One more thought on interactive zoom. As I was trying out the
interactive zoom (not zoom to rect, but right click on pan zoom) on
some image data, I noticed that it would be useful to have some
constraints on the zoom
- zoom only on x. Already the x zoom is determined by the amount of
movement in the horizontal direction, but it would be nice to be
able to ignore the y direction. Candidate key modifier: 'x'
- zoom only on y. ditto. Candidate key modifier: 'y'
- preserve axes aspect ratio. Candidate key modifier: ??. I think
some apps use a SHIFT or a CTRL modifier for this. Is there any
consensus or common practice?