Cocoa: support modal windows

Qt::WindowModal windows and dialogs are shown using [NSApp
beginSheet:modalForWindow:modalDelegate:didEndSelector:contextInfo:] as
long as they have a valid parent. Otherwise they are behave as
application modal.

Use the existing modal session support in the QCocoaEventDispatcher
(which was inherited from Qt 4) to support Qt::ApplicationModal
windows and dialogs. Some changes to this code are needed to ensure
proper behavior:

1. Window level modification is now done in
QCocoaWindow::recreateWindow() instead of in QCocoaEventDispatcher.
2. Make interrupt() use [NSApp abortModal] to stop a modal session
(previously we were freeing memory from under Cocoa's feet, causing
tools like valgrind and Instruments.app to complain)
3. Do not remove an item from a list and use a const reference to the
removed item immediately after (minor bug fix).

Also make sure that QCocoaEventDispatcher cleans up any modal sessions
and retained user input events on destruction (otherwise we leave
NSApplication in a weird state, which causes some autotest failures).

Change-Id: Iaeefa025400f324b5348b8c81a40384ef026efb4
Reviewed-by: Morten Johan Sørvig <morten.sorvig@nokia.com>

1 files changed, 38 insertions, 5 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm
index 5c8ea055b5..32c87e752a 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.mm
+++ b/src/plugins/platforms/cocoa/qcocoawindow.mm
@@ -41,6 +41,7 @@
 #include "qcocoawindow.h"
 #include "qnswindowdelegate.h"
 #include "qcocoaautoreleasepool.h"
+#include "qcocoaeventdispatcher.h"
 #include "qcocoaglcontext.h"
 #include "qcocoahelpers.h"
 #include "qnsview.h"
@@ -98,6 +99,7 @@ QCocoaWindow::QCocoaWindow(QWindow *tlw)
     , m_nsWindow(0)
     , m_inConstructor(true)
     , m_glContext(0)
+    , m_hasModalSession(false)
 {
     QCocoaAutoReleasePool pool;
 
@@ -145,7 +147,10 @@ void QCocoaWindow::setVisible(bool visible)
     qDebug() << "QCocoaWindow::setVisible" << window() << visible;
 #endif
     if (visible) {
+        QCocoaWindow *parentCocoaWindow = 0;
         if (window()->transientParent()) {
+            parentCocoaWindow = static_cast<QCocoaWindow *>(window()->transientParent()->handle());
+
             // The parent window might have moved while this window was hidden,
             // update the window geometry if there is a parent.
             setGeometry(window()->geometry());
@@ -154,8 +159,6 @@ void QCocoaWindow::setVisible(bool visible)
             // close them when needed.
             if (window()->windowType() == Qt::Popup) {
                 // qDebug() << "transientParent and popup" << window()->windowType() << Qt::Popup << (window()->windowType() & Qt::Popup);
-
-                QCocoaWindow *parentCocoaWindow = static_cast<QCocoaWindow *>(window()->transientParent()->handle());
                 parentCocoaWindow->m_activePopupWindow = window();
             }
 
@@ -170,16 +173,40 @@ void QCocoaWindow::setVisible(bool visible)
             syncWindowState(window()->windowState());
 
             if (window()->windowState() != Qt::WindowMinimized) {
-                if ([m_nsWindow canBecomeKeyWindow])
+                if ((window()->windowModality() == Qt::WindowModal
+                     || window()->windowType() == Qt::Sheet)
+                        && parentCocoaWindow) {
+                    // show the window as a sheet
+                    [NSApp beginSheet:m_nsWindow modalForWindow:parentCocoaWindow->m_nsWindow modalDelegate:nil didEndSelector:nil contextInfo:nil];
+                } else if (window()->windowModality() != Qt::NonModal) {
+                    // show the window as application modal
+                    QCocoaEventDispatcher *cocoaEventDispatcher = qobject_cast<QCocoaEventDispatcher *>(QGuiApplication::instance()->eventDispatcher());
+                    Q_ASSERT(cocoaEventDispatcher != 0);
+                    QCocoaEventDispatcherPrivate *cocoaEventDispatcherPrivate = static_cast<QCocoaEventDispatcherPrivate *>(QObjectPrivate::get(cocoaEventDispatcher));
+                    cocoaEventDispatcherPrivate->beginModalSession(window());
+                    m_hasModalSession = true;
+                } else if ([m_nsWindow canBecomeKeyWindow]) {
                     [m_nsWindow makeKeyAndOrderFront:nil];
-                else
+                } else {
                     [m_nsWindow orderFront: nil];
+                }
             }
         }
     } else {
         // qDebug() << "close" << this;
-        if (m_nsWindow)
+        if (m_nsWindow) {
+            if (m_hasModalSession) {
+                QCocoaEventDispatcher *cocoaEventDispatcher = qobject_cast<QCocoaEventDispatcher *>(QGuiApplication::instance()->eventDispatcher());
+                Q_ASSERT(cocoaEventDispatcher != 0);
+                QCocoaEventDispatcherPrivate *cocoaEventDispatcherPrivate = static_cast<QCocoaEventDispatcherPrivate *>(QObjectPrivate::get(cocoaEventDispatcher));
+                cocoaEventDispatcherPrivate->endModalSession(window());
+                m_hasModalSession = false;
+            } else {
+                if ([m_nsWindow isSheet])
+                    [NSApp endSheet:m_nsWindow];
+            }
             [m_nsWindow orderOut:m_nsWindow];
+        }
         if (!QCoreApplication::closingDown())
             QWindowSystemInterface::handleExposeEvent(window(), QRegion());
     }
@@ -363,6 +390,12 @@ void QCocoaWindow::recreateWindow(const QPlatformWindow *parentWindow)
         // Create a new NSWindow if this is a top-level window.
         m_nsWindow = createNSWindow();
         setNSWindow(m_nsWindow);
+
+        if (window()->transientParent()) {
+            // keep this window on the same level as its transient parent (which may be a modal dialog, for example)
+            QCocoaWindow *parentCocoaWindow = static_cast<QCocoaWindow *>(window()->transientParent()->handle());
+            [m_nsWindow setLevel:[parentCocoaWindow->m_nsWindow level]];
+        }
     } else {
         // Child windows have no NSWindow, link the NSViews instead.
         const QCocoaWindow *parentCococaWindow = static_cast<const QCocoaWindow *>(parentWindow);