Panning / zooming widgets

With the mouse, when you use the zoom / pan widgets the mouse cursor disappears and you can infinitely drag. However with a tablet, the cursor remains and moves with the pen and will stop at the edges of the window. You have to repick the widget and drag again.

It would be nice if the tablet pen behaved like the mouse and could "infinitely" pan/zoom.

When using the middle mouse to zoom the 3d view, you can press SHIFT to pan. It would be nice if the zoom widget acted the same way.

The zoom widget could also act as a tool that you could click, then drag a region in the view and the view would pan/zoom to fill that region.

This would be easier to do in the 2D Animatation tab and orthographic views as the "depth" is known, and the depth would need to be guesstimated the 3d perspective view.