[tasks] display message in terminal when executing a task

[vince-fugnitto]

Description

The current message-service indicating when a task has been started / stopped can become quite annoying especially when multiple tasks are executed. Instead, we should adopt a more elegant solution and align with vscode which displays task information directly in the terminal
when started / stopped.

[elaihau]

This requires the task code having access to the XTerm.

Given that Xterm is accessible from the TerminalWidgetImpl

theia/packages/terminal/src/browser/terminal-widget-impl.ts

Lines 236 to 238 in c4b4d39

	getTerminal(): Xterm.Terminal {
	return this.term;
	}

but not exposed by the interface

theia/packages/terminal/src/browser/base/terminal-widget.ts

Lines 23 to 50 in c4b4d39

	export abstract class TerminalWidget extends BaseWidget {
	abstract processId: Promise<number>;
	/**
	* Start terminal and return terminal id.
	* @param id - terminal id.
	*/
	abstract start(id?: number): Promise<number>;
	/**
	* Send text to the terminal server.
	* @param text - text content.
	*/
	abstract sendText(text: string): void;
	abstract onDidOpen: Event<void>;
	/**
	* Event which fires when terminal did closed. Event value contains closed terminal widget definition.
	*/
	abstract onTerminalDidClose: Event<TerminalWidget>;
	/**
	* Cleat terminal output.
	*/
	abstract clearOutput(): void;
	}

could I simply add getTerminal(): Xterm.Terminal to the TerminalWidget interface ? @akosyakov

Thank you !

[vince-fugnitto]

@elaihau I was able to do a POC by simply sending text to the terminal, I think it's enough? Did you mean it's difficult right now to do it for an existing terminal? (before it's created)

[elaihau]

@vince-fugnitto I managed sending texts to the terminal. atm I am trying to figure out how to send text the terminal at the right timing.

I tried to use

theia/packages/task/src/common/task-watcher.ts

Line 37 in c4b4d39

onDidStartTaskProcess(event: TaskInfo): void {

and it didn't work at all. This must be a bug .

[elaihau]

Finishing up this one requires the change in #6836 to get merged.