Icons for TreeViewItems fallbacking to default folder item if file uri is used.

[Krzysztof-Cieslak]

Example:

As far as I understand this line is a problem - https://github.com/Microsoft/vscode/blob/5755810a58ac76ffedb037647f1cd6fec406efe9/src/vs/workbench/browser/parts/views/treeView.ts#L334

If an item has Expended or Collapsed state (which basically means it's an item with childs) then we expect folder icon.

In general, I don't think we should have such convention at all, and consumers should be able to set any icon they want - in case of my extension, tree view shows some information from the file, so it makes sense for me to use file icon on the node with child elements.

CC: @sandy081

[sandy081]

@Krzysztof-Cieslak Yes, I was assuming all resources with children as folders which is true in File explorer but not in custom views. So we need a convention to determine if a resource URI is a directory/folder or not.

One convention is to have a trailing slash to indicate if URI is for folder/directory or not.

[Krzysztof-Cieslak]

Couldn't we just check whether URI points towards folder or file with FileSystem API? Or that would be too slow?

[sandy081]

I do not think that is a good idea, because some of the URIs could be pointing to remote locations and it will make tree much slower.

[vbfox]

I need to check a few things before reopening my pr but what i did essentially was to keep the current behavior by default and allow extension developers to be explicit about folder/file

[sandy081]

To verify:

• Contribute a tree view. Refer to documentation and samples.

• If you specify ThemeIcon.Folder to iconPath in your TreeItem, then a folder icon will be provided to your node based on current file icon theme.

• If you specify ThemeIcon.File to iconPath in your TreeItem, then a file icon will be provided to your node based on current file icon theme.

• If you provide a resourceUri and no ThemeIcon to iconPath then the node will get folder icon if it has children otherwise file icon from current file icon theme