Hi everybody,
I am currently trying to resize a QGraphicsRectItem through my QGraphicsScene
using the MouseMoveEvent method.
In the latter, I’m checking if the application is in the “startModifying” mode
(Therefore, if he wants to modify a rectangle) and in which corner the moue is:
IsOnTopLeftCornerPressed: The user is pressing the rectangle’s top left corner
IsOnTopRightCornerPressed: The user is pressing the rectangle’s top right corner
IsOnBottomLeftCornerPressed: The user is pressing the rectangle’s bottom left
corner
IsOnBottomRightCornerPressed: The user is pressing the rectangle’s bottom right
corner
However, it does not work at all. Could you help me please ?
Best regards
Here you have the code:
void ImageGraphicsScene::mouseMoveEvent(QGraphicsSceneMouseEvent *event) {
if(modifyButton==true&&isSelected==true){
this->checkMouseMove(event->scenePos());
}
if(startModifying==true){
if(isOnTopLeftCornerPressed==true){
// The normalized method allow the user to draw rectangles having a
negative height/width
// Remember: The top-left point is in the rectangle's local
coordinates !!!
QRectF
rectangleF(0,0,event->scenePos().x()-rectModified->rect().bottomRight().x(),event->scenePos().y()-rectModified->rect().bottomRight().y());
rectModified->setRect(rectangleF.normalized());
rectModified->setRect(rectangleF);
this->modifyButton=false;
}
if(isOnTopRightCornerPressed==true){
qDebug()<<"I am here in topRight";
rectModified->setPos(rectModified->getBottomLeft().x(),rectModified->getBottomLeft().y());
// The normalized method allow the user to draw rectangles having a
negative height/width
// Remember: The top-left point is in the rectangle's local
coordinates !!!
QRectF
rectangleF(0,0,event->scenePos().x()-rectModified->getBottomLeft().x(),event->scenePos().y()-rectModified->getBottomLeft().y());
rectModified->setRect(rectangleF.normalized());
}
if(isOnBottomLeftCornerPressed==true){
// The normalized method allow the user to draw rectangles having a
negative height/width
// Remember: The top-left point is in the rectangle's local
coordinates !!!
QRectF
rectangleF(0,0,event->scenePos().x()-rectModified->getTopRight().x(),event->scenePos().y()-rectModified->getTopRight().y());
rectModified->setRect(rectangleF.normalized());
}
if(isOnBottomRightCornerPressed==true){
// The normalized method allow the user to draw rectangles having a
negative height/width
// Remember: The top-left point is in the rectangle's local
coordinates !!!
QRectF
rectangleF(0,0,event->scenePos().x()-rectModified->getPoint().x(),event->scenePos().y()-rectModified->getPoint().y());
rectModified->setRect(rectangleF.normalized());
}
}else{
}
/*
* Draw the Rectangle
*/
if(mouseLeftPressed==true&&drawButton==true){
if(!rect){
rect=new RectangleDraw;
this->addItem(rect);
rect->setPen(QPen(Qt::red,4,Qt::SolidLine));
rect->setPos(origPoint.x(),origPoint.y());
rect->setId(id=id+1);
}
// The normalized method allow the user to draw rectangles having a
negative height/width
// Remember: The top-left point is in the rectangle's local coordinates
!!!
QRectF
rectangleF(0,0,event->scenePos().x()-origPoint.x(),event->scenePos().y()-origPoint.y());
rect->setRect(rectangleF.normalized());
// The top-Left point is in local rectangle's coordinates. Therefore, we
have to transform them in scene's absolute
// coordinates using mapToScene.
QPointF point;
point=rect->mapToScene(rect->rect().topLeft());
rect->setPoint(point);
} else{
}
QGraphicsScene::mouseMoveEvent(event);
}
De : Michael Sué
Envoyé : lundi 26 octobre 2015 12:58
À : david.carmon...@gmail.com, interest@qt-project.org
Hi David,
> However, I have some problems when I actually want to draw rectangles with
> negatives width and height. I mean when the values of origPoint.x() and
> origPoint.y() are strictly higher than scenePos().x() and scenePos().y()
> respectively.
You will have to normalize the rectangle coordinates. There is a QRect method
for this. It exchanges coordinates so that width and height is positive. You
can set the rectangle then.
- Michael._______________________________________________
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