Ensure a hierarchy of menus fade out together.

On Mac OS X, when you have a large hierarchies of menus and you select
the item at the end of the hierarchy. It will flash and then the rest
will fade out at the same time. Qt would do a phased approach which was
what no one expected. Introduce a QMacWindowFader class that can hold an
arbitrary number of qwidgets and then on command fade them all down
pased on the set duration. The API is a bit clumsy but is prefect for
this internal API.

Task-#: 251700
Reviewed-by: Richard Moe Gustavsen

2 files changed, 76 insertions, 18 deletions

diff --git a/src/gui/kernel/qt_cocoa_helpers_mac.mm b/src/gui/kernel/qt_cocoa_helpers_mac.mm
index 9165836..554e9d5 100644
--- a/src/gui/kernel/qt_cocoa_helpers_mac.mm
+++ b/src/gui/kernel/qt_cocoa_helpers_mac.mm
@@ -88,6 +88,52 @@
 
 QT_BEGIN_NAMESPACE
 
+Q_GLOBAL_STATIC(QMacWindowFader, macwindowFader);
+
+QMacWindowFader::QMacWindowFader()
+    : m_duration(0.250)
+{
+}
+
+QMacWindowFader *QMacWindowFader::currentFader()
+{
+    return macwindowFader();
+}
+
+void QMacWindowFader::registerWindowToFade(QWidget *window)
+{
+    m_windowsToFade.append(window);
+}
+
+void QMacWindowFader::performFade()
+{
+    const QWidgetList myWidgetsToFade = m_windowsToFade;
+    const int widgetCount = myWidgetsToFade.count();
+#if QT_MAC_USE_COCOA
+    QMacCocoaAutoReleasePool pool;
+    [NSAnimationContext beginGrouping];
+    [[NSAnimationContext currentContext] setDuration:NSTimeInterval(m_duration)];
+#endif
+
+    for (int i = 0; i < widgetCount; ++i) {
+        QWidget *widget = m_windowsToFade.at(i);
+        OSWindowRef window = qt_mac_window_for(widget);
+#if QT_MAC_USE_COCOA
+        [[window animator] setAlphaValue:0.0];
+        QTimer::singleShot(qRound(m_duration * 1000), widget, SLOT(hide()));
+#else
+        TransitionWindowOptions options = {0, m_duration, 0, 0};
+        TransitionWindowWithOptions(window, kWindowFadeTransitionEffect, kWindowHideTransitionAction,
+                                    0, 1, &options);
+#endif
+    }
+#if QT_MAC_USE_COCOA
+    [NSAnimationContext endGrouping];
+#endif
+    m_duration = 0.250;
+    m_windowsToFade.clear();
+}
+
 extern bool qt_sendSpontaneousEvent(QObject *receiver, QEvent *event); // qapplication.cpp;
 extern Qt::MouseButton cocoaButton2QtButton(NSInteger buttonNum); // qcocoaview.mm
 extern QWidget * mac_mouse_grabber;
@@ -95,29 +141,26 @@ extern QWidget * mac_mouse_grabber;
 void macWindowFade(void * /*OSWindowRef*/ window, float durationSeconds)
 {
     OSWindowRef wnd = static_cast<OSWindowRef>(window);
-	if( wnd ) {
+    if (wnd) {
+        QWidget *widget;
 #if QT_MAC_USE_COCOA
-        QMacCocoaAutoReleasePool pool;
-        [NSAnimationContext beginGrouping];
-        [[wnd animator] setAlphaValue:0.0];
-        if (durationSeconds > 0) {
-            [[NSAnimationContext currentContext] setDuration:NSTimeInterval(durationSeconds)];
-        } else {
-            durationSeconds = [[NSAnimationContext currentContext] duration];
-        }
-        [NSAnimationContext endGrouping];
-        QTimer::singleShot(qRound(durationSeconds * 1000), [wnd QT_MANGLE_NAMESPACE(qt_qwidget)], SLOT(hide()));
+        widget = [wnd QT_MANGLE_NAMESPACE(qt_qwidget)];
 #else
-        if (durationSeconds <= 0)
-            durationSeconds = 0.15;
-		TransitionWindowOptions options = {0, durationSeconds, 0, 0};
-		TransitionWindowWithOptions(wnd, kWindowFadeTransitionEffect, kWindowHideTransitionAction, 0, 1, &options);
+    const UInt32 kWidgetCreatorQt = kEventClassQt;
+    enum {
+        kWidgetPropertyQWidget = 'QWId' //QWidget *
+    };
+        if (GetWindowProperty(static_cast<WindowRef>(window), kWidgetCreatorQt, kWidgetPropertyQWidget, sizeof(widget), 0, &widget) != noErr)
+            widget = 0;
 #endif
-	}
+        if (widget) {
+            QMacWindowFader::currentFader()->setFadeDuration(durationSeconds);
+            QMacWindowFader::currentFader()->registerWindowToFade(widget);
+            QMacWindowFader::currentFader()->performFade();
+        }
+    }
 }
 
-
-
 bool macWindowIsTextured( void * /*OSWindowRef*/ window )
 {
     OSWindowRef wnd = static_cast<OSWindowRef>(window);
diff --git a/src/gui/kernel/qt_mac_p.h b/src/gui/kernel/qt_mac_p.h
index ca995dc..3b0f546 100644
--- a/src/gui/kernel/qt_mac_p.h
+++ b/src/gui/kernel/qt_mac_p.h
@@ -120,6 +120,21 @@ public:
     }
 };
 
+// Class for chaining to gether a bunch of fades. It pretty much is only used for qmenu fading.
+class QMacWindowFader
+{
+    QWidgetList m_windowsToFade;
+    float m_duration;
+    Q_DISABLE_COPY(QMacWindowFader)
+public:
+    QMacWindowFader(); // PLEASE DON'T CALL THIS.
+    static QMacWindowFader *currentFader();
+    void registerWindowToFade(QWidget *window);
+    void setFadeDuration(float durationInSecs) { m_duration = durationInSecs; }
+    float fadeDuration() const { return m_duration; }
+    void performFade();
+};
+
 class Q_GUI_EXPORT QMacCocoaAutoReleasePool
 {
 private: