A couple performance enhancements

CHGridLayout/CHGridLayout.h

@@ -33,12 +33,13 @@ static CHSectionRange CHSectionRangeMake(int start, int end){
 	NSMutableArray		*_index;
 	NSMutableArray		*_sectionTitles;
 
-	CGFloat				gridWidth;
-	CGFloat				contentHeight;
+	float				gridWidth;
+	float				contentHeight;
 	CGSize				padding;
 	int					perLine;
-	CGFloat				rowHeight;
-	CGFloat				sectionTitleHeight;
+	float				rowHeight;
+	float				pixelMargin;
+	float				sectionTitleHeight;
 	BOOL				dynamicallyResizeTilesToFillSpace; 
 }
 

CHGridLayout/CHGridLayout.m

@@ -37,6 +37,11 @@ - (void)dealloc{
 
 #pragma mark setters
 
+- (void)setRowHeight:(CGFloat)f{
+	rowHeight = f;
+	pixelMargin = f * 2;
+}
+
 - (void)setSections:(int)sections{
 	[self clearData];
 
@@ -123,13 +128,12 @@ - (void)updateLayout{
 - (int)sectionIndexForContentOffset:(CGFloat)offset{
 	int sectionIndex = 0;
 
-	int i;
-	for(i = 0; i < _sectionTitles.count; i++){
-		CHGridLayoutSection *section = [_sectionTitles objectAtIndex:i];
+	for(CHGridLayoutSection *section in _sectionTitles){
 		if(section.yCoordinate <= offset && offset > 0){
-			sectionIndex = i;
+			sectionIndex = section.section;
 		}
 	}
+
 	return sectionIndex;
 }
 
@@ -142,7 +146,6 @@ - (CHSectionRange)sectionRangeForContentOffset:(CGFloat)offset andHeight:(CGFloa
 	int end = 0;
 
 	BOOL firstRun = YES;
-	float pixelMargin = rowHeight * 2;
 	int currentSection = [self sectionIndexForContentOffset:offset];
 
 	for(CHGridLayoutSection *section in _sectionTitles){
@@ -168,9 +171,7 @@ - (CGRect)tileFrameForIndexPath:(CHGridIndexPath)indexPath{
 }
 
 - (CHGridIndexRange)rangeOfVisibleIndexesForContentOffset:(CGFloat)offset andHeight:(CGFloat)height{
-	float pixelMargin = rowHeight * 2;
 	BOOL first = NO;
-
 	CHGridIndexRange indexRange = {CHGridIndexPathMake(0, 0),CHGridIndexPathMake(0, 0)};
 
 	for(NSMutableArray *sectionArray in _index){
@@ -185,8 +186,6 @@ - (CHGridIndexRange)rangeOfVisibleIndexesForContentOffset:(CGFloat)offset andHei
 		}
 	}
 
-	first = NO;
-
 	return indexRange;
 }
 

CHGridView.m

@@ -16,7 +16,6 @@ - (void)loadVisibleSectionTitlesForSectionRange:(CHSectionRange)range;
 - (void)loadVisibleTilesForIndexPathRange:(CHGridIndexRange)range;
 - (void)loadVisibleTileForIndexPath:(CHGridIndexPath)indexPath;
 - (void)reuseHiddenTiles;
-- (void)reuseTile:(CHTileView *)tile;
 - (void)removeSectionTitleNotInRange:(CHSectionRange)range;
 - (void)removeAllSubviews;
 - (NSMutableArray *)tilesForSection:(int)section;
@@ -178,43 +177,38 @@ - (void)loadVisibleTileForIndexPath:(CHGridIndexPath)indexPath{
 }
 
 - (void)reuseHiddenTiles{
-	NSMutableArray *toReuse = [NSMutableArray array];
+	NSMutableArray *toReuse = [[NSMutableArray alloc] init];
 
 	CGRect b = self.bounds;
 	CGFloat contentOffsetY = self.contentOffset.y;
 	float pixelMargin = rowHeight * 2;
+	int maxReusable = [self maxNumberOfReusableTiles];
 
 	for(CHTileView *tile in visibleTiles){
 		if(tile.frame.origin.y + tile.frame.size.height < (contentOffsetY - pixelMargin) || tile.frame.origin.y > (contentOffsetY + b.size.height + pixelMargin)){
 			[toReuse addObject:tile];
+			if(reusableTiles.count < maxReusable) [reusableTiles addObject:tile];
 		}
 	}
 
-	for(CHTileView *tile in toReuse){
-		[self reuseTile:tile];
-	}
-}
-
-- (void)reuseTile:(CHTileView *)tile{
-	if(reusableTiles.count < [self maxNumberOfReusableTiles]) [reusableTiles addObject:tile];
+	[toReuse makeObjectsPerformSelector:@selector(removeFromSuperview)];
+	[visibleTiles removeObjectsInArray:toReuse];
 
-	[tile removeFromSuperview];
-	[visibleTiles removeObject:tile];
+	[toReuse release];
 }
 
 - (void)removeSectionTitleNotInRange:(CHSectionRange)range{
-	NSMutableArray *toDelete = [NSMutableArray array];
+	NSMutableArray *toDelete = [[NSMutableArray alloc] init];
 
 	for (CHSectionTitleView *title in visibleSectionTitles) {
 		if(title.section < range.start || title.section > range.end){
 			[toDelete addObject:title];
 		}
 	}
 
-	for(CHSectionTitleView *title in toDelete){
-		[title removeFromSuperview];
-		[visibleSectionTitles removeObject:title];
-	}
+	[toDelete makeObjectsPerformSelector:@selector(removeFromSuperview)];
+	[visibleSectionTitles removeObjectsInArray:toDelete];
+	[toDelete release];
 }
 
 - (void)reloadData{
@@ -439,8 +433,6 @@ - (void)calculateSectionTitleOffset{
 				if((offset + sectionTwo.frame.size.height) >= sectionTwo.yCoordinate){
 					f.origin.y = sectionTwo.yCoordinate - sectionTwo.frame.size.height;
 				}
-
-				//[self bringSubviewToFront:sectionTwo];
 			}
 		}else{
 			f.origin.y = title.yCoordinate;

README.markdown

@@ -47,7 +47,7 @@ If you disable scrolling with `setScrollingEnabled`, you can probably use this a
 
 ###Roadmap (roughly in order):
 
-- Match speed and performance found in iPhone's Photos app grid view
+- Match or exceed speed and performance found in iPhone's Photos app grid view
 - More UITableView cloning, like scrolling to a tile at a specific indexPath
 - Tile labels
 - Flexible per-line setting (maybe a range?)