Add QPlatformWindow::initialize() for two-step window creation

The QWindow::create method calls createPlatformWindow, and assigns the
result to d->platformWindow. If the platform sends any sort of events
synchronously during the creation, the event will be delivered to a
QWindow that doesn't have a handle() yet, resulting in noop handling
of the event, or crashes.

To mitigate this situations, platforms should do as little a possible
in the QPlatformWindow constructor, and leave initialization to the
new method, where the QWindow will have a handle().

The macOS platform plugin still has a m_initialized guard, to prevent
sending geometry changes during initialization, as this will result
in a resize event before a show event. This forced behavior seems
dubious, but is left for a followup patch.

Task-number: QTBUG-61977
Change-Id: I04d32d93391e89d068752b719270438e7024ad46
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoawindow.h b/src/plugins/platforms/cocoa/qcocoawindow.h
index 4b616665f7..e2fb372dae 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.h
+++ b/src/plugins/platforms/cocoa/qcocoawindow.h
@@ -95,6 +95,8 @@ public:
     QCocoaWindow(QWindow *tlw, WId nativeHandle = 0);
     ~QCocoaWindow();
 
+    void initialize() override;
+
     void setGeometry(const QRect &rect) Q_DECL_OVERRIDE;
     QRect geometry() const Q_DECL_OVERRIDE;
     void setCocoaGeometry(const QRect &rect);
@@ -250,7 +252,7 @@ public: // for QNSView
     QPointer<QWindow> m_enterLeaveTargetWindow;
     bool m_windowUnderMouse;
 
-    bool m_inConstructor;
+    bool m_initialized;
     bool m_inSetVisible;
     bool m_inSetGeometry;
     bool m_inSetStyleMask;