[Drawkit] Selection behavior with groups

[Graham Cox]

Currently this is the intended behaviour, not because it makes life  
difficult (though I accept it does in your case where your objects are  
very small) but because for the typical case it is more usable. If the  
user has several objects selected but then deliberately clicks in a  
knob, the expected behaviour is to operate that knob as normal (and  
refocusing the selection onto that one object beforehand), not move  
the selected objects. It means that what a knob represents in terms of  
behaviour is consistent.

The problem you're having is of course, that the knobs start to  
overwhelm the objects at very small scales, so it's hard to click  
something that isn't a knob.

I can suggest a few ways out of this. The behaviour is implemented by  
the DKSelectAndEditTool, as part of its mouseDown... method. So you  
could modify that to detect a multiple selection and to treat any knob  
hits as body hits instead. Maybe also factor in the zoom scale and/or  
object size so that at larger scales the usual behaviour is kept the  
same. Another option would be to change the DKKnob scaling ratio and  
knob size so that the knobs are smaller at the scales you are working  
at so they are less likely to get in the way. You could also implement  
your own selection/move tool that ignored knob hits altogether (so  
you'd have separate tools for moving objects and editing them). You  
could also try grouping the objects and moving the group - that  
ignores all knobs for objects within the group (this is more of a  
workaround than a real solution).

If you let me know your preferred approach I can help you out with  
specifics.

cheers, Graham



On 5 Aug 2008, at 9:27 am, Brad Larson wrote:

> One thing I encountered today was a difficulty in moving a large  
> group selection, which might require a change in the way that knobs  
> are selected.  When you select an object with a large number of  
> features, you normally can move that group selection by clicking and  
> dragging on any of the features within the selection.  The problems  
> come in when you have a group selection and click and drag on a knob  
> from one of the selected objects.  It's been my experience in other  
> draw programs that this would also cause a dragging of the whole  
> selection, but in DrawKit that currently causes the selection to be  
> lost and for you to edit the object by dragging that control point.
>
> This really causes a problem with groups containing many fine  
> features, as often the knobs will be the only thing in the selection  
> that you can click on to move it.  For example, in the Beta of  
> SonoDraw, try loading the sample PCBExample.pattern, enlarging the  
> canvas, selecting all objects, copying and pasting another group of  
> objects, then moving the selection.  It is very difficult to do  
> unless you zoom way in and select a non-knob part of one of the lines.
>
> This seems like something that is fundamental in the functioning of  
> the DKKnob, so I didn't know where to start with modifications or  
> even if they were  desired.  Do you prefer this method of  
> selection / editing?