i am using this code for zooming this is perfect but i want zoomout after this zoomin.
CGFloat s = 3;
CGPoint p = CGPointMake(150, 300);
CGAffineTransform tr = CGAffineTransformScale(self.view.transform, s, s);
CGFloat h = self.view.frame.size.height;
CGFloat w = self.view.frame.size.width;
[UIView animateWithDuration:2.5 delay:0 options:0 animations:^{
self.view.transform = tr;
CGFloat cx = w/2-s*(p.x-w/2);
CGFloat cy = h/2-s*(p.y-h/2);
self.view.center = CGPointMake(cx, cy); //was: (w*s/2,h-h*s/2);
} completion:^(BOOL finished) {}];
Try using hitTest and scroll view delegate method i.e, viewForZoomingInScrollView as follows.
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
return yourScrollView;
}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return yourImageView;
}
You can set the selected image in another scrollview and handle the zoom.
- (void)setImage:(UIImage *)image {
[self.imageView setImage:image];
[self.imageView sizeToFit];
//add this image view as subview of scroll view here and set content size accordingly.
CGFloat zoomScale = 1.0;
if (self.imageView.frame.size.width < self.imageView.frame.size.height) {
zoomScale = (self.scrollView.frame.size.width / self.imageView.frame.size.width);
} else {
zoomScale = (self.scrollView.frame.size.height / self.imageView.frame.size.height);
}
[self.scrollView setContentSize:self.imageView.frame.size];
[self.scrollView setMinimumZoomScale:zoomScale];
[self.scrollView setMaximumZoomScale:1.0];
[self.scrollView setZoomScale:zoomScale];
[self.scrollView setContentOffset:CGPointMake((self.imageView.frame.size.width - self.scrollView.frame.size.width) / 2,
(self.imageView.frame.size.height - self.scrollView.frame.size.height) / 2)];
}
Related
I have a UIViewController and it's view hierarchy looks like this:
UIView
UIScrollView
UIImageView
I have code that positions the image view in the middle of the scroll view's frame, like so:
- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
[self recenterContent:scrollView];
}
- (void)recenterContent:(UIScrollView *)scrollView {
//this centers the content when it is smaller than the scrollView's bounds
CGFloat offsetX = MAX((scrollView.bounds.size.width - scrollView.contentSize.width) * 0.5, 0.0);
CGFloat offsetY = MAX((scrollView.bounds.size.height - scrollView.contentSize.height) * 0.5, 0.0);
self.scrollView.contentInset = UIEdgeInsetsMake(offsetY, offsetX, 0.f, 0.f);
}
This works fine when zooming the content, but when the view controller first loads it does not center. This is because the scrollView.contentSize is always 0. So my question is - when should I call this method after the scrollView.contentSize is set? When does that get set?
I have tried in viewDidLayoutSubviews, and the bounds of the scroll view is set then, but not the content size. Is there some method that I can use where the scroll view will be guaranteed to have the content size set?
Or is there a better way to keep the image centered when it is smaller than the scroll view? What I am trying to accomplish is to have it so the image view is not at the top of the scroll view and what I am using works, except when the scroll view's content size is not set. But if there is a better way of doing this without having to adjust the contentInset, I would be fine with that too.
Update
Here is what I have currently.
It is almost working, but no matter what I try, I cannot get it to look correct when the view loads. The way it works now is that it starts out off-center because when it calls the recenterContent method, before the view is displayed the content size of the scroll view is CGSizeZero, so the calculations are wrong. But if I try to recenter the content after the view has been displayed, then there is a visible delay before it gets centered.
I am just confused as to when the contentSize of the scroll view is set if I am using AutoLayout constraints to specify the size.
Here is my code. Can anyone see anything wrong with it?
#interface MyImageViewController ()
#property (strong, nonatomic) UIScrollView *scrollView;
#property (strong, nonatomic) UIImageView *imageView;
#property (assign, nonatomic) BOOL needsZoomScale;
#end
#implementation MyImageViewController
- (void)loadView {
self.view = [[UIView alloc] init];
[self.view addSubview:self.scrollView];
[self.scrollView addSubview:self.imageView];
self.needsZoomScale = YES;
[NSLayoutConstraint activateConstraints:#[
[self.scrollView.leadingAnchor constraintEqualToAnchor:self.view.leadingAnchor],
[self.scrollView.topAnchor constraintEqualToAnchor:self.view.topAnchor],
[self.scrollView.trailingAnchor constraintEqualToAnchor:self.view.trailingAnchor],
[self.scrollView.bottomAnchor constraintEqualToAnchor:self.view.bottomAnchor],
[self.imageView.leadingAnchor constraintEqualToAnchor:self.scrollView.contentLayoutGuide.leadingAnchor],
[self.imageView.topAnchor constraintEqualToAnchor:self.scrollView.contentLayoutGuide.topAnchor],
[self.imageView.trailingAnchor constraintEqualToAnchor:self.scrollView.contentLayoutGuide.trailingAnchor],
[self.imageView.bottomAnchor constraintEqualToAnchor:self.scrollView.contentLayoutGuide.bottomAnchor]
]];
}
- (void)viewDidLoad {
[super viewDidLoad];
UITapGestureRecognizer *doubleTapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(doubleTapZoom:)];
doubleTapGesture.numberOfTapsRequired = 2;
[self.imageView addGestureRecognizer:doubleTapGesture];
}
- (CGRect)zoomRectForScrollView:(UIScrollView *)scrollView withScale:(CGFloat)scale withCenter:(CGPoint)center {
CGRect zoomRect;
//the zoom rect is in the content view's coordinates. At a zoom scale of 1.0, the zoom rect would be the size
//of the scroll view's bounds. As the zoom scale decreases, so more content is visible, the size of the rect
//grows.
zoomRect.size.width = scrollView.frame.size.width / scale;
zoomRect.size.height = scrollView.frame.size.height / 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);
return zoomRect;
}
- (void)doubleTapZoom:(UITapGestureRecognizer *)sender {
UIView *tappedView = sender.view;
CGPoint tappedPoint = [sender locationInView:tappedView];
if (tappedPoint.x <= 0) {
tappedPoint.x = 1;
}
if (tappedPoint.y <= 0) {
tappedPoint.y = 1;
}
if (tappedPoint.x >= tappedView.bounds.size.width) {
tappedPoint.x = tappedView.bounds.size.width - 1;
}
if (tappedPoint.y >= tappedView.bounds.size.height) {
tappedPoint.y = tappedView.bounds.size.height - 1;
}
CGFloat zoomScale;
if (self.scrollView.zoomScale < 1) {
zoomScale = 1;
} else if (self.scrollView.zoomScale < self.scrollView.maximumZoomScale) {
zoomScale = self.scrollView.maximumZoomScale;
} else {
zoomScale = self.scrollView.minimumZoomScale;
}
CGRect zoomRect = [self zoomRectForScrollView:self.scrollView withScale:zoomScale withCenter:tappedPoint];
[self.scrollView zoomToRect:zoomRect animated:YES];
}
- (UIScrollView *)scrollView {
if (!self->_scrollView) {
self->_scrollView = [[UIScrollView alloc] init];
self->_scrollView.translatesAutoresizingMaskIntoConstraints = NO;
self->_scrollView.minimumZoomScale = 0.1f;
self->_scrollView.maximumZoomScale = 4.0f;
self->_scrollView.bounces = YES;
self->_scrollView.bouncesZoom = YES;
self->_scrollView.delegate = self;
self->_scrollView.backgroundColor = [UIColor blackColor];
}
return self->_scrollView;
}
- (UIImageView *)imageView {
if (!self->_imageView) {
self->_imageView = [[UIImageView alloc] init];
self->_imageView.translatesAutoresizingMaskIntoConstraints = NO;
self->_imageView.userInteractionEnabled = YES;
}
return self->_imageView;
}
- (UIImage *)image {
return self.imageView.image;
}
- (void)setImage:(UIImage *)image {
self.imageView.image = image;
self.needsZoomScale = YES;
[self updateZoomScale];
}
- (void)updateZoomScale {
if (self.needsZoomScale && self.image) {
CGSize size = self.view.bounds.size;
if (size.width == 0.0f || size.height == 0.0f) {
return;
}
UIImage *image = self.image;
CGSize imageSize = CGSizeMake(image.size.width * image.scale, image.size.height * image.scale);
if (imageSize.width > 0 && imageSize.height > 0) {
CGFloat widthScale = size.width / imageSize.width;
CGFloat heightScale = size.height / imageSize.height;
CGFloat minScale = MIN(widthScale, heightScale);
self.scrollView.minimumZoomScale = minScale;
self.scrollView.zoomScale = minScale;
self.needsZoomScale = NO;
}
}
}
- (void)viewWillLayoutSubviews {
[super viewWillLayoutSubviews];
[self updateZoomScale];
}
- (void)viewDidLayoutSubviews {
[super viewDidLayoutSubviews];
[self recenterContent:self.scrollView];
}
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[self recenterContent:self.scrollView];
}
#pragma mark - UIScrollViewDelegate
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return self.imageView;
}
- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
[self recenterContent:scrollView];
}
- (void)recenterContent:(UIScrollView *)scrollView {
//this centers the content when it is smaller than the scrollView's bounds
CGFloat offsetX = MAX((scrollView.bounds.size.width - scrollView.contentSize.width) * 0.5, 0.0);
CGFloat offsetY = MAX((scrollView.bounds.size.height - scrollView.contentSize.height) * 0.5, 0.0);
self.scrollView.contentInset = UIEdgeInsetsMake(offsetY, offsetX, 0.f, 0.f);
}
#end
The problem is that a UIImageView has an intrinsic content size of 0,0 -- so your code is initially putting the a 0x0 image view at the center of the scroll view.
I've made a few changes to the code you posted... see comments (I "wrapped" the changes in
// ---------------------------------
comment lines:
#interface MyImageViewController : UIViewController <UIScrollViewDelegate>
#end
#interface MyImageViewController ()
#property (strong, nonatomic) UIScrollView *scrollView;
#property (strong, nonatomic) UIImageView *imageView;
#property (assign, nonatomic) BOOL needsZoomScale;
#end
#implementation MyImageViewController
- (void)loadView {
self.view = [[UIView alloc] init];
[self.view addSubview:self.scrollView];
[self.scrollView addSubview:self.imageView];
self.needsZoomScale = YES;
// ---------------------------------
// respect safe area
UILayoutGuide *g = [self.view safeAreaLayoutGuide];
// saves on a little typing
UILayoutGuide *sg = [self.scrollView contentLayoutGuide];
// ---------------------------------
[NSLayoutConstraint activateConstraints:#[
[self.scrollView.leadingAnchor constraintEqualToAnchor:g.leadingAnchor],
[self.scrollView.topAnchor constraintEqualToAnchor:g.topAnchor],
[self.scrollView.trailingAnchor constraintEqualToAnchor:g.trailingAnchor],
[self.scrollView.bottomAnchor constraintEqualToAnchor:g.bottomAnchor],
[self.imageView.leadingAnchor constraintEqualToAnchor:sg.leadingAnchor],
[self.imageView.topAnchor constraintEqualToAnchor:sg.topAnchor],
[self.imageView.trailingAnchor constraintEqualToAnchor:sg.trailingAnchor],
[self.imageView.bottomAnchor constraintEqualToAnchor:sg.bottomAnchor]
]];
}
- (void)viewDidLoad {
[super viewDidLoad];
UITapGestureRecognizer *doubleTapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(doubleTapZoom:)];
doubleTapGesture.numberOfTapsRequired = 2;
[self.imageView addGestureRecognizer:doubleTapGesture];
}
- (CGRect)zoomRectForScrollView:(UIScrollView *)scrollView withScale:(CGFloat)scale withCenter:(CGPoint)center {
CGRect zoomRect;
//the zoom rect is in the content view's coordinates. At a zoom scale of 1.0, the zoom rect would be the size
//of the scroll view's bounds. As the zoom scale decreases, so more content is visible, the size of the rect
//grows.
zoomRect.size.width = scrollView.frame.size.width / scale;
zoomRect.size.height = scrollView.frame.size.height / 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);
return zoomRect;
}
- (void)doubleTapZoom:(UITapGestureRecognizer *)sender {
UIView *tappedView = sender.view;
CGPoint tappedPoint = [sender locationInView:tappedView];
if (tappedPoint.x <= 0) {
tappedPoint.x = 1;
}
if (tappedPoint.y <= 0) {
tappedPoint.y = 1;
}
if (tappedPoint.x >= tappedView.bounds.size.width) {
tappedPoint.x = tappedView.bounds.size.width - 1;
}
if (tappedPoint.y >= tappedView.bounds.size.height) {
tappedPoint.y = tappedView.bounds.size.height - 1;
}
CGFloat zoomScale;
if (self.scrollView.zoomScale < 1) {
zoomScale = 1;
} else if (self.scrollView.zoomScale < self.scrollView.maximumZoomScale) {
zoomScale = self.scrollView.maximumZoomScale;
} else {
zoomScale = self.scrollView.minimumZoomScale;
}
CGRect zoomRect = [self zoomRectForScrollView:self.scrollView withScale:zoomScale withCenter:tappedPoint];
[self.scrollView zoomToRect:zoomRect animated:YES];
}
- (UIScrollView *)scrollView {
if (!self->_scrollView) {
self->_scrollView = [[UIScrollView alloc] init];
self->_scrollView.translatesAutoresizingMaskIntoConstraints = NO;
self->_scrollView.minimumZoomScale = 0.1f;
self->_scrollView.maximumZoomScale = 4.0f;
self->_scrollView.bounces = YES;
self->_scrollView.bouncesZoom = YES;
self->_scrollView.delegate = self;
self->_scrollView.backgroundColor = [UIColor blackColor];
}
return self->_scrollView;
}
- (UIImageView *)imageView {
if (!self->_imageView) {
self->_imageView = [[UIImageView alloc] init];
self->_imageView.translatesAutoresizingMaskIntoConstraints = NO;
self->_imageView.userInteractionEnabled = YES;
}
return self->_imageView;
}
- (UIImage *)image {
return self.imageView.image;
}
- (void)setImage:(UIImage *)image {
self.imageView.image = image;
// ---------------------------------
// set the frame here
self.imageView.frame = CGRectMake(0.0, 0.0, image.size.width, image.size.height);
// ---------------------------------
// not needed ... unless maybe changing the image while view is showing?
//self.needsZoomScale = YES;
//[self updateZoomScale];
}
- (void)updateZoomScale {
if (self.needsZoomScale && self.image) {
CGSize size = self.view.bounds.size;
if (size.width == 0.0f || size.height == 0.0f) {
return;
}
UIImage *image = self.image;
CGSize imageSize = CGSizeMake(image.size.width * image.scale, image.size.height * image.scale);
if (imageSize.width > 0 && imageSize.height > 0) {
CGFloat widthScale = size.width / imageSize.width;
CGFloat heightScale = size.height / imageSize.height;
CGFloat minScale = MIN(widthScale, heightScale);
self.scrollView.minimumZoomScale = minScale;
self.scrollView.zoomScale = minScale;
self.needsZoomScale = NO;
}
}
}
// ---------------------------------
// Don't need this
//- (void)viewWillLayoutSubviews {
// [super viewWillLayoutSubviews];
// [self updateZoomScale];
//}
// ---------------------------------
- (void)viewDidLayoutSubviews {
[super viewDidLayoutSubviews];
// ---------------------------------
// update zoom scale here
[self updateZoomScale];
// ---------------------------------
[self recenterContent:self.scrollView];
}
// ---------------------------------
// Don't need this
//- (void)viewDidAppear:(BOOL)animated {
// [super viewDidAppear:animated];
// [self recenterContent:self.scrollView];
//}
// ---------------------------------
#pragma mark - UIScrollViewDelegate
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return self.imageView;
}
- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
[self recenterContent:scrollView];
}
- (void)recenterContent:(UIScrollView *)scrollView {
//this centers the content when it is smaller than the scrollView's bounds
CGFloat offsetX = MAX((scrollView.bounds.size.width - scrollView.contentSize.width) * 0.5, 0.0);
CGFloat offsetY = MAX((scrollView.bounds.size.height - scrollView.contentSize.height) * 0.5, 0.0);
self.scrollView.contentInset = UIEdgeInsetsMake(offsetY, offsetX, 0.f, 0.f);
}
#end
and here's how I call it:
MyImageViewController *vc = [MyImageViewController new];
UIImage *img = [UIImage imageNamed:#"bkg"];
if (nil == img) {
NSLog(#"Could not load image!!!!");
return;
}
[vc setImage:img];
[self.navigationController pushViewController:vc animated:YES];
I have several UITextField in a scrollView,
and I custom textFields' border by setting
layer.borderColor = ...,
layer.borderRadius = 3.0,
layer.borderWidth = 0.1,
layer.masksToBounds = YES.
- (void)keyboardWillShow:(NSNotification *)notification {
CGFloat animDuration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
CGRect rect = [self.currentTextField superview].frame;
[UIView animateWithDuration:animDuration animations:^{
[self.scrollView scrollRectToVisible:rect animated:NO];
}];
}
- (void)keyboardWillHide:(NSNotification *)notification {
CGFloat animDuration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
CGRect rect = [self.currentTextField superview].frame;
[UIView animateWithDuration:animDuration animations:^{
[self.scrollView scrollRectToVisible:rect animated:NO];
}];
}
Bug every time I got any textField focused or dismiss the keyboard, all the textfield's border flashes. But if I just scroll the scrollView no flashes
I finally find the resolution.
Use the CoreAnimation rasteraztion, toggle the textField's layer's shouldRasterize to true: textField.layer.shouldRasterize = true
and set the scale: textField.layer.rasterizationScale = UIScreen.mainScreen().scale
shouldRasterize instructs CoreAnimatin to cache the layer contents as an image. You then get rid off the flashing.
To avoid any unnecesary caching, you should turn off rasterization as soon as the animation is done.
The whole code is like:
- (void)keyboardWillShow:(NSNotification *)notification {
CGRect keyboardRectEnd = [notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
CGFloat animDuration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
CGRect rect = [self.currentTextField superview].frame;
self.scrollViewBottomConstraint.constant = keyboardRectEnd.size.height;
[self toggleTextFieldRasterization:YES];
[UIView animateWithDuration:animDuration animations:^{
[self.scrollView scrollRectToVisible:rect animated:NO];
[self layoutIfNeeded];
} completion: ^(BOOL finished) {
[self toggleTextFieldRasterization:NO];
}];
}
- (void)keyboardWillHide:(NSNotification *)notification {
CGFloat animDuration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
CGRect rect = [self.currentTextField superview].frame;
self.scrollViewBottomConstraint.constant = 0.0;
[self toggleTextFieldRasterization:YES];
[UIView animateWithDuration:animDuration animations:^{
[self.scrollView scrollRectToVisible:rect animated:NO];
[self layoutIfNeeded];
} completion:^(BOOL finished) {
[self toggleTextFieldRasterization:NO];
}];
}
- (void)toggleTextFieldRasterization:(BOOL)toggle {
CGFloat scale = UIScreen.mainScreen.scale;
self.textField1.layer.shouldRasterize = toggle;
self.textField1.layer.rasterizationScale = scale;
self.textField2.layer.shouldRasterize = toggle;
self.textField2.layer.rasterizationScale = scale;
self.textField3.layer.shouldRasterize = toggle;
self.textField3.layer.rasterizationScale = scale;
}
I want to zoom out image to original size after scroll slider.
I'm using REPagedScrollView library to implement slider.
I have 5 images in slider. Now zoom-in 1st image and then immediately scroll slider to view 2nd image. Then go back to view 1st image. 1st image not zooming out. That image was still in zoom - in mode.
How can i solved this.
Thanks in advance.
I'm using this below code.
-(void)slideShow
{
[scrollView removeFromSuperview];
scrollView = [[REPagedScrollView alloc] initWithFrame:self.scrollVw.bounds];
scrollView.delegate=self;
scrollView.pageControl.pageIndicatorTintColor=[UIColor clearColor];
scrollView.pageControl.currentPageIndicatorTintColor=[UIColor clearColor];
current_page=0;
for(int i=0;i<[self.PhotoImgArr count];i++){
// Image view
image_scroll = [[UIScrollView alloc] initWithFrame:CGRectMake(0,0,self.scrollVw.frame.size.width,self.scrollVw.frame.size.height)];
self.image_view = [[AsyncImageView alloc] initWithFrame:CGRectMake(0,0, image_scroll.frame.size.width, image_scroll.frame.size.height)];
self.image_view.backgroundColor=[UIColor clearColor];
// self.image_view.contentMode = UIViewContentModeScaleAspectFit;
self.image_view.clipsToBounds = true;
self.image_view.userInteractionEnabled = YES;
//self.image_view.image=[UIImage imageNamed:#"Stars"];
self.image_view.imageURL =[NSURL URLWithString:[self.PhotoImgArr objectAtIndex:i]];
doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleDoubleTap:)];
[doubleTap setNumberOfTapsRequired:2];
[self.image_view addGestureRecognizer:doubleTap];
// twoFingerPinch = [[UIPinchGestureRecognizer alloc]
// initWithTarget:self
// action:#selector(twoFingerPinch:)];
// [self.image_view addGestureRecognizer:twoFingerPinch];
[image_scroll setDelegate:self];
[image_scroll setShowsHorizontalScrollIndicator:NO];
[image_scroll setShowsVerticalScrollIndicator:NO];
image_scroll.tag=i+1;
// image_scroll.backgroundColor=[UIColor purpleColor];
image_scroll.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
self.image_view.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
image_scroll.contentSize = CGSizeMake(self.image_view.bounds.size.width-500, self.image_view.bounds.size.height-300);
image_scroll.decelerationRate = UIScrollViewDecelerationRateFast;
[image_scroll setMaximumZoomScale:4.0];
// image_scroll.minimumZoomScale = 1.0;
[image_scroll setZoomScale:[image_scroll minimumZoomScale]];
//image_scroll.zoomScale = 1.0;
[image_scroll addSubview:self.image_view];
[scrollView addPage:image_scroll];
}
scrollView.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
scrollView.tag=0;
[self.scrollVw addSubview:scrollView];
[scrollView scrollToPageWithIndex:self.selected_index animated:YES];
}
- (void)twoFingerPinch:(UIPinchGestureRecognizer *)recognizer
{
NSLog(#"twoFingerPinch");
float newScale = [image_scroll zoomScale] / 2.0;
CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[recognizer locationInView:recognizer.view]];
[image_scroll zoomToRect:zoomRect animated:YES];
}
- (void)handleDoubleTap:(UIGestureRecognizer *)gestureRecognizer {
// zoom in
NSLog(#"handleDoubleTap");
UIScrollView *imageScroll = (UIScrollView *)[self.view viewWithTag:self.selected_index+1];
float newScale = [imageScroll zoomScale] * 2.0;
if (newScale > imageScroll.maximumZoomScale){
newScale = imageScroll.minimumZoomScale;
CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]];
[imageScroll zoomToRect:zoomRect animated:YES];
}
else{
newScale = imageScroll.maximumZoomScale;
CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]];
[imageScroll zoomToRect:zoomRect animated:YES];
}
}
#pragma mark Utility methods
- (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 = [image_scroll frame].size.height / scale;
zoomRect.size.width = [image_scroll 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);
return zoomRect;
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView1
{
UIScrollView *imageScroll = (UIScrollView *)[self.view viewWithTag:self.selected_index+1];
if(scrollView1.tag ==0){
CGFloat pageWidth = scrollView1.frame.size.width;
current_page = floor((scrollView1.contentOffset.x - pageWidth / 2.0) / pageWidth) + 1;
self.selected_index=current_page;
self.lblHeader.text=[NSString stringWithFormat:#"%ld of %lu",self.selected_index+1,(unsigned long)[self.PhotoImgArr count]];
}
else
{
CGFloat offsetX = (imageScroll.bounds.size.width > imageScroll.contentSize.width)?
(imageScroll.bounds.size.width - imageScroll.contentSize.width) * 0.5 : 0.0;
CGFloat offsetY = (imageScroll.bounds.size.height > imageScroll.contentSize.height)?
(imageScroll.bounds.size.height - imageScroll.contentSize.height) * 0.5 : 0.0;
[scrollView1.subviews objectAtIndex:0].center = CGPointMake(imageScroll.contentSize.width * 0.5 + offsetX,imageScroll.contentSize.height * 0.5 + offsetY);
}
}
-(UIView *) viewForZoomingInScrollView:(UIScrollView *)scrollView1
{
if([scrollView1.subviews count]>0){
return [scrollView1.subviews objectAtIndex:0];
}
return nil;
}
ok first of all, don't use REPagedScrollView instead u can set the pages to scrollview by changing the view's x position, and it is useful for your zooming, if u use REPagedScrollView there are some complications that u can't get the subview's as scrollview, instead u get a UIView instance
Better u use normal UIScrollView it is good for your case, and also set the UIPageControl as they are doing in REPagedScrollView as separately in view controller's view.
first set the pages like below
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
_scrollPager = [[UIScrollView alloc] initWithFrame:self.view.bounds];
_scrollPager.delegate=self;
_scrollPager.pagingEnabled = YES;
_current_page=0;
_prev_next_index = 0;
_PhotoImgArr = [[NSMutableArray alloc] initWithObjects:#"00.jpg",#"01.jpg",#"02.jpg",#"03.jpg", nil];
CGSize totalContentSize = CGSizeMake(self.view.bounds.size.width [_PhotoImgArr count], self.view.bounds.size.height);
_scrollPager.contentSize = totalContentSize;
[self.view addSubview:_scrollPager];
[self setUpPager];
}
- (void)setUpPager
{
for(int i=0;i<[self.PhotoImgArr count];i++)
{
// Image view
UIScrollView *image_scroll = [[UIScrollView alloc] initWithFrame:CGRectMake(i * self.view.bounds.size.width, 0, self.view.bounds.size.width, self.view.bounds.size.height)];
UIImageView *image_view = [[UIImageView alloc] initWithFrame:image_scroll.bounds];
image_view.backgroundColor=[UIColor clearColor];
image_view.clipsToBounds = true;
image_view.image = [UIImage imageNamed:_PhotoImgArr[i]];
UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleDoubleTap:)];
[doubleTap setNumberOfTapsRequired:2];
[image_scroll setDelegate:self];
[image_scroll setShowsHorizontalScrollIndicator:NO];
[image_scroll setShowsVerticalScrollIndicator:NO];
image_scroll.tag=i;
image_scroll.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
image_view.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
image_scroll.contentSize = image_scroll.bounds.size;
image_scroll.decelerationRate = UIScrollViewDecelerationRateFast;
image_scroll.minimumZoomScale = 1.0f;
image_scroll.maximumZoomScale = 3.0f;
[image_scroll addSubview:image_view];
[image_scroll addGestureRecognizer:doubleTap];
[_scrollPager addSubview:image_scroll];
}
_scrollPager.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
_scrollPager.tag=100;
}
Handle the double tap action like below in same view controller
- (void)handleDoubleTap:(UIGestureRecognizer *)gestureRecognizer
{
// zoom in
NSLog(#"handleDoubleTap");
if(gestureRecognizer.view == _scrollPager) return;
UIScrollView *doubleTapScroll = [self getImageScroller];
if(doubleTapScroll)
{
//zoom
CGPoint pointInView = [gestureRecognizer locationInView:self.view];
CGFloat newZoomScale = doubleTapScroll.zoomScale * 1.5f;
newZoomScale = MIN(newZoomScale, doubleTapScroll.maximumZoomScale);
CGRect rectToZoomTo = CGRectZero;
CGFloat currentZoomScale = doubleTapScroll.zoomScale;
if(currentZoomScale == 1.0f)
{
rectToZoomTo = [self zoomRectForScrollView:doubleTapScroll withScale:newZoomScale withCenter:pointInView];//CGRectMake(x, y, w, h);
}
else if (currentZoomScale >= 1.0f)
{
rectToZoomTo = [self zoomRectForScrollView:doubleTapScroll withScale:1 withCenter:self.view.center];
}
[doubleTapScroll zoomToRect:rectToZoomTo animated:YES];
}
}
and one thing for scrollview u don't need to handle pinch, it will automatillcay handled for zooming.
finally handling of the zoom
#pragma mark Utility methods
- (CGRect)zoomRectForScrollView:(UIScrollView *)scrollView withScale:(float)scale withCenter:(CGPoint)center
{
CGRect zoomRect;
zoomRect.size.height = scrollView.frame.size.height / scale;
zoomRect.size.width = scrollView.frame.size.width / scale;
zoomRect.origin.x = center.x - (zoomRect.size.width / 2.0);
zoomRect.origin.y = center.y - (zoomRect.size.height / 2.0);
return zoomRect;
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView1
{
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
if(scrollView == _scrollPager)
{
float currentPage = scrollView.contentOffset.x /scrollView.frame.size.width;
if(currentPage != _current_page)
{
_prev_next_index = _current_page;
_current_page = ceil(currentPage);
[self resetScrollerAtViewIndex:_prev_next_index];
}
}
}
-(UIView *) viewForZoomingInScrollView:(UIScrollView *)scrollView1
{
if(scrollView1 == _scrollPager)
return nil;
else
{
UIScrollView *image_scroll = [self getImageScroller];
if(image_scroll)
if([image_scroll.subviews count]>0)
{
return [image_scroll.subviews objectAtIndex:0];
}
}
return nil;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (UIScrollView *)getImageScroller
{
return [_scrollPager viewWithTag:_current_page];
}
- (void)resetScrollerAtViewIndex:(NSInteger)index
{
UIScrollView *scrollView = [_scrollPager viewWithTag:index];
CGFloat zoomScale = scrollView.zoomScale;
if(zoomScale != 1.0)
[scrollView setZoomScale:1 animated:YES];
}
Edit for zoom out when return to previous or next page
just replace the below method
- (void)resetScrollerAtViewIndex:(NSInteger)index
{
//CGFloat zoomScale = 1.0;
UIScrollView *scrollView = [_scrollPager viewWithTag:index];
CGRect rectToZoomTo = CGRectZero;
rectToZoomTo = [self zoomRectForScrollView:scrollView withScale:1 withCenter:self.view.center];
[scrollView zoomToRect:self.view.bounds animated:YES];
[scrollView setContentOffset:CGPointZero];
[scrollView setContentSize:self.view.bounds.size];
}
I did my Top View and Bottom View (UIViews) hide while the UITableView is scrolling. Now, I need to check if the user begin drag the UITableview to up again and back the uiviews for the initial position. I have the following code to do the first step: hidden/show while scrolling uitableview
-(void)scrollViewDidScroll:(UIScrollView *)scrollView {
if(!self.isScrollingFast) {
CGRect screenBound = [[UIScreen mainScreen] bounds];
CGSize screenSize = screenBound.size;
CGFloat screenWidth = screenSize.width;
CGFloat screenHeight = screenSize.height;
NSInteger yOffset = scrollView.contentOffset.y;
if (yOffset > 0) {
self.tabBar.frame = CGRectMake(self.tabBar.frame.origin.x, self.originalFrame.origin.y + yOffset, self.tabBar.frame.size.width, self.tabBar.frame.size.height);
self.viewTopo.frame = CGRectMake(self.viewTopo.frame.origin.x, self.originalFrameTopo.origin.y - yOffset, self.viewTopo.frame.size.width, self.viewTopo.frame.size.height);
if(self.originalFrameHidingView.origin.y - yOffset >= 0) {
self.hidingView.frame = CGRectMake(self.hidingView.frame.origin.x, self.originalFrameHidingView.origin.y - yOffset, self.hidingView.frame.size.width, self.hidingView.frame.size.height);
}
else {
self.hidingView.frame = CGRectMake(self.hidingView.frame.origin.x, -10, self.hidingView.frame.size.width, self.hidingView.frame.size.height);
}
[self.tbPertos setFrame:CGRectMake(self.tbPertos.frame.origin.x, self.hidingView.frame.origin.y + self.hidingView.frame.size.height, self.tbPertos.frame.size.width, self.tbPertos.frame.size.height)];
if(self.tbPertos.frame.size.height + self.tbPertos.frame.origin.y + yOffset <= screenHeight)
self.tbPertos.frame = CGRectMake(self.tbPertos.frame.origin.x, self.tbPertos.frame.origin.y, self.tbPertos.frame.size.width, self.tbPertos.frame.size
.height+yOffset);
else {
self.tbPertos.frame = CGRectMake(self.tbPertos.frame.origin.x, self.tbPertos.frame.origin.y, self.tbPertos.frame.size.width, screenHeight - self.tbPertos.frame.origin.y);
}
}
if (yOffset < 1) {
self.tabBar.frame = self.originalFrame;
self.viewTopo.frame = self.originalFrameTopo;
self.hidingView.frame = self.originalFrameHidingView;
self.tbPertos.frame = CGRectMake(self.tbPertos.frame.origin.x, self.hidingView.frame.origin.y + self.hidingView.frame.size.height, self.tbPertos.frame.size.width, screenHeight - self.tbPertos.frame.origin.y);
}
}
}
And there's the code which I'm trying to do the Top and Bottom View reappear when the user begin scroll up. Independently wheres the scroll offset.
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
CGPoint currentOffset = scrollView.contentOffset;
NSTimeInterval currentTime = [NSDate timeIntervalSinceReferenceDate];
NSTimeInterval timeDiff = currentTime - self.lastOffsetCapture;
CGFloat distance = currentOffset.y - self.lastOffset.y;
//The multiply by 10, / 1000 isn't really necessary.......
if (distance < 0) {
if(!self.isScrollingFast) {
NSLog(#"voltar posicao normal");
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.5];
[UIView setAnimationDelay:1.0];
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
self.tabBar.frame = self.originalFrame;
self.viewTopo.frame = self.originalFrameTopo;
self.hidingView.frame = self.originalFrameHidingView;
self.tbPertos.frame = self.originalFrameTbPertos;
self.isScrollingFast = YES;
[UIView commitAnimations];
}
} else {
self.isScrollingFast = NO;
}
self.lastOffset = currentOffset;
self.lastOffsetCapture = currentTime;
}
Here i implemented code for UIView Hide / Show when tableview scrolling. When tableview scrolling down then UIView is hidden and when scrolling up then UIView show. I hope it's working for you...!
Step 1:- Make one property in .h file
#property (nonatomic) CGFloat previousContentOffset;
Step 2:- Write down this code in scrollViewDidScroll Method.
-(void)scrollViewDidScroll:(UIScrollView *)scrollView {
CGFloat currentContentOffset = scrollView.contentOffset.y;
if (currentContentOffset > self.previousContentOffset) {
// scrolling towards the bottom
[self.subButtonView setHidden:YES];
} else if (currentContentOffset < self.previousContentOffset) {
// scrolling towards the top
[self.subButtonView setHidden:NO];
}
self.previousContentOffset = currentContentOffset;
}
I'm developing an App which has (image saving) in one of the views, I have three different sizes which I want my images to be saved in after the user zoom and scale the image which is captured from the scroll view when the user click on save.
Below is my Codes:
After the style is selected the width and height is set depending on type chosen and then the scrollview creating method called
-(void)viewDidAppear:(BOOL)animated{
if(!([getColor length] == 0))
{
[theColored setHidden:NO];
[imageView setImage:image];
[theStyle setHidden:NO];
[theStyled setHidden:YES];
}
if(!([getStyle length] == 0))
{
[theColored setHidden:NO];
[imageView setImage:image];
[theStyle setHidden:YES];
[theStyled setHidden:NO];
[Save setHidden:NO];
if([theType isEqual: #"Pant"]){
theW = 200;
theH = 260;
}else if ([theType isEqual:#"Shirt"])
{
theW = 220;
theH = 220;
}else if([theType isEqual:#"Shoes"])
{
theW = 200;
theH = 60;
}
// UIImage *savedImage = image;
CGFloat theScale = 1.0;
[self setTheView:image andFrameW:&theW andFrameH:&theH andTheScale:&theScale];
}}
Below is the method:
-(void)setTheView:(UIImage *)savedImage andFrameW:(CGFloat *)theFW andFrameH:(CGFloat *)theFH andTheScale:(CGFloat *)theScale{
NSLog(#"called");
CGFloat theS = *theScale;
CGFloat imgW ;
CGFloat imgH;
imgW = *theFW * theS;
imgH = *theFH * theS;
// = savedImage.size.height * theS;
[dot removeFromSuperview];
[scrollView setPagingEnabled:NO];
[scrollView setShowsHorizontalScrollIndicator:NO];
[scrollView setShowsVerticalScrollIndicator:NO];
scrollView.layer.masksToBounds=YES;
scrollView.minimumZoomScale = 0.1f;
scrollView.maximumZoomScale = 5.0f;
[scrollView setZoomScale:0.5];
scrollView.layer.borderColor = [UIColor blackColor].CGColor;
scrollView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0);
[scrollView setContentSize:CGSizeMake(imgW*2,imgH*2)];
dot =[[UIImageView alloc] initWithFrame:CGRectMake(imgW/2,imgH/2,imgW,imgH)];
dot.image=savedImage;
dot.contentMode = UIViewContentModeScaleAspectFit;
[scrollView setScrollEnabled:YES];
[scrollView setTranslatesAutoresizingMaskIntoConstraints:YES];
scrollView.frame = CGRectMake(scrollView.frame.origin.x,scrollView.frame.origin.y, *theFW , *theFH);
[scrollView setHidden:NO];
[scrollView setContentOffset:CGPointMake(imgW/2,imgH/2) animated:NO];
[scrollView addSubview:dot];
}
Zooming methods:
- (UIView *) viewForZoomingInScrollView:(UIScrollView *)scrollView {
return dot;
}
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale{
NSLog(#"zoomed");
NSLog(#"%f",scale);
[self setTheView:image andFrameW:&theW andFrameH:&theH andTheScale:&scale];
}
Problem:
I have two problems here:
1- The zoom scale is not starting from last point it reached.
2- While tapping to zoom moves even before start zooming.
Update Edit
Both problems Solved
instead of calling the method again after zooming i just changed the content size
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale{
[self setTheView:image andFrameW:&theW andFrameH:&theH andTheScale:&scale];
}
replaced with
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale{
scrollView.contentSize = CGSizeMake((dot.bounds.size.width*scale)*2,(dot.bounds.size.height*scale)*2);
}
But i have new problem came up, after zooming contentOffSet is not equal up and down and also left and write
Digram explanation:
<----------------------------Content Size---------------------------->
| left offset |<---------Scrollviewframe--------->|Right offset|
i tried to set new content offset:
[scrollView setContentOffset:CGPointMake((dot.bounds.size.width*scale)/2,(dot.bounds.size.height*scale)/2) animated:NO];
but made nothing..
Problem solved i wanted to share the answer if someone wants to use scrollview to crop and zoom while allowsEditing = YES; doesn't gives the ability to set the rect size
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale{
CGFloat zoomedW = dot.bounds.size.width*scale;
CGFloat zoomedH = dot.bounds.size.height*scale;
CGFloat frameW = scrollView.frame.size.width;
CGFloat frameH = scrollView.frame.size.height;
scrollView.contentSize = CGSizeMake(frameW+zoomedW ,frameH+zoomedH);
}