macOS: Use Cocoa to map key events to possible shortcut key sequences

For now we just verify that the Cocoa API produces the same keymaps
as we get from Carbon. Once that's verified we can solidify the code.

Change-Id: I0d2aa1bb0a006d29c0149e3ff2fd5299ba922326
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

1 files changed, 19 insertions, 3 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoakeymapper.mm b/src/plugins/platforms/cocoa/qcocoakeymapper.mm
index 4f3e886a34..bcc5a9ef0c 100644
--- a/src/plugins/platforms/cocoa/qcocoakeymapper.mm
+++ b/src/plugins/platforms/cocoa/qcocoakeymapper.mm
@@ -452,9 +452,6 @@ const QCocoaKeyMapper::KeyMap &QCocoaKeyMapper::keyMapForKey(VirtualKeyCode virt
 
     qCDebug(lcQpaKeyMapper, "Updating key map for virtual key = 0x%02x!", (uint)virtualKey);
 
-    UniCharCount maxStringLength = 10;
-    UniChar unicodeString[maxStringLength];
-
     for (int i = 0; i < 16; ++i) {
         Q_ASSERT(!i || keyMap[i] == 0);
 
@@ -462,6 +459,8 @@ const QCocoaKeyMapper::KeyMap &QCocoaKeyMapper::keyMapForKey(VirtualKeyCode virt
         auto carbonModifiers = toCarbonModifiers(qtModifiers);
         const UInt32 modifierKeyState = (carbonModifiers >> 8) & 0xFF;
 
+        static const UniCharCount maxStringLength = 10;
+        static UniChar unicodeString[maxStringLength];
         UniCharCount actualStringLength = 0;
         OSStatus err = UCKeyTranslate(m_keyboardLayoutFormat, virtualKey,
             kUCKeyActionDown, modifierKeyState, m_keyboardKind, OptionBits(0),
@@ -471,6 +470,23 @@ const QCocoaKeyMapper::KeyMap &QCocoaKeyMapper::keyMapForKey(VirtualKeyCode virt
         if (err == noErr && actualStringLength)
             unicodeKey = QChar(unicodeString[0]);
 
+        if (@available(macOS 10.15, *)) {
+            // Until we've verified that the Cocoa API works as expected
+            // we first run the event through the Carbon APIs and then
+            // compare the results to Cocoa.
+            Q_ASSERT(NSApp.currentEvent);
+            Q_ASSERT(NSApp.currentEvent.type == NSEventTypeKeyDown);
+            auto cocoaModifiers = toCocoaModifiers(qtModifiers);
+            auto *charactersWithModifiers = [NSApp.currentEvent charactersByApplyingModifiers:cocoaModifiers];
+            Q_ASSERT(charactersWithModifiers && charactersWithModifiers.length > 0);
+            auto cocoaUnicodeKey = QChar([charactersWithModifiers characterAtIndex:0]);
+            if (cocoaUnicodeKey != unicodeKey) {
+                qCWarning(lcQpaKeyMapper) << "Mismatch between Cocoa" << cocoaUnicodeKey
+                    << "and Carbon" << unicodeKey << "for virtual key" << virtualKey
+                    << "with" << qtModifiers;
+            }
+        }
+
         int qtkey = toKeyCode(unicodeKey, virtualKey, qtModifiers);
         if (qtkey == Qt::Key_unknown)
             qtkey = unicodeKey.unicode();