }
 }
 
--(void)mouseDown:(NSEvent *)mouseEvent
+- (void)mouseDown:(NSEvent *)mouseEvent
 {
     [self mousePressed:mouseEvent button:Qt::LeftButton];
 }
 
--(void)mouseUp:(NSEvent *)mouseEvent
+- (void)mouseUp:(NSEvent *)mouseEvent
 {
     Q_UNUSED(mouseEvent);
     [self menuTrackingDone:nil];
@@ -333,7 +324,7 @@ QT_END_NAMESPACE
     [self mousePressed:mouseEvent button:Qt::RightButton];
 }
 
--(void)rightMouseUp:(NSEvent *)mouseEvent
+- (void)rightMouseUp:(NSEvent *)mouseEvent
 {
     Q_UNUSED(mouseEvent);
     [self menuTrackingDone:nil];
@@ -344,21 +335,28 @@ QT_END_NAMESPACE
     [self mousePressed:mouseEvent button:cocoaButton2QtButton([mouseEvent buttonNumber])];
 }
 
--(void)otherMouseUp:(NSEvent *)mouseEvent
+- (void)otherMouseUp:(NSEvent *)mouseEvent
 {
     Q_UNUSED(mouseEvent);
     [self menuTrackingDone:nil];
 }
 
--(void)drawRect:(NSRect)rect {
+- (void)drawRect:(NSRect)rect {
     [[parent item] drawStatusBarBackgroundInRect:rect withHighlight:down];
     [super drawRect:rect];
 }
 @end
 
-@implementation QNSStatusItem
+@implementation QNSStatusItem {
+    QCocoaSystemTrayIcon *systray;
+    NSStatusItem *item;
+    QT_MANGLE_NAMESPACE(QNSImageView) *imageCell;
+}
+
+@synthesize menu = menu;
+@synthesize icon = icon;
 
--(id)initWithSysTray:(QCocoaSystemTrayIcon *)sys
+- (instancetype)initWithSysTray:(QCocoaSystemTrayIcon *)sys
 {
     self = [super init];
     if (self) {
@@ -371,19 +369,19 @@ QT_END_NAMESPACE
     return self;
 }
 
--(void)dealloc {
+- (void)dealloc {
     [[NSStatusBar systemStatusBar] removeStatusItem:item];
     [[NSNotificationCenter defaultCenter] removeObserver:imageCell];
     [imageCell release];
     [item release];
     [super dealloc];
-
 }
 
--(NSStatusItem*)item {
+- (NSStatusItem *)item {
     return item;
 }
--(QRectF)geometry {
+
+- (QRectF)geometry {
     if (NSWindow *window = [[item view] window]) {
         NSRect screenRect = [[window screen] frame];
         NSRect windowRect = [window frame];
diff --git a/src/plugins/platforms/cocoa/qcocoatheme.mm b/src/plugins/platforms/cocoa/qcocoatheme.mm
index 93f0400916..f73db8873b 100644
--- a/src/plugins/platforms/cocoa/qcocoatheme.mm
+++ b/src/plugins/platforms/cocoa/qcocoatheme.mm
@@ -77,26 +77,24 @@
 
 #include <Carbon/Carbon.h>
 
-@interface QT_MANGLE_NAMESPACE(QCocoaThemeNotificationReceiver) : NSObject {
-QCocoaTheme *mPrivate;
-}
-- (id)initWithPrivate:(QCocoaTheme *)priv;
-- (void)systemColorsDidChange:(NSNotification *)notification;
+@interface QT_MANGLE_NAMESPACE(QCocoaThemeNotificationReceiver) : NSObject
 @end
 
 QT_NAMESPACE_ALIAS_OBJC_CLASS(QCocoaThemeNotificationReceiver);
 
-@implementation QCocoaThemeNotificationReceiver
-- (id)initWithPrivate:(QCocoaTheme *)priv
+@implementation QCocoaThemeNotificationReceiver {
+    QCocoaTheme *mPrivate;
+}
+
+- (instancetype)initWithPrivate:(QCocoaTheme *)priv
 {
-    self = [super init];
-    mPrivate = priv;
+    if ((self = [self init]))
+        mPrivate = priv;
     return self;
 }
 
-- (void)systemColorsDidChange:(NSNotification *)notification
+- (void)systemColorsDidChange:(NSNotification *)__unused notification
 {
-    Q_UNUSED(notification);
     mPrivate->reset();
     QWindowSystemInterface::handleThemeChange(nullptr);
 }
diff --git a/src/plugins/platforms/cocoa/qnsview.h b/src/plugins/platforms/cocoa/qnsview.h
index e2ea862cd5..23c3b6100e 100644
--- a/src/plugins/platforms/cocoa/qnsview.h
+++ b/src/plugins/platforms/cocoa/qnsview.h
@@ -42,52 +42,22 @@
 
 #include <AppKit/AppKit.h>
 
-#include <QtCore/QPointer>
-#include <QtCore/QSet>
-#include <QtGui/QImage>
-#include <QtGui/QAccessible>
-
 #include "private/qcore_mac_p.h"
 
 QT_BEGIN_NAMESPACE
 class QCocoaWindow;
 class QCocoaGLContext;
+class QPointF;
 QT_END_NAMESPACE
 
 Q_FORWARD_DECLARE_OBJC_CLASS(QT_MANGLE_NAMESPACE(QNSViewMouseMoveHelper));
 
-@interface QT_MANGLE_NAMESPACE(QNSView) : NSView <NSTextInputClient> {
-    QPointer<QCocoaWindow> m_platformWindow;
-    NSTrackingArea *m_trackingArea;
-    Qt::MouseButtons m_buttons;
-    Qt::MouseButtons m_acceptedMouseDowns;
-    Qt::MouseButtons m_frameStrutButtons;
-    QString m_composingText;
-    QPointer<QObject> m_composingFocusObject;
-    bool m_sendKeyEvent;
-    QStringList *currentCustomDragTypes;
-    bool m_dontOverrideCtrlLMB;
-    bool m_sendUpAsRightButton;
-    Qt::KeyboardModifiers currentWheelModifiers;
-#ifndef QT_NO_OPENGL
-    QCocoaGLContext *m_glContext;
-    bool m_shouldSetGLContextinDrawRect;
-#endif
-    NSString *m_inputSource;
-    QT_MANGLE_NAMESPACE(QNSViewMouseMoveHelper) *m_mouseMoveHelper;
-    bool m_resendKeyEvent;
-    bool m_scrolling;
-    bool m_updatingDrag;
-    NSEvent *m_currentlyInterpretedKeyEvent;
-    bool m_isMenuView;
-    QSet<quint32> m_acceptedKeyDowns;
-    bool m_updateRequested;
-}
+@interface QT_MANGLE_NAMESPACE(QNSView) : NSView <NSTextInputClient>
 
 @property (nonatomic, retain) NSCursor *cursor;
 
-- (id)init;
-- (id)initWithCocoaWindow:(QCocoaWindow *)platformWindow;
+- (instancetype)init;
+- (instancetype)initWithCocoaWindow:(QCocoaWindow *)platformWindow;
 #ifndef QT_NO_OPENGL
 - (void)setQCocoaGLContext:(QCocoaGLContext *)context;
 #endif
diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index fd7f216e10..6a79c76991 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -51,7 +51,11 @@
 #include <qpa/qwindowsysteminterface.h>
 #include <QtGui/QTextFormat>
 #include <QtCore/QDebug>
+#include <QtCore/QPointer>
+#include <QtCore/QSet>
 #include <QtCore/qsysinfo.h>
+#include <QtGui/QAccessible>
+#include <QtGui/QImage>
 #include <private/qguiapplication_p.h>
 #include <private/qcoregraphics_p.h>
 #include <private/qwindow_p.h>
@@ -72,11 +76,8 @@ Q_LOGGING_CATEGORY(lcQpaGestures, "qt.qpa.input.gestures")
 Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 
 @interface QT_MANGLE_NAMESPACE(QNSViewMouseMoveHelper) : NSObject
-{
-    QNSView *view;
-}
 
-- (id)initWithView:(QNSView *)theView;
+- (instancetype)initWithView:(QNSView *)theView;
 
 - (void)mouseMoved:(NSEvent *)theEvent;
 - (void)mouseEntered:(NSEvent *)theEvent;
@@ -85,9 +86,11 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 
 @end
 
-@implementation QT_MANGLE_NAMESPACE(QNSViewMouseMoveHelper)
+@implementation QT_MANGLE_NAMESPACE(QNSViewMouseMoveHelper) {
+    QNSView *view;
+}
 
-- (id)initWithView:(QNSView *)theView
+- (instancetype)initWithView:(QNSView *)theView
 {
     self = [super init];
     if (self) {
@@ -123,9 +126,35 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 - (BOOL)isTransparentForUserInput;
 @end
 
-@implementation QT_MANGLE_NAMESPACE(QNSView)
+@implementation QT_MANGLE_NAMESPACE(QNSView) {
+    QPointer<QCocoaWindow> m_platformWindow;
+    NSTrackingArea *m_trackingArea;
+    Qt::MouseButtons m_buttons;
+    Qt::MouseButtons m_acceptedMouseDowns;
+    Qt::MouseButtons m_frameStrutButtons;
+    QString m_composingText;
+    QPointer<QObject> m_composingFocusObject;
+    bool m_sendKeyEvent;
+    QStringList *currentCustomDragTypes;
+    bool m_dontOverrideCtrlLMB;
+    bool m_sendUpAsRightButton;
+    Qt::KeyboardModifiers currentWheelModifiers;
+#ifndef QT_NO_OPENGL
+    QCocoaGLContext *m_glContext;
+    bool m_shouldSetGLContextinDrawRect;
+#endif
+    NSString *m_inputSource;
+    QT_MANGLE_NAMESPACE(QNSViewMouseMoveHelper) *m_mouseMoveHelper;
+    bool m_resendKeyEvent;
+    bool m_scrolling;
+    bool m_updatingDrag;
+    NSEvent *m_currentlyInterpretedKeyEvent;
+    bool m_isMenuView;
+    QSet<quint32> m_acceptedKeyDowns;
+    bool m_updateRequested;
+}
 
-- (id) init
+- (instancetype)init
 {
     if (self = [super initWithFrame:NSZeroRect]) {
         m_buttons = Qt::NoButton;
@@ -168,7 +197,7 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
     [super dealloc];
 }
 
-- (id)initWithCocoaWindow:(QCocoaWindow *)platformWindow
+- (instancetype)initWithCocoaWindow:(QCocoaWindow *)platformWindow
 {
     self = [self init];
     if (!self)
@@ -1432,7 +1461,7 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
                 if (imEnabled && !(hints & Qt::ImhDigitsOnly || hints & Qt::ImhFormattedNumbersOnly || hints & Qt::ImhHiddenText)) {
                     // pass the key event to the input method. note that m_sendKeyEvent may be set to false during this call
                     m_currentlyInterpretedKeyEvent = nsevent;
-                    [self interpretKeyEvents:[NSArray arrayWithObject:nsevent]];
+                    [self interpretKeyEvents:@[nsevent]];
                     m_currentlyInterpretedKeyEvent = 0;
                 }
             }
@@ -1790,7 +1819,7 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
     return NSNotFound;
 }
 
-- (NSArray*)validAttributesForMarkedText
+- (NSArray<NSString *> *)validAttributesForMarkedText
 {
     if (!m_platformWindow)
         return nil;
@@ -1809,8 +1838,7 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
         return nil;
 
     // Support only underline color/style.
-    return [NSArray arrayWithObjects:NSUnderlineColorAttributeName,
-                                     NSUnderlineStyleAttributeName, nil];
+    return @[NSUnderlineColorAttributeName, NSUnderlineStyleAttributeName];
 }
 
 -(void)registerDragTypes
@@ -1821,8 +1849,9 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
         if (currentCustomDragTypes == 0)
             currentCustomDragTypes = new QStringList();
         *currentCustomDragTypes = customTypes;
-        const NSString* mimeTypeGeneric = @"com.trolltech.qt.MimeTypeName";
-        NSMutableArray *supportedTypes = [NSMutableArray arrayWithObjects:NSColorPboardType,
+        NSString * const mimeTypeGeneric = @"com.trolltech.qt.MimeTypeName";
+        NSMutableArray<NSString *> *supportedTypes = [NSMutableArray<NSString *> arrayWithArray:@[
+                       NSColorPboardType,
                        NSFilenamesPboardType, NSStringPboardType,
                        NSFilenamesPboardType, NSPostScriptPboardType, NSTIFFPboardType,
                        NSRTFPboardType, NSTabularTextPboardType, NSFontPboardType,
@@ -1830,7 +1859,7 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
                        NSRTFDPboardType, NSHTMLPboardType,
                        NSURLPboardType, NSPDFPboardType, NSVCardPboardType,
                        NSFilesPromisePboardType, NSInkTextPboardType,
-                       NSMultipleTextSelectionPboardType, mimeTypeGeneric, nil];
+                       NSMultipleTextSelectionPboardType, mimeTypeGeneric]];
         // Add custom types supported by the application.
         for (int i = 0; i < customTypes.size(); i++) {
            [supportedTypes addObject:customTypes[i].toNSString()];
diff --git a/src/plugins/platforms/cocoa/qnsviewaccessibility.mm b/src/plugins/platforms/cocoa/qnsviewaccessibility.mm
index 645a93edf7..ab0036e175 100644
--- a/src/plugins/platforms/cocoa/qnsviewaccessibility.mm
+++ b/src/plugins/platforms/cocoa/qnsviewaccessibility.mm
@@ -53,14 +53,12 @@
 @implementation QNSView (QNSViewAccessibility)
 
 - (id)childAccessibleElement {
-    if (m_platformWindow.isNull())
+    QCocoaWindow *platformWindow = self.platformWindow;
+    if (!platformWindow || !platformWindow->window()->accessibleRoot())
         return nil;
 
-    if (!m_platformWindow->window()->accessibleRoot())
-        return nil;
-
-    QAccessible::Id childId = QAccessible::uniqueId(m_platformWindow->window()->accessibleRoot());
-    return [QMacAccessibilityElement elementWithId: childId];
+    QAccessible::Id childId = QAccessible::uniqueId(platformWindow->window()->accessibleRoot());
+    return [QMacAccessibilityElement elementWithId:childId];
 }
 
 // The QNSView is a container that the user does not interact directly with:
diff --git a/src/plugins/platforms/cocoa/qnswindow.mm b/src/plugins/platforms/cocoa/qnswindow.mm
index cb13b7d184..086a4f8af2 100644
--- a/src/plugins/platforms/cocoa/qnswindow.mm
+++ b/src/plugins/platforms/cocoa/qnswindow.mm
@@ -38,7 +38,6 @@
 ****************************************************************************/
 
 #include "qnswindow.h"
-#include "qnswindowdelegate.h"
 #include "qcocoawindow.h"
 #include "qcocoahelpers.h"
 #include "qcocoaeventdispatcher.h"
@@ -72,7 +71,7 @@ static bool isMouseEvent(NSEvent *ev)
     [center addObserverForName:NSWindowDidEnterFullScreenNotification object:nil queue:nil
         usingBlock:^(NSNotification *notification) {
             objc_setAssociatedObject(notification.object, @selector(qt_fullScreen),
-                [NSNumber numberWithBool:YES], OBJC_ASSOCIATION_RETAIN);
+                @(YES), OBJC_ASSOCIATION_RETAIN);
         }
     ];
     [center addObserverForName:NSWindowDidExitFullScreenNotification object:nil queue:nil
@@ -267,14 +266,14 @@ static bool isMouseEvent(NSEvent *ev)
     if (__builtin_available(macOS 10.12, *)) {
         // Unfortunately there's no NSWindowListOrderedBackToFront,
         // so we have to manually reverse the order using an array.
-        NSMutableArray *windows = [[[NSMutableArray alloc] init] autorelease];
+        NSMutableArray<NSWindow *> *windows = [NSMutableArray<NSWindow *> new];
         [application enumerateWindowsWithOptions:NSWindowListOrderedFrontToBack
             usingBlock:^(NSWindow *window, BOOL *) {
                 // For some reason AppKit will give us nil-windows, skip those
                 if (!window)
                     return;
 
-                [(NSMutableArray*)windows addObject:window];
+                [windows addObject:window];
             }
         ];
 
diff --git a/src/plugins/platforms/cocoa/qnswindowdelegate.h b/src/plugins/platforms/cocoa/qnswindowdelegate.h
index d2078b5786..e71afcbb2a 100644
--- a/src/plugins/platforms/cocoa/qnswindowdelegate.h
+++ b/src/plugins/platforms/cocoa/qnswindowdelegate.h
@@ -41,20 +41,16 @@
 #define QNSWINDOWDELEGATE_H
 
 #include <AppKit/AppKit.h>
+#include <QtCore/private/qcore_mac_p.h>
 
-#include "qcocoawindow.h"
+QT_BEGIN_NAMESPACE
+class QCocoaWindow;
+QT_END_NAMESPACE
 
 @interface QT_MANGLE_NAMESPACE(QNSWindowDelegate) : NSObject <NSWindowDelegate>
-{
-    QCocoaWindow *m_cocoaWindow;
-}
 
-- (id)initWithQCocoaWindow:(QCocoaWindow *)cocoaWindow;
+- (instancetype)initWithQCocoaWindow:(QT_PREPEND_NAMESPACE(QCocoaWindow) *)cocoaWindow;
 
-- (BOOL)windowShouldClose:(NSNotification *)notification;
-
-- (BOOL)window:(NSWindow *)window shouldPopUpDocumentPathMenu:(NSMenu *)menu;
-- (BOOL)window:(NSWindow *)window shouldDragDocumentWithEvent:(NSEvent *)event from:(NSPoint)dragImageLocation withPasteboard:(NSPasteboard *)pasteboard;
 @end
 
 QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSWindowDelegate);
diff --git a/src/plugins/platforms/cocoa/qnswindowdelegate.mm b/src/plugins/platforms/cocoa/qnswindowdelegate.mm
index 6e5623d679..1888dc1c90 100644
--- a/src/plugins/platforms/cocoa/qnswindowdelegate.mm
+++ b/src/plugins/platforms/cocoa/qnswindowdelegate.mm
@@ -39,20 +39,23 @@
 
 #include "qnswindowdelegate.h"
 #include "qcocoahelpers.h"
+#include "qcocoawindow.h"
 
 #include <QDebug>
+#include <QtCore/private/qcore_mac_p.h>
 #include <qpa/qplatformscreen.h>
 #include <qpa/qwindowsysteminterface.h>
 
 static QRegExp whitespaceRegex = QRegExp(QStringLiteral("\\s*"));
 
-@implementation QNSWindowDelegate
+@implementation QNSWindowDelegate {
+    QCocoaWindow *m_cocoaWindow;
+}
 
-- (id)initWithQCocoaWindow:(QCocoaWindow *)cocoaWindow
+- (instancetype)initWithQCocoaWindow:(QCocoaWindow *)cocoaWindow
 {
-    if (self = [super init])
+    if ((self = [self init]))
         m_cocoaWindow = cocoaWindow;
-
     return self;
 }
 
diff --git a/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosimagepickercontroller.h b/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosimagepickercontroller.h
index c52d498cd4..201b277494 100644
--- a/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosimagepickercontroller.h
+++ b/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosimagepickercontroller.h
@@ -41,8 +41,6 @@
 
 #include "../../qiosfiledialog.h"
 
-@interface QIOSImagePickerController : UIImagePickerController <UIImagePickerControllerDelegate, UINavigationControllerDelegate> {
-    QIOSFileDialog *m_fileDialog;
-}
-- (id)initWithQIOSFileDialog:(QIOSFileDialog *)fileDialog;
+@interface QIOSImagePickerController : UIImagePickerController <UIImagePickerControllerDelegate, UINavigationControllerDelegate>
+- (instancetype)initWithQIOSFileDialog:(QIOSFileDialog *)fileDialog;
 @end
diff --git a/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosimagepickercontroller.mm b/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosimagepickercontroller.mm
index 78e0f00ab4..79d4ecf83f 100644
--- a/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosimagepickercontroller.mm
+++ b/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosimagepickercontroller.mm
@@ -41,15 +41,17 @@
 
 #include "qiosimagepickercontroller.h"
 
-@implementation QIOSImagePickerController
+@implementation QIOSImagePickerController {
+    QIOSFileDialog *m_fileDialog;
+}
 
-- (id)initWithQIOSFileDialog:(QIOSFileDialog *)fileDialog
+- (instancetype)initWithQIOSFileDialog:(QIOSFileDialog *)fileDialog
 {
     self = [super init];
     if (self) {
         m_fileDialog = fileDialog;
-        [self setSourceType:UIImagePickerControllerSourceTypePhotoLibrary];
-        [self setDelegate:self];
+        self.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
+        self.delegate = self;
     }
     return self;
 }
@@ -57,8 +59,8 @@
 - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
 {
     Q_UNUSED(picker);
-    NSURL *url = [info objectForKey:UIImagePickerControllerReferenceURL];
-    QUrl fileUrl = QUrl::fromLocalFile(QString::fromNSString([url description]));
+    NSURL *url = info[UIImagePickerControllerReferenceURL];
+    QUrl fileUrl = QUrl::fromLocalFile(QString::fromNSString(url.description));
     m_fileDialog->selectedFilesChanged(QList<QUrl>() << fileUrl);
     emit m_fileDialog->accept();
 }
diff --git a/src/plugins/platforms/ios/qiosclipboard.mm b/src/plugins/platforms/ios/qiosclipboard.mm
index 9a975eadc9..6bdbf94d3f 100644
--- a/src/plugins/platforms/ios/qiosclipboard.mm
+++ b/src/plugins/platforms/ios/qiosclipboard.mm
@@ -46,11 +46,11 @@
 #include <QtGui/QGuiApplication>
 
 @interface UIPasteboard (QUIPasteboard)
-    + (UIPasteboard *)pasteboardWithQClipboardMode:(QClipboard::Mode)mode;
++ (instancetype)pasteboardWithQClipboardMode:(QClipboard::Mode)mode;
 @end
 
 @implementation UIPasteboard (QUIPasteboard)
-+ (UIPasteboard *)pasteboardWithQClipboardMode:(QClipboard::Mode)mode
++ (instancetype)pasteboardWithQClipboardMode:(QClipboard::Mode)mode
 {
     NSString *name = (mode == QClipboard::Clipboard) ? UIPasteboardNameGeneral : UIPasteboardNameFind;
     return [UIPasteboard pasteboardWithName:name create:NO];
@@ -60,17 +60,15 @@
 // --------------------------------------------------------------------
 
 @interface QUIClipboard : NSObject
-{
-@public
+@end
+
+@implementation QUIClipboard {
     QIOSClipboard *m_qiosClipboard;
     NSInteger m_changeCountClipboard;
     NSInteger m_changeCountFindBuffer;
 }
-@end
-
-@implementation QUIClipboard
 
-- (id)initWithQIOSClipboard:(QIOSClipboard *)qiosClipboard
+- (instancetype)initWithQIOSClipboard:(QIOSClipboard *)qiosClipboard
 {
     self = [super init];
     if (self) {
@@ -149,7 +147,7 @@ QStringList QIOSMimeData::formats() const
 {
     QStringList foundMimeTypes;
     UIPasteboard *pb = [UIPasteboard pasteboardWithQClipboardMode:m_mode];
-    NSArray *pasteboardTypes = [pb pasteboardTypes];
+    NSArray<NSString *> *pasteboardTypes = [pb pasteboardTypes];
 
     for (NSUInteger i = 0; i < [pasteboardTypes count]; ++i) {
         QString uti = QString::fromNSString([pasteboardTypes objectAtIndex:i]);
@@ -164,7 +162,7 @@ QStringList QIOSMimeData::formats() const
 QVariant QIOSMimeData::retrieveData(const QString &mimeType, QVariant::Type) const
 {
     UIPasteboard *pb = [UIPasteboard pasteboardWithQClipboardMode:m_mode];
-    NSArray *pasteboardTypes = [pb pasteboardTypes];
+    NSArray<NSString *> *pasteboardTypes = [pb pasteboardTypes];
 
     foreach (QMacInternalPasteboardMime *converter,
              QMacInternalPasteboardMime::all(QMacInternalPasteboardMime::MIME_ALL)) {
@@ -213,12 +211,12 @@ void QIOSClipboard::setMimeData(QMimeData *mimeData, QClipboard::Mode mode)
 
     UIPasteboard *pb = [UIPasteboard pasteboardWithQClipboardMode:mode];
     if (!mimeData) {
-        pb.items = [NSArray array];
+        pb.items = [NSArray<NSDictionary<NSString *, id> *> array];
         return;
     }
 
     mimeData->deleteLater();
-    NSMutableDictionary *pbItem = [NSMutableDictionary dictionaryWithCapacity:mimeData->formats().size()];
+    NSMutableDictionary<NSString *, id> *pbItem = [NSMutableDictionary<NSString *, id> dictionaryWithCapacity:mimeData->formats().size()];
 
     foreach (const QString &mimeType, mimeData->formats()) {
         foreach (QMacInternalPasteboardMime *converter,
@@ -246,7 +244,7 @@ void QIOSClipboard::setMimeData(QMimeData *mimeData, QClipboard::Mode mode)
         }
     }
 
-    pb.items = [NSArray arrayWithObject:pbItem];
+    pb.items = @[pbItem];
 }
 
 bool QIOSClipboard::supportsMode(QClipboard::Mode mode) const
diff --git a/src/plugins/platforms/ios/qioseventdispatcher.mm b/src/plugins/platforms/ios/qioseventdispatcher.mm
index a6f6a7aac9..7a2399efcd 100644
--- a/src/plugins/platforms/ios/qioseventdispatcher.mm
+++ b/src/plugins/platforms/ios/qioseventdispatcher.mm
@@ -245,7 +245,7 @@ extern "C" int main(int argc, char *argv[]);
 
 static void __attribute__((noinline, noreturn)) user_main_trampoline()
 {
-    NSArray *arguments = [[NSProcessInfo processInfo] arguments];
+    NSArray<NSString *> *arguments = [[NSProcessInfo processInfo] arguments];
     int argc = arguments.count;
     char **argv = new char*[argc];
 
diff --git a/src/plugins/platforms/ios/qiosinputcontext.mm b/src/plugins/platforms/ios/qiosinputcontext.mm
index 050c592aca..3e22634071 100644
--- a/src/plugins/platforms/ios/qiosinputcontext.mm
+++ b/src/plugins/platforms/ios/qiosinputcontext.mm
@@ -67,7 +67,7 @@ static QUIView *focusView()
 
 @implementation QIOSLocaleListener
 
-- (id)init
+- (instancetype)init
 {
     if (self = [super init]) {
         NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
@@ -95,16 +95,15 @@ static QUIView *focusView()
 
 // -------------------------------------------------------------------------
 
-@interface QIOSKeyboardListener : UIGestureRecognizer <UIGestureRecognizerDelegate> {
-  @private
-    QT_PREPEND_NAMESPACE(QIOSInputContext) *m_context;
-}
+@interface QIOSKeyboardListener : UIGestureRecognizer <UIGestureRecognizerDelegate>
 @property BOOL hasDeferredScrollToCursor;
 @end
 
-@implementation QIOSKeyboardListener
+@implementation QIOSKeyboardListener {
+    QT_PREPEND_NAMESPACE(QIOSInputContext) *m_context;
+}
 
-- (id)initWithQIOSInputContext:(QT_PREPEND_NAMESPACE(QIOSInputContext) *)context
+- (instancetype)initWithQIOSInputContext:(QT_PREPEND_NAMESPACE(QIOSInputContext) *)context
 {
     if (self = [super initWithTarget:self action:@selector(gestureStateChanged:)]) {
 
@@ -574,7 +573,7 @@ void QIOSInputContext::scroll(int y)
 
             // Raise all known windows to above the status-bar if we're scrolling the screen,
             // while keeping the relative window level between the windows the same.
-            NSArray *applicationWindows = [[UIApplication sharedApplication] windows];
+            NSArray<UIWindow *> *applicationWindows = [[UIApplication sharedApplication] windows];
             static QHash<UIWindow *, UIWindowLevel> originalWindowLevels;
             for (UIWindow *window in applicationWindows) {
                 if (keyboardScrollIsActive && !originalWindowLevels.contains(window))
diff --git a/src/plugins/platforms/ios/qiosintegration.mm b/src/plugins/platforms/ios/qiosintegration.mm
index 92c1e39d72..5f9f7ad96d 100644
--- a/src/plugins/platforms/ios/qiosintegration.mm
+++ b/src/plugins/platforms/ios/qiosintegration.mm
@@ -97,7 +97,7 @@ QIOSIntegration::QIOSIntegration()
     QDir::setCurrent(QString::fromUtf8([[[NSBundle mainBundle] bundlePath] UTF8String]));
 
     UIScreen *mainScreen = [UIScreen mainScreen];
-    NSMutableArray *screens = [[[UIScreen screens] mutableCopy] autorelease];
+    NSMutableArray<UIScreen *> *screens = [[[UIScreen screens] mutableCopy] autorelease];
     if (![screens containsObject:mainScreen]) {
         // Fallback for iOS 7.1 (QTBUG-42345)
         [screens insertObject:mainScreen atIndex:0];
diff --git a/src/plugins/platforms/ios/qiosmenu.mm b/src/plugins/platforms/ios/qiosmenu.mm
index 6c70676a31..74a77de757 100644
--- a/src/plugins/platforms/ios/qiosmenu.mm
+++ b/src/plugins/platforms/ios/qiosmenu.mm
@@ -60,14 +60,14 @@ QIOSMenu *QIOSMenu::m_currentMenu = 0;
 
 static NSString *const kSelectorPrefix = @"_qtMenuItem_";
 
-@interface QUIMenuController : UIResponder {
-    QIOSMenuItemList m_visibleMenuItems;
-}
+@interface QUIMenuController : UIResponder
 @end
 
-@implementation QUIMenuController
+@implementation QUIMenuController {
+    QIOSMenuItemList m_visibleMenuItems;
+}
 
-- (id)initWithVisibleMenuItems:(const QIOSMenuItemList &)visibleMenuItems
+- (instancetype)initWithVisibleMenuItems:(const QIOSMenuItemList &)visibleMenuItems
 {
     if (self = [super init]) {
         [self setVisibleMenuItems:visibleMenuItems];
@@ -80,7 +80,7 @@ static NSString *const kSelectorPrefix = @"_qtMenuItem_";
     return self;
 }
 
--(void)dealloc
+- (void)dealloc
 {
     [[NSNotificationCenter defaultCenter]
         removeObserver:self
@@ -91,7 +91,7 @@ static NSString *const kSelectorPrefix = @"_qtMenuItem_";
 - (void)setVisibleMenuItems:(const QIOSMenuItemList &)visibleMenuItems
 {
     m_visibleMenuItems = visibleMenuItems;
-    NSMutableArray *menuItemArray = [NSMutableArray arrayWithCapacity:m_visibleMenuItems.size()];
+    NSMutableArray<UIMenuItem *> *menuItemArray = [NSMutableArray<UIMenuItem *> arrayWithCapacity:m_visibleMenuItems.size()];
     // Create an array of UIMenuItems, one for each visible QIOSMenuItem. Each
     // UIMenuItem needs a callback assigned, so we assign one of the placeholder methods
     // added to UIWindow (QIOSMenuActionTargets) below. Each method knows its own index, which
@@ -107,7 +107,7 @@ static NSString *const kSelectorPrefix = @"_qtMenuItem_";
         [[UIMenuController sharedMenuController] setMenuVisible:YES animated:NO];
 }
 
--(void)menuClosed
+- (void)menuClosed
 {
     QIOSMenu::currentMenu()->dismiss();
 }
@@ -141,19 +141,19 @@ static NSString *const kSelectorPrefix = @"_qtMenuItem_";
 
 // -------------------------------------------------------------------------
 
-@interface QUIPickerView : UIPickerView <UIPickerViewDelegate, UIPickerViewDataSource> {
-    QIOSMenuItemList m_visibleMenuItems;
-    QPointer<QObject> m_focusObjectWithPickerView;
-    NSInteger m_selectedRow;
-}
+@interface QUIPickerView : UIPickerView <UIPickerViewDelegate, UIPickerViewDataSource>
 
 @property(retain) UIToolbar *toolbar;
 
 @end
 
-@implementation QUIPickerView
+@implementation QUIPickerView {
+    QIOSMenuItemList m_visibleMenuItems;
+    QPointer<QObject> m_focusObjectWithPickerView;
+    NSInteger m_selectedRow;
+}
 
-- (id)initWithVisibleMenuItems:(const QIOSMenuItemList &)visibleMenuItems selectItem:(const QIOSMenuItem *)selectItem
+- (instancetype)initWithVisibleMenuItems:(const QIOSMenuItemList &)visibleMenuItems selectItem:(const QIOSMenuItem *)selectItem
 {
     if (self = [super init]) {
         [self setVisibleMenuItems:visibleMenuItems selectItem:selectItem];
@@ -172,7 +172,7 @@ static NSString *const kSelectorPrefix = @"_qtMenuItem_";
         UIBarButtonItem *doneButton = [[[UIBarButtonItem alloc]
                 initWithBarButtonSystemItem:UIBarButtonSystemItemDone
                 target:self action:@selector(closeMenu)] autorelease];
-        [self.toolbar setItems:[NSArray arrayWithObjects:cancelButton, spaceButton, doneButton, nil]];
+        [self.toolbar setItems:@[cancelButton, spaceButton, doneButton]];
 
         [self setDelegate:self];
         [self setDataSource:self];
diff --git a/src/plugins/platforms/ios/qiosoptionalplugininterface.h b/src/plugins/platforms/ios/qiosoptionalplugininterface.h
index 660c74e856..bae9e5a0d8 100644
--- a/src/plugins/platforms/ios/qiosoptionalplugininterface.h
+++ b/src/plugins/platforms/ios/qiosoptionalplugininterface.h
@@ -44,10 +44,10 @@
 
 #include "qiosfiledialog.h"
 
-QT_BEGIN_NAMESPACE
-
 Q_FORWARD_DECLARE_OBJC_CLASS(UIViewController);
 
+QT_BEGIN_NAMESPACE
+
 #define QIosOptionalPluginInterface_iid "org.qt-project.Qt.QPA.ios.optional"
 
 class QIosOptionalPluginInterface
diff --git a/src/plugins/platforms/ios/qiosscreen.mm b/src/plugins/platforms/ios/qiosscreen.mm
index c394592d76..91d26c88c2 100644
--- a/src/plugins/platforms/ios/qiosscreen.mm
+++ b/src/plugins/platforms/ios/qiosscreen.mm
@@ -130,16 +130,14 @@ static QIOSScreen* qtPlatformScreenFor(UIScreen *uiScreen)
 
 // -------------------------------------------------------------------------
 
-@interface QIOSOrientationListener : NSObject {
-    @public
-    QIOSScreen *m_screen;
-}
-- (id)initWithQIOSScreen:(QIOSScreen *)screen;
+@interface QIOSOrientationListener : NSObject
 @end
 
-@implementation QIOSOrientationListener
+@implementation QIOSOrientationListener {
+    QIOSScreen *m_screen;
+}
 
-- (id)initWithQIOSScreen:(QIOSScreen *)screen
+- (instancetype)initWithQIOSScreen:(QIOSScreen *)screen
 {
     self = [super init];
     if (self) {
@@ -193,7 +191,7 @@ static QIOSScreen* qtPlatformScreenFor(UIScreen *uiScreen)
 
 @implementation QUIWindow
 
-- (id)initWithFrame:(CGRect)frame
+- (instancetype)initWithFrame:(CGRect)frame
 {
     if ((self = [super initWithFrame:frame]))
         self->_sendingEvent = NO;
diff --git a/src/plugins/platforms/ios/qiostextinputoverlay.mm b/src/plugins/platforms/ios/qiostextinputoverlay.mm
index fe3c29d037..ff696f5b7f 100644
--- a/src/plugins/platforms/ios/qiostextinputoverlay.mm
+++ b/src/plugins/platforms/ios/qiostextinputoverlay.mm
@@ -96,7 +96,7 @@ static void executeBlockWithoutAnimation(Block block)
 
 @implementation QIOSEditMenu
 
-- (id)init
+- (instancetype)init
 {
     if (self = [super init]) {
         NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
@@ -160,7 +160,13 @@ static void executeBlockWithoutAnimation(Block block)
 
 // -------------------------------------------------------------------------
 
-@interface QIOSLoupeLayer : CALayer {
+@interface QIOSLoupeLayer : CALayer
+@property (nonatomic, retain) UIView *targetView;
+@property (nonatomic, assign) CGPoint focalPoint;
+@property (nonatomic, assign) BOOL visible;
+@end
+
+@implementation QIOSLoupeLayer {
     UIView *_snapshotView;
     BOOL _pendingSnapshotUpdate;
     UIView *_loupeImageView;
@@ -168,14 +174,8 @@ static void executeBlockWithoutAnimation(Block block)
     CGFloat _loupeOffset;
     QTimer _updateTimer;
 }
-@property (nonatomic, retain) UIView *targetView;
-@property (nonatomic, assign) CGPoint focalPoint;
-@property (nonatomic, assign) BOOL visible;
-@end
 
-@implementation QIOSLoupeLayer
-
-- (id)initWithSize:(CGSize)size cornerRadius:(CGFloat)cornerRadius bottomOffset:(CGFloat)bottomOffset
+- (instancetype)initWithSize:(CGSize)size cornerRadius:(CGFloat)cornerRadius bottomOffset:(CGFloat)bottomOffset
 {
     if (self = [super init]) {
         _loupeOffset = bottomOffset + (size.height / 2);
@@ -301,26 +301,22 @@ static void executeBlockWithoutAnimation(Block block)
 
 // -------------------------------------------------------------------------
 
-#if QT_IOS_PLATFORM_SDK_EQUAL_OR_ABOVE(__IPHONE_10_0)
-@interface QIOSHandleLayer : CALayer <CAAnimationDelegate> {
-#else
-@interface QIOSHandleLayer : CALayer {
-#endif
-    CALayer *_handleCursorLayer;
-    CALayer *_handleKnobLayer;
-    Qt::Edge _selectionEdge;
-}
+@interface QIOSHandleLayer : CALayer <CAAnimationDelegate>
 @property (nonatomic, assign) CGRect cursorRectangle;
 @property (nonatomic, assign) CGFloat handleScale;
 @property (nonatomic, assign) BOOL visible;
 @property (nonatomic, copy) Block onAnimationDidStop;
 @end
 
-@implementation QIOSHandleLayer
+@implementation QIOSHandleLayer {
+    CALayer *_handleCursorLayer;
+    CALayer *_handleKnobLayer;
+    Qt::Edge _selectionEdge;
+}
 
 @dynamic handleScale;
 
-- (id)initWithKnobAtEdge:(Qt::Edge)selectionEdge
+- (instancetype)initWithKnobAtEdge:(Qt::Edge)selectionEdge
 {
     if (self = [super init]) {
         CGColorRef bgColor = [UIColor colorWithRed:0.1 green:0.4 blue:0.9 alpha:1].CGColor;
@@ -355,16 +351,8 @@ static void executeBlockWithoutAnimation(Block block)
             // The handle should "bounce" in when becoming visible
             CAKeyframeAnimation * animation = [CAKeyframeAnimation animationWithKeyPath:key];
             [animation setDuration:0.5];
-            animation.values = [NSArray arrayWithObjects:
-                [NSNumber numberWithFloat:0],
-                [NSNumber numberWithFloat:1.3],
-                [NSNumber numberWithFloat:1.3],
-                [NSNumber numberWithFloat:1], nil];
-            animation.keyTimes = [NSArray arrayWithObjects:
-                [NSNumber numberWithFloat:0],
-                [NSNumber numberWithFloat:0.3],
-                [NSNumber numberWithFloat:0.9],
-                [NSNumber numberWithFloat:1], nil];
+            animation.values = @[@(0.0f), @(1.3f), @(1.3f), @(1.0f)];
+            animation.keyTimes = @[@(0.0f), @(0.3f), @(0.9f), @(1.0f)];
             return animation;
         } else {
             CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:key];
@@ -436,8 +424,13 @@ static void executeBlockWithoutAnimation(Block block)
   below will inherit. It takes care of creating and showing a magnifier
   glass depending on the current gesture state.
   */
-@interface QIOSLoupeRecognizer : UIGestureRecognizer <UIGestureRecognizerDelegate> {
-@public
+@interface QIOSLoupeRecognizer : UIGestureRecognizer <UIGestureRecognizerDelegate>
+@property (nonatomic, assign) QPointF focalPoint;
+@property (nonatomic, assign) BOOL dragTriggersGesture;
+@property (nonatomic, readonly) UIView *focusView;
+@end
+
+@implementation QIOSLoupeRecognizer {
     QIOSLoupeLayer *_loupeLayer;
     UIView *_desktopView;
     CGPoint _firstTouchPoint;
@@ -445,14 +438,8 @@ static void executeBlockWithoutAnimation(Block block)
     QTimer _triggerStateBeganTimer;
     int _originalCursorFlashTime;
 }
-@property (nonatomic, assign) QPointF focalPoint;
-@property (nonatomic, assign) BOOL dragTriggersGesture;
-@property (nonatomic, readonly) UIView *focusView;
-@end
 
-@implementation QIOSLoupeRecognizer
-
-- (id)init
+- (instancetype)init
 {
     if (self = [super initWithTarget:self action:@selector(gestureStateChanged)]) {
         self.enabled = NO;
@@ -657,7 +644,10 @@ static void executeBlockWithoutAnimation(Block block)
   on the sides. If the user starts dragging on a handle (or do a press and
   hold), it will show a magnifier glass that follows the handle as it moves.
   */
-@interface QIOSSelectionRecognizer : QIOSLoupeRecognizer {
+@interface QIOSSelectionRecognizer : QIOSLoupeRecognizer
+@end
+
+@implementation QIOSSelectionRecognizer {
     CALayer *_clipRectLayer;
     QIOSHandleLayer *_cursorLayer;
     QIOSHandleLayer *_anchorLayer;
@@ -669,11 +659,8 @@ static void executeBlockWithoutAnimation(Block block)
     QMetaObject::Connection _anchorConnection;
     QMetaObject::Connection _clipRectConnection;
 }
-@end
-
-@implementation QIOSSelectionRecognizer
 
-- (id)init
+- (instancetype)init
 {
     if (self = [super init]) {
         self.delaysTouchesBegan = YES;
@@ -889,15 +876,15 @@ static void executeBlockWithoutAnimation(Block block)
   visibility of the edit menu will be toggled. Otherwise, if there's a selection, a
   first tap will close the edit menu (if any), and a second tap will remove the selection.
   */
-@interface QIOSTapRecognizer : UITapGestureRecognizer {
+@interface QIOSTapRecognizer : UITapGestureRecognizer
+@end
+
+@implementation QIOSTapRecognizer {
     int _cursorPosOnPress;
     UIView *_focusView;
 }
-@end
-
-@implementation QIOSTapRecognizer
 
-- (id)init
+- (instancetype)init
 {
     if (self = [super initWithTarget:self action:@selector(gestureStateChanged)]) {
         self.enabled = NO;
diff --git a/src/plugins/platforms/ios/qiostextresponder.h b/src/plugins/platforms/ios/qiostextresponder.h
index 77be2cf2fe..074598c1c3 100644
--- a/src/plugins/platforms/ios/qiostextresponder.h
+++ b/src/plugins/platforms/ios/qiostextresponder.h
@@ -49,16 +49,8 @@ class QIOSInputContext;
 QT_END_NAMESPACE
 
 @interface QIOSTextInputResponder : UIResponder <UITextInputTraits, UIKeyInput, UITextInput>
-{
-  @private
-    QT_PREPEND_NAMESPACE(QIOSInputContext) *m_inputContext;
-    QT_PREPEND_NAMESPACE(QInputMethodQueryEvent) *m_configuredImeState;
-    QString m_markedText;
-    BOOL m_inSendEventToFocusObject;
-    BOOL m_inSelectionChange;
-}
 
-- (id)initWithInputContext:(QT_PREPEND_NAMESPACE(QIOSInputContext) *)context;
+- (instancetype)initWithInputContext:(QT_PREPEND_NAMESPACE(QIOSInputContext) *)context;
 - (BOOL)needsKeyboardReconfigure:(Qt::InputMethodQueries)updatedProperties;
 
 - (void)notifyInputDelegate:(Qt::InputMethodQueries)updatedProperties;
diff --git a/src/plugins/platforms/ios/qiostextresponder.mm b/src/plugins/platforms/ios/qiostextresponder.mm
index b029c49a67..91a088ede1 100644
--- a/src/plugins/platforms/ios/qiostextresponder.mm
+++ b/src/plugins/platforms/ios/qiostextresponder.mm
@@ -55,13 +55,13 @@
 @interface QUITextPosition : UITextPosition
 
 @property (nonatomic) NSUInteger index;
-+ (QUITextPosition *)positionWithIndex:(NSUInteger)index;
++ (instancetype)positionWithIndex:(NSUInteger)index;
 
 @end
 
 @implementation QUITextPosition
 
-+ (QUITextPosition *)positionWithIndex:(NSUInteger)index
++ (instancetype)positionWithIndex:(NSUInteger)index
 {
     QUITextPosition *pos = [[QUITextPosition alloc] init];
     pos.index = index;
@@ -75,15 +75,15 @@
 @interface QUITextRange : UITextRange
 
 @property (nonatomic) NSRange range;
-+ (QUITextRange *)rangeWithNSRange:(NSRange)range;
++ (instancetype)rangeWithNSRange:(NSRange)range;
 
 @end
 
 @implementation QUITextRange
 
-+ (QUITextRange *)rangeWithNSRange:(NSRange)nsrange
++ (instancetype)rangeWithNSRange:(NSRange)nsrange
 {
-    QUITextRange *range = [[QUITextRange alloc] init];
+    QUITextRange *range = [[self alloc] init];
     range.range = nsrange;
     return [range autorelease];
 }
@@ -117,7 +117,7 @@
 
 @implementation WrapperView
 
-- (id)initWithView:(UIView *)view
+- (instancetype)initWithView:(UIView *)view
 {
     if (self = [self init]) {
         [self addSubview:view];
@@ -132,7 +132,7 @@
 
 - (void)layoutSubviews
 {
-    UIView* view = [self.subviews firstObject];
+    UIView *view = [self.subviews firstObject];
     view.frame = self.bounds;
 
     // FIXME: During orientation changes the size and position
@@ -161,9 +161,15 @@
 
 // -------------------------------------------------------------------------
 
-@implementation QIOSTextInputResponder
+@implementation QIOSTextInputResponder {
+    QT_PREPEND_NAMESPACE(QIOSInputContext) *m_inputContext;
+    QT_PREPEND_NAMESPACE(QInputMethodQueryEvent) *m_configuredImeState;
+    QString m_markedText;
+    BOOL m_inSendEventToFocusObject;
+    BOOL m_inSelectionChange;
+}
 
-- (id)initWithInputContext:(QT_PREPEND_NAMESPACE(QIOSInputContext) *)inputContext
+- (instancetype)initWithInputContext:(QT_PREPEND_NAMESPACE(QIOSInputContext) *)inputContext
 {
     if (!(self = [self init]))
         return self;
@@ -548,7 +554,7 @@
     [self sendKeyPressRelease:key modifiers:modifiers];
 }
 
-- (void)addKeyCommandsToArray:(NSMutableArray *)array key:(NSString *)key
+- (void)addKeyCommandsToArray:(NSMutableArray<UIKeyCommand *> *)array key:(NSString *)key
 {
     SEL s = @selector(keyCommandTriggered:);
     [array addObject:[UIKeyCommand keyCommandWithInput:key modifierFlags:0 action:s]];
@@ -559,19 +565,19 @@
     [array addObject:[UIKeyCommand keyCommandWithInput:key modifierFlags:UIKeyModifierCommand|UIKeyModifierShift action:s]];
 }
 
-- (NSArray *)keyCommands
+- (NSArray<UIKeyCommand *> *)keyCommands
 {
     // Since keyCommands is called for every key
     // press/release, we cache the result
     static dispatch_once_t once;
-    static NSMutableArray *array;
+    static NSMutableArray<UIKeyCommand *> *array;
 
     dispatch_once(&once, ^{
         // We let Qt move the cursor around when the arrow keys are being used. This
         // is normally implemented through UITextInput, but since IM in Qt have poor
         // support for moving the cursor vertically, and even less support for selecting
         // text across multiple paragraphs, we do this through key events.
-        array = [NSMutableArray new];
+        array = [NSMutableArray<UIKeyCommand *> new];
         [self addKeyCommandsToArray:array key:UIKeyInputUpArrow];
         [self addKeyCommandsToArray:array key:UIKeyInputDownArrow];
         [self addKeyCommandsToArray:array key:UIKeyInputLeftArrow];
@@ -825,13 +831,13 @@
     return startRect.united(endRect).toCGRect();
 }
 
-- (NSArray *)selectionRectsForRange:(UITextRange *)range
+- (NSArray<UITextSelectionRect *> *)selectionRectsForRange:(UITextRange *)range
 {
     Q_UNUSED(range);
     // This method is supposed to return a rectangle for each line with selection. Since we don't
     // expose an API in Qt/IM for getting this information, and since we never seems to be getting
     // a call from UIKit for this, we return an empty array until a need arise.
-    return [[NSArray new] autorelease];
+    return [[NSArray<UITextSelectionRect *> new] autorelease];
 }
 
 - (CGRect)caretRectForPosition:(UITextPosition *)position
@@ -916,7 +922,7 @@
 
     QObject *focusObject = QGuiApplication::focusObject();
     if (!focusObject)
-        return [NSDictionary dictionary];
+        return @{};
 
     // Assume position is the same as the cursor for now. QInputMethodQueryEvent with Qt::ImFont
     // needs to be extended to take an extra position argument before this can be fully correct.
@@ -925,8 +931,8 @@
     QFont qfont = qvariant_cast<QFont>(e.value(Qt::ImFont));
     UIFont *uifont = [UIFont fontWithName:qfont.family().toNSString() size:qfont.pointSize()];
     if (!uifont)
-        return [NSDictionary dictionary];
-    return [NSDictionary dictionaryWithObject:uifont forKey:NSFontAttributeName];
+        return @{};
+    return @{NSFontAttributeName: uifont};
 }
 #endif
 
diff --git a/src/plugins/platforms/ios/qiosviewcontroller.h b/src/plugins/platforms/ios/qiosviewcontroller.h
index 07d5535e1a..7af4c83b48 100644
--- a/src/plugins/platforms/ios/qiosviewcontroller.h
+++ b/src/plugins/platforms/ios/qiosviewcontroller.h
@@ -48,7 +48,7 @@ QT_END_NAMESPACE
 
 @interface QIOSViewController : UIViewController
 
-- (id)initWithQIOSScreen:(QT_PREPEND_NAMESPACE(QIOSScreen) *)screen;
+- (instancetype)initWithQIOSScreen:(QT_PREPEND_NAMESPACE(QIOSScreen) *)screen;
 - (void)updateProperties;
 
 #ifndef Q_OS_TVOS
diff --git a/src/plugins/platforms/ios/qiosviewcontroller.mm b/src/plugins/platforms/ios/qiosviewcontroller.mm
index a7663b9e94..787c6b8409 100644
--- a/src/plugins/platforms/ios/qiosviewcontroller.mm
+++ b/src/plugins/platforms/ios/qiosviewcontroller.mm
@@ -56,12 +56,8 @@
 
 // -------------------------------------------------------------------------
 
-@interface QIOSViewController () {
-  @public
-    QPointer<QT_PREPEND_NAMESPACE(QIOSScreen)> m_screen;
-    BOOL m_updatingProperties;
-    QMetaObject::Connection m_focusWindowChangeConnection;
-}
+@interface QIOSViewController ()
+@property (nonatomic, assign) QPointer<QT_PREPEND_NAMESPACE(QIOSScreen)> platformScreen;
 @property (nonatomic, assign) BOOL changingOrientation;
 @end
 
@@ -72,7 +68,7 @@
 
 @implementation QIOSDesktopManagerView
 
-- (id)init
+- (instancetype)init
 {
     if (!(self = [super init]))
         return nil;
@@ -125,7 +121,7 @@
 {
     Q_UNUSED(subview);
 
-    QT_PREPEND_NAMESPACE(QIOSScreen) *screen = self.qtViewController->m_screen;
+    QT_PREPEND_NAMESPACE(QIOSScreen) *screen = self.qtViewController.platformScreen;
 
     // The 'window' property of our view is not valid until the window
     // has been shown, so we have to access it through the QIOSScreen.
@@ -170,7 +166,7 @@
         // here. iOS will still use the latest rendered frame to create the
         // application switcher thumbnail, but it will be based on the last
         // active orientation of the application.
-        QIOSScreen *screen = self.qtViewController->m_screen;
+        QIOSScreen *screen = self.qtViewController.platformScreen;
         qCDebug(lcQpaWindow) << "ignoring layout of subviews while suspended,"
             << "likely system snapshot of" << screen->screen()->primaryOrientation();
         return;
@@ -246,7 +242,10 @@
 
 // -------------------------------------------------------------------------
 
-@implementation QIOSViewController
+@implementation QIOSViewController {
+    BOOL m_updatingProperties;
+    QMetaObject::Connection m_focusWindowChangeConnection;
+}
 
 #ifndef Q_OS_TVOS
 @synthesize prefersStatusBarHidden;
@@ -254,11 +253,10 @@
 @synthesize preferredStatusBarStyle;
 #endif
 
-- (id)initWithQIOSScreen:(QT_PREPEND_NAMESPACE(QIOSScreen) *)screen
+- (instancetype)initWithQIOSScreen:(QT_PREPEND_NAMESPACE(QIOSScreen) *)screen
 {
     if (self = [self init]) {
-        m_screen = screen;
-
+        self.platformScreen = screen;
 
         self.changingOrientation = NO;
 #ifndef Q_OS_TVOS
@@ -316,7 +314,7 @@
 - (BOOL)shouldAutorotate
 {
 #ifndef Q_OS_TVOS
-    return m_screen && m_screen->uiScreen() == [UIScreen mainScreen] && !self.lockedOrientation;
+    return self.platformScreen && self.platformScreen->uiScreen() == [UIScreen mainScreen] && !self.lockedOrientation;
 #else
     return NO;
 #endif
@@ -396,8 +394,8 @@
     if (!QCoreApplication::instance())
         return;
 
-    if (m_screen)
-        m_screen->updateProperties();
+    if (self.platformScreen)
+        self.platformScreen->updateProperties();
 }
 
 // -------------------------------------------------------------------------
@@ -407,12 +405,12 @@
     if (!isQtApplication())
         return;
 
-    if (!m_screen || !m_screen->screen())
+    if (!self.platformScreen || !self.platformScreen->screen())
         return;
 
     // For now we only care about the main screen, as both the statusbar
     // visibility and orientation is only appropriate for the main screen.
-    if (m_screen->uiScreen() != [UIScreen mainScreen])
+    if (self.platformScreen->uiScreen() != [UIScreen mainScreen])
         return;
 
     // Prevent recursion caused by updating the status bar appearance (position
@@ -434,7 +432,7 @@
         return;
 
     // We only care about changes to focusWindow that involves our screen
-    if (!focusWindow->screen() || focusWindow->screen()->handle() != m_screen)
+    if (!focusWindow->screen() || focusWindow->screen()->handle() != self.platformScreen)
         return;
 
     // All decisions are based on the the top level window
diff --git a/src/plugins/platforms/ios/qioswindow.mm b/src/plugins/platforms/ios/qioswindow.mm
index 6ee258e363..cdec57de71 100644
--- a/src/plugins/platforms/ios/qioswindow.mm
+++ b/src/plugins/platforms/ios/qioswindow.mm
@@ -96,7 +96,7 @@ QIOSWindow::~QIOSWindow()
     [m_view touchesCancelled:[NSSet set] withEvent:0];
 
     clearAccessibleCache();
-    m_view->m_qioswindow = 0;
+    m_view.platformWindow = 0;
     [m_view removeFromSuperview];
     [m_view release];
 }
@@ -139,7 +139,7 @@ void QIOSWindow::setVisible(bool visible)
     } else if (!visible && [m_view isActiveWindow]) {
         // Our window was active/focus window but now hidden, so relinquish
         // focus to the next possible window in the stack.
-        NSArray *subviews = m_view.viewController.view.subviews;
+        NSArray<UIView *> *subviews = m_view.viewController.view.subviews;
         for (int i = int(subviews.count) - 1; i >= 0; --i) {
             UIView *view = [subviews objectAtIndex:i];
             if (view.hidden)
@@ -301,7 +301,7 @@ void QIOSWindow::raiseOrLower(bool raise)
     if (!isQtApplication())
         return;
 
-    NSArray *subviews = m_view.superview.subviews;
+    NSArray<UIView *> *subviews = m_view.superview.subviews;
     if (subviews.count == 1)
         return;
 
diff --git a/src/plugins/platforms/ios/quiaccessibilityelement.h b/src/plugins/platforms/ios/quiaccessibilityelement.h
index 03abf5407e..6b8efdcede 100644
--- a/src/plugins/platforms/ios/quiaccessibilityelement.h
+++ b/src/plugins/platforms/ios/quiaccessibilityelement.h
@@ -45,13 +45,12 @@
 
 #ifndef QT_NO_ACCESSIBILITY
 
-@interface QMacAccessibilityElement : UIAccessibilityElement
-{}
+@interface QT_MANGLE_NAMESPACE(QMacAccessibilityElement) : UIAccessibilityElement
 
 @property (readonly) QAccessible::Id axid;
 
-- (id)initWithId:(QAccessible::Id)anId withAccessibilityContainer:(id)view;
-+ (QMacAccessibilityElement *)elementWithId:(QAccessible::Id)anId withAccessibilityContainer:(id)view;
+- (instancetype)initWithId:(QAccessible::Id)anId withAccessibilityContainer:(id)view;
++ (instancetype)elementWithId:(QAccessible::Id)anId withAccessibilityContainer:(id)view;
 
 @end
 
diff --git a/src/plugins/platforms/ios/quiaccessibilityelement.mm b/src/plugins/platforms/ios/quiaccessibilityelement.mm
index a26ba61b3c..3154536aad 100644
--- a/src/plugins/platforms/ios/quiaccessibilityelement.mm
+++ b/src/plugins/platforms/ios/quiaccessibilityelement.mm
@@ -42,20 +42,23 @@
 #ifndef QT_NO_ACCESSIBILITY
 
 #include "private/qaccessiblecache_p.h"
+#include "private/qcore_mac_p.h"
+
+QT_NAMESPACE_ALIAS_OBJC_CLASS(QMacAccessibilityElement);
 
 @implementation QMacAccessibilityElement
 
-- (id)initWithId:(QAccessible::Id)anId withAccessibilityContainer:(id)view
+- (instancetype)initWithId:(QAccessible::Id)anId withAccessibilityContainer:(id)view
 {
     Q_ASSERT((int)anId < 0);
-    self = [super initWithAccessibilityContainer: view];
+    self = [super initWithAccessibilityContainer:view];
     if (self)
         _axid = anId;
 
     return self;
 }
 
-+ (id)elementWithId:(QAccessible::Id)anId withAccessibilityContainer:(id)view
++ (instancetype)elementWithId:(QAccessible::Id)anId withAccessibilityContainer:(id)view
 {
     Q_ASSERT(anId);
     if (!anId)
@@ -63,10 +66,10 @@
 
     QAccessibleCache *cache = QAccessibleCache::instance();
 
-    QT_MANGLE_NAMESPACE(QMacAccessibilityElement) *element = cache->elementForId(anId);
+    QMacAccessibilityElement *element = cache->elementForId(anId);
     if (!element) {
         Q_ASSERT(QAccessible::accessibleInterface(anId));
-        element = [[self alloc] initWithId:anId withAccessibilityContainer: view];
+        element = [[self alloc] initWithId:anId withAccessibilityContainer:view];
         cache->insertElement(anId, element);
     }
     return element;
diff --git a/src/plugins/platforms/ios/quiview.h b/src/plugins/platforms/ios/quiview.h
index 3e3c579075..e1d5d5af0c 100644
--- a/src/plugins/platforms/ios/quiview.h
+++ b/src/plugins/platforms/ios/quiview.h
@@ -53,21 +53,10 @@ QT_END_NAMESPACE
 @class QIOSViewController;
 
 @interface QUIView : UIView
-{
-  @public
-    QT_PREPEND_NAMESPACE(QIOSWindow) *m_qioswindow;
-  @private
-    QHash<UITouch *, QWindowSystemInterface::TouchPoint> m_activeTouches;
-    UITouch *m_activePencilTouch;
-    int m_nextTouchId;
-
-  @private
-    NSMutableArray *m_accessibleElements;
-};
-
-- (id)initWithQIOSWindow:(QT_PREPEND_NAMESPACE(QIOSWindow) *)window;
+- (instancetype)initWithQIOSWindow:(QT_PREPEND_NAMESPACE(QIOSWindow) *)window;
 - (void)sendUpdatedExposeEvent;
 - (BOOL)isActiveWindow;
+@property (nonatomic, assign) QT_PREPEND_NAMESPACE(QIOSWindow) *platformWindow;
 @end
 
 @interface QUIView (Accessibility)
diff --git a/src/plugins/platforms/ios/quiview.mm b/src/plugins/platforms/ios/quiview.mm
index 584dfe9b41..53a4485609 100644
--- a/src/plugins/platforms/ios/quiview.mm
+++ b/src/plugins/platforms/ios/quiview.mm
@@ -55,7 +55,12 @@
 
 Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 
-@implementation QUIView
+@implementation QUIView {
+    QHash<UITouch *, QWindowSystemInterface::TouchPoint> m_activeTouches;
+    UITouch *m_activePencilTouch;
+    int m_nextTouchId;
+    NSMutableArray<UIAccessibilityElement *> *m_accessibleElements;
+}
 
 + (void)load
 {
@@ -82,25 +87,26 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
     return [CAEAGLLayer class];
 }
 
-- (id)initWithQIOSWindow:(QT_PREPEND_NAMESPACE(QIOSWindow) *)window
+- (instancetype)initWithQIOSWindow:(QT_PREPEND_NAMESPACE(QIOSWindow) *)window
 {
     if (self = [self initWithFrame:window->geometry().toCGRect()]) {
-        m_qioswindow = window;
-        m_accessibleElements = [[NSMutableArray alloc] init];
+        self.platformWindow = window;
+        m_accessibleElements = [[NSMutableArray<UIAccessibilityElement *> alloc] init];
     }
 
     return self;
 }
 
-- (id)initWithFrame:(CGRect)frame
+- (instancetype)initWithFrame:(CGRect)frame
 {
     if ((self = [super initWithFrame:frame])) {
         // Set up EAGL layer
         CAEAGLLayer *eaglLayer = static_cast<CAEAGLLayer *>(self.layer);
         eaglLayer.opaque = TRUE;
-        eaglLayer.drawableProperties = [NSDictionary dictionaryWithObjectsAndKeys:
-            [NSNumber numberWithBool:YES], kEAGLDrawablePropertyRetainedBacking,
-            kEAGLColorFormatRGBA8, kEAGLDrawablePropertyColorFormat, nil];
+        eaglLayer.drawableProperties = @{
+            kEAGLDrawablePropertyRetainedBacking: @(YES),
+            kEAGLDrawablePropertyColorFormat: kEAGLColorFormatRGBA8
+        };
 
         if (isQtApplication())
             self.hidden = YES;
@@ -156,7 +162,7 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 #ifndef QT_NO_DEBUG_STREAM
     QString platformWindowDescription;
     QDebug debug(&platformWindowDescription);
-    debug.nospace() << "; " << m_qioswindow << ">";
+    debug.nospace() << "; " << self.platformWindow << ">";
     NSRange lastCharacter = [description rangeOfComposedCharacterSequenceAtIndex:description.length - 1];
     [description replaceCharactersInRange:lastCharacter withString:platformWindowDescription.toNSString()];
 #endif
@@ -210,10 +216,10 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
     if (!CGAffineTransformIsIdentity(self.transform))
         qWarning() << self << "has a transform set. This is not supported.";
 
-    QWindow *window = m_qioswindow->window();
+    QWindow *window = self.platformWindow->window();
     QRect lastReportedGeometry = qt_window_private(window)->geometry;
     QRect currentGeometry = QRectF::fromCGRect(self.frame).toRect();
-    qCDebug(lcQpaWindow) << m_qioswindow << "new geometry is" << currentGeometry;
+    qCDebug(lcQpaWindow) << self.platformWindow << "new geometry is" << currentGeometry;
     QWindowSystemInterface::handleGeometryChange(window, currentGeometry);
 
     if (currentGeometry.size() != lastReportedGeometry.size()) {
@@ -237,29 +243,29 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 {
     QRegion region;
 
-    if (m_qioswindow->isExposed()) {
+    if (self.platformWindow->isExposed()) {
         QSize bounds = QRectF::fromCGRect(self.layer.bounds).toRect().size();
 
-        Q_ASSERT(m_qioswindow->geometry().size() == bounds);
-        Q_ASSERT(self.hidden == !m_qioswindow->window()->isVisible());
+        Q_ASSERT(self.platformWindow->geometry().size() == bounds);
+        Q_ASSERT(self.hidden == !self.platformWindow->window()->isVisible());
 
         region = QRect(QPoint(), bounds);
     }
 
-    qCDebug(lcQpaWindow) << m_qioswindow << region << "isExposed" << m_qioswindow->isExposed();
-    QWindowSystemInterface::handleExposeEvent(m_qioswindow->window(), region);
+    qCDebug(lcQpaWindow) << self.platformWindow << region << "isExposed" << self.platformWindow->isExposed();
+    QWindowSystemInterface::handleExposeEvent(self.platformWindow->window(), region);
 }
 
 - (void)safeAreaInsetsDidChange
 {
-    QWindowSystemInterface::handleSafeAreaMarginsChanged(m_qioswindow->window());
+    QWindowSystemInterface::handleSafeAreaMarginsChanged(self.platformWindow->window());
 }
 
 // -------------------------------------------------------------------------
 
 - (BOOL)canBecomeFirstResponder
 {
-    return !(m_qioswindow->window()->flags() & Qt::WindowDoesNotAcceptFocus);
+    return !(self.platformWindow->window()->flags() & Qt::WindowDoesNotAcceptFocus);
 }
 
 - (BOOL)becomeFirstResponder
@@ -280,10 +286,10 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
         qImDebug() << self << "became first responder";
     }
 
-    if (qGuiApp->focusWindow() != m_qioswindow->window())
-        QWindowSystemInterface::handleWindowActivated(m_qioswindow->window());
+    if (qGuiApp->focusWindow() != self.platformWindow->window())
+        QWindowSystemInterface::handleWindowActivated(self.platformWindow->window());
     else
-        qImDebug() << m_qioswindow->window() << "already active, not sending window activation";
+        qImDebug() << self.platformWindow->window() << "already active, not sending window activation";
 
     return YES;
 }
@@ -361,7 +367,7 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 
 -(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
 {
-    if (m_qioswindow->window()->flags() & Qt::WindowTransparentForInput)
+    if (self.platformWindow->window()->flags() & Qt::WindowTransparentForInput)
         return NO;
     return [super pointInside:point withEvent:event];
 }
@@ -378,7 +384,7 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
         for (UITouch *cTouch in cTouches) {
             QPointF localViewPosition = QPointF::fromCGPoint([cTouch preciseLocationInView:self]);
             QPoint localViewPositionI = localViewPosition.toPoint();
-            QPointF globalScreenPosition = m_qioswindow->mapToGlobal(localViewPositionI) +
+            QPointF globalScreenPosition = self.platformWindow->mapToGlobal(localViewPositionI) +
                     (localViewPosition - localViewPositionI);
             qreal pressure = cTouch.force / cTouch.maximumPossibleForce;
             // azimuth unit vector: +x to the right, +y going downwards
@@ -391,7 +397,7 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
             qCDebug(lcQpaTablet) << i << ":" << timeStamp << localViewPosition << pressure << state << "azimuth" << azimuth.dx << azimuth.dy
                      << "angle" << azimuthAngle << "altitude" << cTouch.altitudeAngle
                      << "xTilt" << qBound(-60.0, altitudeAngle * azimuth.dx, 60.0) << "yTilt" << qBound(-60.0, altitudeAngle * azimuth.dy, 60.0);
-            QWindowSystemInterface::handleTabletEvent(m_qioswindow->window(), timeStamp, localViewPosition, globalScreenPosition,
+            QWindowSystemInterface::handleTabletEvent(self.platformWindow->window(), timeStamp, localViewPosition, globalScreenPosition,
                     // device, pointerType, buttons
                     QTabletEvent::RotationStylus, QTabletEvent::Pen, state == Qt::TouchPointReleased ? Qt::NoButton : Qt::LeftButton,
                     // pressure, xTilt, yTilt
@@ -415,12 +421,12 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
             // just map from the local view position to global coordinates.
             // tvOS: all touches start at the center of the screen and move from there.
             QPoint localViewPosition = QPointF::fromCGPoint([uiTouch locationInView:self]).toPoint();
-            QPoint globalScreenPosition = m_qioswindow->mapToGlobal(localViewPosition);
+            QPoint globalScreenPosition = self.platformWindow->mapToGlobal(localViewPosition);
 
             touchPoint.area = QRectF(globalScreenPosition, QSize(0, 0));
 
             // FIXME: Do we really need to support QTouchDevice::NormalizedPosition?
-            QSize screenSize = m_qioswindow->screen()->geometry().size();
+            QSize screenSize = self.platformWindow->screen()->geometry().size();
             touchPoint.normalPosition = QPointF(globalScreenPosition.x() / screenSize.width(),
                                                 globalScreenPosition.y() / screenSize.height());
 
@@ -439,7 +445,7 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
     }
     if (m_activeTouches.isEmpty())
             return;
-    QWindowSystemInterface::handleTouchEvent<QWindowSystemInterface::SynchronousDelivery>(m_qioswindow->window(), timeStamp, iosIntegration->touchDevice(), m_activeTouches.values());
+    QWindowSystemInterface::handleTouchEvent<QWindowSystemInterface::SynchronousDelivery>(self.platformWindow->window(), timeStamp, iosIntegration->touchDevice(), m_activeTouches.values());
     if (!static_cast<QUIWindow *>(self.window).sendingEvent) {
         // The event is likely delivered as part of delayed touch delivery, via
         // _UIGestureEnvironmentSortAndSendDelayedTouches, due to one of the two
@@ -450,10 +456,10 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
         // alert dialog, will fail to recognize. To be on the safe side, we deliver
         // the event asynchronously.
         QWindowSystemInterface::handleTouchEvent<QWindowSystemInterface::AsynchronousDelivery>(
-            m_qioswindow->window(), timeStamp, iosIntegration->touchDevice(), m_activeTouches.values());
+            self.platformWindow->window(), timeStamp, iosIntegration->touchDevice(), m_activeTouches.values());
     } else {
         QWindowSystemInterface::handleTouchEvent<QWindowSystemInterface::SynchronousDelivery>(
-            m_qioswindow->window(), timeStamp, iosIntegration->touchDevice(), m_activeTouches.values());
+            self.platformWindow->window(), timeStamp, iosIntegration->touchDevice(), m_activeTouches.values());
     }
 }
 
@@ -481,8 +487,8 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 #endif
     }
 
-    if (m_qioswindow->shouldAutoActivateWindow() && m_activeTouches.size() == 1) {
-        QPlatformWindow *topLevel = m_qioswindow;
+    if (self.platformWindow->shouldAutoActivateWindow() && m_activeTouches.size() == 1) {
+        QPlatformWindow *topLevel = self.platformWindow;
         while (QPlatformWindow *p = topLevel->parent())
             topLevel = p;
         if (topLevel->window() != QGuiApplication::focusWindow())
@@ -552,7 +558,7 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
     NSTimeInterval timestamp = event ? event.timestamp : [[NSProcessInfo processInfo] systemUptime];
 
     QIOSIntegration *iosIntegration = static_cast<QIOSIntegration *>(QGuiApplicationPrivate::platformIntegration());
-    QWindowSystemInterface::handleTouchCancelEvent(m_qioswindow->window(), ulong(timestamp * 1000), iosIntegration->touchDevice());
+    QWindowSystemInterface::handleTouchCancelEvent(self.platformWindow->window(), ulong(timestamp * 1000), iosIntegration->touchDevice());
 }
 
 - (int)mapPressTypeToKey:(UIPress*)press
@@ -580,7 +586,7 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
         int key = [self mapPressTypeToKey:press];
         if (key == Qt::Key_unknown)
             continue;
-        if (QWindowSystemInterface::handleKeyEvent(m_qioswindow->window(), type, key, Qt::NoModifier))
+        if (QWindowSystemInterface::handleKeyEvent(self.platformWindow->window(), type, key, Qt::NoModifier))
             handled = true;
     }
 
@@ -634,7 +640,7 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 - (QWindow *)qwindow
 {
     if ([self isKindOfClass:[QUIView class]]) {
-        if (QT_PREPEND_NAMESPACE(QIOSWindow) *w = static_cast<QUIView *>(self)->m_qioswindow)
+        if (QT_PREPEND_NAMESPACE(QIOSWindow) *w = static_cast<QUIView *>(self).platformWindow)
             return w->window();
     }
     return nil;
diff --git a/src/plugins/platforms/ios/quiview_accessibility.mm b/src/plugins/platforms/ios/quiview_accessibility.mm
index 69a4d375bd..a3f4156a59 100644
--- a/src/plugins/platforms/ios/quiview_accessibility.mm
+++ b/src/plugins/platforms/ios/quiview_accessibility.mm
@@ -49,8 +49,9 @@
     if (!iface || iface->state().invisible || (iface->text(QAccessible::Name).isEmpty() && iface->text(QAccessible::Value).isEmpty() && iface->text(QAccessible::Description).isEmpty()))
         return;
     QAccessible::Id accessibleId = QAccessible::uniqueId(iface);
-    UIAccessibilityElement *elem = [[QMacAccessibilityElement alloc] initWithId: accessibleId withAccessibilityContainer: self];
-    [m_accessibleElements addObject:[elem autorelease]];
+    UIAccessibilityElement *elem = [[QT_MANGLE_NAMESPACE(QMacAccessibilityElement) alloc] initWithId:accessibleId withAccessibilityContainer:self];
+    [m_accessibleElements addObject:elem];
+    [elem release];
 }
 
 - (void)createAccessibleContainer:(QAccessibleInterface *)iface
@@ -73,7 +74,7 @@
     if ([m_accessibleElements count])
         return;
 
-    QWindow *win = m_qioswindow->window();
+    QWindow *win = self.platformWindow->window();
     QAccessibleInterface *iface = win->accessibleRoot();
     if (iface)
         [self createAccessibleContainer: iface];
diff --git a/src/plugins/styles/mac/qmacstyle_mac.mm b/src/plugins/styles/mac/qmacstyle_mac.mm
index 9e8af78a8e..cdddf227ac 100644
--- a/src/plugins/styles/mac/qmacstyle_mac.mm
+++ b/src/plugins/styles/mac/qmacstyle_mac.mm
@@ -145,22 +145,12 @@ static QWindow *qt_getWindow(const QWidget *widget)
     return widget ? widget->window()->windowHandle() : 0;
 }
 
-@interface QT_MANGLE_NAMESPACE(NotificationReceiver) : NSObject {
-QMacStylePrivate *mPrivate;
-}
-- (id)initWithPrivate:(QMacStylePrivate *)priv;
-- (void)scrollBarStyleDidChange:(NSNotification *)notification;
+@interface QT_MANGLE_NAMESPACE(NotificationReceiver) : NSObject
 @end
 
 QT_NAMESPACE_ALIAS_OBJC_CLASS(NotificationReceiver);
 
 @implementation NotificationReceiver
-- (id)initWithPrivate:(QMacStylePrivate *)priv
-{
-    self = [super init];
-    mPrivate = priv;
-    return self;
-}
 
 - (void)scrollBarStyleDidChange:(NSNotification *)notification
 {
@@ -2285,7 +2275,7 @@ QMacStyle::QMacStyle()
     Q_D(QMacStyle);
     QMacAutoReleasePool pool;
 
-    d->receiver = [[NotificationReceiver alloc] initWithPrivate:d];
+    d->receiver = [[NotificationReceiver alloc] init];
     [[NSNotificationCenter defaultCenter] addObserver:d->receiver
                                              selector:@selector(scrollBarStyleDidChange:)
                                                  name:NSPreferredScrollerStyleDidChangeNotification
@@ -4513,7 +4503,7 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
             const auto cw = QMacStylePrivate::CocoaControl(ct, QStyleHelper::SizeLarge);
             auto *sv = static_cast<NSSplitView *>(d->cocoaControl(cw));
             sv.frame = opt->rect.toCGRect();
-            d->drawNSViewInRect(cw, sv, opt->rect, p, w != nullptr, ^(CGContextRef ctx, const CGRect &rect) {
+            d->drawNSViewInRect(cw, sv, opt->rect, p, w != nullptr, ^(CGContextRef __unused ctx, const CGRect &rect) {
                 [sv drawDividerInRect:rect];
             });
         } else {
@@ -6209,7 +6199,7 @@ QSize QMacStyle::sizeFromContents(ContentsType ct, const QStyleOption *opt,
     switch (ct) {
 #if QT_CONFIG(spinbox)
     case CT_SpinBox:
-        if (const QStyleOptionSpinBox *vopt = qstyleoption_cast<const QStyleOptionSpinBox *>(opt)) {
+        if (qstyleoption_cast<const QStyleOptionSpinBox *>(opt)) {
             const int buttonWidth = 20; // FIXME Use subControlRect()
             sz += QSize(buttonWidth, -3);
         }
diff --git a/src/printsupport/dialogs/qpagesetupdialog_mac.mm b/src/printsupport/dialogs/qpagesetupdialog_mac.mm
index 1e398452f7..a3511fe7b6 100644
--- a/src/printsupport/dialogs/qpagesetupdialog_mac.mm
+++ b/src/printsupport/dialogs/qpagesetupdialog_mac.mm
@@ -52,16 +52,13 @@ QT_USE_NAMESPACE
 @class QT_MANGLE_NAMESPACE(QCocoaPageLayoutDelegate);
 
 @interface QT_MANGLE_NAMESPACE(QCocoaPageLayoutDelegate) : NSObject
-{
+@end
+
+@implementation QT_MANGLE_NAMESPACE(QCocoaPageLayoutDelegate) {
     NSPrintInfo *printInfo;
 }
-- (id)initWithNSPrintInfo:(NSPrintInfo *)nsPrintInfo;
-- (void)pageLayoutDidEnd:(NSPageLayout *)pageLayout
-        returnCode:(int)returnCode contextInfo:(void *)contextInfo;
-@end
 
-@implementation QT_MANGLE_NAMESPACE(QCocoaPageLayoutDelegate)
-- (id)initWithNSPrintInfo:(NSPrintInfo *)nsPrintInfo
+- (instancetype)initWithNSPrintInfo:(NSPrintInfo *)nsPrintInfo
 {
     self = [super init];
     if (self) {
diff --git a/src/printsupport/dialogs/qprintdialog_mac.mm b/src/printsupport/dialogs/qprintdialog_mac.mm
index 854779977c..ed2d0908c4 100644
--- a/src/printsupport/dialogs/qprintdialog_mac.mm
+++ b/src/printsupport/dialogs/qprintdialog_mac.mm
@@ -77,22 +77,20 @@ QT_USE_NAMESPACE
 @class QT_MANGLE_NAMESPACE(QCocoaPrintPanelDelegate);
 
 @interface QT_MANGLE_NAMESPACE(QCocoaPrintPanelDelegate) : NSObject
-{
+@end
+
+@implementation QT_MANGLE_NAMESPACE(QCocoaPrintPanelDelegate) {
     NSPrintInfo *printInfo;
 }
-- (id)initWithNSPrintInfo:(NSPrintInfo *)nsPrintInfo;
-- (void)printPanelDidEnd:(NSPrintPanel *)printPanel
-        returnCode:(int)returnCode contextInfo:(void *)contextInfo;
-@end
 
-@implementation QT_MANGLE_NAMESPACE(QCocoaPrintPanelDelegate)
-- (id)initWithNSPrintInfo:(NSPrintInfo *)nsPrintInfo
+- (instancetype)initWithNSPrintInfo:(NSPrintInfo *)nsPrintInfo
 {
-    if (self = [super init]) {
+    if ((self = [self init])) {
         printInfo = nsPrintInfo;
     }
     return self;
 }
+
 - (void)printPanelDidEnd:(NSPrintPanel *)printPanel
         returnCode:(int)returnCode contextInfo:(void *)contextInfo
 {
@@ -102,8 +100,8 @@ QT_USE_NAMESPACE
     QPrinter *printer = dialog->printer();
 
     if (returnCode == NSModalResponseOK) {
-        PMPrintSession session = static_cast<PMPrintSession>([printInfo PMPrintSession]);
-        PMPrintSettings settings = static_cast<PMPrintSettings>([printInfo PMPrintSettings]);
+        PMPrintSession session = static_cast<PMPrintSession>(printInfo.PMPrintSession);
+        PMPrintSettings settings = static_cast<PMPrintSettings>(printInfo.PMPrintSettings);
 
         UInt32 frompage, topage;
         PMGetFirstPage(settings, &frompage);
@@ -192,6 +190,7 @@ QT_USE_NAMESPACE
 
     dialog->done((returnCode == NSModalResponseOK) ? QDialog::Accepted : QDialog::Rejected);
 }
+
 @end
 
 QT_BEGIN_NAMESPACE
diff --git a/src/testlib/qxctestlogger.mm b/src/testlib/qxctestlogger.mm
index 62fd73070f..9fa9da2fdd 100644
--- a/src/testlib/qxctestlogger.mm
+++ b/src/testlib/qxctestlogger.mm
@@ -200,7 +200,7 @@ private:
     [autoreleasepool release];
 }
 
-+ (id)defaultTestSuite
++ (QTestLibTests *)defaultTestSuite
 {
     return [[QtTestLibTests alloc] initWithName:@"QtTestLib"];
 }
@@ -255,7 +255,7 @@ static XCTestSuiteRun *s_qtTestSuiteRun = 0;
 
 @implementation QtTestLibTest
 
-- (id)initWithInvocation:(NSInvocation *)invocation
+- (instancetype)initWithInvocation:(NSInvocation *)invocation
 {
     if (self = [super initWithInvocation:invocation]) {
         // The test object name and function name are used by XCTest after QtTestLib has
@@ -322,7 +322,7 @@ QXcodeTestLogger *QXcodeTestLogger::s_currentTestLogger = 0;
 
 QXcodeTestLogger::QXcodeTestLogger()
     : QAbstractTestLogger(0)
-    , m_testRuns([[NSMutableArray arrayWithCapacity:2] retain])
+    , m_testRuns([[NSMutableArray<XCTestRun *> arrayWithCapacity:2] retain])
 
 {
     Q_ASSERT(!s_currentTestLogger);
@@ -383,11 +383,11 @@ static bool isTestFunctionInActiveScope(const char *function)
 
     Q_ASSERT(activeScope == Selected);
 
-    static NSArray *forcedTests = [@[ @"initTestCase", @"initTestCase_data", @"cleanupTestCase" ] retain];
+    static NSArray<NSString *> *forcedTests = [@[ @"initTestCase", @"initTestCase_data", @"cleanupTestCase" ] retain];
     if ([forcedTests containsObject:[NSString stringWithUTF8String:function]])
         return true;
 
-    static NSArray *testsInScope = [[testScope componentsSeparatedByString:@","] retain];
+    static NSArray<NSString *> *testsInScope = [[testScope componentsSeparatedByString:@","] retain];
     bool inScope = [testsInScope containsObject:[NSString stringWithFormat:@"%s/%s",
                         QTestResult::currentTestObjectName(), function]];
 
diff --git a/src/testlib/qxctestlogger_p.h b/src/testlib/qxctestlogger_p.h
index 1b641f18af..8baa5aa27f 100644
--- a/src/testlib/qxctestlogger_p.h
+++ b/src/testlib/qxctestlogger_p.h
@@ -90,7 +90,7 @@ private:
     void pushTestRunForTest(XCTest *test, bool start);
     XCTestRun *popTestRun();
 
-    NSMutableArray *m_testRuns;
+    NSMutableArray<XCTestRun *> *m_testRuns;
 
     static QXcodeTestLogger *s_currentTestLogger;
 };
diff --git a/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.mm b/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.mm
index e9407fd903..4ebf7a37f9 100644
--- a/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.mm
+++ b/tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac_helpers.mm
@@ -101,9 +101,9 @@ QDebug operator<<(QDebug dbg, AXErrorTag err)
 
 @implementation TestAXObject
 
-- (id) initWithAXUIElementRef: (AXUIElementRef) ref {
+- (instancetype)initWithAXUIElementRef:(AXUIElementRef)ref {
 
-    if ( self = [super init] ) {
+    if ((self = [super init])) {
         reference = ref;
     }
     return self;
diff --git a/tests/manual/cocoa/qmaccocoaviewcontainer/TestMouseMovedNSView.h b/tests/manual/cocoa/qmaccocoaviewcontainer/TestMouseMovedNSView.h
index be716aa582..4a145a729f 100644
--- a/tests/manual/cocoa/qmaccocoaviewcontainer/TestMouseMovedNSView.h
+++ b/tests/manual/cocoa/qmaccocoaviewcontainer/TestMouseMovedNSView.h
@@ -28,10 +28,5 @@
 
 #import <AppKit/AppKit.h>
 
-@interface TestMouseMovedNSView : NSView {
-    NSPoint mouseMovedPoint_;
-    BOOL wasAcceptingMouseEvents_;
-    NSTrackingRectTag trackingRect_;
-    NSTrackingArea* trackingArea_;
-}
+@interface TestMouseMovedNSView : NSView
 @end
diff --git a/tests/manual/cocoa/qmaccocoaviewcontainer/TestMouseMovedNSView.m b/tests/manual/cocoa/qmaccocoaviewcontainer/TestMouseMovedNSView.m
index 65b42dbb2f..20a3fcc513 100644
--- a/tests/manual/cocoa/qmaccocoaviewcontainer/TestMouseMovedNSView.m
+++ b/tests/manual/cocoa/qmaccocoaviewcontainer/TestMouseMovedNSView.m
@@ -28,9 +28,14 @@
 
 #import "TestMouseMovedNSView.h"
 
-@implementation TestMouseMovedNSView
+@implementation TestMouseMovedNSView {
+    NSPoint mouseMovedPoint_;
+    BOOL wasAcceptingMouseEvents_;
+    NSTrackingRectTag trackingRect_;
+    NSTrackingArea* trackingArea_;
+}
 
-- (id)initWithFrame:(NSRect)frame
+- (instancetype)initWithFrame:(NSRect)frame
 {
     self = [super initWithFrame:frame];
     if (self)
@@ -40,13 +45,13 @@
 
 - (void)viewDidMoveToWindow
 {
-    trackingArea_ = [[NSTrackingArea alloc] initWithRect:[self bounds] options: (NSTrackingMouseEnteredAndExited | NSTrackingActiveAlways) owner:self userInfo:nil];
+    trackingArea_ = [[NSTrackingArea alloc] initWithRect:self.bounds options:(NSTrackingMouseEnteredAndExited | NSTrackingActiveAlways) owner:self userInfo:nil];
     [self addTrackingArea:trackingArea_];
 }
 
 - (void)viewWillMoveToWindow:(NSWindow *)newWindow
 {
-    if ([self window] && trackingArea_)
+    if (self.window && trackingArea_)
         [self removeTrackingArea:trackingArea_];
 }
 
@@ -54,7 +59,7 @@
 {
     [super updateTrackingAreas];
     [self removeTrackingArea: trackingArea_];
-    trackingArea_ = [[NSTrackingArea alloc] initWithRect:[self bounds] options: (NSTrackingMouseEnteredAndExited | NSTrackingActiveAlways) owner:self userInfo:nil];
+    trackingArea_ = [[NSTrackingArea alloc] initWithRect:self.bounds options:(NSTrackingMouseEnteredAndExited | NSTrackingActiveAlways) owner:self userInfo:nil];
     [self addTrackingArea:trackingArea_];
 }
 
@@ -64,20 +69,20 @@
 - (void)mouseEntered:(NSEvent *)theEvent
 {
     wasAcceptingMouseEvents_ = [[self window] acceptsMouseMovedEvents];
-    [[self window] setAcceptsMouseMovedEvents:YES];
-    [[self window] makeFirstResponder:self];
+    [self.window setAcceptsMouseMovedEvents:YES];
+    [self.window makeFirstResponder:self];
 }
 
 - (void)mouseExited:(NSEvent *)theEvent
 {
-    [[self window] setAcceptsMouseMovedEvents:wasAcceptingMouseEvents_];
+    [self.window setAcceptsMouseMovedEvents:wasAcceptingMouseEvents_];
     [self setNeedsDisplay:YES];
     [self displayIfNeeded];
 }
 
 -(void)mouseMoved:(NSEvent *)pTheEvent
 {
-    mouseMovedPoint_ = [self convertPoint:[pTheEvent locationInWindow] fromView:nil];
+    mouseMovedPoint_ = [self convertPoint:pTheEvent.locationInWindow fromView:nil];
     [self setNeedsDisplay:YES];
     [self displayIfNeeded];
 }
@@ -88,7 +93,7 @@
     NSRectFill(dirtyRect);
 
     NSGraphicsContext *nsGraphicsContext = [NSGraphicsContext currentContext];
-    CGContextRef cgContextRef = (CGContextRef) [nsGraphicsContext graphicsPort];
+    CGContextRef cgContextRef = nsGraphicsContext.CGContext;
 
     CGContextSetRGBStrokeColor(cgContextRef, 0, 0, 0, .5);
     CGContextSetLineWidth(cgContextRef, 1.0);
diff --git a/tests/manual/cocoa/qmaccocoaviewcontainer/main.mm b/tests/manual/cocoa/qmaccocoaviewcontainer/main.mm
index 9cf06391ca..8b05b64a1e 100644
--- a/tests/manual/cocoa/qmaccocoaviewcontainer/main.mm
+++ b/tests/manual/cocoa/qmaccocoaviewcontainer/main.mm
@@ -83,7 +83,7 @@ int main(int argc, char **argv)
     w.resize(300, 300);
     w.setWindowTitle("QMacCocoaViewContainer");
     NSRect r = NSMakeRect(0, 0, 100, 100);
-    NSView *view = [[TestMouseMovedNSView alloc] initWithFrame: r];
+    NSView *view = [[TestMouseMovedNSView alloc] initWithFrame:r];
     QMacCocoaViewContainer *nativeChild = new QMacCocoaViewContainer(view, &w);
     QVBoxLayout *vbox = new QVBoxLayout;
     vbox->addWidget(nativeChild);
diff --git a/tests/manual/cocoa/qt_on_cocoa/main.mm b/tests/manual/cocoa/qt_on_cocoa/main.mm
index 805ef0d7c2..e6218e48ac 100644
--- a/tests/manual/cocoa/qt_on_cocoa/main.mm
+++ b/tests/manual/cocoa/qt_on_cocoa/main.mm
@@ -50,31 +50,30 @@
 }
 @end
 
-@interface AppDelegate : NSObject <NSApplicationDelegate> {
+@interface AppDelegate : NSObject <NSApplicationDelegate>
+@end
+
+@implementation AppDelegate {
     QGuiApplication *m_app;
     QWindow *m_window;
 }
-- (AppDelegate *) initWithArgc:(int)argc argv:(const char **)argv;
-- (void) applicationWillFinishLaunching: (NSNotification *)notification;
-- (void)applicationWillTerminate:(NSNotification *)notification;
-@end
-
 
-@implementation AppDelegate
-- (AppDelegate *) initWithArgc:(int)argc argv:(const char **)argv
+- (instancetype)initWithArgc:(int)argc argv:(const char **)argv
 {
-    m_app = new QGuiApplication(argc, const_cast<char **>(argv));
+    if ((self = [self init])) {
+        m_app = new QGuiApplication(argc, const_cast<char **>(argv));
+    }
     return self;
 }
 
-- (void) applicationWillFinishLaunching: (NSNotification *)notification
+- (void)applicationWillFinishLaunching:(NSNotification *)notification
 {
     Q_UNUSED(notification);
 
     // Create the NSWindow
     NSRect frame = NSMakeRect(500, 500, 500, 500);
-    NSWindow* window  = [[NSWindow alloc] initWithContentRect:frame
-                        styleMask:NSTitledWindowMask |  NSClosableWindowMask | NSMiniaturizableWindowMask | NSResizableWindowMask
+    NSWindow *window  = [[NSWindow alloc] initWithContentRect:frame
+                        styleMask:NSTitledWindowMask | NSClosableWindowMask | NSMiniaturizableWindowMask | NSResizableWindowMask
                         backing:NSBackingStoreBuffered
                         defer:NO];
 
@@ -100,7 +99,7 @@
     childWindow->setGeometry(50, 50, 100, 100);
 
     NSTextField *textField = [[NSTextField alloc] initWithFrame:NSMakeRect(10, 10, 80, 25)];
-    [(NSView*)childWindow->winId() addSubview:textField];
+    [reinterpret_cast<NSView *>(childWindow->winId()) addSubview:textField];
 
     [contentView addSubview:reinterpret_cast<NSView *>(m_window->winId())];
 
@@ -125,10 +124,7 @@
 int main(int argc, const char *argv[])
 {
     // Create NSApplicaiton with delgate
-    NSApplication *app =[NSApplication sharedApplication];
+    NSApplication *app = [NSApplication sharedApplication];
     app.delegate = [[AppDelegate alloc] initWithArgc:argc argv:argv];
-    return NSApplicationMain (argc, argv);
+    return NSApplicationMain(argc, argv);
 }
-
-
-