iPhone：UITableViewController中的触摸点捕获

Question

I want to capture x position of the touch point in UITableViewController . The most simply solution described in the web is UITapGestureRecognizer : enter link description here

But in this case, didSelectRowAtIndexPath are stopped.

How tu use both of the events, or how to get (NSIndexPath *)indexPath parameter inside singleTapGestureCaptured ?

Regards

[edit] I can't answer my question. The solution is:

NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:touchPoint]

Answer 1

I doubt the OP is still waiting for an answer, but for the benefit of future searchers:

You can grab the touch event inside the cell, act, then either discard it, or pass it up the chain:

@interface MyCell : UITableViewCell
// ...
@end

@implementation MyCell
// ...

- (void) touchesBegan: (NSSet*) touches withEvent: (UIEvent*) event
{
    UITouch* touch = [[event allTouches] anyObject];
    CGPoint someLocation = [touch locationInView: someView];
    CGPoint otherLocation = [touch locationInView: otherView];
    if ([someView pointInside: someLocation: withEvent: event])
    {
        // The touch was inside someView. Do some stuff, 
        // but don't invoke tableView:didSelectRowAtIndexPath: on the delegate.
    }
    else if ([otherView pointInside: otherLocation: withEvent: event])
    {
        // The touch was inside otherView. Do other stuff.

        // Send the touch on for processing, and tableView:didSelectRowAtIndexPath: handling.
        [super touchesBegan: touches withEvent: event];
    }
    else
    {
        // Send the touch on for processing, and tableView:didSelectRowAtIndexPath: handling.
        [super touchesBegan: touches withEvent: event];
    }
}
@end

Answer 2

The OP posted the essence of his answer, and it worked. Here are the details. In my case, I just needed to know if the touch was in the left or the right half of the cell.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = ...;

    // Do this once for each cell when setting up the new cells...
    UITapGestureRecognizer *cellTapGestureRecognizer = [[UITapGestureRecognizer alloc]
                                                        initWithTarget:self
                                                        action:@selector(cellTapGesture:)];
    [cell.contentView addGestureRecognizer:cellTapGestureRecognizer];

    // ...
    return cell;
}

Process the touch or pass it on to didSelectRowAtIndexPath:

- (void)cellTapGesture:(UITapGestureRecognizer *)sender
{
    CGPoint touchPoint = [sender locationInView:self.tableView];
    NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:touchPoint];
    rightBOOL = ( touchPoint.x > self.tableView.contentSize.width/2 ); // iVar

    // The UITapGestureRecognizer prevents didSelectRowAtIndexPath, so procees
    // the touch here.  Or, since only one row can be selected at a time,
    // call the old code in didSelectRowAtIndexPath and let it access
    // rightBOOL as an iVar (or pass it some other way).  Anyway, x location is known.
    [self tableView:self.tableView didSelectRowAtIndexPath:indexPath];
}

Answer 3

You can't add a gesture recognizer without messing up the table view's handling of touch events.

You don't say exactly what you're trying to achieve so it's not possible to recommend an alternative. Anything related to capturing touch events is going to be complicated: the responder chain is complicated.

The straightforward way would seem to be overload didSelectRowAtIndexPath in a child class and do whatever you want before calling super ...