CODEWITHSUNDEEP
iosobjective-cuicollectionview
Typewriter
Typewriter

Reputation: 1246

Why does UICollectionView not scroll with UIButtons inside it?

Given the following scenario:

There is a UICollectionView containing UICollectionViewCells (naturally). Each UICollectionViewCell contains a UIButton with a target action associated with it.

Problem:

The UICollectionView does not scroll upon swipe/drag. The UIButtons instead intercept touches, and make it difficult to drag the UICollectionView.

Additionally:

The UIButtons are set to UIControlEventTouchUpInside The UICollectionView is set to canCancelTouches = YES

**Why are the UIButtons inside UICollectionViewCells preventing the UICollectionView from responding to drag/swipe gestures? **

Upvotes: 1

Views: 686

Answers (1)

Typewriter
Typewriter

Reputation: 1246

The reason that the UICollectionView doesn't scroll properly is because the UIButtons are intercepting and rerouting the responder chain.

Solution:

Remove the UIButtons from the UICollectionViewCell.
Instead use the delegate method for UICollectionViewDelegate :

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath

Explanation:

When we added a UIButton to the UICollectionViewCell, we were thinking that the best way to capture a tap was to add a button to the cell. However, by adding the UIButton, we broke the responder chain.

We don't need the button inside the UICollectionViewCell, because the UICollectionViewCell already detects tap events with it's delegate method :

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath

Use the provided method to detect taps on a collection cell, and replace the UIButtons with UIImageView-s or similar.

We don't need the event handing of a button when working with collection cells.

Upvotes: 1

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