Question

I am making a grid view. It subclasses tableview and lays out multiple subcells (columns) per cell. That’s all working fine.

Now, I need to detect when an individual sub-cell is tapped. I have overriden touchesEnded in the grid view. Is there a way I can take that NSSet of UITouch objects and detect whether it was a touch up inside or some other gesture?

I could write custom code, but it might be hard to get it perfect.

Answer 1

UIControlEvents like UIControlEventTouchUpInside are used with UIControl objects. In a UIView you’ll need to do your own testing.

Now I don’t know how you’ve structured your grid view, or exactly what kind of touches you want to detect, but normally you need to have something like this. This looks for a single tap and what cell was tapped.

- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    if ([touches count] == 1) {
        UITouch * touch = [touches anyObject];
        if ([touch tapCount] == 1) {
            // This is a simple tap
            CGPoint point = [touch locationInView:self.view];
            GridCell * cell = nil;
            for (GridCell * aCell in cells) {
                if (CGRectContainsPoint(aCell.frame, point)) {
                    cell = aCell;
                    break;
                }
            }
            if (cell) {
                // The tap was inside this cell
            }
        }

    }
}