Implementing TreeView in an extension

[NoahTheDuke]

I'm trying to implement TreeView in coc-clojure, and the documentation + types isn't enough for me to figure it out. There aren't any examples in the tests, just a lot of unit tests. Has anyone implemented TreeView in an extension so I can see an example?

[fannheyward]

coc-clangd uses tree virw to display AST, hope this can help you https://github.com/clangd/coc-clangd/blob/master/src/ast.ts

[NoahTheDuke]

Thank you, that's helpful. I've implemented a working TreeView for coc-clojure with that as an example, but I have a few more questions.

1. What is the list of commands for the returned item in getTreeItem? I have borrowed clang-d's "Jump to", which works for items that have ranges, but if they don't, clicking on an item throws an error which is shown in the status line, saying Error on notification doKeymap Error: Failed to resolve command from TreeItem. How do I avoid this? Is there a no-op command I can send to do nothing?

2. setRoot is called when initializing the Tree View. Is it (and the associated event emitter) necessary? I'm not sure what it's providing (other than being able to say return [this.root]; in getChildren).

3. Would you be interested in a small tutorial/set of docs for writing one's own TreeView? The existing documentation/examples are pretty threadbare, and I'm willing to help.

[hexh250786313]

@NoahTheDuke

1. item is a instance of TreeItem which define every nodes of treeview. Its command means the action you trigger in it and you can use commandsMap to define your custom commands. For example, https://github.com/hexh250786313/coc-todo-tree/blob/60dd8a86eeb899c9abe6e2b6e4f3ef49067b3555/src/tree.ts#L276 will trigger a open command defined in https://github.com/hexh250786313/coc-todo-tree/blob/60dd8a86eeb899c9abe6e2b6e4f3ef49067b3555/src/tree.ts#L111 which actually do nothing. So if you don't do anything for some tree nodes you can handle it like what I done.
2. My treeview extension coc-todo-tree doesn't have setRoot, so I think it is not necessary.

[NoahTheDuke]

Thank you, that's very helpul.