Windows: Show context menu on mouse release.

Introduce a hint to QPlatformTheme to control the behavior.

Task-number: QTBUG-35231

Change-Id: Ia28e153a8dd3f1931321a222d8906ca87166ed62
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

4 files changed, 13 insertions, 3 deletions

diff --git a/src/gui/kernel/qplatformtheme.cpp b/src/gui/kernel/qplatformtheme.cpp
index 1844232efe..3548ec0199 100644
--- a/src/gui/kernel/qplatformtheme.cpp
+++ b/src/gui/kernel/qplatformtheme.cpp
@@ -142,6 +142,8 @@ QT_BEGIN_NAMESPACE
     \value DialogSnapToDefaultButton (bool) Whether the mouse should snap to the default button when a dialog
                                      becomes visible.
 
+    \value ContextMenuOnMouseRelease (bool) Whether the context menu should be shown on mouse release.
+
     \sa themeHint(), QStyle::pixelMetric()
 */
 
@@ -487,6 +489,7 @@ QVariant QPlatformTheme::defaultThemeHint(ThemeHint hint)
     case IconPixmapSizes:
         return QVariant::fromValue(QList<int>());
     case DialogSnapToDefaultButton:
+    case ContextMenuOnMouseRelease:
         return QVariant(false);
     }
     return QVariant();
diff --git a/src/gui/kernel/qplatformtheme.h b/src/gui/kernel/qplatformtheme.h
index 4bddac5b1b..5cdec48ca3 100644
--- a/src/gui/kernel/qplatformtheme.h
+++ b/src/gui/kernel/qplatformtheme.h
@@ -106,7 +106,8 @@ public:
         TabAllWidgets,
         IconPixmapSizes,
         PasswordMaskCharacter,
-        DialogSnapToDefaultButton
+        DialogSnapToDefaultButton,
+        ContextMenuOnMouseRelease
     };
 
     enum DialogType {
diff --git a/src/plugins/platforms/windows/qwindowstheme.cpp b/src/plugins/platforms/windows/qwindowstheme.cpp
index eb1bbd1ab0..00a5da8f44 100644
--- a/src/plugins/platforms/windows/qwindowstheme.cpp
+++ b/src/plugins/platforms/windows/qwindowstheme.cpp
@@ -383,6 +383,8 @@ QVariant QWindowsTheme::themeHint(ThemeHint hint) const
     }
     case DialogSnapToDefaultButton:
         return QVariant(booleanSystemParametersInfo(SPI_GETSNAPTODEFBUTTON, false));
+    case ContextMenuOnMouseRelease:
+        return QVariant(true);
     default:
         break;
     }
diff --git a/src/widgets/kernel/qwidgetwindow.cpp b/src/widgets/kernel/qwidgetwindow.cpp
index 2e96247873..167102c633 100644
--- a/src/widgets/kernel/qwidgetwindow.cpp
+++ b/src/widgets/kernel/qwidgetwindow.cpp
@@ -49,6 +49,7 @@
 #endif
 #include <private/qwidgetbackingstore_p.h>
 #include <qpa/qwindowsysteminterface_p.h>
+#include <qpa/qplatformtheme.h>
 #include <private/qgesturemanager_p.h>
 
 QT_BEGIN_NAMESPACE
@@ -354,6 +355,9 @@ void QWidgetWindow::handleNonClientAreaMouseEvent(QMouseEvent *e)
 
 void QWidgetWindow::handleMouseEvent(QMouseEvent *event)
 {
+    static const QEvent::Type contextMenuTrigger =
+        QGuiApplicationPrivate::platformTheme()->themeHint(QPlatformTheme::ContextMenuOnMouseRelease).toBool() ?
+        QEvent::MouseButtonRelease : QEvent::MouseButtonPress;
     if (qApp->d_func()->inPopupMode()) {
         QWidget *activePopupWidget = qApp->activePopupWidget();
         QWidget *popup = activePopupWidget;
@@ -438,7 +442,7 @@ void QWidgetWindow::handleMouseEvent(QMouseEvent *event)
             }
             qt_replay_popup_mouse_event = false;
 #ifndef QT_NO_CONTEXTMENU
-        } else if (event->type() == QEvent::MouseButtonPress
+        } else if (event->type() == contextMenuTrigger
                    && event->button() == Qt::RightButton
                    && (openPopupCount == oldOpenPopupCount)) {
             QWidget *popupEvent = popup;
@@ -487,7 +491,7 @@ void QWidgetWindow::handleMouseEvent(QMouseEvent *event)
                                         qt_last_mouse_receiver);
 
 #ifndef QT_NO_CONTEXTMENU
-    if (event->type() == QEvent::MouseButtonPress && event->button() == Qt::RightButton) {
+    if (event->type() == contextMenuTrigger && event->button() == Qt::RightButton) {
         QContextMenuEvent e(QContextMenuEvent::Mouse, mapped, event->globalPos(), event->modifiers());
         QGuiApplication::sendSpontaneousEvent(receiver, &e);
     }