Show default shortcut menu when user right click window's caption

In windows platform, Qt5 will not show the system default shortcut menu
when the user right click in the window's caption. This is a regression
from Qt4.
This patch will let DefWindowProc() to handle the message WM_CONTEXTMENU
if the mouse pointer is in the non-client area of the window. Thus the
default Windows shortcut menu will show up.

Change-Id: I88638ad1d4f0e73b088204b83c3f7ec0fe2033f0
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>

2 files changed, 16 insertions, 4 deletions

diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index 44f1a438b8..99ef3aacf3 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -874,8 +874,7 @@ bool QWindowsContext::windowsProc(HWND hwnd, UINT message,
 #endif
 #ifndef QT_NO_CONTEXTMENU
     case QtWindows::ContextMenu:
-        handleContextMenuEvent(platformWindow->window(), msg);
-        return true;
+        return handleContextMenuEvent(platformWindow->window(), msg);
 #endif
     default:
         break;
@@ -909,7 +908,7 @@ void QWindowsContext::handleFocusEvent(QtWindows::WindowsEventType et,
 }
 
 #ifndef QT_NO_CONTEXTMENU
-void QWindowsContext::handleContextMenuEvent(QWindow *window, const MSG &msg)
+bool QWindowsContext::handleContextMenuEvent(QWindow *window, const MSG &msg)
 {
     bool mouseTriggered = false;
     QPoint globalPos;
@@ -919,10 +918,23 @@ void QWindowsContext::handleContextMenuEvent(QWindow *window, const MSG &msg)
         globalPos.setX(msg.pt.x);
         globalPos.setY(msg.pt.y);
         pos = QWindowsGeometryHint::mapFromGlobal(msg.hwnd, globalPos);
+
+        RECT clientRect;
+        if (GetClientRect(msg.hwnd, &clientRect)) {
+            if (pos.x() < (int)clientRect.left || pos.x() >= (int)clientRect.right ||
+                pos.y() < (int)clientRect.top || pos.y() >= (int)clientRect.bottom)
+            {
+                // This is the case that user has right clicked in the window's caption,
+                // We should call DefWindowProc() to display a default shortcut menu
+                // instead of sending a Qt window system event.
+                return false;
+            }
+        }
     }
 
     QWindowSystemInterface::handleContextMenuEvent(window, mouseTriggered, pos, globalPos,
                                                    QWindowsKeyMapper::queryKeyboardModifiers());
+    return true;
 }
 #endif
 
diff --git a/src/plugins/platforms/windows/qwindowscontext.h b/src/plugins/platforms/windows/qwindowscontext.h
index bfe56ed246..1fe71e3aff 100644
--- a/src/plugins/platforms/windows/qwindowscontext.h
+++ b/src/plugins/platforms/windows/qwindowscontext.h
@@ -192,7 +192,7 @@ public:
 private:
     void handleFocusEvent(QtWindows::WindowsEventType et, QWindowsWindow *w);
 #ifndef QT_NO_CONTEXTMENU
-    void handleContextMenuEvent(QWindow *window, const MSG &msg);
+    bool handleContextMenuEvent(QWindow *window, const MSG &msg);
 #endif
     void unregisterWindowClasses();