Question

i am using ktphotobrowser for my app. in big image screen (ktphotoscrollviewcontroller) when i zoom image with two times tapping, the content size of scrollview (ktphotoview – it is an uiscrollview object) grows to bound.size * maximumzoomscale but my zoomed image size still smaller than contentsize of scrollview. both zoomed image size and the scrollview’s contentsize must be same so where can i do these calculation on the code?

if anybody use ktphotobrowser could help me about this problem, i will very appreciate.

i find the tap count but after this code i couldnt find where is the contentsize growing (zoom) or image growing (zoom) code

below you can find the whole code of ktphotoview.h page where the tapping count and zooming actions are coded:

#import "KTPhotoView.h"
#import "KTPhotoScrollViewController.h"
#import <QuartzCore/QuartzCore.h>

@interface KTPhotoView (KTPrivateMethods)
- (void)loadSubviewsWithFrame:(CGRect)frame;
- (BOOL)isZoomed;
- (void)toggleChromeDisplay;
@end

@implementation KTPhotoView

@synthesize scroller = scroller_;
@synthesize index = index_;



- (id)initWithFrame:(CGRect)frame
{
   self = [super initWithFrame:frame];
   if (self) {
      [self setDelegate:self];
      [self setMaximumZoomScale:2.0];
      [self setShowsHorizontalScrollIndicator:NO];
      [self setShowsVerticalScrollIndicator:NO];
      [self loadSubviewsWithFrame:frame];

        NSLog(@"scrollview2 %f",self.contentSize.height);
   }
   return self;
}

- (void)loadSubviewsWithFrame:(CGRect)frame
{
   imageView_ = [[UIImageView alloc] initWithFrame:frame];
   [imageView_ setContentMode:UIViewContentModeScaleAspectFit];
   [self addSubview:imageView_];
}

- (void)setImage:(UIImage *)newImage 
{
   [imageView_ setImage:newImage];
}

- (void)layoutSubviews 
{
   [super layoutSubviews];

   if ([self isZoomed] == NO && CGRectEqualToRect([self bounds], [imageView_ frame]) == NO) {
      [imageView_ setFrame:[self bounds]];
   }
}

- (void)toggleChromeDisplay
{
   if (scroller_) {
      [scroller_ toggleChromeDisplay];
   }
}

- (BOOL)isZoomed
{
   return !([self zoomScale] == [self minimumZoomScale]);
}

- (CGRect)zoomRectForScale:(float)scale withCenter:(CGPoint)center 
{

   CGRect zoomRect;

   // the zoom rect is in the content view's coordinates. 
   //    At a zoom scale of 1.0, it would be the size of the imageScrollView's bounds.
   //    As the zoom scale decreases, so more content is visible, the size of the rect grows.
   zoomRect.size.height = [self frame].size.height / scale;
   zoomRect.size.width  = [self frame].size.width  / scale;

   // choose an origin so as to get the right center.
   zoomRect.origin.x    = center.x - (zoomRect.size.width  / 2.0);
   zoomRect.origin.y    = center.y - (zoomRect.size.height / 2.0);
    NSLog(@"zoomRectHeight %f",[self frame].size.height);
   return zoomRect;
}

- (void)zoomToLocation:(CGPoint)location
{
   float newScale;
   CGRect zoomRect;
   if ([self isZoomed]) {
      zoomRect = [self bounds];

   } else {
      newScale = [self maximumZoomScale];
      zoomRect = [self zoomRectForScale:newScale withCenter:location];

   }
  // NSLog(@"zoomRectHeight %f",location.);
   [self zoomToRect:zoomRect animated:YES];
}

- (void)turnOffZoom
{
   if ([self isZoomed]) {
      [self zoomToLocation:CGPointZero];
   }
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{
   UITouch *touch = [touches anyObject];

   if ([touch view] == self) {
      if ([touch tapCount] == 2) {
         [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(toggleChromeDisplay) object:nil];
         [self zoomToLocation:[touch locationInView:self]];
      }
   }
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
   UITouch *touch = [touches anyObject];

   if ([touch view] == self) {
      if ([touch tapCount] == 1) {
         [self performSelector:@selector(toggleChromeDisplay) withObject:nil afterDelay:0.5];
      }
   }
}

#pragma mark -
#pragma mark UIScrollViewDelegate Methods

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
   UIView *viewToZoom = imageView_;
    NSLog(@"scrollview %f",self.contentSize.height);
   return viewToZoom;
}

Answer 1

i use the below code in ktphotoview.m file to solve my problem hope this helps:

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{
UITouch *touch = [touches anyObject];

if ([touch view] == self) {
  if ([touch tapCount] == 2) {


     [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(toggleChromeDisplay) object:nil];
      [self zoomToRect:[self zoomRectForScale:[self maximumZoomScale] withCenter:[touch locationInView:self]] animated:YES];
      float abc=(self.contentSize.height-(imageView_.image.size.height*320/imageView_.image.size.width*self.maximumZoomScale))/2 *-1;

      [self setContentInset:UIEdgeInsetsMake(abc, 0, abc, 0)];





  }
}
}