When you create a output channel without showing it be default , data are not visible in it if you open the output table after.

[STDeslandes]

Bug Description:

My use case is the following one:
I want to logs information in a dedicated channel of the output console, but by default I don't want to show the output console. Then I add logs inside my channel.
But when I want to see the output console, the channel is available and seems selected , but I need to select the channel again in the pick list to see the logs.

Steps to Reproduce:

1. Create an outputchannel but don't use the channel.show().
2. Add logs in this channel.
3. Open the output console, the channel seems selected but the logs are not visible.

What I can see is that the output widget is not refreshed for the following events :
onSelectedChannelChanged
onChannelAdded
But only on
onChannelWasHidden
onChannelWasShown

I corrected the code of OutputChannelManager and OutputWidget to make it work. But I'm not so sure about all the side effects :

getChannel(name: string): OutputChannel {
        const existing = this.channels.get(name);
        if (existing) {
            return existing;
        }

        // We have to register the resource first, because `textModelService#createModelReference` will require it
        // right after creating the monaco.editor.ITextModel.
        // All `append` and `appendLine` will be deferred until the underlying text-model instantiation.
        let resource = this.resources.get(name);
        if (!resource) {
            const uri = OutputUri.create(name);
            const editorModelRef = new Deferred<IReference<MonacoEditorModel>>();
            resource = this.createResource({ uri, editorModelRef });
            this.resources.set(name, resource);
            this.textModelService.createModelReference(uri).then(ref => editorModelRef.resolve(ref));
        }

        const channel = this.createChannel(resource);
        this.channels.set(name, channel);
        this.toDisposeOnChannelDeletion.set(name, this.registerListeners(channel));
       
        if (!this.selectedChannel) {
            this.selectedChannel = channel;
        }
        this.channelAddedEmitter.fire(channel);
        return channel;
    }

Here I moved the this.channelAddedEmitter.fire(channel) after the this.selectedChannel = channel; to be sure that the widget has the right channel to manage.
And for the init of OutputWidget , I added the listener of channel added :

@postConstruct()
    protected init(): void {
        this.toDispose.pushAll([
            this.outputChannelManager.onChannelAdded(() => this.refreshEditorWidget()),
            this.outputChannelManager.onChannelWasHidden(() => this.refreshEditorWidget()),
            this.outputChannelManager.onChannelWasShown(({ preserveFocus }) => this.refreshEditorWidget({ preserveFocus: !!preserveFocus })),
            this.toDisposeOnSelectedChannelChanged,
            this.onStateChangedEmitter,
            this.onStateChanged(() => this.update())
        ]);
        this.refreshEditorWidget();
    }

What is your view on it ?
I can provide the PR if needed.

Additional Information

• Operating System: Ubuntu & Windows
• Theia Version: 1.55.1

[JonasHelming]

@rschnekenbu