Accessibility improvements

[devinprater]

This pull request introduces major accessibility improvements for the Termux terminal view, focusing on screen reader support and improved virtual key handling. The most significant changes include the addition of a custom accessibility helper for the terminal view, enhanced accessibility event handling, and improved toggling and feedback for virtual Control and Fn keys. These updates make the terminal experience much more usable for users relying on assistive technologies.

Accessibility Enhancements:

• Added a new TerminalAccessibilityHelper class that implements ExploreByTouchHelper, enabling semantic navigation and interaction for screen readers by exposing logical text blocks (paragraphs/lines) in the terminal (terminal-view/src/main/java/com/termux/view/TerminalAccessibilityHelper.java).
• Integrated the accessibility helper into TerminalView, registering it as the accessibility delegate and tracking screen/cursor state for accessibility announcements (terminal-view/src/main/java/com/termux/view/TerminalView.java). [1] [2]
• Implemented a sophisticated accessibility event processor in TerminalView to announce content changes, cursor movement, and text deletions in a way that is compatible with screen readers and (usually) avoids redundant feedback (terminal-view/src/main/java/com/termux/view/TerminalView.java).
• Modified input connection setup to provide appropriate IME types and options when accessibility is enabled, ensuring compatibility with accessibility keyboards such as Braille Keyboard (terminal-view/src/main/java/com/termux/view/TerminalView.java). [1] [2]

Virtual Key Handling Improvements:

• Changed the logic for virtual Control and Fn keys to use toggling (on/off) with assertive accessibility announcements, ensuring users are informed of the current modifier state. This includes renaming variables for clarity and resetting state after use (app/src/main/java/com/termux/app/terminal/TermuxTerminalViewClient.java). [1] [2] [3] [4]
• Added an assertive announcement method using AccessibilityManager to provide immediate feedback when toggling modifier keys (app/src/main/java/com/termux/app/terminal/TermuxTerminalViewClient.java).

Dependency Updates:

• Added dependencies on androidx.core and androidx.customview to support the new accessibility features (terminal-view/build.gradle).

[devinprater]

Just a note that this was vibe coded, but was checked to make sure it works well enough. Focus tracking could be better, but I can easily install packages, review output line by line, and page through info pages.

[robertkirkman]

what happened here?

[devinprater]

Sorry, I was originally going to just have it be a separate app, but other people encouraged me to just submit a PR and so I reverted most of the changes. This last commit should fix that issue.

[fornwall]

@devinprater This is a really valuable and important effort 🙏! Will review and test it.

Could you rebase on top of the master branch, where 53f75a8 was just merged which updated the tooling (note: java 17 or later is now required)? That should fix the currently failing CI pipeline.

[devinprater]

Okay, that should be updated.

[aryanchoudharypro]

Okay, that should be updated.

thanks for this pr, i was going to do something like this myself and submit one.