flash animation
I set a CalendarViewController's view as menuitem.view, when touch the bottom of menuitem.view, menuitem.view will begin animate, but i found the animation appears flashing. What can i do that make the animation become more smooth.
- (IBAction)respondToTapBottomView:(NSButton *)sender {
NSSize size = self.view.frame.size;
NSLog(#"%#", NSStringFromRect(self.view.window.frame));
[NSAnimationContext runAnimationGroup:^(NSAnimationContext * _Nonnull context) {
context.duration = 0.5;
CGFloat height = 10;
if (self.bottomContentHeightConstraint.constant >= 30) {
height = 10;
} else {
height = 97;
}
CGFloat windowHeight = self.calendarView.frame.size.height + height;
self.view.animator.frame = CGRectMake(0, 0, size.width, windowHeight);
self.bottomContentHeightConstraint.animator.constant = height;
} completionHandler:^{
NSLog(#"%#", NSStringFromRect(self.view.window.frame));
}];
}
I gave up using this method, finaly, i work around the problem by draw a custom popoverView rather than use menuItem.view.
Related
I have a navigation bar that I've manually coded to animate the frame of depending on the offset of the scrollView (tableView). Below is a screenshot of what it looks like unscrolled.
Now after setScrollOffset:(0,0) is invoked (by scrollsToTop, not me manually - e.g. by tapping status bar), the scrollview scrolls to the top, but at the position at which there used to be no navigation bar. I can manually scroll the last 44px or so after the animation happens, but obviously thats not the behavior that's expected.
Here is my code for hiding the navbar:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGRect frame = self.navigationController.navigationBar.frame;
CGFloat size = frame.size.height - kMacro1;
CGFloat framePercentageHidden = ((kMacro2 - frame.origin.y) / (frame.size.height - 1));
CGFloat scrollOffset = scrollView.contentOffset.y;
CGFloat scrollDiff = scrollOffset - self.previousScrollViewYOffset;
CGFloat scrollHeight = scrollView.frame.size.height;
CGFloat scrollContentSizeHeight = scrollView.contentSize.height + scrollView.contentInset.bottom;
if (scrollOffset <= -scrollView.contentInset.top) {
frame.origin.y = kMacro2;
} else if ((scrollOffset + scrollHeight) >= scrollContentSizeHeight) {
frame.origin.y = -size;
} else {
frame.origin.y = MIN(kMacro2, MAX(-size, frame.origin.y - scrollDiff));
}
[self.navigationController.navigationBar setFrame:frame];
[self updateBarButtonItems:(1 - framePercentageHidden)];
self.previousScrollViewYOffset = scrollOffset;
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
[self stoppedScrolling];
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView
willDecelerate:(BOOL)decelerate
{
if (!decelerate) {
[self stoppedScrolling];
}
}
- (void)stoppedScrolling
{
CGRect frame = self.navigationController.navigationBar.frame;
if (frame.origin.y < kMacro2) {
[self animateNavBarTo:-(frame.size.height - kMacro1)];
}
}
- (void)animateNavBarTo:(CGFloat)y
{
[UIView animateWithDuration:0.2 animations:^{
CGRect frame = self.navigationController.navigationBar.frame;
CGFloat alpha = (frame.origin.y >= y ? 0 : 1);
frame.origin.y = y;
[self.navigationController.navigationBar setFrame:frame];
[self updateBarButtonItems:alpha];
}];
}
When scrolling content in Safari, the title bar animates to a smaller version of its self. What is the best way to implement this?
Currently, I am changing the size of the frame like so:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
//
// Table view
//
CGFloat currentPosition = scrollView.contentOffset.y - CGRectGetHeight(self.tableView.tableHeaderView.frame) + CGRectGetHeight(self.navigationController.navigationBar.frame) + CGRectGetHeight([[UIApplication sharedApplication] statusBarFrame]);
if ([scrollView isKindOfClass:[HeadlinesHeadlinesTableView class]]) {
ScrollDirection scrollDirection;
if (self.lastContentOffset > scrollView.contentOffset.y) {
scrollDirection = ScrollDirectionDown;
} else if (self.lastContentOffset < scrollView.contentOffset.y) {
scrollDirection = ScrollDirectionUp;
}
self.lastContentOffset = scrollView.contentOffset.y;
CGRect frame = self.navigationController.navigationBar.frame;
CGFloat minimumFrameHeight = 30.0f;
CGFloat maximumFrameHeight = 44.0f;
CGFloat titleSize = [[self.navigationController.navigationBar.titleTextAttributes objectForKey:NSFontAttributeName] pointSize];
CGFloat minimumTitleHeight = 22.0f;
CGFloat maximumTitleHeight = 30.0f;
if (currentPosition > 0 && CGRectGetHeight(frame) >= minimumFrameHeight && CGRectGetHeight(frame) <= maximumFrameHeight) {
switch (scrollDirection) {
case ScrollDirectionUp:
frame.size.height--;
titleSize--;
break;
case ScrollDirectionDown:
frame.size.height++;
titleSize++;
break;
default:
break;
}
if (CGRectGetHeight(frame) <= minimumFrameHeight) {
frame.size.height = minimumFrameHeight;
}
if (CGRectGetHeight(frame) >= maximumFrameHeight) {
frame.size.height = maximumFrameHeight;
}
if (titleSize <= minimumTitleHeight) {
titleSize = minimumTitleHeight;
}
if (titleSize >= maximumTitleHeight) {
titleSize = maximumTitleHeight;
}
}
[self.navigationController.navigationBar setFrame:frame];
[self.navigationController.navigationBar setTitleTextAttributes: #{ NSFontAttributeName : [UIFont fontWithName:#"Canterbury-Regular" size:titleSize] }];
}
}
Naturally, this way is not smooth and a lot of code, not to mention the fact that I need to fade out bar button items as well.
Thanks in advance!
Take a look at AMScrollingNavbar, it already has fading support.
You can try to change font size of NavigationBar to make the title smaller.
I tried to implement paging with 2 views from this tutorial:
Multiple virtual pages in a UIScrollView with just 2 child views
I wanted to modify this by putting UIScrollView to pages and in every page updating it with new content:
-(void)addContent:(NSString*)txt{
int size = 5;
UITextView *txtView;
int row = 0;
//from left
int xPlace = 0;
//space between row's
int rowSpace = 20;
//from top
int yPlace = 10;
// int button_with = scrollView.frame.size.width;
int button_height = 20;
for (int i = 0; i < size; i++) {
txtView = [[UITextView alloc] initWithFrame:CGRectMake(xPlace, row*rowSpace+yPlace, scrollView.frame.size.width, 2*button_height)];
[txtView setFont:[UIFont fontWithName:#"ArialMT" size:14]];
txtView.backgroundColor = [UIColor blueColor];
[txtView setText:[NSString stringWithFormat:#"Numer %# - %i",txt,i]];
// answerCheck.titleLabel.font = [UIFont boldSystemFontOfSize:fontSize];
[scrollView addSubview:txtView];
[txtView release];
row++;
}
[scrollView setContentSize:CGSizeMake(scrollView.frame.size.width, txtView.frame.size.height*size)];
}
The idea is when scrolling just replace uiviewcontroller with new content. It calls:
- (void)setPageIndex:(NSInteger)newPageIndex
{
pageIndex = newPageIndex;
if (pageIndex >= 0 && pageIndex < [[DataSource sharedDataSource] numDataPages])
{
NSDictionary *pageData =
[[DataSource sharedDataSource] dataForPage:pageIndex];
label.text = #"Tekstas";//[pageData objectForKey:#"pageName"];
textView.text = [pageData objectForKey:#"pageText"];
[self addContent:[pageData objectForKey:#"pageText"]];
CGRect absoluteRect = [self.view.window
convertRect:textView.bounds
fromView:textView];
if (!self.view.window ||
!CGRectIntersectsRect(
CGRectInset(absoluteRect, TEXT_VIEW_PADDING, TEXT_VIEW_PADDING),
[self.view.window bounds]))
{
textViewNeedsUpdate = YES;
}
}
}
Well here I stuck. My text view is updating but new content of UIscrollView don't update in iPad simulator.
Yea I mean in iphone it works while in iPad it don't. What I could improve if I want to achieve this functionality?
Maybe there are other way to do paging from iOS 5?
I would put source that a tried to make working.
Download source
You can just use a nib file add a UIScrollView with fix width and height. Now make some pages as a UIView and add them to UIScrollView with same size and same origin. In the main UIView:
- (void)viewDidLoad
{
[super viewDidLoad];
scrollView.contentSize = CGSizeMake(scrollView.frame.size.width, scrollView.frame.size.height * 2);
}
-(void)viewWillAppear:(BOOL)animated{
CGFloat h = scrollView.frame.size.height;
[pageView1 setFrame:CGRectMake(0, 0, pageView1.frame.size.width, pageView1.frame.size.height)];
[pageView2 setFrame:CGRectMake(0, h, pageView2.frame.size.width, pageView2.frame.size.height)];
}
And don't forget to check Paging Enabled for UIScrollView in the Attributes in the nib file.
I hope be useful for you!
Is it possible create an UIImage or an UIImageView with rounded corners? Because I want take an UIImage and show it inside an UIImageView, but I don't know how to do it.
Yes, it is possible.
Import the QuartzCore (#import <QuartzCore/QuartzCore.h>) header and play with the layer property of the UIImageView.
yourImageView.layer.cornerRadius = yourRadius;
yourImageView.clipsToBounds = YES;
See the CALayer class reference for more info.
Try this Code For Round Image Import QuartzCore framework
simple way to create Round Image
imageView.layer.backgroundColor=[[UIColor clearColor] CGColor];
imageView.layer.cornerRadius=20;
imageView.layer.borderWidth=2.0;
imageView.layer.masksToBounds = YES;
imageView.layer.borderColor=[[UIColor redColor] CGColor];
Objective-C
-(UIImage *)makeRoundedImage:(UIImage *) image
radius: (float) radius;
{
CALayer *imageLayer = [CALayer layer];
imageLayer.frame = CGRectMake(0, 0, image.size.width, image.size.height);
imageLayer.contents = (id) image.CGImage;
imageLayer.masksToBounds = YES;
imageLayer.cornerRadius = radius;
UIGraphicsBeginImageContext(image.size);
[imageLayer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *roundedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return roundedImage;
}
Swift 3
func makeRoundedImage(image: UIImage, radius: Float) -> UIImage {
var imageLayer = CALayer()
imageLayer.frame = CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height)
imageLayer.contents = image.cgImage
imageLayer.masksToBounds = true
imageLayer.cornerRadius = radius
UIGraphicsBeginImageContext(image.size)
imageLayer.render(in: UIGraphicsGetCurrentContext())
var roundedImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return roundedImage
}
uiimageview.layer.cornerRadius = uiimageview.frame.size.height/2;
uiimageview.clipToBounds = YES;
#import <QuartzCore/QuartzCore.h>
// UIImageView+OSExt.h
#import <UIKit/UIKit.h>
#interface UIImageView (OSExt)
- (void)setBorder:(CGFloat)borderWidth color:(UIColor*)color;
#end
// UIImageView+OSExt.m
#import "UIImageView+OSExt.h"
#implementation UIImageView (OSExt)
- (void)layoutSublayersOfLayer:(CALayer *)layer
{
for ( CALayer *sub in layer.sublayers )
{
if ( YES == [sub.name isEqual:#"border-shape"])
{
CGFloat borderHalf = floor([(CAShapeLayer*)sub lineWidth] * .5);
sub.frame = layer.bounds;
[sub setBounds:CGRectInset(layer.bounds, borderHalf, borderHalf)];
[sub setPosition:CGPointMake(CGRectGetMidX(layer.bounds),
CGRectGetMidY(layer.bounds))];
}
}
}
- (void)setBorder:(CGFloat)borderWidth color:(UIColor*)color
{
assert(self.frame.size.width == self.frame.size.height);
for ( CALayer *sub in [NSArray arrayWithArray:self.layer.sublayers] )
{
if ( YES == [sub.name isEqual:#"border-shape"])
{
[sub removeFromSuperlayer];
break;
}
}
CGFloat borderHalf = floor(borderWidth * .5);
self.layer.cornerRadius = self.layer.bounds.size.width * .5;
CAShapeLayer *circleLayer = [CAShapeLayer layer];
self.layer.delegate = (id<CALayerDelegate>)self;
circleLayer.name = #"border-shape";
[circleLayer setBounds:CGRectInset(self.bounds, borderHalf, borderHalf)];
[circleLayer setPosition:CGPointMake(CGRectGetMidX(self.layer.bounds),
CGRectGetMidY(self.layer.bounds))];
[circleLayer setPath:[[UIBezierPath bezierPathWithOvalInRect:circleLayer.bounds] CGPath]];
[circleLayer setStrokeColor:color.CGColor];
[circleLayer setFillColor:[UIColor clearColor].CGColor];
[circleLayer setLineWidth:borderWidth];
{
circleLayer.shadowOffset = CGSizeZero;
circleLayer.shadowColor = [[UIColor whiteColor] CGColor];
circleLayer.shadowRadius = borderWidth;
circleLayer.shadowOpacity = .9f;
circleLayer.shadowOffset = CGSizeZero;
}
// Add the sublayer to the image view's layer tree
[self.layer addSublayer:circleLayer];
// old variant
//CALayer *layer = self.layer;
//layer.masksToBounds = YES;
//layer.cornerRadius = self.frame.size.width * 0.5;
//layer.borderWidth = borderWidth;
//layer.borderColor = color;
}
#end
Setting cornerRadius and clipsToBounds is the right way to do this. However if the view's size changes, the radius will not update. In order to get proper resizing and animation behavior, you need to create a UIImageView subclass.
class RoundImageView: UIImageView {
override var bounds: CGRect {
get {
return super.bounds
}
set {
super.bounds = newValue
setNeedsLayout()
}
}
override func layoutSubviews() {
super.layoutSubviews()
layer.cornerRadius = bounds.width / 2.0
clipsToBounds = true
}
}
Try this to get rounded corners of the image View and also to colour the corners:
imageView.layer.cornerRadius = imageView.frame.size.height/2;
imageView.layer.masksToBounds = YES;
imageView.layer.borderColor = [UIColor colorWithRed:148/255. green:79/255. blue:216/255. alpha:1.0].CGColor;
imageView.layer.borderWidth=2;
Condition*: The height and the width of the imageView must be same to get rounded corners.
layer.cornerRadius = imageviewHeight/2
layer.masksToBounds = true
It is possible but I'll advice you to create transparent png image (mask) with round corners and place it over you image with UIImageView. It might be quicker solution (for example if you need animations or scrolling).
Here how i set my rounded avatar at the center of it contain view:
-(void)setRoundedAvatar:(UIImageView *)avatarView toDiameter:(float)newSize atView:(UIView *)containedView;
{
avatarView.layer.cornerRadius = newSize/2;
avatarView.clipsToBounds = YES;
avatarView.frame = CGRectMake(0, 0, newSize, newSize);
CGPoint centerValue = CGPointMake(containView.frame.size.width/2, containedView.frame.size.height/2);
avatarView.center = centerValue;
}
Circle with UIBeizerPath #Swift-3 && #imageExtension
class ViewController: UIViewController {
#IBOutlet weak var imageOutlet: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
let image = UIImage(named: "IMG_0001.JPG")
if let image = image {
let renderimage = image.imageCroppingBezierPath(path: UIBezierPath(arcCenter: CGPoint(x:image.size.width/2,y:image.size.width/2 ) , radius: 200, startAngle: 0, endAngle: (2 * CGFloat(M_PI) ), clockwise: true) )
imageOutlet.image = renderimage
}
}
}
extension UIImage {
func imageCroppingBezierPath(path:UIBezierPath) ->UIImage {
let frame = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
//Defining a graphic context to paint on
UIGraphicsBeginImageContextWithOptions(self.size, false, 0.0)
//Get the current graphics context (if it exists)
let context = UIGraphicsGetCurrentContext()
//save the current graphic context
context?.saveGState()
// clipping area
path.addClip()
self.draw(in: frame)
//To extract an image from our canvas
let image = UIGraphicsGetImageFromCurrentImageContext()
//restore graphic context
context?.restoreGState()
//remove current context from stack
UIGraphicsEndImageContext()
return image!
}
}
# import QuartzCore framework
imageView.layer.cornerRadius=imgvwUser.frame.size.width/2;
imageView.layer.masksToBounds = YES;
The height and the width of the imageView must be same to get rounded corners.
I would like to zoom in/out an UIImage object when the user performs the standard pinch action on my application. I'm currently using a UIImageView to display my image, if that detail helps in any way.
I'm trying to figure out how to do this, but no such luck so far.
Any clues?
As others described, the easiest solution is to put your UIImageView into a UIScrollView. I did this in the Interface Builder .xib file.
In viewDidLoad, set the following variables. Set your controller to be a UIScrollViewDelegate.
- (void)viewDidLoad {
[super viewDidLoad];
self.scrollView.minimumZoomScale = 0.5;
self.scrollView.maximumZoomScale = 6.0;
self.scrollView.contentSize = self.imageView.frame.size;
self.scrollView.delegate = self;
}
You are required to implement the following method to return the imageView you want to zoom.
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imageView;
}
In versions prior to iOS9, you may also need to add this empty delegate method:
- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale
{
}
The Apple Documentation does a good job of describing how to do this:
Another easy way to do this is to place your UIImageView within a UIScrollView. As I describe here, you need to set the scroll view's contentSize to be the same as your UIImageView's size. Set your controller instance to be the delegate of the scroll view and implement the viewForZoomingInScrollView: and scrollViewDidEndZooming:withView:atScale: methods to allow for pinch-zooming and image panning. This is effectively what Ben's solution does, only in a slightly more lightweight manner, as you don't have the overhead of a full web view.
One issue you may run into is that the scaling within the scroll view comes in the form of transforms applied to the image. This may lead to blurriness at high zoom factors. For something that can be redrawn, you can follow my suggestions here to provide a crisper display after the pinch gesture is finished. hniels' solution could be used at that point to rescale your image.
Shefali's solution for UIImageView works great, but it needs a little modification:
- (void)pinch:(UIPinchGestureRecognizer *)gesture {
if (gesture.state == UIGestureRecognizerStateEnded
|| gesture.state == UIGestureRecognizerStateChanged) {
NSLog(#"gesture.scale = %f", gesture.scale);
CGFloat currentScale = self.frame.size.width / self.bounds.size.width;
CGFloat newScale = currentScale * gesture.scale;
if (newScale < MINIMUM_SCALE) {
newScale = MINIMUM_SCALE;
}
if (newScale > MAXIMUM_SCALE) {
newScale = MAXIMUM_SCALE;
}
CGAffineTransform transform = CGAffineTransformMakeScale(newScale, newScale);
self.transform = transform;
gesture.scale = 1;
}
}
(Shefali's solution had the downside that it did not scale continuously while pinching. Furthermore, when starting a new pinch, the current image scale was reset.)
Below code helps to zoom UIImageView without using UIScrollView :
-(void)HandlePinch:(UIPinchGestureRecognizer*)recognizer{
if ([recognizer state] == UIGestureRecognizerStateEnded) {
NSLog(#"======== Scale Applied ===========");
if ([recognizer scale]<1.0f) {
[recognizer setScale:1.0f];
}
CGAffineTransform transform = CGAffineTransformMakeScale([recognizer scale], [recognizer scale]);
imgView.transform = transform;
}
}
Keep in mind that you're NEVER zooming in on a UIImage. EVER.
Instead, you're zooming in and out on the view that displays the UIImage.
In this particular case, you chould choose to create a custom UIView with custom drawing to display the image, a UIImageView which displays the image for you, or a UIWebView which will need some additional HTML to back it up.
In all cases, you'll need to implement touchesBegan, touchesMoved, and the like to determine what the user is trying to do (zoom, pan, etc.).
Here is a solution I've used before that does not require you to use the UIWebView.
- (UIImage *)scaleAndRotateImage(UIImage *)image
{
int kMaxResolution = 320; // Or whatever
CGImageRef imgRef = image.CGImage;
CGFloat width = CGImageGetWidth(imgRef);
CGFloat height = CGImageGetHeight(imgRef);
CGAffineTransform transform = CGAffineTransformIdentity;
CGRect bounds = CGRectMake(0, 0, width, height);
if (width > kMaxResolution || height > kMaxResolution) {
CGFloat ratio = width/height;
if (ratio > 1) {
bounds.size.width = kMaxResolution;
bounds.size.height = bounds.size.width / ratio;
}
else {
bounds.size.height = kMaxResolution;
bounds.size.width = bounds.size.height * ratio;
}
}
CGFloat scaleRatio = bounds.size.width / width;
CGSize imageSize = CGSizeMake(CGImageGetWidth(imgRef), CGImageGetHeight(imgRef));
CGFloat boundHeight;
UIImageOrientation orient = image.imageOrientation;
switch(orient) {
case UIImageOrientationUp: //EXIF = 1
transform = CGAffineTransformIdentity;
break;
case UIImageOrientationUpMirrored: //EXIF = 2
transform = CGAffineTransformMakeTranslation(imageSize.width, 0.0);
transform = CGAffineTransformScale(transform, -1.0, 1.0);
break;
case UIImageOrientationDown: //EXIF = 3
transform = CGAffineTransformMakeTranslation(imageSize.width, imageSize.height);
transform = CGAffineTransformRotate(transform, M_PI);
break;
case UIImageOrientationDownMirrored: //EXIF = 4
transform = CGAffineTransformMakeTranslation(0.0, imageSize.height);
transform = CGAffineTransformScale(transform, 1.0, -1.0);
break;
case UIImageOrientationLeftMirrored: //EXIF = 5
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(imageSize.height, imageSize.width);
transform = CGAffineTransformScale(transform, -1.0, 1.0);
transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationLeft: //EXIF = 6
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(0.0, imageSize.width);
transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationRightMirrored: //EXIF = 7
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeScale(-1.0, 1.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0);
break;
case UIImageOrientationRight: //EXIF = 8
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(imageSize.height, 0.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0);
break;
default:
[NSException raise:NSInternalInconsistencyException format:#"Invalid image orientation"];
}
UIGraphicsBeginImageContext(bounds.size);
CGContextRef context = UIGraphicsGetCurrentContext();
if (orient == UIImageOrientationRight || orient == UIImageOrientationLeft) {
CGContextScaleCTM(context, -scaleRatio, scaleRatio);
CGContextTranslateCTM(context, -height, 0);
}
else {
CGContextScaleCTM(context, scaleRatio, -scaleRatio);
CGContextTranslateCTM(context, 0, -height);
}
CGContextConcatCTM(context, transform);
CGContextDrawImage(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, width, height), imgRef);
UIImage *imageCopy = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return imageCopy;
}
The article can be found on Apple Support at:
http://discussions.apple.com/message.jspa?messageID=7276709#7276709
Shafali and JRV's answers extended to include panning and pinch to zoom:
#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;
}
}
The simplest way to do this, if all you want is pinch zooming, is to place your image inside a UIWebView (write small amount of html wrapper code, reference your image, and you're basically done). The more complcated way to do this is to use touchesBegan, touchesMoved, and touchesEnded to keep track of the user's fingers, and adjust your view's transform property appropriately.
Keep in mind that you don't want to zoom in/out UIImage. Instead try to zoom in/out the View which contains the UIImage View Controller.
I have made a solution for this problem. Take a look at my code:
#IBAction func scaleImage(sender: UIPinchGestureRecognizer) {
self.view.transform = CGAffineTransformScale(self.view.transform, sender.scale, sender.scale)
sender.scale = 1
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
view.backgroundColor = UIColor.blackColor()
}
N.B.: Don't forget to hook up the PinchGestureRecognizer.