在UITableView中用手指在屏幕上绘制

Question

I am following this excellent small tutorial about drawing on screen in the layer of a UIView (subclass). http://spritebandits.wordpress.com/ It just works.

There is just one thing. I placed this view as subview of a UITableViewCell which, naturally, is displayed as part of a UITableView. I guess I would have the same issue when I would place it within an UIScrollView. (UITableView inherits from UIScrollView anyway)

Touches are triggered by my painting view as long as their related movement is horizontal. As soon as I move the finger kinda vertical, even partly, then the UITableView takes over and scrolls the table.

Is there any proper way of stopping the Table to taike control of the touches while the touch is actually within my view?

If it is of importance: I am using storyboard. The cell is a prototype cell with its own subclass of UITableViewCell.

Answer 1

I've implemented this using the same class "Canvas" you're saying and also inside a UITableViewCell. But I didn't use the entire cell for drawing, only a UIView inside of the UITableView as a subview.

I reached the whole user experience by activating and deactivating the UITableView scrolling when that UIView (subview of the cell where I allow the drawing) fires touchesBegan or touchesEnded. So when they touch/move inside the UIView, they're drawing. When it's outside, they're scrolling. So they can't scroll on the UIView because they will be drawing.

The problem in your case is that since the whole cell is the view for drawing, the user cannot scroll in this concrete cell because it's the drawing one.

Hope this will help.

Answer 2

I dont have an answer for that. But there is essentially a work around.

You could get the user in to a drawing mode, where the scrolling for a UItableviewcell is disabled and then

once the user is done with drawing, you could enable scrolling again.

Inclusion of a button anywhere on the screen would help you switch modes.