src/vs/editor/browser/controller/mouseHandler.ts/MouseDownOperation/_onMouseDownThenMove
class MouseDownOperation:	private _onMouseDownThenMove(e: EditorMouseEvent): void {
		this._lastMouseEvent = e;
		this._mouseState.setModifiers(e);

		const position = this._findMousePosition(e, false);
		if (!position) {
			// Ignoring because position is unknown
			return;
		}

		if (this._mouseState.isDragAndDrop) {
			this._viewController.emitMouseDrag({
				event: e,
				target: position
			});
		} else {
			if (position.type === MouseTargetType.OUTSIDE_EDITOR && (position.outsidePosition === 'above' || position.outsidePosition === 'below')) {
				this._topBottomDragScrolling.start(position, e);
			} else {
				this._topBottomDragScrolling.stop();
				this._dispatchMouse(position, true, NavigationCommandRevealType.Minimal);
			}
		}
	}