Automatically expand the last expanded folder when the page is refreshed in web.

[yiliang114]

For example when I open a project in vscode.de v, I expand the folder on the file tree. When I refresh the whole page, the default behavior now is that the folders are collapsed, which means that I need to expand the folders one by one again the last time I opened them.

[yiliang114]

If the expansion state of the file tree folder can remember the last expansion like tabs, similar to the gif below, I think this is a better effect.

[yiliang114]

I have fixed this problem and will mention a pr later.

[yiliang114]

@lramos15 The reason for this problem is that there are multiple calls to the this.tree.setInput function during the rendering of the file tree.

The state will be read from the cache for the first time, but before the execution is completed for the first time, the setInput will be executed again. At this time, the tree already has a value. However, because the file tree data is not ready (because the data on the Web side is asynchronous), the state returned by the getViewState function is empty, resulting in the final file tree returning to the default collapsed state.

vscode/src/vs/workbench/contrib/files/browser/views/explorerView.ts

Line 681 in 43650e2

if (this.tree && this.tree.getInput()) {