[accessibility] Add support for a text selection mode

[ofek]

Background

I have a severe neuromuscular disorder which makes physical activities extremely strenuous, such as moving the mouse around to copy/paste.

ConEmu supports this feature which is why I'm using it but I'd like to switch to a more performant terminal with configuration not in XML or a GUI. Therefore, I have opened a feature request here and to Alacritty 😄

Description of the new feature/enhancement

Entering text selection mode can happen in 2 ways:

1.) click and drag (highlight) somewhere with the mouse
2.) press any arrow key while holding shift

At this point you can release the left-click (1) or shift (2). The cursor will change somehow (ConEmu makes it a yellow block) and you can now move anywhere with just the arrow keys. To highlight you then hold shift while using arrow keys similar to the highlighting logic of holding left-click while moving the mouse.

I should emphasize that both methods of entering text selection mode are necessary. If you want to copy something no longer in view, having only 2.) means you'd have to hold the up arrow for a long time. With 1.), you have the option to PgUp as needed then initiate with the mouse.

Copying can happen in 2 ways:

1. the standard shortcuts, which will not exit text selection mode
2. pressing Enter, which will exit text selection mode

Exiting text selection mode can occur at any time by pressing Esc

Proposed technical implementation details (optional)

No idea!

[DHowett]

Thanks for the request! We're actually tracking this in #715 (keyboard-only text selection, navigation), and it's currently in specification review at #2840! There's a sidecar specification that calls out support for a modal keyboard selection mode analogous to the traditional console's "mark mode" in #5804.

/dup #715.

/cc @carlos-zamora for use case visibility.

[ghost]

Hi! We've identified this issue as a duplicate of another one that already exists on this Issue Tracker. This specific instance is being closed in favor of tracking the concern over on the referenced thread. Thanks for your report!

[ofek]

@DHowett That's great, thank you!