BT: Prevent crash in Designer when using a scroll wheel to change a property.

There was some strangeness happening here with parents, but the main
problem was the fact that wheel was getting sent to the focusframe and
not to the widget below. However, the focusframe has the "transparent
for mouse events" flag set and wheel events probably should be
transparent as well.

Task-number: 253539
Reviewed-by: Richard Moe Gustavsen
(cherry picked from commit e77f2e595d9b9a6f078f37894733c52bbcfeb695)

1 files changed, 20 insertions, 8 deletions

diff --git a/src/gui/kernel/qcocoaview_mac.mm b/src/gui/kernel/qcocoaview_mac.mm
index 35f7f77..38f6466 100644
--- a/src/gui/kernel/qcocoaview_mac.mm
+++ b/src/gui/kernel/qcocoaview_mac.mm
@@ -789,10 +789,22 @@ extern "C" {
     bool wheelOK = false;
     Qt::KeyboardModifiers keyMods = qt_cocoaModifiers2QtModifiers([theEvent modifierFlags]);
 
+    QWidget *widgetToGetMouse = qwidget;
+    if (widgetToGetMouse->testAttribute(Qt::WA_TransparentForMouseEvents)) {
+        // Simulate passing the event through since Cocoa doesn't do that for us.
+        // Start by building a tree up.
+        NSView *candidateView = [self viewUnderTransparentForMouseView:self
+                                                       widget:widgetToGetMouse
+                                                       withWindowPoint:windowPoint];
+        if (candidateView != nil) {
+            widgetToGetMouse = QWidget::find(WId(candidateView));
+        }
+    }
+
     // Mouse wheel deltas seem to tick in at increments of 0.1. Qt widgets
-    // expect the delta to be a multiple of 120. 
+    // expect the delta to be a multiple of 120.
     const int ScrollFactor = 10 * 120;
-    //                                              The qMax(...) factor reduces the 
+    //                                              The qMax(...) factor reduces the
     //                                              acceleration for large wheel deltas.
     int deltaX = [theEvent deltaX] * ScrollFactor * qMax(0.6, 1.1 - qAbs([theEvent deltaX]));
     int deltaY = [theEvent deltaY] * ScrollFactor * qMax(0.6, 1.1 - qAbs([theEvent deltaY]));
@@ -800,10 +812,10 @@ extern "C" {
 
     if (deltaX != 0) {
         QWheelEvent qwe(qlocal, qglobal, deltaX, buttons, keyMods, Qt::Horizontal);
-        qt_sendSpontaneousEvent(qwidget, &qwe);
+        qt_sendSpontaneousEvent(widgetToGetMouse, &qwe);
         wheelOK = qwe.isAccepted();
         if (!wheelOK && QApplicationPrivate::focus_widget
-            && QApplicationPrivate::focus_widget != qwidget) {
+            && QApplicationPrivate::focus_widget != widgetToGetMouse) {
             QWheelEvent qwe2(QApplicationPrivate::focus_widget->mapFromGlobal(qglobal), qglobal,
                              deltaX, buttons, keyMods, Qt::Horizontal);
             qt_sendSpontaneousEvent(QApplicationPrivate::focus_widget, &qwe2);
@@ -813,10 +825,10 @@ extern "C" {
 
     if (deltaY) {
         QWheelEvent qwe(qlocal, qglobal, deltaY, buttons, keyMods, Qt::Vertical);
-        qt_sendSpontaneousEvent(qwidget, &qwe);
+        qt_sendSpontaneousEvent(widgetToGetMouse, &qwe);
         wheelOK = qwe.isAccepted();
         if (!wheelOK && QApplicationPrivate::focus_widget
-            && QApplicationPrivate::focus_widget != qwidget) {
+            && QApplicationPrivate::focus_widget != widgetToGetMouse) {
             QWheelEvent qwe2(QApplicationPrivate::focus_widget->mapFromGlobal(qglobal), qglobal,
                              deltaY, buttons, keyMods, Qt::Vertical);
             qt_sendSpontaneousEvent(QApplicationPrivate::focus_widget, &qwe2);
@@ -828,10 +840,10 @@ extern "C" {
         // Qt doesn't explicitly support wheels with a Z component. In a misguided attempt to
         // try to be ahead of the pack, I'm adding this extra value.
         QWheelEvent qwe(qlocal, qglobal, deltaZ, buttons, keyMods, (Qt::Orientation)3);
-        qt_sendSpontaneousEvent(qwidget, &qwe);
+        qt_sendSpontaneousEvent(widgetToGetMouse, &qwe);
         wheelOK = qwe.isAccepted();
         if (!wheelOK && QApplicationPrivate::focus_widget
-            && QApplicationPrivate::focus_widget != qwidget) {
+            && QApplicationPrivate::focus_widget != widgetToGetMouse) {
             QWheelEvent qwe2(QApplicationPrivate::focus_widget->mapFromGlobal(qglobal), qglobal,
                              deltaZ, buttons, keyMods, (Qt::Orientation)3);
             qt_sendSpontaneousEvent(QApplicationPrivate::focus_widget, &qwe2);