Microsoft-ui-xaml: Proposal: Alt, or Shift whilst using Scroll Wheel to scroll Horizontally - Mouse Wheel held down to Drag

[mdtauk]

Proposal: Alt, or Shift whilst using Scroll Wheel to scroll Horizontally - Mouse Wheel held down to Drag

Summary

When using the ScrollViewer or any scrollable view that is set to scroll Horizontally & Vertically, it should be possible to hold down either Alt, or Shift so when using the scroll wheel it will scroll on the Horizontal axis instead of only working on the Vertical one.

Rationale

Software like Adobe Photoshop and Illustrator allow you to hold down Ctrl whilst using the Mouse Wheel to scroll horizontally when working on a large or zoomed in canvas. It makes it easier to navigate a view without having to change your mental space and move to drag the scroll bar thumb.

Ctrl is currently used to Zoom in the control, so I have proposed Alt or Shift

Paint 3D also enables pressing and holding down the Mouse Wheel to drag the view in both axies.

Scope

| Capability | Priority |
| :---------- | :------- |
| These behaviours should be baked into the updated ScrollViewer control | Must |
| These behaviours could be made toggles so they are easy to turn off if that is needed | Could |
| The keyboard modifier could be customised, but should pick a platform default | Could |

Related to #108

Open Questions

[micahl]

I like it! @likuba as fyi since this is something we've talked about before.

[adrientetar]

Qt's QScrollArea uses Alt+scroll to scroll horizontally.

[micahl]

Thanks, that's good to know. I don't know if there's any consistency across apps today so having something built-in to the control would be helpful here. Both Edge and Chrome support Shift+scroll to scroll horizontally.

[adrientetar]

Ouch! indeed no real consistency here, probably because win32 apps don't usually do it so no established shortcut... Adobe XD uses Shift as well, though I kinda think Alt makes more sense as it's the "Alternate" key.

[shaheedmalik]

Shift sounds like the best one.