support active/focused view or panel when clause context

[akosyakov]

What it does

• fix support active/focused view or panel when closures #4104: support active/focused view or panel when clause context

See https://code.visualstudio.com/docs/getstarted/keybindings#_activefocused-view-or-panel-when-clause-context for requirements. Important: in this context active means visible, not focused as usual.

In VS Code there are viewlets, panels and views:

• viewlet is a tab in the left area (explorer, scm, search, debug, etc.)
• panel is a tab in the bottom area (terminals, markers, output, debug console, etc.)
• view is a part in the viewlet, e.g. files and outline are views in the explorer viewlet

Important difference to Theia that VS Code does not allow to move individual viewlets or panels to other areas. It means that there is always only one visible viewlet or panel in VS Code, but in Theia it can be that several viewlets and panels widgets are visible. This PR implements the difference by setting context keys to last focused visible viewlet or panel widget.

How to test

• install https://github.com/akosyakov/vscode-view-when-sample/blob/master/vscode-view-when-sample-0.0.1.vsix
• to test activeViewlet and activePanel: open quick command palette and type Test you should see commands visible in the current context https://github.com/akosyakov/vscode-view-when-sample/blob/dd61713e5124d10e744d02d0694f177b3d46af3f/package.json#L69-L109
• to test focusedView: focus contributed nodeDependencies view in the explorer tab and type ctrlcmd+f1, it should trigger a notification bound to this keybinding when this view is focused: https://github.com/akosyakov/vscode-view-when-sample/blob/dd61713e5124d10e744d02d0694f177b3d46af3f/package.json#L112-L118

Review checklist

• as an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• as a reviewer, I agree to behave in accordance with the review guidelines

[vince-fugnitto]

Using your provided vsix, I was able to successfully test the scenarios you mentioned:

activeViewlet & activePanel

Viewlet	Status
Explorer	👍
Search	👍
SCM	👍
Debug	👍
Markers	👍
Output	👍
Terminal	👍

I'm not sure which view repl is or how to trigger the search panel.

focusedView

Viewlet	Status
Node Dependencies	👍

[akosyakov]

• repl is the debug console, you can open it from the debug view
• search panel is then search view is located not in the side areas, but in main or bottom

[vince-fugnitto]

• repl is the debug console, you can open it from the debug view
• search panel is then search view is located not in the side areas, but in main or bottom

I quickly tested, both cases work as well :)