Back and Forwards navigation buttons

Your idea

Implement new toolbar buttons and shortcut assignable-actions:

• Back: Jump to where the previous action was performed.
• Forwards: Jump to where you were before you pressed Back.

These actions would scroll the view AND create a selection at the new location.

[!NOTE]
The new selection is necessary for keyboard users (e.g. blind users) who rely on focus-based navigation.

If a modifier key is held (e.g. Alt/Option) we could scroll the view without making a new selection. This would be useful in cases where you want to preserve the existing selection.

Problem to be solved

It's often necessary to scroll back to where you were previously, for example, when copying and pasting nearby content from one location to another:

1. Copy something at the current location (e.g. a note or measure).
2. Scroll elsewhere in the score.
3. Select a target and paste.
4. Press Back to return to the original location (without having to scroll this time).
5. Copy something nearby.
6. Press Forwards to go to where you pasted before (again, without having to scroll).
7. Select a nearby target and paste.

The copy location might be in a separate instrumental part to the paste location.

Prior art

Editors / IDEs

The Back and Fowards buttons in VS Code exhibit the exact behaviour described.

In Qt Creator it's almost the same. Copy isn't added to the Back queue, but other actions are.

Web browsers

Web browsers have Back and Forwards buttons. Normally these jump to different documents rather than different regions of the current document, but if you click on anchor links (e.g. to headings on the same page) then they exhibit the behavior described.

Additional context

1. The Back and Forwards queues shouldn't be limited to actions shown in the History panel.
   • For example, the Copy action isn't displayed in the History panel, but it's still useful to navigate Back to where you copied something.
2. After navigating Back, performing new actions shouldn't clear the Back or Forwards queues.
   • Instead, new actions should be inserted at the front of the Back queue.
   • Forwards should retain its functionality regardless of new actions.
3. If the user performs the Undo action (Ctrl+Z), we should drop the undone action from the Back/Forwards queue, and possibly jump to that location in the score.
4. Back and Forwards should be able to jump between instrmental parts if necesary, unless the action performed was to delete a part.

Checklist

• This request follows the guidelines for reporting issues
• I have verified that this feature request has not been logged before, by searching the issue tracker for similar requests