Implement configurable accelerators support for wxOSX

Use the new API, i.e. call ClaimsKeyBeforeAccelerator() and send
wxEVT_ACCELERATOR_KEY, in wxOSX too, whenever possible, i.e. not for
Cmd-Letter used by the menu items as we never get key events for them at
all.

This probably could be worked around by overriding performKeyEquivalent:
but for now leave it like this because hopefully there should be no
conflict between menu accelerators and standard text editing keys as
Cmd+C etc act on the focused window anyhow by default, so the behaviour
should be already correct anyhow.

include/wx/osx/window.h

@@ -319,6 +319,18 @@ public:
 
     virtual bool        OSXHandleClicked( double timestampsec );
     virtual bool        OSXHandleKeyEvent( wxKeyEvent& event );
+
+#if wxUSE_ACCEL
+    // Return false if the menu accelerator using the key corresponding to the
+    // given event shouldn't be used because this window needs this key for
+    // its own purposes.
+    //
+    // Note that this function only deals with the accelerators of the menu
+    // items, the ones defined by wxAcceleratorTable are checked later, from
+    // OSXHandleKeyEvent() itself.
+    bool                OSXShouldUseMenuAcceleratorForKey( const wxKeyEvent& event );
+#endif // wxUSE_ACCEL
+
     virtual void        OSXSimulateFocusEvents();
 
     bool                IsNativeWindowWrapper() const { return m_isNativeWindowWrapper; }

interface/wx/event.h

@@ -1780,6 +1780,14 @@ public:
     the parents of this window, up to the top level one, which allows to handle
     it in the frame containing the control having the focus.
 
+    @note Under macOS this event is sent before `wxEVT_CHAR_HOOK` and not after
+        it. It is also not generated at all for the key combinations
+        involving the Command key used by the menu items because such keys are
+        handled by the system before the application has any chance to
+        intercept them. This is not usually a problem because the standard
+        macOS shortcuts such as `Cmd-C` are implemented by the menu items
+        acting on the currently focused control anyhow.
+
     @beginEventTable{wxAcceleratorKeyEvent}
     @event{EVT_ACCELERATOR_KEY(func)}
         Process a `wxEVT_ACCELERATOR_KEY` event.

src/osx/cocoa/window.mm

@@ -1706,11 +1706,31 @@ void wxWidgetCocoaImpl::keyEvent(WX_NSEvent event, WXWidget slf, void *_cmd)
     {
         // there are key equivalents that are not command-combos and therefore not handled by cocoa automatically,
         // therefore we call the menubar directly here, exit if the menu is handling the shortcut
-        if ( [[[NSApplication sharedApplication] mainMenu] performKeyEquivalent:event] )
+#if wxUSE_ACCEL
+        // The focused window may want to handle this key itself instead of
+        // letting the menu use it as an accelerator, so ask it first.
+        bool useMenuAccel = true;
+
+        if ( wxWindowMac* const peer = GetWXPeer() )
         {
-            wxLogTrace(TRACE_KEYS, "%s processed as key equivalent by the menu",
-                       wxDumpSelector((SEL)_cmd));
-            return;
+            wxKeyEvent wxevent(wxEVT_KEY_DOWN);
+            SetupKeyEvent(wxevent, event);
+
+            // SetupKeyEvent() may change the event type, so check that this
+            // is really a key press.
+            if ( wxevent.GetEventType() == wxEVT_KEY_DOWN )
+                useMenuAccel = peer->OSXShouldUseMenuAcceleratorForKey(wxevent);
+        }
+
+        if ( useMenuAccel )
+#endif // wxUSE_ACCEL
+        {
+            if ( [[[NSApplication sharedApplication] mainMenu] performKeyEquivalent:event] )
+            {
+                wxLogTrace(TRACE_KEYS, "%s processed as key equivalent by the menu",
+                           wxDumpSelector((SEL)_cmd));
+                return;
+            }
         }
 
         BeginNativeKeyDownEvent(event);

src/osx/window_osx.cpp

@@ -2616,11 +2616,16 @@ bool wxWindowMac::OSXHandleKeyEvent( wxKeyEvent& event )
 #if wxUSE_ACCEL
     if (event.GetEventType() == wxEVT_CHAR_HOOK)
     {
-        wxWindow *ancestor = this;
-        while (ancestor)
+        // Check if this key is used by one of the accelerators defined by
+        // wxAcceleratorTable: note that the accelerators of the menu items
+        // are not handled here, they are used by the menu bar itself, see
+        // OSXShouldUseMenuAcceleratorForKey().
+        wxAcceleratorEntry entry;
+        wxWindow* ancestor = nullptr;
+        if ( FindAcceleratorForKey(event, entry, &ancestor) && !entry.GetMenuItem() )
         {
-            int command = ancestor->GetAcceleratorTable()->GetCommand( event );
-            if (command != -1)
+            const int command = entry.GetCommand();
+            if ( ShouldUseAcceleratorForKey(event, command, nullptr) )
             {
                 wxEvtHandler * const handler = ancestor->GetEventHandler();
 
@@ -2636,11 +2641,6 @@ bool wxWindowMac::OSXHandleKeyEvent( wxKeyEvent& event )
                 // accelerator.
                 return true;
             }
-
-            if (ancestor->IsTopNavigationDomain(wxWindow::Navigation_Accel))
-                break;
-
-            ancestor = ancestor->GetParent();
         }
     }
 #endif // wxUSE_ACCEL
@@ -2648,6 +2648,32 @@ bool wxWindowMac::OSXHandleKeyEvent( wxKeyEvent& event )
     return false;
 }
 
+#if wxUSE_ACCEL
+
+bool wxWindowMac::OSXShouldUseMenuAcceleratorForKey( const wxKeyEvent& event )
+{
+    wxAcceleratorEntry entry;
+    if ( !FindAcceleratorForKey(event, entry, nullptr /* don't need owner */) )
+    {
+        // This key is not used by any accelerator at all.
+        return true;
+    }
+
+    wxMenuItem* const item = entry.GetMenuItem();
+    if ( !item )
+    {
+        // This one comes from wxAcceleratorTable and will be dealt with in
+        // OSXHandleKeyEvent() when we get wxEVT_CHAR_HOOK for this key, don't
+        // do anything here (and, in particular, don't send the accelerator
+        // event twice for the same key).
+        return true;
+    }
+
+    return ShouldUseAcceleratorForKey(event, entry.GetCommand(), item);
+}
+
+#endif // wxUSE_ACCEL
+
 wxSize wxWindowMac::GetDPI() const
 {
     return MakeDPIFromScaleFactor(GetDPIScaleFactor());