I have a UIScrollView, which hold an UIImageView. I have a requirements to reach and zoom to particular location in UIImageView.
So for e.g. I want to start from (x: 0, y: 0) to specified location.
What's the best practice to do that?
This is how I'm achieving this:
- (void) setInitialZoomLevelAndShowImageInCenter {
CGRect scrollViewFrame = scrollViewMap.frame;
CGFloat scaleWidth = scrollViewFrame.size.width / scrollViewMap.contentSize.width;
CGFloat scaleHeight = scrollViewFrame.size.height / scrollViewMap.contentSize.height;
CGFloat minScale = MIN(scaleWidth, scaleHeight);
scrollViewMap.minimumZoomScale = minScale/1.5;
scrollViewMap.maximumZoomScale = 10.0f;
scrollViewMap.zoomScale = minScale;
CGFloat newZoomScale = scrollViewMap.zoomScale * 2.80f;
CGFloat xPos = 0;
CGFloat yPos = 0;
BOOL isMatched = NO;
while (!isMatched) {
[self zoomToPoint:CGPointMake(xPos, yPos) withScale:newZoomScale animated:YES];
BOOL isAnyChange = NO;
if(xPos <= slotItem.xCord) {
xPos+=1.0f;
isAnyChange = YES;
}
if(yPos <= slotItem.yCord) {
yPos+=1.0f;
isAnyChange = YES;
}
if(!isAnyChange) {
isMatched = YES;
}
}
}
- (void)zoomToPoint:(CGPoint)zoomPoint withScale: (CGFloat)scale animated: (BOOL)animated
{
//Normalize current content size back to content scale of 1.0f
CGSize contentSize;
contentSize.width = (scrollViewMap.contentSize.width / scrollViewMap.zoomScale);
contentSize.height = (scrollViewMap.contentSize.height / scrollViewMap.zoomScale);
//derive the size of the region to zoom to
CGSize zoomSize;
zoomSize.width = scrollViewMap.bounds.size.width / scale;
zoomSize.height = scrollViewMap.bounds.size.height / scale;
//offset the zoom rect so the actual zoom point is in the middle of the rectangle
CGRect zoomRect;
zoomRect.origin.x = zoomPoint.x - zoomSize.width / 2.0f;
zoomRect.origin.y = zoomPoint.y - zoomSize.height / 2.0f;
zoomRect.size.width = zoomSize.width;
zoomRect.size.height = zoomSize.height;
//apply the resize
[scrollViewMap zoomToRect: zoomRect animated: animated];
}
Related
I have a UIImageView i am performing pinch zoom & move image on full zoom.I am able to move the image but the issue is even if the image is not zoomed in it still moves on the screen.Please tell me how can i prevent it?
Here is the code for that
#define MINIMUM_SCALE 0.5
#define MAXIMUM_SCALE 6.0
#property CGPoint translation;
- (void)pan:(UIPanGestureRecognizer *)gesture {
static CGPoint currentTranslation;
static CGFloat currentScale = 0;
if (gesture.state == UIGestureRecognizerStateBegan) {
currentTranslation = _translation;
currentScale = self.view.frame.size.width / self.view.bounds.size.width;
}
if (gesture.state == UIGestureRecognizerStateEnded || gesture.state == UIGestureRecognizerStateChanged) {
CGPoint translation = [gesture translationInView:self.view];
_translation.x = translation.x + currentTranslation.x;
_translation.y = translation.y + currentTranslation.y;
CGAffineTransform transform1 = CGAffineTransformMakeTranslation(_translation.x , _translation.y);
CGAffineTransform transform2 = CGAffineTransformMakeScale(currentScale, currentScale);
CGAffineTransform transform = CGAffineTransformConcat(transform1, transform2);
self.view.transform = transform;
}
}
- (void)pinch:(UIPinchGestureRecognizer *)gesture {
if (gesture.state == UIGestureRecognizerStateEnded || gesture.state == UIGestureRecognizerStateChanged) {
// NSLog(#"gesture.scale = %f", gesture.scale);
CGFloat currentScale = self.view.frame.size.width / self.view.bounds.size.width;
CGFloat newScale = currentScale * gesture.scale;
if (newScale < MINIMUM_SCALE) {
newScale = MINIMUM_SCALE;
}
if (newScale > MAXIMUM_SCALE) {
newScale = MAXIMUM_SCALE;
}
CGAffineTransform transform1 = CGAffineTransformMakeTranslation(_translation.x, _translation.y);
CGAffineTransform transform2 = CGAffineTransformMakeScale(newScale, newScale);
CGAffineTransform transform = CGAffineTransformConcat(transform1, transform2);
self.view.transform = transform;
gesture.scale = 1;
}
}
**PS:**ImageView should only move when image is zoomed otherwise it should not be moveable.
I suggest a different approach:
Create a UIScrollView add the UIImageView into the scrollView's contentView and allow scrolling and zooming on the scrollView.
To prevent scrolling when not zoomed, set setScrollEnabled to NO and enable it in scrollViewDidZoom if the zoomLevel reaches a custom threshold.
So sth. like this should make make it much easier what you're trying to accomplish with a lot less code.
- (void)viewDidLoad:(BOOL)animated {
[super viewDidLoad:animated];
self.scrollView.scrollEnabled = NO;
self.scrollView.minimumZoomScale = 1;
}
- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
if (scrollView.zoomLevel > 1) {
scrollView.scrollEnabled = YES;
} else {
scrollView.scrollEnabled = NO;
}
}
I re-post the code I gave you in your first question on the subject ( Pinch zoom shifting image to most left corner on iPad in iOS? ), because I think the way you do it does not work as expected ( as far as I have tested ).
The pinch zoom is supposed to zoom on the middle of the fingers, and not on the middle of the image. If you really want to apply the zoom on center, I have added a boolean property zoomOnCenter.
The boundaries checking is done in the translateBy method.
Here is a link on the xCode test project: https://drive.google.com/file/d/0B88aMtNA0z2aWVBIbGZGdVhpdWM/view?usp=sharing
Interface
#interface PinchViewController : UIViewController
#property(nonatomic,strong) IBOutlet UIView* contentView;
#property(nonatomic,assign) BOOL zoomOnCenter;
#end
Implementation
#implementation PinchViewController
{
CGPoint translation;
CGFloat scale;
CGAffineTransform scaleTransform;
CGAffineTransform translateTransform;
CGPoint previousTranslation;
CGFloat previousScale;
NSUInteger previousNumTouches;
}
-(void)viewDidLoad
{
scale = 1.0f;
scaleTransform = CGAffineTransformIdentity;
translateTransform = CGAffineTransformIdentity;
previousTranslation = CGPointZero;
previousNumTouches = 0;
UIPinchGestureRecognizer *pinch=[[UIPinchGestureRecognizer alloc]initWithTarget:self action:#selector(handlePinch:)];
[self.view addGestureRecognizer:pinch];
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePan:)];
[panGesture setMinimumNumberOfTouches:1];
[panGesture setMaximumNumberOfTouches:1];
[self.view addGestureRecognizer:panGesture];
}
-(void)handlePinch:(UIPinchGestureRecognizer*)recognizer
{
// 1 - find pinch center
CGPoint mid = self.zoomOnCenter ? CGPointZero : [self computePinchCenter:recognizer];
mid.x-= recognizer.view.bounds.size.width / 2.0f;
mid.y-= recognizer.view.bounds.size.height / 2.0f;
// 2 - compute deltas
NSUInteger numTouches = recognizer.numberOfTouches;
if ( (recognizer.state==UIGestureRecognizerStateBegan) || ( previousNumTouches != numTouches ) ) {
previousScale = recognizer.scale;
previousTranslation = mid;
previousNumTouches = numTouches;
}
CGFloat deltaScale = ( recognizer.scale - previousScale ) * scale;
previousScale = recognizer.scale;
CGPoint deltaTranslation = CGPointMake(mid.x-previousTranslation.x, mid.y-previousTranslation.y);
previousTranslation = mid;
deltaTranslation.x/=scale;
deltaTranslation.y/=scale;
// 3 - apply
scale+=deltaScale;
if (scale<0.01) scale = 0.01; else if (scale>10) scale = 10;
scaleTransform = CGAffineTransformMakeScale(scale, scale);
[self translateBy:deltaTranslation];
}
- (void)handlePan:(UIPanGestureRecognizer *)recognizer
{
if (recognizer.state==UIGestureRecognizerStateBegan) previousTranslation = CGPointZero;
CGPoint recognizerTranslation = [recognizer translationInView:self.contentView];
CGPoint deltaTranslation = CGPointMake(recognizerTranslation.x - previousTranslation.x,recognizerTranslation.y - previousTranslation.y);
previousTranslation = recognizerTranslation;
[self translateBy:deltaTranslation];
}
-(void)translateBy:(CGPoint)delta
{
CGSize contentSize = self.contentView.bounds.size;
CGSize viewSize = self.view.bounds.size;
CGSize scaledViewSize = viewSize;
scaledViewSize.width/=scale;
scaledViewSize.height/=scale;
CGPoint maxTranslation = CGPointMake( (contentSize.width-scaledViewSize.width) / 2.0f , (contentSize.height-scaledViewSize.height) / 2.0f );
if ( contentSize.width*scale < viewSize.width ) {
delta.x=0;
translation.x = 0;
} else {
translation.x+=delta.x;
if ( translation.x < - maxTranslation.x ) {
translation.x = - maxTranslation.x;
}
else if ( translation.x > maxTranslation.x ) {
translation.x = maxTranslation.x;
}
}
if ( contentSize.height*scale < viewSize.height ) {
delta.y=0; translation.y = 0;
} else {
translation.y+=delta.y;
if ( translation.y < - maxTranslation.y ) {
translation.y = - maxTranslation.y;
}
else if ( translation.y > maxTranslation.y ) {
translation.y = maxTranslation.y;
}
}
translateTransform = CGAffineTransformMakeTranslation(translation.x,translation.y);
self.contentView.transform = CGAffineTransformConcat(translateTransform,scaleTransform);
}
-(CGPoint)computePinchCenter:(UIPinchGestureRecognizer*)recognizer
{
// 1 - handle up to 3 touches
NSUInteger numTouches = recognizer.numberOfTouches;
if (numTouches>3) numTouches = 3;
// 2 - Find fingers middle point - with (0,0) being the center of the view
CGPoint pt1,pt2,pt3,mid;
switch (numTouches) {
case 3:
pt3 = [recognizer locationOfTouch:2 inView:recognizer.view];
case 2:
pt2 = [recognizer locationOfTouch:1 inView:recognizer.view];
case 1:
pt1 = [recognizer locationOfTouch:0 inView:recognizer.view];
}
switch (numTouches) {
case 3:
mid = CGPointMake( ( ( pt1.x + pt2.x ) / 2.0f + pt3.x ) / 2.0f, ( ( pt1.y + pt2.y ) / 2.0f + pt3.y ) / 2.0f );
break;
case 2:
mid = CGPointMake( ( pt1.x + pt2.x ) / 2.0f, ( pt1.y + pt2.y ) / 2.0f );
break;
case 1:
mid = CGPointMake( pt1.x, pt1.y);
break;
}
return mid;
}
#end
You can check the frame of your imageView and if it is same it means imageview has not been zoomed So you can disable the pan gesture if frame of imageview is same ......and if frame has changed then you can enable the pan gesture.....
I call this function at viewDidLoad and didRotateFromInterfaceOrientation
-(void) makeBox{
[self.view1 removeFromSuperview];
float viewWidth = CGRectGetWidth(self.view.frame);
float viewHeight = CGRectGetHeight(self.view.frame);
float startx = (viewWidth / 100) * 10;
float starty = (viewHeight /100) * 20;
float width = (viewWidth / 100) * 80;
float height = (viewHeight /100) * 60;
CGRect frame1 = CGRectMake(startx, starty, width, height);
self.view1 = [[UIView alloc] initWithFrame:frame1];
[self.view1 setBackgroundColor:[UIColor redColor]];
[self.view addSubview:self.view1];
}
When the view does change, its very 'sketchy' & not very graceful at all. I'm using simulator but i assume that it would be the same if i were to run on a device. How would i go about making this transition smoother? I would post to user experiance page, but i wish todo this programmatically
The overall point of this, other than to learn, is to achieve orientation independent graphics from code (without autolayout).
There's no need to remove the view and create a new one with the desired frame if its the only thing you're changing. Just modify the view frame in-place:
- (void)makeBox {
CGFloat viewWidth = CGRectGetWidth(self.view.frame);
CGFloat viewHeight = CGRectGetHeight(self.view.frame);
CGFloat startx = (viewWidth / 100) * 10;
CGFloat starty = (viewHeight /100) * 20;
CGFloat width = (viewWidth / 100) * 80;
CGFloat height = (viewHeight /100) * 60;
CGRect view1Frame = CGRectMake(startx, starty, width, height);
if (!self.view1) {
// The view doesn't exists yet, we create it
self.view1 = [[UIView alloc] initWithFrame:view1Frame];
[self.view1 setBackgroundColor:[UIColor redColor]];
[self.view addSubview:self.view1];
}
else {
// Just update the frame
self.view1.frame = view1Frame;
}
}
For extra-nice UX, wrap the frame update in an animation block:
// ... snip ...
else {
[UIView animateWithDuration:0.3 animations:^() {
self.view1.frame = view1Frame;
}];
}
I have a collectionView which works well in iOS 7 and now in iOS 8 is acts strangely.
when collectionView appears it only displays one cell: (it must be 2)
but after scrolling a bit the second cell appears
Im using a custom collectionViewFlowLayout. but changing to UICollectionViewFlowLayout doesn't fix the issue.
Cell Size : 657, 500
Min Spacing For Lines : 100
Min Spacing For Cells : 10
I have added left and right edge insets: (if I remove the insets it works well. but I must use insets to keep my cell at the center of view)
- (UIEdgeInsets)collectionView:(UICollectionView *)cv
layout:(UICollectionViewLayout *)cvl
insetForSectionAtIndex:(NSInteger)section {
return UIEdgeInsetsMake(0, (cv.bounds.size.width - 657) / 2.0f, 0,
(cv.bounds.size.width - 657) / 2.0f);
}
Here is my custom flow layout:
#import "CoverFlowLayout.h"
static const CGFloat kMaxDistancePercentage = 0.3f;
//static const CGFloat kMaxRotation = (CGFloat)(50.0 * (M_PI / 180.0));
static const CGFloat kMaxZoom = 0.1f;
#implementation CoverFlowLayout
- (id)init {
if ((self = [super init])) {
self.scrollDirection = UICollectionViewScrollDirectionHorizontal;
self.minimumLineSpacing = 10000.0f; }
return self;
}
- (NSArray*)layoutAttributesForElementsInRect:(CGRect)rect {
// 1
CGRect visibleRect =
(CGRect){.origin = self.collectionView.contentOffset,
.size = self.collectionView.bounds.size};
CGFloat maxDistance =
visibleRect.size.width * kMaxDistancePercentage;
// 2
NSArray *array = [super layoutAttributesForElementsInRect:rect];
for (UICollectionViewLayoutAttributes *attributes in array) {
// 3
CGFloat distance =
CGRectGetMidX(visibleRect) - attributes.center.x;
// 4
CGFloat normalizedDistance = distance / maxDistance;
normalizedDistance = MIN(normalizedDistance, 1.0f);
normalizedDistance = MAX(normalizedDistance, -1.0f);
// 5
//CGFloat rotation = normalizedDistance * kMaxRotation;
CGFloat zoom = 1.0f + ((1.0f - ABS(normalizedDistance)) * kMaxZoom);
// 6
CATransform3D transform = CATransform3DIdentity;
transform.m34 = 1.0 / -1000.0;
//transform = CATransform3DRotate(transform,
// rotation, 0.0f, 1.0f, 0.0f);
transform = CATransform3DScale(transform, zoom, zoom, zoom);
attributes.transform3D = transform;
}
// 7
return array;
}
- (BOOL)shouldInvalidateLayoutForBoundsChange:(CGRect)newBounds {
return YES;
}
- (CGPoint)targetContentOffsetForProposedContentOffset: (CGPoint)proposedContentOffset withScrollingVelocity:(CGPoint)velocity
{
// 1
CGFloat offsetAdjustment = CGFLOAT_MAX;
CGFloat horizontalCenter = proposedContentOffset.x +
(CGRectGetWidth(self.collectionView.bounds) / 2.0f);
// 2
CGRect targetRect = CGRectMake(proposedContentOffset.x,
0.0f, self.collectionView.bounds.size.width, self.collectionView.bounds.size.height);
NSArray *array =
[super layoutAttributesForElementsInRect:targetRect];
for (UICollectionViewLayoutAttributes* layoutAttributes in array)
{
// 3
CGFloat distanceFromCenter = layoutAttributes.center.x - horizontalCenter;
if (ABS(distanceFromCenter) < ABS(offsetAdjustment))
{
offsetAdjustment = distanceFromCenter;
}
}
// 4
return CGPointMake(proposedContentOffset.x + offsetAdjustment,
proposedContentOffset.y);
}
initially in overrided layoutAttributesForElementsInRect visible rect is {0,0, 1024, 768}
but [super layoutAttributesForElementsInRect:rect]; returns only one UICollectionViewCellAttribute. (it should be 2)
is any idea how can I fix this?
I don know How it can be cause of the issue but it was originated from:
NSIndexPath *visibleIndexPath = [self.collectionView indexPathForItemAtPoint:midPoint];
I want to update my pageControl to indicate which cell is at the center of screen.
I Changed my method and now it works well:
//*****updating page control*****
// get the visible rect
CGRect visibleRect = (CGRect) {.origin = self.collectionView.contentOffset,
.size = self.collectionView.bounds.size};
// get the mid point in the visible rect
CGPoint midPoint = CGPointMake(CGRectGetMidX(visibleRect), CGRectGetMidY(visibleRect));
// find indexPath of the item in that midPoint
//in iOS 8 Cause the second cell disappear
//NSIndexPath *visibleIndexPath = [self.collectionView indexPathForItemAtPoint:midPoint];
//iterating through visble cells to find the cell which contains midpoint then get get that cell indexpath
for (UICollectionViewCell *cell in [self.collectionView visibleCells]) {
if (CGRectContainsPoint(cell.frame, midPoint)) {
NSIndexPath *indexPath = [self.collectionView indexPathForCell:cell];
//update page control
self.pageControl.currentPage = indexPath.row;
//quiting loop
break;
}
}
Im trying to create a horizontal collection view by subclassing UICollectionViewFlowLayout.
which the center cell be scaled a little more to be focused on the view.
see the screen shot:
but UICollectionViewCell doesn't capture touch events. I mean when I tap on the cell the delegate method - (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath won't called.
but when I remove the scale transform from the cell, the above method called!
#import "CoverFlowLayout.h"
static const CGFloat kMaxDistancePercentage = 0.3f;
static const CGFloat kMaxRotation = (CGFloat)(50.0 * (M_PI / 180.0));
static const CGFloat kMaxZoom = 0.1f;
#implementation CoverFlowLayout
- (id)init {
if ((self = [super init])) {
self.scrollDirection = UICollectionViewScrollDirectionHorizontal;
self.minimumLineSpacing = 10000.0f; }
return self;
}
- (NSArray*)layoutAttributesForElementsInRect:(CGRect)rect {
// 1
CGRect visibleRect =
(CGRect){.origin = self.collectionView.contentOffset,
.size = self.collectionView.bounds.size};
CGFloat maxDistance =
visibleRect.size.width * kMaxDistancePercentage;
// 2
NSArray *array =
[super layoutAttributesForElementsInRect:rect];
for (UICollectionViewLayoutAttributes *attributes in array) {
// 3
CGFloat distance =
CGRectGetMidX(visibleRect) - attributes.center.x;
// 4
CGFloat normalizedDistance = distance / maxDistance;
normalizedDistance = MIN(normalizedDistance, 1.0f);
normalizedDistance = MAX(normalizedDistance, -1.0f);
// 5
CGFloat rotation = normalizedDistance * kMaxRotation;
CGFloat zoom = 1.0f + ((1.0f - ABS(normalizedDistance)) * kMaxZoom);
// 6
CATransform3D transform = CATransform3DIdentity;
transform.m34 = 1.0 / -1000.0;
//transform = CATransform3DRotate(transform,
// rotation, 0.0f, 1.0f, 0.0f);
transform = CATransform3DScale(transform, zoom, zoom, 0.0f);
attributes.transform3D = transform;
}
// 7
return array;
}
- (BOOL)shouldInvalidateLayoutForBoundsChange:(CGRect)newBounds {
return YES;
}
- (CGPoint)targetContentOffsetForProposedContentOffset: (CGPoint)proposedContentOffset withScrollingVelocity:(CGPoint)velocity
{
// 1
CGFloat offsetAdjustment = CGFLOAT_MAX;
CGFloat horizontalCenter = proposedContentOffset.x +
(CGRectGetWidth(self.collectionView.bounds) / 2.0f);
// 2
CGRect targetRect = CGRectMake(proposedContentOffset.x,
0.0f, self.collectionView.bounds.size.width, self.collectionView.bounds.size.height);
NSArray *array =
[super layoutAttributesForElementsInRect:targetRect];
for (UICollectionViewLayoutAttributes* layoutAttributes in array)
{
// 3
CGFloat distanceFromCenter = layoutAttributes.center.x - horizontalCenter;
if (ABS(distanceFromCenter) < ABS(offsetAdjustment))
{
offsetAdjustment = distanceFromCenter;
}
}
// 4
return CGPointMake(proposedContentOffset.x + offsetAdjustment,
proposedContentOffset.y);
}
any idea?
You don't need to scale on z-axis, the problem is caused because you were scaling on z to zero
The scale on z-axis should be greater than zero; Making it zero causes the button to have "no depth", so the touches are not recognized. (Although you can still see the button)
Scaling is a computed using a multiplication, so in order to cause "no transformation on z-axis", the value should be 1, rather than 0
I had to scale the cell along the Z axis too:
transform = CATransform3DScale(transform, zoom, zoom, zoom);
the cell touch events works.
does anyone knows why scaling along Z axis is necessary?
My problem is i am not able to get the exact CGRect value after zooming for zooming in UIScrollview i am using zoomToRect method of UIScrollview. while zooming i am setting the contentOffset property.
Code follows:
if(image != nil) {
CGSize zoomViewSize = image.frame.size;
CGSize scrollViewSize = self.bounds.size;
if(zoomViewSize.width < scrollViewSize.width) {
anOffset.x = -(scrollViewSize.width - zoomViewSize.width) / 2.0;
}
if(zoomViewSize.height < scrollViewSize.height) {
anOffset.y = -(scrollViewSize.height - zoomViewSize.height) / 2.0;
}
}
super.contentOffset = anOffset;
after zooming i am setting the content inset property so that image comes in the center. for content inset the code is given below.
-(void)zoomtorect:(CGRect)rect animated:(BOOL)animated {
[super zoomtorect:rect animated:YES];
CGFloat pageWidth = image.image.size.height;
CGSize imageSize = rect.size;
CGSize zoomedImageSize = CGSizeMake(imageSize.width * 0.2, imageSize.height * 0.2);
CGSize pageSize = self.bounds.size;
//scLayer.frame = rect;
UIEdgeInsets inset = UIEdgeInsetsZero;
if (pageSize.width > zoomedImageSize.width) {
inset.left = (pageSize.width - zoomedImageSize.width) / 2;
inset.right = inset.left;
}
if (pageSize.height > zoomedImageSize.height) {
inset.top = (pageSize.height - zoomedImageSize.height) / 2;
inset.bottom = inset.top;
}
self.contentInset = inset;
}
this code shifts my image view between screen. Every thing works fine here. My problem is i have to show only zoom portion of the imageView rest will be black. For calculating the zoomed area i am doing the following calculation.
CGSize imageSize = rect.size;
CGSize zoomedImageSize = CGSizeMake(imageSize.width * scroll.maximumZoomScale, imageSize.height *scroll.maximumZoomScale);
CGSize pageSize = scroll.bounds.size;
UIEdgeInsets inset = UIEdgeInsetsZero;
if (pageSize.width > zoomedImageSize.width) {
inset.left = (pageSize.width - zoomedImageSize.width) / 2;
inset.right = inset.left;
}
if (pageSize.height > zoomedImageSize.height) {
inset.top = (pageSize.height - zoomedImageSize.height) / 2;
inset.bottom = inset.top;
}
CGRect zoomRect = [scroll convertRect:rect fromView:image];
CGRect zoomRect1 = CGRectMake(inset.left, inset.top+50, zoomRect.size.width, zoomRect.size.height);
this zoomRect1 is the zoomed area of the image this value is not exact what i am seeing in the screen. some where i am doing calculation mistake please help me out. But i am not getting the exact value of the zoomed image area.
Thanks in advance
Use this.. Works Perfectly
- (void)handleDoubleTap:(UIGestureRecognizer *)recognizer
{
if(isAlreadyZoomed)
{
CGPoint Pointview = [recognizer locationInView:recognizer.view];
CGFloat newZoomscal = 3.0;
CGSize scrollViewSize = self.scrollContainer.bounds.size;
CGFloat width = scrollViewSize.width/newZoomscal;
CGFloat height = scrollViewSize.height /newZoomscal;
CGFloat xPos = Pointview.x-(width/2.0);
CGFloat yPos = Pointview.y-(height/2.0);
CGRect rectTozoom=CGRectMake(xPos, yPos, width, height);
[self.scrollContainer zoomToRect:rectTozoom animated:YES];
[self.scrollContainer setZoomScale:3.0 animated:YES];
isAlreadyZoomed = NO;
}
else
{
[self.scrollContainer setZoomScale:1.0 animated:YES];
isAlreadyZoomed = YES;
}
}
isAlreadyZoomed is a BOOL value