Merge remote-tracking branch 'origin/stable' into dev

Conflicts:
	src/widgets/styles/qstyleanimation.cpp

Change-Id: Iae570895be6544de80f9c1ec309d1a08c59daff8

3 files changed, 25 insertions, 9 deletions

diff --git a/src/plugins/platforms/windows/qwindowsbackingstore.cpp b/src/plugins/platforms/windows/qwindowsbackingstore.cpp
index b7937b4d84..5d3822d2cd 100644
--- a/src/plugins/platforms/windows/qwindowsbackingstore.cpp
+++ b/src/plugins/platforms/windows/qwindowsbackingstore.cpp
@@ -45,6 +45,7 @@
 #include "qwindowscontext.h"
 
 #include <QtGui/QWindow>
+#include <QtGui/QPainter>
 
 #include <QtCore/QDebug>
 
@@ -147,8 +148,10 @@ void QWindowsBackingStore::resize(const QSize &size, const QRegion &region)
                 nsp << " from: " << m_image->image().size();
         }
 #endif
-        m_image.reset(new QWindowsNativeImage(size.width(), size.height(),
-                                              QWindowsNativeImage::systemFormat()));
+        QImage::Format format = QWindowsNativeImage::systemFormat();
+        if (format == QImage::Format_RGB32 && rasterWindow()->window()->format().hasAlpha())
+            format = QImage::Format_ARGB32;
+        m_image.reset(new QWindowsNativeImage(size.width(), size.height(), format));
     }
 }
 
@@ -168,9 +171,16 @@ bool QWindowsBackingStore::scroll(const QRegion &area, int dx, int dy)
 
 void QWindowsBackingStore::beginPaint(const QRegion &region)
 {
-    Q_UNUSED(region);
     if (QWindowsContext::verboseBackingStore > 1)
         qDebug() << __FUNCTION__;
+
+    if (m_image->image().hasAlphaChannel()) {
+        QPainter p(&m_image->image());
+        p.setCompositionMode(QPainter::CompositionMode_Source);
+        const QColor blank = Qt::transparent;
+        foreach (const QRect &r, region.rects())
+            p.fillRect(r, blank);
+    }
 }
 
 QWindowsWindow *QWindowsBackingStore::rasterWindow() const
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 50fd7a0792..23ebd6bd9e 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -267,7 +267,7 @@ static void setWindowOpacity(HWND hwnd, Qt::WindowFlags flags, qreal level)
 struct WindowCreationData
 {
     typedef QWindowsWindow::WindowData WindowData;
-    enum Flags { ForceChild = 0x1 };
+    enum Flags { ForceChild = 0x1, ForceTopLevel = 0x2 };
 
     WindowCreationData() : parentHandle(0), type(Qt::Widget), style(0), exStyle(0),
         topLevel(false), popup(false), dialog(false), desktop(false),
@@ -319,7 +319,13 @@ void WindowCreationData::fromWindow(const QWindow *w, const Qt::WindowFlags flag
         parentHandle = (HWND)prop.value<WId>();
     }
 
-    topLevel = ((creationFlags & ForceChild) || embedded) ? false : w->isTopLevel();
+    if (creationFlags & ForceChild) {
+        topLevel = false;
+    } else if (creationFlags & ForceTopLevel) {
+        topLevel = true;
+    } else {
+        topLevel = w->isTopLevel();
+    }
 
     if (topLevel && flags == 1) {
         flags |= Qt::WindowTitleHint|Qt::WindowSystemMenuHint|Qt::WindowMinimizeButtonHint
@@ -1022,10 +1028,9 @@ void QWindowsWindow::setParent_sys(const QPlatformWindow *parent) const
 
         // WS_CHILD/WS_POPUP must be manually set/cleared in addition
         // to dialog frames, etc (see  SetParent() ) if the top level state changes.
-        if (wasTopLevel != isTopLevel) {
-            const unsigned flags = isTopLevel ? unsigned(0) : unsigned(WindowCreationData::ForceChild);
-            setWindowFlags_sys(window()->flags(), flags);
-        }
+        // Force toplevel state as QWindow::isTopLevel cannot be relied upon here.
+        if (wasTopLevel != isTopLevel)
+            setWindowFlags_sys(window()->flags(), unsigned(isTopLevel ? WindowCreationData::ForceTopLevel : WindowCreationData::ForceChild));
     }
 }
 
diff --git a/src/plugins/platforms/windows/qwindowswindow.h b/src/plugins/platforms/windows/qwindowswindow.h
index 4e82938cf4..f98855d84d 100644
--- a/src/plugins/platforms/windows/qwindowswindow.h
+++ b/src/plugins/platforms/windows/qwindowswindow.h
@@ -158,6 +158,7 @@ public:
 
     virtual void setVisible(bool visible);
     bool isVisible() const;
+    virtual bool isExposed() const { return m_windowState != Qt::WindowMinimized && isVisible(); }
     virtual bool isActive() const;
     virtual bool isEmbedded(const QPlatformWindow *parentWindow) const;
     virtual QPoint mapToGlobal(const QPoint &pos) const;