Bugfix for "Get wrong minimumInteritemSpacing when have multi-section"

Author: jinyu

Example/Example/ExampleViewController.m

@@ -58,12 +58,12 @@ - (void)viewWillDisappear:(BOOL)animated
 
 - (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
 {
-    return 1;
+    return 2;
 }
 
 - (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
 {
-    return 100;
+    return section == 0 ? 20 : 80;
 }
 
 - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
@@ -86,7 +86,7 @@ - (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollection
 
 - (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section
 {
-    return 5;
+    return section == 0 ? 15 : 5;
 }
 
 - (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section

UICollectionViewLeftAlignedLayout/UICollectionViewLeftAlignedLayout.m

@@ -85,17 +85,17 @@ - (UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSInde
     }
 
     CGRect frame = currentItemAttributes.frame;
-    frame.origin.x = previousFrameRightPoint + [self evaluatedMinimumInteritemSpacingForItemAtIndex:indexPath.row];
+    frame.origin.x = previousFrameRightPoint + [self evaluatedMinimumInteritemSpacingForSectionAtIndex:indexPath.section];
     currentItemAttributes.frame = frame;
     return currentItemAttributes;
 }
 
-- (CGFloat)evaluatedMinimumInteritemSpacingForItemAtIndex:(NSInteger)index
+- (CGFloat)evaluatedMinimumInteritemSpacingForSectionAtIndex:(NSInteger)section
 {
     if ([self.collectionView.delegate respondsToSelector:@selector(collectionView:layout:minimumInteritemSpacingForSectionAtIndex:)]) {
         id<UICollectionViewDelegateLeftAlignedLayout> delegate = (id<UICollectionViewDelegateLeftAlignedLayout>)self.collectionView.delegate;
 
-        return [delegate collectionView:self.collectionView layout:self minimumInteritemSpacingForSectionAtIndex:index];
+        return [delegate collectionView:self.collectionView layout:self minimumInteritemSpacingForSectionAtIndex:section];
     } else {
         return self.minimumInteritemSpacing;
     }