Prevent multiple layout attrs for the same object #166
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I've been getting a crash recently when trying to add headers to sections using your layout:
```
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'layout attributes for supplementary item at index path (<NSIndexPath: 0xc000000000000116> {length = 2, path = 1 - 0}) changed from <UICollectionViewLayoutAttributes: 0x6100003e1f00> index path: (<NSIndexPath: 0xc000000000000116> {length = 2, path = 1 - 0}); element kind: (CHTCollectionElementKindSectionHeader); frame = (0 490; 768 20); to <UICollectionViewLayoutAttributes: 0x6080003e1200> index path: (<NSIndexPath: 0xc000000000000116> {length = 2, path = 1 - 0}); element kind: (CHTCollectionElementKindSectionHeader); frame = (0 530; 768 20); without invalidating the layout'
```
What I noticed is that multiple attributes were being generated for the same index path in `layoutAttributesForElementsInRect` so the `UICollectionView` got confused towards which one to use. This fix prevents that from happening.
chiahsien
reviewed
May 23, 2017
| NSMutableArray *attrs = [NSMutableArray array]; | ||
| NSMutableDictionary *cellAttrDict = [NSMutableDictionary dictionary]; | ||
| NSMutableDictionary *supplAttrDict = [NSMutableDictionary dictionary]; | ||
| NSMutableDictionary *decorAttrDict = [NSMutableDictionary dictionary]; |
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Do we really need 3 dictionaries? Or what we need is one dictionary and use attr.indexPath as the key?
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The problem is indexPaths can be the same and collide between each of those three object categories. I actually tried that approach on the first commit but it didn't work because of that. Items were overwritten by decorators or supplemental views and viceversa.
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I've been getting a crash recently when trying to add headers to sections using your layout:
What I noticed is that multiple attributes were being generated for the same index path in
layoutAttributesForElementsInRectso theUICollectionViewgot confused towards which one to use. This fix prevents that from happening.