1555620 - WebExtensions command don't work when the key combination is used by the webpage

Status: NEW

(WebExtensions :: Frontend, enhancement, P5)

Description

[YUKI "Piro" Hiroshi]

Abstract

Any keyboard shortcut for a WebExtensions command doesn't work if the shortcut is already used by the webpage currently shown.

Steps to reproduce

1. Install any addon providing commands, for example: Second Search. It provides a keyboard shortcut Ctrl-Shift-L by default to open its toolbar button popup.
2. Open http://example.com/ in the current tab.
3. Hit Ctrl-Shift-L to confirm the effectivity of the shortcut.
4. Hit Ctrl-Shift-K to open the web console.
5. Run a script: addEventListener('keydown', e => { e.stopPropagation(); e.preventDefault(); }, true); with the console.
6. Hit Ctrl-Shift-L.

Actual result

Nothing happen.

Expected result

The keyboard shortcut triggers its WebExtensions command.

Environment

• Firefox 67.0 (64bit, build ID: 20190516215225) on Windows 10
• Nightly 69.0a1 (64bit, build ID: 20190529215251) on Windows 10

Comment 1

[YUKI "Piro" Hiroshi]

This is a Firefox specific restriction, and doesn't happen onChromium (Google Chrome). Steps to reproduce:

1. Install any extension with commands, for example Reopen closed tab Button™. It reopens most recently closed tab.
2. Go to chrome://extensions/shortcuts
3. Set keyboard shortcut Ctrl-Shift-L for Reopen closed tab Button™.
4. Open http://example.com/ in the current tab.
5. Hit Ctrl-Shift-L to confirm the effectivity of the shortcut.
6. Hit Ctrl-Shift-J to open the web console.
7. Run a script: addEventListener('keydown', e => { e.stopPropagation(); e.preventDefault(); }, true); with the console.
8. Hit Ctrl-Shift-L.

Then the command is invoked and most recently closed tab is restored for me.

Comment 2

[Kris Maglione [:kmag]]

This is more or less expected. We use the same command key processing for extension commands as for built-in commands, and we allow those to be overridden by site key listeners.

Comment 3

[YUKI "Piro" Hiroshi]

Then, this looks related to another bug 1325692. Due to the restriction, now priority order of shortcuts are:

1. Important shortcuts of Firefox itself (highest priority, impossible to change/disable, impossible to be overridden by anyone)
2. Shortcuts defined by the webpage (impossible to change/disable)
3. Regular shortcuts of Firefox itself (impossible to change/disable)
4. Shortcuts for WebExtensions commands (lowest priority, possible to change/disable)

As the result, shortcuts provided by addons are actually almost unusable. Firefox now allows us to customize shortcuts on about:addons, but it looks almost mean-less, because shortcuts defined by Firefox and webpages are basically uncustomizable.

Originally this bug was reported as an issue of my addon, and its motivation is that allowing to use a fixed shortcut for features used by the user himself very frequently. So, I think the following order looks better:

1. Important shortcuts of Firefox itself (highest priority, impossible to change/disable, impossible to be overridden by anyone)
2. Shortcuts for WebExtensions commands (possible to change/disable)
3. Shortcuts defined by the webpage (impossible to change/disable)
4. Regular shortcuts of Firefox itself (lowest priority, impossible to change/disable)

because only shortcuts for WebExtensions commands are customizable/clearable by the user himself. How about this viewpoint?

Comment 4

[Rob Wu [:robwu]]

We are not convinced that extensions taking precedence over everything else is the majority case.
However, we are supportive of a way for users to opt in to allowing extension shortcuts to take precedence over web pages (e.g. via the shortcut management page at about:addons). There are clearly use cases (e.g Vimium extension, bug 1713794), and the current alternative is the use of a global content scripts (which is a less reliable and worse performing solution than a built-in feature).

As for choosing extension shortcuts without conflicts, we would prefer offering a way to query the availability of a shortcut over somehow magically resolving conflicts (which is not feasible) - bug 1654403.

Patches are welcome.

Comment 5

[Fabien Givors]

This bug is growing more and more painful as a lot of websites find it's a good idea to remap lots and lots of keyboard shortcuts.
This makes a lot of firefox extensions break randomly.
This even makes Firefox (eg. quickfind) break randomly (please reopen #1455101)