QToolButton popup menu is shown at wrong position when embedded in a

QGraphicsView.

The main problem here is that QWidget assume that they are in the screen
somewhere, which means inside the available geometry provided by
QDesktopWidget. But in QGraphicsView the button can be in a position
that is way bigger than the screen resolution. Lot of widgets make
this assumption when positionning subpopups or submenus. Instead of
applying the same code on tons of QWidgets, it's better to have an
helper function in desktop widget which catch this case. It's not
pretty (since it has nothing to do with QDesktopWidget) but we don't
have better solution.

Task-number:QTBUG-3822
Reviewed-by:brad

1 files changed, 51 insertions, 2 deletions

diff --git a/src/gui/kernel/qwidget_p.h b/src/gui/kernel/qwidget_p.h
index a549740..2132474 100644
--- a/src/gui/kernel/qwidget_p.h
+++ b/src/gui/kernel/qwidget_p.h
@@ -63,7 +63,9 @@
 #include "QtGui/qstyle.h"
 #include "QtGui/qapplication.h"
 #include <private/qgraphicseffect_p.h>
-
+#include "QtGui/qgraphicsproxywidget.h"
+#include "QtGui/qgraphicsscene.h"
+#include "QtGui/qgraphicsview.h"
 #include <private/qgesture_p.h>
 
 #ifdef Q_WS_WIN
@@ -180,7 +182,9 @@ struct QWExtra {
     // Regular pointers (keep them together to avoid gaps on 64 bits architectures).
     void *glContext; // if the widget is hijacked by QGLWindowSurface
     QTLWExtra *topextra; // only useful for TLWs
+#ifndef QT_NO_GRAPHICSVIEW
     QGraphicsProxyWidget *proxyWidget; // if the widget is embedded
+#endif
 #ifndef QT_NO_CURSOR
     QCursor *curs;
 #endif
@@ -235,6 +239,24 @@ struct QWExtra {
 #endif
 };
 
+/*!
+    \internal
+
+    Returns true if \a p or any of its parents enable the
+    Qt::BypassGraphicsProxyWidget window flag. Used in QWidget::show() and
+    QWidget::setParent() to determine whether it's necessary to embed the
+    widget into a QGraphicsProxyWidget or not.
+*/
+static inline bool bypassGraphicsProxyWidget(const QWidget *p)
+{
+    while (p) {
+        if (p->windowFlags() & Qt::BypassGraphicsProxyWidget)
+            return true;
+        p = p->parentWidget();
+    }
+    return false;
+}
+
 class Q_GUI_EXPORT QWidgetPrivate : public QObjectPrivate
 {
     Q_DECLARE_PUBLIC(QWidget)
@@ -344,7 +366,9 @@ public:
 
     QPainter *beginSharedPainter();
     bool endSharedPainter();
-    static QGraphicsProxyWidget * nearestGraphicsProxyWidget(QWidget *origin);
+#ifndef QT_NO_GRAPHICSVIEW
+    static QGraphicsProxyWidget * nearestGraphicsProxyWidget(const QWidget *origin);
+#endif
     QWindowSurface *createDefaultWindowSurface();
     QWindowSurface *createDefaultWindowSurface_sys();
     void repaint_sys(const QRegion &rgn);
@@ -441,6 +465,31 @@ public:
 
     void setModal_sys();
 
+    // This is an helper function that return the available geometry for
+    // a widget and takes care is this one is in QGraphicsView.
+    // If the widget is not embed in a scene then the geometry available is
+    // null, we let QDesktopWidget decide for us.
+    static QRect screenGeometry(const QWidget *widget)
+    {
+        QRect screen;
+#ifndef QT_NO_GRAPHICSVIEW
+        QGraphicsProxyWidget *ancestorProxy = widget->d_func()->nearestGraphicsProxyWidget(widget);
+        //It's embedded if it has an ancestor
+        if (ancestorProxy) {
+            if (!bypassGraphicsProxyWidget(widget)) {
+                // One view, let be smart and return the viewport rect then the popup is aligned
+                if (ancestorProxy->scene()->views().size() == 1) {
+                    QGraphicsView *view = ancestorProxy->scene()->views().at(0);
+                    screen = view->mapToScene(view->viewport()->rect()).boundingRect().toRect();
+                } else {
+                    screen = ancestorProxy->scene()->sceneRect().toRect();
+                }
+            }
+        }
+#endif
+        return screen;
+    }
+
     inline void setRedirected(QPaintDevice *replacement, const QPoint &offset)
     {
         Q_ASSERT(q_func()->testAttribute(Qt::WA_WState_InPaintEvent));