Unexpected folder behavior with file icon theme contribution from VS Code extension

[jcortell68]

Bug Description:

I was playing around creating a file icon theme with a VS Code extension. My theme has but one icon--it tries to replace what's shown for a folder.

And it works...kind of. My icon is shown when the folder is collapsed, but isn't shown when the folder is expanded. In VS Code, my icon override is shown in both collapsed and expanded states.

In Theia, it ends up looking like this:

BTW, when the default icon theme is active, the folder icon is shown in both states.

Steps to Reproduce:

git clone -b icon_themes https://github.com/jcortell68/theiasandbox
cd theiasandbox
yarn
yarn start:electron

Choose My File Icon Theme as the icon theme in Theia's preferences.

Additional Information

• Operating System: Windows
• Theia Version: 1.39

[cdamus]

I'll be happy to look into this.

[cdamus]

Hi, @jcortell68 . This appears to be working as expected. VS Code (and also Theia) distinguishes between "folder" and "folderExpanded" in the icon themes, to allow for visual differentiation of the expansion state. See the VS Code API documentation for details.

I've created a PR on your sandbox repo that fixes the problem: jcortell68/theiasandbox#2

[cdamus]

Oops, sorry, I did not observe (or forgot) that this shouldn't be necessary as it is not required in VS Code, where the expanded icon defaults to the folder icon if absent from the theme definition. Theia should provide the same fall-back behaviour.

[cdamus]

Oops, sorry, I did not observe (or forgot) that this shouldn't be necessary as it is not required in VS Code, where the expanded icon defaults to the folder icon if absent from the theme definition. Theia should provide the same fall-back behaviour.

I've created PR #12776 to implement ape the VS Code fall-back behaviour.