[vscode] support viewsWelcome contribution point

[akosyakov]

There is a new contribution point which allow to control welcome view for contributed views: https://github.com/microsoft/vscode/blob/cce81b98b9507b9f4baee1fcf4c9972e88d65a48/src/vs/workbench/contrib/welcome/common/viewsWelcomeExtensionPoint.ts

It's already used by latest version of vscode built-in git extension: microsoft/vscode#61491 (comment)

[alex-gilin]

We've introduced viewsWelcome contributed point in some custom extensions... Can you prioritize this task?

[akosyakov]

@alex-gilin There is no really "you"? There are different adopters contributing to this project. For now i am not sure there anyone has capacity for it. I've added to next dev meeting to raise it, but one should point out some interesting VS Code extensions to justify it for concrete adopter. PRs are also welcomed. Usually one study VS Code implementation for a reference and then port it to Theia trying not break APIs outside of the plugin system.

[akosyakov]

Supporting this would be interesting for better initial git and debug views.

[amiramw]

@EstherPerelman will try to work on it

[clovis-dugue]

Hi ; has this issue been fixed ? I can see the PR has been merged and the changelog mentions it, however my custom extension's viewsWelcome does not show., using a clone of Theia's master branch's browser example (v1.12)

Maybe opening a new issue for this would be relevant but I would rather note duplicate this one

[EstherPerelman]

@clovis-dugue The issue has been fixed, What is your code for viewsWelcome? Are you sure it has to work?

[clovis-dugue]

@EstherPerelman Thanks for the lightning fast answer.

My code (inside the package.json.) is as simple as :

"viewsWelcome": [
  {
    "view": "mission-panel",
    "contents": "[Show mission](command:side-mission-panel.show-mission)\n[End mission](command:side-mission-panel.end-mission)\n[Cancel mission](command:side-mission-panel.cancel-mission)\n"
  }
]

It does work as intended when packaged as a vsix and used inside of VSCode, but not when when used inside Theia, whether it is packaged as a .theia or a .vsix file

EDIT: Perhaps closing the issue would be relevant as to not mislead people encountering similar issues since the PR has been merged

[EstherPerelman]

@clovis-dugue It's very strange, Has to work as explained in How to test PR #8678

[clovis-dugue]

@EstherPerelman It does indeed ; the main difference between these two plugins being that mine fails to activate (for testing purposes).
However when failing to activate inside VSCode, it still shows the ViewsWelcome. In Theia, this does not seem to be the case ; which might be an oversight in the API implementation.

[EstherPerelman]

@EstherPerelman It does indeed ; the main difference between these two plugins being that mine fails to activate (for testing purposes).
However when failing to activate inside VSCode, it still shows the ViewsWelcome. In Theia, this does not seem to be the case ; which might be an oversight in the API implementation.

You should really open a new issue for that case.. Might be that Theia won't support it..

[clovis-dugue]

Further investigation shows that a "Hello World" plug-in straight from VSCode's generator will have the same issue ; the example provided in the PR still works. I'm opening a new issue.

Thank you for your help!

[davide-sergi]

You need to register a TreeDataProvider which return an empty tree. This is not required for vscode environment.
You can keep same package.json.

I solved with following code:

import * as vscode from 'vscode';

export async function activate(context: vscode.ExtensionContext) { 
  vscode.window.registerTreeDataProvider(
	  "my-view-id",
	  new EmptyTreeDataProvider()
  );
}

export function deactivate() {}

export class EmptyTreeDataProvider implements vscode.TreeDataProvider<any> {
	constructor() {}

	getTreeItem(element: any): vscode.TreeItem {
		return {};
	}

	getChildren(element?: any): Thenable<any[]> {
		return new Promise((resolve) => resolve([]));
	}
}

[tsmaeder]

The contribution point has been implemented, but there remains an issue: #9361