macOS: Only show menu and allow dragging on proxy when a file path is set

If there is no file path set then it should not be possible to see a
menu or to drag from a proxy icon in the titlebar.

Task-number: QTBUG-56082
Change-Id: Ib8305bcab5717bc8cb7ddabbb079f152debbdded
Reviewed-by: Jake Petroules <jake.petroules@qt.io>

src/plugins/platforms/cocoa/qcocoawindow.h

@@ -346,6 +346,7 @@ public: // for QNSView
     // This object is tracked by QCocoaWindowPointer,
     // preventing the use of dangling pointers.
     QObject sentinel;
+    bool m_hasWindowFilePath;
 };
 
 QT_END_NAMESPACE

src/plugins/platforms/cocoa/qcocoawindow.mm

@@ -379,6 +379,7 @@ QCocoaWindow::QCocoaWindow(QWindow *tlw)
     , m_topContentBorderThickness(0)
     , m_bottomContentBorderThickness(0)
     , m_normalGeometry(QRect(0,0,-1,-1))
+    , m_hasWindowFilePath(false)
 {
 #ifdef QT_COCOA_ENABLE_WINDOW_DEBUG
     qDebug() << "QCocoaWindow::QCocoaWindow" << this;
@@ -941,6 +942,7 @@ void QCocoaWindow::setWindowFilePath(const QString &filePath)
 
     QFileInfo fi(filePath);
     [m_nsWindow setRepresentedFilename: fi.exists() ? QCFString::toNSString(filePath) : @""];
+    m_hasWindowFilePath = fi.exists();
 }
 
 void QCocoaWindow::setWindowIcon(const QIcon &icon)

src/plugins/platforms/cocoa/qnswindowdelegate.h

@@ -51,7 +51,8 @@
 - (void)windowWillMove:(NSNotification *)notification;
 - (BOOL)windowShouldClose:(NSNotification *)notification;
 - (BOOL)windowShouldZoom:(NSWindow *)window toFrame:(NSRect)newFrame;
-
+- (BOOL)window:(NSWindow *)window shouldPopUpDocumentPathMenu:(NSMenu *)menu;
+- (BOOL)window:(NSWindow *)window shouldDragDocumentWithEvent:(NSEvent *)event from:(NSPoint)dragImageLocation withPasteboard:(NSPasteboard *)pasteboard;
 @end
 
 QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSWindowDelegate);

src/plugins/platforms/cocoa/qnswindowdelegate.mm

@@ -109,4 +109,19 @@
     return YES;
 }
 
+- (BOOL)window:(NSWindow *)window shouldPopUpDocumentPathMenu:(NSMenu *)menu
+{
+    Q_UNUSED(window);
+    Q_UNUSED(menu);
+    return m_cocoaWindow && m_cocoaWindow->m_hasWindowFilePath;
+}
+
+- (BOOL)window:(NSWindow *)window shouldDragDocumentWithEvent:(NSEvent *)event from:(NSPoint)dragImageLocation withPasteboard:(NSPasteboard *)pasteboard
+{
+    Q_UNUSED(window);
+    Q_UNUSED(event);
+    Q_UNUSED(dragImageLocation);
+    Q_UNUSED(pasteboard);
+    return m_cocoaWindow && m_cocoaWindow->m_hasWindowFilePath;
+}
 @end