[Qt-interest] Malfunctioning QGraphicsItem::ItemIsMovable?

[Stephen Chu]

You probably run into this bug: 
<http://bugreports.qt.nokia.com/browse/QTBUG-17985>

And I submitted a merge request for it: 
<http://bugreports.qt.nokia.com/browse/QTBUG-17985>

So far it's only been reviewed on the formatting of the code, not the 
fix itself. :(


In article <BANLkTi=fAHhEzB8M4banSkQTKz8eHy+Rzw at mail.gmail.com>,
 Sherif Ghali <sherif.ghali.1 at gmail.com> wrote:

> It occasionally seems that the index of QGraphicsScene is not
> right. The code below demonstrates one case. If I drag the red,
> green, or blue node, another node will move instead. If I replace
> '-0.05' with '-0.5', dragging works normally.
> 
> // MyGraphicsScene.h
> #include <QtGui>
> 
> class MyGraphicsScene : public QGraphicsScene
> {
>     Q_OBJECT
> public:
>     MyGraphicsScene()
>     {
>         setSceneRect(QRectF(QPointF(-2,-2), QSizeF(4,4)));
>         setBackgroundBrush(Qt::black);
> 
>         insert_node( QPointF( -0.05,-0.05), Qt::red );
>         insert_node( QPointF( 1,-0.05), Qt::green );
>         insert_node( QPointF( -0.05,1), Qt::blue );
>         insert_node( QPointF( 1,1), Qt::yellow );
>     }
> private:
>     QGraphicsEllipseItem * insert_node(const QPointF & p, const QColor & 
>     color)
>     {
>         const QRectF n(QPointF(-0.1,-0.1), QSizeF(0.2,0.2));
>         QGraphicsEllipseItem * node = new QGraphicsEllipseItem( n );
>         node->setPen(color);
>         node->setBrush(color);
>         node->setFlags(QGraphicsItem::ItemIsMovable);
>         node->setPos(p);
>         addItem(node);
>         return node;
>     }
> };
> 
> // main.cpp
> #include "MyGraphicsScene.h"
> #include <QtGui>
> 
> int main(int argc, char * argv[])
> {
>     QApplication app(argc, argv);
>     MyGraphicsScene * scene = new MyGraphicsScene;
>     QGraphicsView * view = new QGraphicsView(scene);
>     view->fitInView(scene->sceneRect() , Qt::KeepAspectRatio);
>     view->setMinimumSize(QSize(640,480));
>     view->show();
>     return app.exec();
> }

-- 
Stephen Chu