src/vs/editor/standalone/browser/accessibilityHelp/accessibilityHelp.ts/AccessibilityHelpWidget/_layout
class AccessibilityHelpWidget:	private _layout(): void {
		let editorLayout = this._editor.getLayoutInfo();

		let w = Math.max(5, Math.min(AccessibilityHelpWidget.WIDTH, editorLayout.width - 40));
		let h = Math.max(5, Math.min(AccessibilityHelpWidget.HEIGHT, editorLayout.height - 40));

		this._domNode.setWidth(w);
		this._domNode.setHeight(h);

		let top = Math.round((editorLayout.height - h) / 2);
		this._domNode.setTop(top);

		let left = Math.round((editorLayout.width - w) / 2);
		this._domNode.setLeft(left);
	}