qgraphicsitem

Sometimes selected items do not move together. This happens in an application with two types of items: "regular items" "handles" with ItemIgnoresTransformations flag (they must keep the same size upon zooming) When they are selected together, and moved by mouse, they are expected to be translated by the same amount (they should move as a whole). It works fine when only "regular items" or only "handles" are moved, but not when both types are selected. Here is a minimal example displaying the problem. It can also be found on sourceforge , together with an enhanced version displaying also some

I'm trying to create something similar to terragens node network view in python using PySide. I subclassed QGraphicsRectItem using this code. class Node(QGraphicsRectItem): def __init__(self,pos): QGraphicsRectItem.__init__(self,pos.x()-100,pos.y()-30,200,60) self.setFlag(QGraphicsItem.ItemIsMovable,True) (...) Which gives this (with some fancy painting): I'd like to implent connecting nodes by dragging the mouse from one small rectangle to another, but this results in moving the whole node. So I don't want the QGraphicsRectItem getting moved when the mouse is pressed inside a small rectangle.

I have a problem , that update() function in QGraphicsItem doesn't work. What I want to do is , when I move circle , other QGraphicsItem ( in the mean time roundrect ) changes color. This is a example, what I want to do: circle.cpp: void CircleItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event) { // RoundRect Object RectItem->SetBackGround(); QGraphicsItem::mouseMoveEvent( event ); } RoundRect.cpp: void RoundRectItem::SetBackGround() { ChangeBackground = true; update(); } void RoundRectItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) { QRectF rec =

I have a QGraphicsScene which contains custom objects (with QGraphicsItem as base class). I can retrieve these objects with: foreach (QGraphicsItem* item, items()) { if (item->type() == CustomItem::Type) qgraphicsitem_cast<CustomItem*>(item).doStuff(...); } Is it possible to write a custom iterator for just this type of objects? I want to be able to use range-based for-loops and algorithms from the STL. for(CustomItem& a : custom_items()) a.doStuff(...); I want to avoid storing pointers to these objects manually (for example in a vector) since this involves additional book-keeping when objects

I can't understand how scaling and rotation are applied to QGraphicsItem . I need to be able to apply rotation and scaling ( not necessarily keeping aspect ratio ) and I get fully unexpected results. Rotation must be around the item center. I seem to have no problem doing that - yet if I try to debug the bounding rectangle, I get seemingly wrong values. If I don't keep aspect ratio, instead of rotation I get a very weird skew, and I have been struggling for quite a while to find the cause and correct it. I hope anybody can find a solution. For many items - like rectangles - my solution was to