QGraphicsScene and mouseEvent

lenina15i25

Good afternoon. There is a tied QGraphicsScene to QGraphicsView. I overloaded the mouse event, for drawing on the stage. But I do not understand how to return a pointer to the selected drawn object. By default, double-clicking the mouse highlights the object, I set the flag: line-> setFlag (QGraphicsItem :: ItemIsSelectable).
Object: QGraphicsLineItem * line = new QGraphicsLineItem .
Help to return the pointer to the selected object, to change it and view the coordinates of the line (beginning and end).

SGaist

Hi,

Did you already took a look at the Graphics View Examples ? You might find there several source of inspiration for your application.

samdol

@lenina15i25
Have you looked at
http://doc.qt.io/qt-5/qtwidgets-graphicsview-diagramscene-example.html
I also tried to get the pointer of drawn object on scene by passing pointer. Strange, but I could not get it.
In the example,

bool DiagramScene::isItemChange(int type)
{
    foreach (QGraphicsItem *item, selectedItems()) {
        if (item->type() == type)
            return true;
    }
    return false;
}

It might be the function you need.
Then you try something like

void DiagramScene::setLineColor(const QColor &color)
{
    myLineColor = color;
    if (isItemChange(Arrow::Type)) {
        Arrow *item = qgraphicsitem_cast<Arrow *>(selectedItems().first());
        item->setColor(myLineColor);
        update();
    }
}

to get the pointer of selected item and do something on it.