Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Update PSCollectionView.m #26

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Update PSCollectionView.m #26

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
58 changes: 25 additions & 33 deletions PSCollectionView.m
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@

#import "PSCollectionView.h"

#define kMargin 8.0
#define kMargin 5.0

static inline NSString * PSCollectionKeyForIndex(NSInteger index) {
return [NSString stringWithFormat:@"%d", index];
Expand Down Expand Up @@ -152,7 +152,6 @@ - (id)initWithFrame:(CGRect)frame {

self.lastOffset = 0.0;
self.offsetThreshold = floorf(self.height / 4.0);

self.colWidth = 0.0;
self.numCols = 0;
self.numColsPortrait = 0;
Expand All @@ -163,6 +162,9 @@ - (id)initWithFrame:(CGRect)frame {
self.visibleViews = [NSMutableDictionary dictionary];
self.viewKeysToRemove = [NSMutableArray array];
self.indexToRectMap = [NSMutableDictionary dictionary];

self.verticalMargin = kMargin;
self.horizontalMargin = kMargin;
}
return self;
}
Expand Down Expand Up @@ -197,10 +199,8 @@ - (void)layoutSubviews {
} else {
// Recycles cells
CGFloat diff = fabsf(self.lastOffset - self.contentOffset.y);

if (diff > self.offsetThreshold) {
self.lastOffset = self.contentOffset.y;

[self removeAndAddCellsIfNecessary];
}
}
Expand All @@ -211,29 +211,24 @@ - (void)layoutSubviews {
- (void)relayoutViews {
self.numCols = UIInterfaceOrientationIsPortrait(self.orientation) ? self.numColsPortrait : self.numColsLandscape;

// Reset all state
[self.visibleViews enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
PSCollectionViewCell *view = (PSCollectionViewCell *)obj;
[self enqueueReusableView:view];
}];
[self.visibleViews removeAllObjects];
[self.viewKeysToRemove removeAllObjects];
// Reset all state
[self.indexToRectMap removeAllObjects];

// This is where we should layout the entire grid first
NSInteger numViews = [self.collectionViewDataSource numberOfRowsInCollectionView:self];

CGFloat totalHeight = 0.0;
CGFloat top = kMargin;
CGFloat top = self.verticalMargin;

// Add headerView if it exists
if (self.headerView) {
top = self.headerView.top;
self.headerView.width = self.width;
[self addSubview:self.headerView];
top += self.headerView.height;
if (self.headerView.superview == nil)
[self addSubview:self.headerView];
top = top + self.headerView.height + self.verticalMargin;
}

if (numViews > 0) {
// This array determines the last height offset on a column
NSMutableArray *colOffsets = [NSMutableArray arrayWithCapacity:self.numCols];
Expand All @@ -242,10 +237,10 @@ - (void)relayoutViews {
}

// Calculate index to rect mapping
self.colWidth = floorf((self.width - kMargin * (self.numCols + 1)) / self.numCols);
self.colWidth = floorf((self.width - self.horizontalMargin * (self.numCols + 1)) / self.numCols);

for (NSInteger i = 0; i < numViews; i++) {
NSString *key = PSCollectionKeyForIndex(i);

// Find the shortest column
NSInteger col = 0;
CGFloat minHeight = [[colOffsets objectAtIndex:col] floatValue];
Expand All @@ -257,8 +252,8 @@ - (void)relayoutViews {
minHeight = colHeight;
}
}
CGFloat left = kMargin + (col * kMargin) + (col * self.colWidth);

CGFloat left = self.horizontalMargin + (col * self.horizontalMargin) + (col * self.colWidth);
CGFloat top = [[colOffsets objectAtIndex:col] floatValue];
CGFloat colHeight = [self.collectionViewDataSource collectionView:self heightForRowAtIndex:i];

Expand All @@ -268,8 +263,8 @@ - (void)relayoutViews {
[self.indexToRectMap setObject:NSStringFromCGRect(viewRect) forKey:key];

// Update the last height offset for this column
CGFloat heightOffset = colHeight > 0 ? top + colHeight + kMargin : top;
CGFloat heightOffset = colHeight > 0 ? top + colHeight + self.verticalMargin : top;

[colOffsets replaceObjectAtIndex:col withObject:[NSNumber numberWithFloat:heightOffset]];
}

Expand All @@ -284,7 +279,8 @@ - (void)relayoutViews {
if (self.footerView) {
self.footerView.top = totalHeight;
self.footerView.width = self.width;
[self addSubview:self.footerView];
if (self.footerView.superview == nil)
[self addSubview:self.footerView];
totalHeight += self.footerView.height;
}

Expand All @@ -304,25 +300,23 @@ - (void)removeAndAddCellsIfNecessary {

if (numViews == 0) return;

// NSLog(@"diff: %f, lastOffset: %f", diff, self.lastOffset);

// Find out what rows are visible
CGRect visibleRect = CGRectMake(self.contentOffset.x, self.contentOffset.y, self.width, self.height);
visibleRect = CGRectInset(visibleRect, 0, -1.0 * self.offsetThreshold);

// Remove all rows that are not inside the visible rect
[self.visibleViews enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
PSCollectionViewCell *view = (PSCollectionViewCell *)obj;
CGRect viewRect = view.frame;
if (!CGRectIntersectsRect(visibleRect, viewRect)) {
if (!CGRectIntersectsRect(visibleRect, viewRect) || (PSCollectionIndexForKey(key) >= numViews)) {
[self enqueueReusableView:view];
[self.viewKeysToRemove addObject:key];
}
}];

[self.visibleViews removeObjectsForKeys:self.viewKeysToRemove];
[self.viewKeysToRemove removeAllObjects];

if ([self.visibleViews count] == 0) {
topIndex = 0;
bottomIndex = numViews;
Expand All @@ -336,24 +330,21 @@ - (void)removeAndAddCellsIfNecessary {
return (NSComparisonResult)NSOrderedSame;
}
}];

topIndex = [[sortedKeys objectAtIndex:0] integerValue];
bottomIndex = [[sortedKeys lastObject] integerValue];

topIndex = MAX(0, topIndex - (bufferViewFactor * self.numCols));
bottomIndex = MIN(numViews, bottomIndex + (bufferViewFactor * self.numCols));
}
// NSLog(@"topIndex: %d, bottomIndex: %d", topIndex, bottomIndex);

// Add views
for (NSInteger i = topIndex; i < bottomIndex; i++) {
NSString *key = PSCollectionKeyForIndex(i);
CGRect rect = CGRectFromString([self.indexToRectMap objectForKey:key]);

// If view is within visible rect and is not already shown
if (![self.visibleViews objectForKey:key] && CGRectIntersectsRect(visibleRect, rect)) {
// Only add views if not visible
PSCollectionViewCell *newCell = [self.collectionViewDataSource collectionView:self cellForRowAtIndex:i];
newCell.frame = CGRectFromString([self.indexToRectMap objectForKey:key]);
newCell.frame = rect;
[self addSubview:newCell];

// Setup gesture recognizer
Expand All @@ -367,6 +358,7 @@ - (void)removeAndAddCellsIfNecessary {
[self.visibleViews setObject:newCell forKey:key];
}
}

}

#pragma mark - Reusing Views
Expand Down