src/vs/workbench/browser/layout.ts/Layout/focusPart
class Layout:	focusPart(part: Parts): void {
		switch (part) {
			case Parts.EDITOR_PART:
				this.editorGroupService.activeGroup.focus();
				break;
			case Parts.PANEL_PART:
				const activePanel = this.panelService.getActivePanel();
				if (activePanel) {
					activePanel.focus();
				}
				break;
			case Parts.SIDEBAR_PART:
				const activeViewlet = this.viewletService.getActiveViewlet();
				if (activeViewlet) {
					activeViewlet.focus();
				}
				break;
			case Parts.ACTIVITYBAR_PART:
				this.activityBarService.focusActivityBar();
				break;
			case Parts.STATUSBAR_PART:
				this.statusBarService.focus();
			default:
				// Title Bar & Banner simply pass focus to container
				const container = this.getContainer(part);
				if (container) {
					container.focus();
				}
		}
	}