Introduce 'window.withProgress' API endpoint

[vinokurig]

fixes #2802 Introduce 'window.withProgress' API endpoint

This is needed to run vsCode Kubernetes plugin in Theia. The plugin calls window.withProgress method

[akosyakov]

@AlexTugarev please review core and messages extensions

[AlexTugarev]

I'm going to review and test this PR today.

[AlexTugarev]

we need to synchronize this feature with https://github.com/theia-ide/theia/pull/2461/files somehow. it looks competing at first appearance, but I think there are different use cases in mind.

[AlexTugarev]

I reviewed core/message parts, and would like to do a next iteration. Currently I don't see this working. There is no caller in FE, and jsonrpc won't work. Proposal for changes to the API of MessageService coming next...

[AlexTugarev]

@vinokurig, could your try with a different progress API in the core? In the end it should also work for progress reports from BE.

Maybe something as simple as this:

// an alternative to `newProgress` could be a token factory as function
newProgress(): Promise<ProgressToken> {
    return Promise.resolve({ id: 'GENERATED-UUID' }); 
}
reportProgress(progress: ProgressToken, update: ProgressUpdate): Promise<void> {
    return this.client.reportProgress(progress, update);
}

interface ProgressToken {
    id: string;
}

interface ProgressUpdate {
    value: string;
    requestCancellation: boolean;
}

[vinokurig]

@AlexTugarev Thank you for your feedback, I am going on vocation, so I will follow it in 3 weeks.

[vinokurig]

@AlexTugarev Fixed all your comments, could you please take a look

[benoitf]

hello @AlexTugarev did you were able to review this PR ?

[AlexTugarev]

@benoitf, I'll provide a sample for the core part as mentioned previously. The current implementation won't work for the BE case, as callbacks cannot be passed via jsonrpc. Just synchronized with @vinokurig via PM on this.

[vinokurig]

@AlexTugarev So what will be the next step?, Is it ready for merge now?

Changes applied.

[vinokurig]

@AlexTugarev Could you please review my last changes

[AlexTugarev]

LGTM! @vinokurig, please squash the commits. Let's wait for CI builds.

[vinokurig]

@AlexTugarev looks like all CI builds have passed successfully, can we merge it?

[AlexTugarev]

LGTM!