From c9c33bd227f0199b368d92131a0ee566d2651061 Mon Sep 17 00:00:00 2001
From: Lars Knoll <lars.knoll@nokia.com>
Date: Tue, 20 Sep 2011 18:10:39 +0200
Subject: [PATCH] Fix support for drag pixmaps
MIME-Version: 1.0
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Re-add the support for drag pixmaps to qdnd.
Use the new WindowTransparentForMouseEvents
flag for the window that shows the drag pixmap.

Change-Id: I4b594085c161475988b9be0ffdc02c75fcc37f66
Reviewed-on: http://codereview.qt-project.org/5261
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>
---
 src/gui/kernel/qdnd.cpp | 68 ++++++++++++++++++++++++++++-------------
 src/gui/kernel/qdnd_p.h | 42 +++++++------------------
 2 files changed, 57 insertions(+), 53 deletions(-)

diff --git a/src/gui/kernel/qdnd.cpp b/src/gui/kernel/qdnd.cpp
index 4ed2515115..9a90c213cf 100644
--- a/src/gui/kernel/qdnd.cpp
+++ b/src/gui/kernel/qdnd.cpp
@@ -51,6 +51,7 @@
 #include "qpoint.h"
 #include "qbuffer.h"
 #include "qimage.h"
+#include "qpainter.h"
 #include "qregexp.h"
 #include "qdir.h"
 #include "qdnd_p.h"
@@ -277,7 +278,6 @@ QObject *QDragManager::currentTarget()
 }
 
 
-static QPixmap *defaultPm = 0;
 static const int default_pm_hotx = -2;
 static const int default_pm_hoty = -16;
 static const char *const default_pm[] = {
@@ -297,39 +297,65 @@ static const char *const default_pm[] = {
 };
 
 
+QShapedPixmapWindow::QShapedPixmapWindow()
+    : QWindow()
+{
+    setSurfaceType(RasterSurface);
+    setWindowFlags(Qt::Tool | Qt::FramelessWindowHint |
+                   Qt::X11BypassWindowManagerHint | Qt::WindowTransparentForInput);
+    create();
+    backingStore = new QBackingStore(this);
+}
+
+void QShapedPixmapWindow::render()
+{
+    QRect rect(QPoint(), geometry().size());
+    backingStore->resize(rect.size());
+
+    backingStore->beginPaint(rect);
+
+    QPaintDevice *device = backingStore->paintDevice();
+
+    {
+        QPainter p(device);
+        p.drawPixmap(0, 0, pixmap);
+    }
+
+    backingStore->endPaint();
+    backingStore->flush(rect);
+}
+
+
+
+
 static Qt::KeyboardModifiers oldstate;
 
 void QDragManager::updatePixmap()
 {
     if (shapedPixmapWindow) {
-        QPixmap pm;
-        QPoint pm_hot(default_pm_hotx,default_pm_hoty);
+        shapedPixmapWindow->pixmap = QPixmap();
+        shapedPixmapWindow->hotSpot = QPoint(default_pm_hotx,default_pm_hoty);
         if (object) {
-            pm = object->pixmap();
-            if (!pm.isNull())
-                pm_hot = object->hotSpot();
-        }
-        if (pm.isNull()) {
-            if (!defaultPm)
-                defaultPm = new QPixmap(default_pm);
-            pm = *defaultPm;
-        }
-        shapedPixmapWindow->setPixmap(pm);
-        shapedPixmapWindow->move(QCursor::pos()-pm_hot);
-        if (willDrop) {
-            shapedPixmapWindow->show();
-        } else {
-            shapedPixmapWindow->hide();
+            shapedPixmapWindow->pixmap = object->pixmap();
+            if (!shapedPixmapWindow->pixmap.isNull())
+                shapedPixmapWindow->hotSpot = object->hotSpot();
         }
+        if (shapedPixmapWindow->pixmap.isNull())
+            shapedPixmapWindow->pixmap = QPixmap(default_pm);
+        shapedPixmapWindow->setGeometry(QRect(QCursor::pos() - shapedPixmapWindow->hotSpot, shapedPixmapWindow->pixmap.size()));
+        shapedPixmapWindow->show();
+        shapedPixmapWindow->render();
     }
 }
 
 void QDragManager::updateCursor()
 {
+    if (shapedPixmapWindow) {
+        shapedPixmapWindow->render(); // ### Hack
+        shapedPixmapWindow->move(QCursor::pos() - shapedPixmapWindow->hotSpot);
+    }
 #ifndef QT_NO_CURSOR
     if (willDrop) {
-        if (shapedPixmapWindow)
-            shapedPixmapWindow->show();
         if (currentActionForOverrideCursor != global_accepted_action) {
             QGuiApplication::changeOverrideCursor(QCursor(dragCursor(global_accepted_action), 0, 0));
             currentActionForOverrideCursor = global_accepted_action;
@@ -340,8 +366,6 @@ void QDragManager::updateCursor()
             QGuiApplication::changeOverrideCursor(QCursor(Qt::ForbiddenCursor));
             currentActionForOverrideCursor = Qt::IgnoreAction;
         }
-        if (shapedPixmapWindow)
-            shapedPixmapWindow->hide();
     }
 #endif
 }
diff --git a/src/gui/kernel/qdnd_p.h b/src/gui/kernel/qdnd_p.h
index 2a81de5c7f..a94d439811 100644
--- a/src/gui/kernel/qdnd_p.h
+++ b/src/gui/kernel/qdnd_p.h
@@ -62,7 +62,7 @@
 #include "QtGui/qwindow.h"
 #include "QtCore/qpoint.h"
 #include "private/qobject_p.h"
-
+#include "QtGui/qbackingstore.h"
 QT_BEGIN_NAMESPACE
 
 class QEventLoop;
@@ -109,41 +109,21 @@ public:
     Qt::DropAction defaultDropAction;
 };
 
-class QShapedPixmapWindow : public QWindow {
-    QPixmap pixmap;
+class QShapedPixmapWindow : public QWindow
+{
 public:
-    QShapedPixmapWindow() :
-        QWindow()
+    QShapedPixmapWindow();
+
+    void exposeEvent(QExposeEvent *)
     {
-        setWindowFlags(Qt::Tool | Qt::FramelessWindowHint | Qt::X11BypassWindowManagerHint);
-        // ### Should we set the surface type to raster?
-        // ### FIXME
-//            setAttribute(Qt::WA_TransparentForMouseEvents);
+        render();
     }
 
-    void move(const QPoint &p) {
-        QRect g = geometry();
-        g.setTopLeft(p);
-        setGeometry(g);
-    }
-    void setPixmap(QPixmap pm)
-    {
-        pixmap = pm;
-        // ###
-//        if (!pixmap.mask().isNull()) {
-//            setMask(pixmap.mask());
-//        } else {
-//            clearMask();
-//        }
-        setGeometry(QRect(geometry().topLeft(), pm.size()));
-    }
+    void render();
 
-    // ### Get it painted again!
-//    void paintEvent(QPaintEvent*)
-//    {
-//        QPainter p(this);
-//        p.drawPixmap(0,0,pixmap);
-//    }
+    QBackingStore *backingStore;
+    QPixmap pixmap;
+    QPoint hotSpot;
 };