macOS: support shortcut for Ctrl-modified Tab

Ctrl+(Shift/Option/Cmd)+Tab presses are not handled as a regular key
events, and are not seen by our NSView.keyDown implementation. But
they are delivered to a performKeyEquivalent implementation, so if we
see a Tab key being pressed with the Ctrl modifier down, then send
a shortcut event and stop processing if that event got accepted by Qt.

Pick-to: 6.7
Fixes: QTBUG-113492
Task-number: QTBUG-8596
Change-Id: Id3aa7021a689b94d97eb881b19ddf7cb039e1bd2
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 29 insertions, 10 deletions

diff --git a/src/plugins/platforms/cocoa/qnsview_keys.mm b/src/plugins/platforms/cocoa/qnsview_keys.mm
index d9d9f0a794..abee622e65 100644
--- a/src/plugins/platforms/cocoa/qnsview_keys.mm
+++ b/src/plugins/platforms/cocoa/qnsview_keys.mm
@@ -30,8 +30,36 @@ static bool isSpecialKey(const QString &text)
     return false;
 }
 
+static bool sendAsShortcut(const KeyEvent &keyEvent, QWindow *window)
+{
+    KeyEvent shortcutEvent = keyEvent;
+    shortcutEvent.type = QEvent::Shortcut;
+    qCDebug(lcQpaKeys) << "Trying potential shortcuts in" << window
+                        << "for" << shortcutEvent;
+
+    if (shortcutEvent.sendWindowSystemEvent(window)) {
+        qCDebug(lcQpaKeys) << "Found matching shortcut; will not send as key event";
+        return true;
+    }
+    qCDebug(lcQpaKeys) << "No matching shortcuts; continuing with key event delivery";
+    return false;
+}
+
 @implementation QNSView (Keys)
 
+- (bool)performKeyEquivalent:(NSEvent *)nsevent
+{
+    // Implemented to handle shortcuts for modified Tab keys, which are
+    // handled by Cocoa and not delivered to your keyDown implementation.
+    if (nsevent.type == NSEventTypeKeyDown && m_composingText.isEmpty()) {
+        const bool ctrlDown = [nsevent modifierFlags] & NSEventModifierFlagControl;
+        const bool isTabKey = nsevent.keyCode == kVK_Tab;
+        if (ctrlDown && isTabKey && sendAsShortcut(KeyEvent(nsevent), [self topLevelWindow]))
+            return YES;
+    }
+    return NO;
+}
+
 - (bool)handleKeyEvent:(NSEvent *)nsevent
 {
     qCDebug(lcQpaKeys) << "Handling" << nsevent;
@@ -52,17 +80,8 @@ static bool isSpecialKey(const QString &text)
     if (keyEvent.type == QEvent::KeyPress) {
 
         if (m_composingText.isEmpty()) {
-            KeyEvent shortcutEvent = keyEvent;
-            shortcutEvent.type = QEvent::Shortcut;
-            qCDebug(lcQpaKeys) << "Trying potential shortcuts in" << window
-                               << "for" << shortcutEvent;
-
-            if (shortcutEvent.sendWindowSystemEvent(window)) {
-                qCDebug(lcQpaKeys) << "Found matching shortcut; will not send as key event";
+            if (sendAsShortcut(keyEvent, window))
                 return true;
-            } else {
-                qCDebug(lcQpaKeys) << "No matching shortcuts; continuing with key event delivery";
-            }
         }
 
         QObject *focusObject = m_platformWindow ? m_platformWindow->window()->focusObject() : nullptr;