Flickering "Whatsthis" pointer in Cocoa

Since mouse tracking is always enabled on all QCocoaView-s, we are
getting mouseMoved events for both parent and child (if mouse is over
the child). In such cases the mouseMoved events are ignored for the
parent view.
We are using the native NSCursor stack for setting the override cursor.
The current implementation for changeOverrideCursor is modified to keep
this stack in sync with Qt's internal list.

Task-number: 258173
Reviewed-by: Morten Sorvig

4 files changed, 31 insertions, 1 deletions

diff --git a/src/gui/kernel/qapplication.cpp b/src/gui/kernel/qapplication.cpp
index 574d845..ccf6ac9 100644
--- a/src/gui/kernel/qapplication.cpp
+++ b/src/gui/kernel/qapplication.cpp
@@ -101,6 +101,10 @@ extern bool qt_wince_is_pocket_pc();  //qguifunctions_wince.cpp
 
 #include "qdatetime.h"
 
+#ifdef QT_MAC_USE_COCOA
+#include <private/qt_cocoa_helpers_mac_p.h>
+#endif
+
 //#define ALIEN_DEBUG
 
 static void initResources()
@@ -3477,6 +3481,15 @@ void QApplication::changeOverrideCursor(const QCursor &cursor)
     if (qApp->d_func()->cursor_list.isEmpty())
         return;
     qApp->d_func()->cursor_list.removeFirst();
+#ifdef QT_MAC_USE_COCOA
+    // We use native NSCursor stacks in Cocoa. The currentCursor is the
+    // top of this stack. So to avoid flickering of cursor, we have to
+    // change the cusor instead of pop-ing the existing OverrideCursor
+    // and pushing the new one.
+    qApp->d_func()->cursor_list.prepend(cursor);
+    qt_cocoaChangeOverrideCursor(cursor);
+    return;
+#endif
     setOverrideCursor(cursor);
 }
 #endif
diff --git a/src/gui/kernel/qcocoaview_mac.mm b/src/gui/kernel/qcocoaview_mac.mm
index 7ac0d89..5a0209d 100644
--- a/src/gui/kernel/qcocoaview_mac.mm
+++ b/src/gui/kernel/qcocoaview_mac.mm
@@ -667,7 +667,15 @@ extern "C" {
 
 - (void)mouseMoved:(NSEvent *)theEvent
 {
-    qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseMove, Qt::NoButton);
+    // We always enable mouse tracking for all QCocoaView-s. In cases where we have
+    // child views, we will receive mouseMoved for both parent & the child (if
+    // mouse is over the child). We need to ignore the parent mouseMoved in such
+    // cases.
+    NSPoint windowPoint = [theEvent locationInWindow];
+    NSView *candidateView = [[[self window] contentView] hitTest:windowPoint];
+    if (candidateView && candidateView == self) {
+        qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseMove, Qt::NoButton);
+    }
 }
 
 - (void)mouseDown:(NSEvent *)theEvent
diff --git a/src/gui/kernel/qt_cocoa_helpers_mac.mm b/src/gui/kernel/qt_cocoa_helpers_mac.mm
index 7596802..a9b8970 100644
--- a/src/gui/kernel/qt_cocoa_helpers_mac.mm
+++ b/src/gui/kernel/qt_cocoa_helpers_mac.mm
@@ -1238,4 +1238,12 @@ void qt_mac_menu_collapseSeparators(void */*NSMenu **/ theMenu, bool collapse)
     }
 }
 
+#ifdef QT_MAC_USE_COCOA
+void qt_cocoaChangeOverrideCursor(const QCursor &cursor)
+{
+    QMacCocoaAutoReleasePool pool;
+    [static_cast<NSCursor *>(qt_mac_nsCursorForQCursor(cursor)) set];
+}
+#endif
+
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qt_cocoa_helpers_mac_p.h b/src/gui/kernel/qt_cocoa_helpers_mac_p.h
index 24d7096..932abef 100644
--- a/src/gui/kernel/qt_cocoa_helpers_mac_p.h
+++ b/src/gui/kernel/qt_cocoa_helpers_mac_p.h
@@ -133,6 +133,7 @@ bool qt_mac_checkForNativeSizeGrip(const QWidget *widget);
 void qt_dispatchTabletProximityEvent(void * /*NSEvent * */ tabletEvent);
 #ifdef QT_MAC_USE_COCOA
 bool qt_dispatchKeyEventWithCocoa(void * /*NSEvent * */ keyEvent, QWidget *widgetToGetEvent);
+void qt_cocoaChangeOverrideCursor(const QCursor &cursor);
 #endif
 void qt_mac_menu_collapseSeparators(void * /*NSMenu */ menu, bool collapse);
 bool qt_dispatchKeyEvent(void * /*NSEvent * */ keyEvent, QWidget *widgetToGetEvent);