src/vs/base/browser/ui/tree/abstractTree.ts/FindController/open
class FindController:	open(): void {
		if (this.widget) {
			this.widget.focus();
			this.widget.select();
			return;
		}

		this.mode = this.tree.options.defaultFindMode ?? TreeFindMode.Highlight;
		this.widget = new FindWidget(this.view.getHTMLElement(), this.tree, this.contextViewProvider, this.mode, this.options);
		this.enabledDisposables.add(this.widget);

		this.widget.onDidChangeValue(this.onDidChangeValue, this, this.enabledDisposables);
		this.widget.onDidChangeMode(mode => this.mode = mode, undefined, this.enabledDisposables);
		this.widget.onDidDisable(this.close, this, this.enabledDisposables);

		this.widget.layout(this.width);
		this.widget.focus();

		this.widget.value = this.previousPattern;
		this.widget.select();

		this._onDidChangeOpenState.fire(true);
	}