- Click into the drawing area to start the selection frame
- move the mouse to resize the selection frame
- Release the mouse button to resize the selection frame
new features :
- circles are draggable
- circles can be selected (multiple selections possible by pressing CTRL while clicking a circle)
- the selection frame selects all circles within the frame (by pressing CTRL the selected circles will be appended to current selection)
- multiple selected circles will be dragged simultaneous