Mouse wheel zoom & scroll behavior

[Skaven252]

First off: Thanks for implementing mouse wheel zoom and pan to Xara, it's a great speed booster when you need to zoom in and out a lot to tweak minute details.

I've noticed a couple of odd behaviors though:

- If I hold the mouse wheel pressed down to pan while zoomed, and accidentally scroll the wheel (while it's being held down), the document snap-pans a long distance to an odd location. I suppose it happens because the zoom level changes while panning (or something)

It's a bit difficult to avoid scrolling the mouse wheel when click-dragging at least with my mouse, where the wheel click is a bit stiff. Would anyone have anything against it if there was a "disable mouse wheel zoom while the mouse wheel is pressed" check?

- Pressing the mouse wheel has the same effect as pressing the right arrow? At least on my system, if something is selected and I press the mouse wheel to pan, the selected object may shift right. Anyone else getting this?

[Charles Moir]

Clicking the center mouse button (wheel) moves the click point to the center of the screen. I think this explains the 'jumping' behavior you describe.

[jclements]

Slaven, I think I'm experience what you've discoverd.

1- Press middle button and pan and don't release the middle button (no problem ... pans nice and smoothly),

2- then scroll and again don't release the middle button (no problem ... the view zooms to tip of cursor as Charles describes),

3- now drag then mouse a bit . The views jumps (leaps) radically.

[Skaven252]

Yep, that's exactly what happens. You can reproduce it quite easily by holding down the wheel, panning around, and then rolling the wheel while it's still pressed. The view leaps.

Also; It always happens if you zoom *while* panning. It's pretty easy to do this by mistake, if you quickly try to zoom from one part of the document to another.