infinite carousel with objective-c - objective-c

Question

I'm facing 2 problems with my code and i would like to see if somebody can help me to fix it?
here is my code:
#import "ViewController.h"
#interface ViewController () {
#private NSInteger index;
#private NSInteger iterations;
#private UIButton* buttons[6];
#private CGPoint centers[6];
#private CGRect bounds[6];
#private CGFloat opacities[6];
#private CGFloat opacitieOffsets[6];
#private CGPoint centerOffsets[6];
#private CGRect boundOffsets[6];
#private NSString* titles[6];
}
#property (strong, nonatomic) NSTimer *timer;
#end
#implementation ViewController
#synthesize Button1;
#synthesize Button2;
#synthesize Button3;
#synthesize Button4;
#synthesize Button5;
#synthesize Button6;
#synthesize TitleLabel;
- (void)viewDidLoad
{
[super viewDidLoad];
buttons[0] = Button1;
titles[0] = #"btnTitle1";
buttons[1] = Button2;
titles[1] = #"btnTitle2";
buttons[2] = Button3;
titles[2] = #"btnTitle3";
buttons[3] = Button4;
titles[3] = #"btnTitle4";
buttons[4] = Button5;
titles[4] = #"btnTitle5";
buttons[5] = Button6;
titles[5] = #"btnTitle6";
for (NSInteger i = 0; i < 6; i++)
{
centers[i] = buttons[i].center;
bounds[i] = buttons[i].bounds;
opacities[i] = buttons[i].alpha;
}
}
- (void)viewDidUnload
{
[self stopAnimation];
[self setButton1:nil];
[self setButton2:nil];
[self setButton3:nil];
[self setButton4:nil];
[self setButton5:nil];
[self setButton6:nil];
[self setTitleLabel:nil];
[super viewDidUnload];
}
/////////////////////////////////////////////////////
- (IBAction)swipeLeft:(UISwipeGestureRecognizer *)sender {
[self stopAnimation];
buttons[index].enabled = NO;
{
TitleLabel.text = #"";
index = [self next:index];
[self startAnimation];
}
}
- (IBAction)swipeRight:(UISwipeGestureRecognizer *)sender {
[self stopAnimation];
buttons[index].enabled = NO;
{
TitleLabel.text = #"";
index = [self back:index];
[self startAnimation];
}
}
///////////////////////////////////////////////////
- (void)startAnimation
{
[self prepareForUpdate];
[self.timer invalidate];
self.timer = [NSTimer scheduledTimerWithTimeInterval:0 target:self selector:#selector(update) userInfo:nil repeats:YES];
}
- (void)stopAnimation
{
[self.timer invalidate];
[self finalizeUpdate];
self.timer = nil;
}
- (void)prepareForUpdate
{
NSInteger i = 0;
NSInteger iter = index;
do
{
centerOffsets[iter] = CGPointMake
(
(centers[i].x - buttons[iter].center.x) / 30,
(centers[i].y - buttons[iter].center.y) / 30
);
boundOffsets[iter] = CGRectMake
(
(bounds[i].origin.x - buttons[iter].bounds.origin.x) / 30,
(bounds[i].origin.y - buttons[iter].bounds.origin.y) / 30,
(bounds[i].size.width - buttons[iter].bounds.size.width) / 30,
(bounds[i].size.height - buttons[iter].bounds.size.height) / 30
);
opacitieOffsets[iter] = (opacities[i] - buttons[iter].alpha) / 30;
i++;
iter = [self next:iter];
}
while ( iter != index);
iterations = 30;
}
- (void)update
{
if (iterations <= 1)
{
}
if (iterations > 0)
{
for (NSInteger i = 0; i < 6; i++)
{
buttons[i].center = CGPointMake
(
centerOffsets[i].x + buttons[i].center.x,
centerOffsets[i].y + buttons[i].center.y
);
buttons[i].bounds = CGRectMake
(
boundOffsets[i].origin.x + buttons[i].bounds.origin.x,
boundOffsets[i].origin.y + buttons[i].bounds.origin.y,
boundOffsets[i].size.width + buttons[i].bounds.size.width,
boundOffsets[i].size.height + buttons[i].bounds.size.height
);
buttons[i].alpha = buttons[i].alpha + opacitieOffsets[i];
}
iterations--;
}
else [self stopAnimation];
}
- (void)finalizeUpdate
{
NSInteger i = 0;
NSInteger iter = index;
do
{
buttons[iter].center = centers[i];
buttons[iter].bounds = bounds[i];
buttons[iter].alpha = opacities[i];
i++;
iter = [self next:iter];
}
while ( iter != index);
iterations = 0;
buttons[index].enabled = YES;
TitleLabel.text = titles[index];
}
- (NSInteger)back:(NSInteger) i
{
return i == 0 ? 5 : i - 1;
}
- (NSInteger)next:(NSInteger) i
{
return i == 5 ? 0 : i + 1;
}
i want to said that my code work, but need some adjustment or many probably!!
1) first problem it's that the carousel go left/right very slow, I change the time but i still haven't figure out??????
2) I can still see the buttons from the carousel when they rotating in the back, i set alpha to 0 but i can still see them????
I'm new to objective-c so sorry for my mistake, objective-c is very different than c++
help and advice please???

Answer 1

The following line is incorrect:
self.timer = [NSTimer scheduledTimerWithTimeInterval:0 target:self selector:#selector(update) userInfo:nil repeats:YES];
You are scheduling a timer to fire every 0 seconds, which is consuming the runloop by trying to execute continuously. You have to change that line to schedule the timer with a value greater than 0, for example:
self.timer = [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:#selector(update) userInfo:nil repeats:YES];