src/vs/editor/browser/controller/mouseHandler.ts/MouseDownOperation/_findMousePosition
class MouseDownOperation:	private _findMousePosition(e: EditorMouseEvent, testEventTarget: boolean): IMouseTarget | null {
		const positionOutsideEditor = this._getPositionOutsideEditor(e);
		if (positionOutsideEditor) {
			return positionOutsideEditor;
		}

		const t = this._createMouseTarget(e, testEventTarget);
		const hintedPosition = t.position;
		if (!hintedPosition) {
			return null;
		}

		if (t.type === MouseTargetType.CONTENT_VIEW_ZONE || t.type === MouseTargetType.GUTTER_VIEW_ZONE) {
			const newPosition = this._helpPositionJumpOverViewZone(t.detail);
			if (newPosition) {
				return MouseTarget.createViewZone(t.type, t.element, t.mouseColumn, newPosition, t.detail);
			}
		}

		return t;
	}