Separate application into platform specific files. (#4799)

Signed-off-by: Yaakuro <y1@codeposer.net>

Code/Editor/Platform/Mac/Editor/Core/QtEditorApplication_mac.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project.
+ * For complete copyright and license terms please see the LICENSE at the root of this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#include <Editor/Core/QtEditorApplication.h>
+
+namespace Editor
+{
+    class EditorQtApplicationMac : public EditorQtApplication
+    {
+        Q_OBJECT
+    public:
+        EditorQtApplicationMac(int& argc, char** argv)
+            : EditorQtApplication(argc, argv)
+        {
+        }
+
+        // QAbstractNativeEventFilter:
+        bool nativeEventFilter(const QByteArray& eventType, void* message, long* result) override;
+    };
+} // namespace Editor

Code/Editor/Platform/Mac/Editor/Core/QtEditorApplication_mac.mm

@@ -0,0 +1,51 @@
+
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project.
+ * For complete copyright and license terms please see the LICENSE at the root of this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+#import <AppKit/NSEvent.h>
+
+#include "EditorDefs.h"
+#include "QtEditorApplication.h"
+
+// AzFramework
+#include <AzFramework/Input/Buses/Notifications/RawInputNotificationBus_Platform.h>
+
+// Qt
+#include <QCursor>
+
+namespace Editor
+{
+    EditorQtApplication* EditorQtApplication::newInstance(int& argc, char** argv)
+    {
+        QCoreApplication::setAttribute(Qt::AA_DontUseNativeMenuBar);
+
+        return new EditorQtApplicationMac(argc, argv);
+    }
+
+    bool EditorQtApplicationMac::nativeEventFilter(const QByteArray& eventType, void* message, long* result)
+    {
+        NSEvent* event = (NSEvent*)message;
+        if (GetIEditor()->IsInGameMode())
+        {
+            AzFramework::RawInputNotificationBusMac::Broadcast(&AzFramework::RawInputNotificationsMac::OnRawInputEvent, event);
+            return true;
+        }
+
+        if ([event type] == NSEventTypeMouseEntered)
+        {
+            // filter out mouse enter events when the widget the mouse entered into
+            // does not exist anymore. This happened occasionally on startup when hovering
+            // over the splash screen - LY-84100
+            if (widgetAt(QCursor::pos()) == nullptr)
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+} // end namespace Editor

Code/Editor/Platform/Mac/platform_mac_files.cmake

@@ -7,7 +7,7 @@
 #
 
 set(FILES
-    ../../Core/QtEditorApplication_mac.mm
+    Editor/Core/QtEditorApplication_mac.mm
     ../../LogFile_mac.mm
     ../../WindowObserver_mac.h
     ../../WindowObserver_mac.mm