src/vs/workbench/contrib/files/browser/views/explorerView.ts/ExplorerView/onFocusChanged
class ExplorerView:	private onFocusChanged(elements: ExplorerItem[]): void {
		const stat = elements && elements.length ? elements[0] : undefined;
		this.setContextKeys(stat);

		if (stat) {
			const enableTrash = this.configurationService.getValue<IFilesConfiguration>().files.enableTrash;
			const hasCapability = this.fileService.hasCapability(stat.resource, FileSystemProviderCapabilities.Trash);
			this.resourceMoveableToTrash.set(enableTrash && hasCapability);
		} else {
			this.resourceMoveableToTrash.reset();
		}

		const compressedNavigationController = stat && this.renderer.getCompressedNavigationController(stat);

		if (!compressedNavigationController) {
			this.compressedFocusContext.set(false);
			return;
		}

		this.compressedFocusContext.set(true);
		this.updateCompressedNavigationContextKeys(compressedNavigationController);
	}