How to improve UITableView scrolling performance? What I am I missing? - ios

Question

I know the basics, what not to do in cellForRowAtIndexPath:, that may cause scrolling performance to be hindered. And I believe I have followed those rules, which is why I have gotten this far. My UITableView is horrible at scrolling, does so very well, but there are times where it stutters for split seconds to seconds, noticeable when it starts to slow down a bit.
Without revealing too much of my code, what here am I doing that could be causing this. I think I have gone over everything and eliminated something that could be causing it, but the problem persists. I feel as if it is something that is obvious and I am overlooking. Help is tremendously appreciated.
Thank you.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *simpleTableIdentifier = #"tweetCell";
TweetCell *cell = (TweetCell *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
NSDictionary *tweet = _tweets[indexPath.row];
NSString *username = tweet[#"username"];
CGFloat tweetHeight = [tweet[#"contentHeight"] floatValue];
cell.tweet.frame = ({
CGRect frame = cell.tweet.frame;
frame.size.height = tweetHeight + 2;
frame.origin.y = cell.bounds.size.height / 2 - frame.size.height / 2;
frame;
});
cell.tweet.attributedText = tweet[#"attributedText"];
cell.imageView.image = [_profilePhotos[username] valueForKey:#"image"];
cell.date.text = tweet[#"dateString"];
if (tweet[#"media"]) {
cell.tweetImage.image = tweet[#"media"];
cell.tweetImage.hidden = NO;
} else {
cell.tweetImage.image = nil;
cell.tweetImage.hidden = YES;
}
NSMutableAttributedString *attributedText = [tweet[#"attributedText"] mutableCopy];
if ([[NSUserDefaults standardUserDefaults] boolForKey:#"useDynamicTextSize"]) {
UIFont *font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
if (cell.tweet.font.pointSize != font.pointSize) {
cell.tweet.font = [UIFont fontWithName:#"HelveticaNeue-Light" size:font.pointSize];
cell.username.font = [UIFont fontWithName:#"HelveticaNeue-Light" size:font.pointSize];
cell.date.font = [UIFont fontWithName:#"HelveticaNeue-Light" size:font.pointSize];
[attributedText addAttribute:NSFontAttributeName value:[UIFont fontWithName:#"HelveticaNeue-Light" size:font.pointSize] range:NSMakeRange(0, attributedText.length)];
} else {
[attributedText addAttribute:NSFontAttributeName value:[UIFont fontWithName:#"HelveticaNeue-Light" size:cell.tweet.font.pointSize] range:NSMakeRange(0, attributedText.length)];
}
} else {
[attributedText addAttribute:NSFontAttributeName value:[UIFont fontWithName:#"HelveticaNeue-Light" size:17] range:NSMakeRange(0, attributedText.length)];
}
cell.tweet.attributedText = attributedText;
cell.username.adjustsFontSizeToFitWidth = YES;
NSString *color = [[NSUserDefaults standardUserDefaults] objectForKey:#"color"];
if ([color isEqualToString:#"automatic"]) {
color = ([[UIScreen mainScreen] brightness] <= .5) ? #"black" : #"white";
}
[cell.imageView.layer setMasksToBounds:YES];
[cell.imageView.layer setCornerRadius:5];
[cell.imageView.layer setBorderColor:[[UIColor colorWithRed:0/255.0 green:0/255.0 blue:0/255.0 alpha:0.55] CGColor]];
[cell.imageView.layer setBorderWidth:0.5];
[cell.tweetImage.layer setMasksToBounds:YES];
[cell.tweetImage.layer setCornerRadius:5];
[cell.tweetImage.layer setBorderColor:[[UIColor colorWithRed:0/255.0 green:0/255.0 blue:0/255.0 alpha:0.55] CGColor]];
[cell.tweetImage.layer setBorderWidth:0.65];
// [UIView beginAnimations:nil context:nil];
// [UIView setAnimationDuration:0.25];
// [UIView setAnimationDelegate:self];
if ([color isEqualToString: #"white"]) {
cell.tweet.textColor =[UIColor blackColor];
cell.date.textColor = [UIColor blackColor];
cell.username.textColor = [UIColor blackColor];
cell.backgroundColor = [UIColor whiteColor];
cell.tweet.linkTextAttributes = #{NSForegroundColorAttributeName:[UIColor blueColor]};
[tweet[#"attributedText"] addAttribute:NSForegroundColorAttributeName
value:[UIColor blackColor]
range:NSMakeRange(0, cell.tweet.attributedText.length)];
} else /*if ([color isEqualToString: #"black"])*/ {
cell.tweet.textColor = [UIColor whiteColor];
cell.date.textColor = [UIColor whiteColor];
cell.username.textColor = [UIColor whiteColor];
cell.backgroundColor = [UIColor colorWithRed:52/255.0 green:52/255.0 blue:52/255.0 alpha:1];
cell.tweet.linkTextAttributes = #{NSForegroundColorAttributeName: [UIColor colorWithRed:0.66 green:0.82 blue:1 alpha:1]};
[tweet[#"attributedText"] addAttribute:NSForegroundColorAttributeName
value:[UIColor whiteColor]
range:NSMakeRange(0, cell.tweet.attributedText.length)];
}
// [UIView commitAnimations];
if (_retweets[_tweets[indexPath.row][#"id"]]) {
if ([color isEqualToString: #"white"]) {
cell.backgroundColor = [UIColor colorWithRed:0.945 green:0.945 blue:0.945 alpha:1];
} else if ([color isEqualToString: #"black"]) {
cell.backgroundColor = [UIColor colorWithRed:0.114 green:0.114 blue:0.114 alpha:1];
}
// cell.separatorInset = UIEdgeInsetsMake(0, 0, 0, cell.bounds.size.width);
} else {
if ([color isEqualToString: #"white"]) {
[cell setBackgroundColor:[UIColor whiteColor]];
} else if ([color isEqualToString: #"black"]) {
cell.backgroundColor = [UIColor colorWithRed:52/255.0 green:52/255.0 blue:52/255.0 alpha:1];
}
// cell.separatorInset = UIEdgeInsetsMake(0, 80, 0, 0);
}
cell.tweet.tag = indexPath.row;
cell.tweetImage.userInteractionEnabled = YES;
cell.tweet.frame = ({
CGRect frame = cell.tweet.frame;
frame.size.height = tweetHeight + 2;
frame.origin.y = cell.bounds.size.height / 2 - frame.size.height / 2;
if (tweet[#"media"]) {
frame.size.width = 164;
} else {
frame.size.width = 224;
}
frame;
});
cell.tweet.delegate = self;
UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(retweetTweet:)];
doubleTap.numberOfTapsRequired = 2;
[cell addGestureRecognizer:doubleTap];
[cell.tweet addGestureRecognizer:doubleTap];
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(showImage:)];
tap.numberOfTapsRequired = 1;
[cell.tweetImage addGestureRecognizer:tap];
UITapGestureRecognizer *tapToViewProfile = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(viewProfile:)];
tap.numberOfTapsRequired = 1;
[cell.imageView setUserInteractionEnabled:YES];
[cell.imageView addGestureRecognizer:tapToViewProfile];
return cell;
}
TweetCell.m:
//
// TweetCell.m
// Khabara
//
// Created by Isa Ranjha on 3/26/14.
// Copyright (c) 2014 Isa Ranjha. All rights reserved.
//
#import "TweetCell.h"
#implementation TweetCell
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
// Initialization code
}
return self;
}
- (void)layoutSubviews {
[super layoutSubviews];
//self.imageView.frame = CGRectMake(self.imageView.frame.origin.x,self.imageView.frame.origin.y,45,45);
self.imageView.frame = ({
CGRect frame = self.imageView.frame;
frame.size = CGSizeMake(48, 48);
frame.origin.y = self.bounds.size.height / 2 - frame.size.height / 2;
frame;
});
self.imageView.backgroundColor = [UIColor whiteColor];
}
- (void)awakeFromNib
{
//_tweet.numberOfLines = 0;
_tweet.textContainerInset = UIEdgeInsetsZero;
_tweet.canCancelContentTouches = YES;
// _tweet.autoresizingMask = (UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleTopMargin);
}
- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
[super setSelected:selected animated:animated];
// Configure the view for the selected state
}
#end

Answer 1

Do not use the set layer corner radius on cell. It make the problem. Instead of this, you better create a frame .png image.