I have a UIView with a UITextView and 2 buttons inside of it. When the user wants to comment on a post, the view moves above the keyboard (this works fine).
When the user starts entering text, the UIView and the UITextView will grow accordingly to the content. This works on every device except iPods and the iPhone 4S. On those devices the textView and the UIView grow behind the keyboard. I've tried changing the vertical content compression resistance priority, but to no avail.
iPhone 4s:
iPhone 7:
Time for the code:
- (void)textViewDidChange:(UITextView *)textView {
[self updateInputPanel];
}
- (void)updateInputPanel {
__weak __typeof__(self) weakSelf = self;
dispatch_async (dispatch_get_main_queue (), ^{
__typeof__(self) strongSelf = weakSelf;
CGFloat widthText = textInput.frame.size.width, heightText;
CGSize sizeText = [textInput sizeThatFits:CGSizeMake (widthText, MAXFLOAT)];
heightText = fmaxf (36.5, sizeText.height);
heightText = fminf (110.0, heightText);
CGFloat heightInput = heightText + (51.0 - 36.5);
CGRect frameViewInput = viewInput.frame;
frameViewInput.origin.y = heightView - heightInput;
frameViewInput.size.height = heightInput;
viewInput.frame = frameViewInput;
[viewInput layoutIfNeeded];
CGRect frameTextInput = textInput.frame;
frameTextInput.size.height = heightText;
textInput.frame = frameTextInput;
CGPoint offset = CGPointMake (0, sizeText.height - heightText);
[textInput setContentOffset:offset animated:NO];
[strongSelf scrollToBottom:NO];
});
}
- (void)keyboardShow:(NSNotification *)notification {
NSDictionary *info = [notification userInfo];
CGRect keyboard = [[info valueForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
NSTimeInterval duration = [[info valueForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
CGFloat heightKeyboard = keyboard.size.height;
[UIView animateWithDuration:duration
delay:0
options:UIViewAnimationOptionAllowUserInteraction
animations:^{
self.view.center = CGPointMake (centerView.x, centerView.y - heightKeyboard);
}
completion:nil];
}
Related
I have several text fields on screen. When I tap inside of the one towards the bottom, the keyboard appears over them.
I've referred to apple's documentation and used the following code to try and tackle this.
// Call this method somewhere in your view controller setup code.
- (void)registerForKeyboardNotifications
{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(keyboardWasShown:)
name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(keyboardWillBeHidden:)
name:UIKeyboardWillHideNotification object:nil];
}
// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWasShown:(NSNotification*)aNotification
{
NSDictionary* info = [aNotification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
scrollView.contentInset = contentInsets;
scrollView.scrollIndicatorInsets = contentInsets;
// If active text field is hidden by keyboard, scroll it so it's visible
// Your app might not need or want this behavior.
CGRect aRect = self.view.frame;
aRect.size.height -= kbSize.height;
if (!CGRectContainsPoint(aRect, activeField.frame.origin) ) {
[self.scrollView scrollRectToVisible:activeField.frame animated:YES];
}
}
// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
UIEdgeInsets contentInsets = UIEdgeInsetsZero;
scrollView.contentInset = contentInsets;
scrollView.scrollIndicatorInsets = contentInsets;
}
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
activeField = textField;
}
- (void)textFieldDidEndEditing:(UITextField *)textField
{
activeField = nil;
}
What i'd like to happen, when the keyboard appears the text fields that in side the scroll field will move up. Any help is appreciated.
Use This Code for Move the view up..........
-(void) textFieldDidBeginEditing:(UITextField*)textField
{
[self slideViewUpForTextField:textField];
}
-(void) slideViewUpForTextField:(UITextField *)textField
{
CGRect textFieldRect = [self.view.window convertRect:textField.bounds fromView:textField];
CGRect viewRect = [self.view.window convertRect:self.view.bounds fromView:self.view];
CGFloat midline = textFieldRect.origin.y + 3.0 * textFieldRect.size.height;
CGFloat numerator = midline - viewRect.origin.y - MINIMUM_SCROLL_FRACTION * viewRect.size.height;
CGFloat denominator = (MAXIMUM_SCROLL_FRACTION - MINIMUM_SCROLL_FRACTION) * viewRect.size.height;
CGFloat heightFraction = numerator / denominator;
if (heightFraction < 0.0)
heightFraction = 0.0;
else if (heightFraction > 1.0)
heightFraction = 1.0;
UIInterfaceOrientation orientation =
[[UIApplication sharedApplication] statusBarOrientation];
if (orientation == UIInterfaceOrientationPortrait || orientation == UIInterfaceOrientationPortraitUpsideDown)
animatedDistance = floor(PORTRAIT_KEYBOARD_HEIGHT * heightFraction);
else
animatedDistance = floor(LANDSCAPE_KEYBOARD_HEIGHT * heightFraction);
CGRect viewFrame = self.view.frame;
viewFrame.origin.y -= animatedDistance;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];
[self.view setFrame:viewFrame];
[UIView commitAnimations];
}
And write these on top of the class
And After #import"".....
static const CGFloat KEYBOARD_ANIMATION_DURATION = 0.3;
static const CGFloat MINIMUM_SCROLL_FRACTION = 0.2;
static const CGFloat MAXIMUM_SCROLL_FRACTION = 0.8;
static const CGFloat PORTRAIT_KEYBOARD_HEIGHT = 158;
static const CGFloat LANDSCAPE_KEYBOARD_HEIGHT = 162;
This is also write ....
-(void) textFieldDidEndEditing:(UITextField*) textField
{
CGRect viewFrame = self.view.frame;
viewFrame.origin.y += animatedDistance;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];
[self.view setFrame:viewFrame];
[UIView commitAnimations];
}
This question has been asked a couple of times, but I wasn't really able to find an answer...
In iOS6 I used the following to resize an UITextView whenever the keyboard appeared. Under iOS7 behavior is not as it should be (in my case, it seems like nothing is resizing at all). I suspect the cause to be the auto-layout / constraint behavior of iOS7. Any suggestions? ("notePad" is my UITextView)?
- (void)keyboardWasShown:(NSNotification*)aNotification
{
NSDictionary* info = [aNotification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
//NSLog(#"KeyboardSize: %f.%f", kbSize.width, kbSize.height);
UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, (kbSize.width > kbSize.height ?
kbSize.height : kbSize.width), 0);
self.notePad.contentInset = contentInsets;
self.notePad.scrollIndicatorInsets = contentInsets;
}
If you're using auto-layout at your views the following method may help you.
First define a IBOutlet for your bottom layout guide constraint and link with storyboard element.
#property (weak, nonatomic) IBOutlet NSLayoutConstraint *textViewBottomConst;
Second add observers for keyboard notifications.
- (void)observeKeyboard {
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}
Finally the methods that handles keyboard changes.
- (void)keyboardWillShow:(NSNotification *)notification {
NSDictionary *info = [notification userInfo];
NSValue *kbFrame = [info objectForKey:UIKeyboardFrameEndUserInfoKey];
NSTimeInterval animationDuration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
CGRect keyboardFrame = [kbFrame CGRectValue];
CGRect finalKeyboardFrame = [self.view convertRect:keyboardFrame fromView:self.view.window];
int kbHeight = finalKeyboardFrame.size.height;
int height = kbHeight + self.textViewBottomConst.constant;
self.textViewBottomConst.constant = height;
[UIView animateWithDuration:animationDuration animations:^{
[self.view layoutIfNeeded];
}];
}
- (void)keyboardWillHide:(NSNotification *)notification {
NSDictionary *info = [notification userInfo];
NSTimeInterval animationDuration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
self.textViewBottomConst.constant = 10;
[UIView animateWithDuration:animationDuration animations:^{
[self.view layoutIfNeeded];
}];
}
This method supports orientation changes and different keyboard sizes. Hope it helps.
Your code is logically correct. When keyboard appear you shouldn't almost never change the frame of an object with the scrollview behaviour, but you should only change the insets.
The insets should change relative to the current version because iOS7 take care of adjust for navigation bar. If you provide a new insets probably you will broke something in UI.
Your code is broken on iOS7 for two main reason:
You must add auto layout constraint to textview container. (Probably your text view is bigger then you expect)
You shouldn't change insets in absolute way.
Here are the steps to properly configure a textview:
In xib (or storyboard) add constraint to top, left, right, bottom to the container (in my case {0, 0, 0, 0} as shown below
Register for keyboard notifications
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
In keyboardWillShow and keyboardWillHide don't change the frame, but change the insets relatively to the existing one.
- (void)keyboardWillShow:(NSNotification *)notification
{
// Take frame with key: UIKeyboardFrameEndUserInfoKey because we want the final frame not the begin one
NSValue *keyboardFrameValue = [notification.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
CGRect keyboardFrame = [keyboardFrameValue CGRectValue];
UIEdgeInsets contentInsets = self.textView.contentInset;
contentInsets.bottom = CGRectGetHeight(keyboardFrame);
self.textView.contentInset = contentInsets;
self.textView.scrollIndicatorInsets = contentInsets;
}
- (void)keyboardWillHide:(NSNotification *)notification
{
UIEdgeInsets contentInsets = self.textView.contentInset;
contentInsets.bottom = .0;
self.textView.contentInset = contentInsets;
self.textView.scrollIndicatorInsets = contentInsets;
}
Then remember to remove observers
#BoranA has the correct answer, but requires tweaking for full functionality for ALL keyboards.
Follow the code below:
Attach the below to your Vertical Space - Bottom Layout Guide - TextField
#property (weak, nonatomic) IBOutlet NSLayoutConstraint *textViewBottomConst;
Second add observers for keyboard notifications.
- (void)observeKeyboard {
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}
Add this to your viewDidLoad
[self observeKeyboard];
Finally the methods that handles keyboard changes.
- (void)keyboardWillShow:(NSNotification *)notification {
//THIS WILL MAKE SURE KEYBOARD DOESNT JUMP WHEN OPENING QUICKTYPE/EMOJI OR OTHER KEYBOARDS.
kbHeight = 0;
height = 0;
self.textViewBottomConst.constant = height;
self.btnViewBottomConst.constant = height;
NSDictionary *info = [notification userInfo];
NSValue *kbFrame = [info objectForKey:UIKeyboardFrameEndUserInfoKey];
NSTimeInterval animationDuration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
CGRect keyboardFrame = [kbFrame CGRectValue];
CGRect finalKeyboardFrame = [self.view convertRect:keyboardFrame fromView:self.view.window];
int kbHeight = finalKeyboardFrame.size.height;
int height = kbHeight + self.textViewBottomConst.constant;
self.textViewBottomConst.constant = height;
[UIView animateWithDuration:animationDuration animations:^{
[self.view layoutIfNeeded];
}];
}
- (void)keyboardWillHide:(NSNotification *)notification {
NSDictionary *info = [notification userInfo];
NSTimeInterval animationDuration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
self.textViewBottomConst.constant = 10;
[UIView animateWithDuration:animationDuration animations:^{
[self.view layoutIfNeeded];
}];
}
I found I had to call [self layoutIfNeeded] in order my insets to take effect.
My keyboard notification method looks like this (I prefer to animate the change):
-(void)keyboardWillShow:(NSNotification*)notification;
{
NSDictionary *userInfo = [notification userInfo];
NSValue *keyboardBoundsValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
CGFloat keyboardHeight = [keyboardBoundsValue CGRectValue].size.width;
CGFloat duration = [[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] floatValue];
NSInteger animationCurve = [[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
[UIView animateWithDuration:duration delay:0. options:animationCurve animations:^{
[[self textView] setContentInset:UIEdgeInsetsMake(0., 0., keyboardHeight, 0.)];
[[self view] layoutIfNeeded];
} completion:nil];
}
You need to resize your UITextView when your keyboard appears.
So have a look to a previous answer I made here.
You need to call the following method to resize your UITextView depending of the width of your keyboard and the text :
- (CGFloat)textViewHeightForAttributedText:(NSAttributedString*)text andWidth:(CGFloat)width
{
UITextView *calculationView = [[UITextView alloc] init];
[calculationView setAttributedText:text];
CGSize size = [calculationView sizeThatFits:CGSizeMake(width, FLT_MAX)];
return size.height;
}
Your code using my method :
- (void)keyboardWasShown:(NSNotification*)aNotification
{
NSDictionary* info = [aNotification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
// Get your text to NSAttributedString
NSAttributedString *as = [[NSAttributedString alloc] initWithString:self.notePad.text];
// Resize UITextView
self.notePad.frame = CGRectMake(0, 0, CGRectGetWidth(self.notePad.frame), [self textViewHeightForAttributedText:as andWidth:kbSize.width)]);
}
I’d been battling with this for a week and I found that adding the keyboard size’s height to the bottom contentInset didn’t work.
What worked was subtracting it from the top, like so:
UIEdgeInsets insets = UIEdgeInsetsMake(-(kbSize.height), 0.0, 0.0, 0.0);
[self.textView setContentInset:insets];
I have enabled my Cocoa Touch app to be navigable by swiping left or right to alter positions in history. The animation is kind of done like Android's "card" style. Where swiping to the left (<--) just moves the current screen image out of the way, while showing the previous view beneath it.
This works fine, but when I want to swipe the other way (-->), to go back, I need to get the previous image, and move that over the current view. Now, I had this working if I only store the previous image, but what if I go <-- a few times, then I will not have enough images.
So, the solution is obvious, use an NSMutableArray and just throw the latest image at the front of the array, and when you swipe the other way, just use the first image in the array. However, the image never shows when I start the animation. It just shows nothing. Here's the required methods you should see:
-(void)animateBack {
CGRect screenRect = [self.view bounds];
UIImage *screen = [self captureScreen];
[imageArray insertObject:screen atIndex:0]; //Insert the screenshot at the first index
imgView = [[UIImageView alloc] initWithFrame:screenRect];
imgView.image = screen;
[imgView setHidden:NO];
NSLog(#"Center of imgView is x = %f, y = %f", imgView.center.x, imgView.center.y);
CGFloat startPointX = imgView.center.x;
CGFloat width = screenRect.size.width;
NSLog(#"Width = %f", width);
imgView.center = CGPointMake(imgView.center.x, imgView.center.y);
[self.view addSubview: imgView];
[self navigateBackInHistory];
[UIView animateWithDuration:.3 animations:^{
isSwiping = 1;
imgView.center = CGPointMake(startPointX - width, imgView.center.y);
} completion:^(BOOL finished){
// Your animation is finished
[self clearImage];
isSwiping = 0;
}];
}
-(void)animateForward {
CGRect screenRect = [self.view bounds];
//UIImage *screen = [self captureScreen];
UIImage *screen = [imageArray objectAtIndex:0]; //Get the latest image
imgView = [[UIImageView alloc] initWithFrame:screenRect];
imgView.image = screen;
[imgView setHidden:NO];
NSLog(#"Center of imgView is x = %f, y = %f", imgView.center.x, imgView.center.y);
CGFloat startPointX = imgView.center.x;
CGFloat width = screenRect.size.width;
NSLog(#"Width = %f", width);
imgView.center = CGPointMake(imgView.center.x - width, imgView.center.y);
[self.view addSubview: imgView];
[UIView animateWithDuration:.3 animations:^{
isSwiping = 1;
imgView.center = CGPointMake(startPointX, imgView.center.y);
} completion:^(BOOL finished){
// Your animation is finished
[self navigateForwardInHistory];
[self clearImage];
isSwiping = 0;
}];
}
-(void)clearImage {
[imgView setHidden:YES];
imgView.image = nil;
}
-(void)navigateBackInHistory {
[self saveItems:self];
[self alterIndexBack];
item = [[[LEItemStore sharedStore] allItems] objectAtIndex:currentHistoryIndex];
[self loadItems:self];
}
-(void)navigateForwardInHistory {
[imageArray removeObjectAtIndex:0]; //Remove the latest image, since we just finished swiping this way.
[self saveItems:self];
[self alterIndexForward];
item = [[[LEItemStore sharedStore] allItems] objectAtIndex:currentHistoryIndex];
[self loadItems:self];
}
Note that imgView is a class-level UIImageView and imageArray is a class level array.
Any ideas? Thanks.
Edit
Here's the code at the top of my .m to initalize it. Still does not work.
.....
NSMutableArray *imageArray;
- (void)viewDidLoad
{
[super viewDidLoad];
imageArray = [imageArray initWithObjects:nil];
It looks like you forgot to create the array. Something like this at the appropriate time would do (assuming ARC):
imageArray = [NSMutableArray array];
Glad that worked out.
Im stuck trying to animate a table view smoothly which has an autolayout contraint. I have a reference to the constraint "keyboardHeight" in my .h and have linked this up in IB. All i want to do is animate the table view with the keyboard when it pops up. Here is my code:
- (void)keyboardWillShow:(NSNotification *)notification
{
NSDictionary *info = [notification userInfo];
NSValue *kbFrame = [info objectForKey:UIKeyboardFrameEndUserInfoKey];
NSTimeInterval animationDuration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
CGRect keyboardFrame = [kbFrame CGRectValue];
CGFloat height = keyboardFrame.size.height;
[UIView animateWithDuration:animationDuration animations:^{
self.keyboardHeight.constant = -height;
[self.view setNeedsLayout];
}];
}
The thing is the animation block is instantaneous and I see white space appear before the keyboard has finished its animation. So basically I see the white background of the view as the keyboard is animating. I cannot make the animation last for as long as the keyboard is animating.
Am i approaching this the wrong way? Thanks in advance!
Try it this way:
self.keyboardHeight.constant = -height;
[self.view setNeedsUpdateConstraints];
[UIView animateWithDuration:animationDuration animations:^{
[self.view layoutIfNeeded];
}];
Remember this pattern because this should be the correct way to update constraint-based layouts (according to WWDC). You can also add or remove NSLayoutConstraints as long as you call setNeedsUpdateConstraints after.
If you're using UITableViewController, keyboard size should be automatically accommodated by iOS to adjust the contentInsets. But if your tableView is inside a UIViewController, you probably wanted to use this:
KeyboardLayoutConstraint in the Spring framework. Simplest solution I've found so far.
Try the next code. In this case table view lays out at the bottom edge of the screen.
- (void)keyboardWillShow:(NSNotification *)notification { // UIKeyboardWillShowNotification
NSDictionary *info = [notification userInfo];
NSValue *keyboardFrameValue = [info objectForKey:UIKeyboardFrameEndUserInfoKey];
NSTimeInterval animationDuration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
CGRect keyboardFrame = [keyboardFrameValue CGRectValue];
BOOL isPortrait = UIDeviceOrientationIsPortrait([UIApplication sharedApplication].statusBarOrientation);
CGFloat keyboardHeight = isPortrait ? keyboardFrame.size.height : keyboardFrame.size.width;
// constrBottom is a constraint defining distance between bottom edge of tableView and bottom edge of its superview
constrBottom.constant = keyboardHeight;
// or constrBottom.constant = -keyboardHeight - in case if you create constrBottom in code (NSLayoutConstraint constraintWithItem:...:toItem:...) and set views in inverted order
[UIView animateWithDuration:animationDuration animations:^{
[tableView layoutIfNeeded];
}];
}
- (void)keyboardWillHide:(NSNotification *)notification { // UIKeyboardWillHideNotification
NSDictionary *info = [notification userInfo];
NSTimeInterval animationDuration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
constrBottom.constant = 0;
[UIView animateWithDuration:animationDuration animations:^{
[tableView layoutIfNeeded];
}];
}
The approach I took is to add a view which follows the size of the keyboard. Add it below your tableview, or text input or whatever and it will push things up when the keyboard appears.
This is how I set up the view hierarchy:
NSDictionary *views = #{#"chats": self.chatsListView, #"reply": self.replyBarView, #"fakeKeyboard":self.fakeKeyboardView};
[self.view addVisualConstraints:#"V:|-30-[chats][reply][fakeKeyboard]|" views:views];
And then the key bits of the keyboard-size-following view look like this:
- (void)keyboardWillShow:(NSNotification *)notification
{
// Save the height of keyboard and animation duration
NSDictionary *userInfo = [notification userInfo];
CGRect keyboardRect = [userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
self.desiredHeight = CGRectGetHeight(keyboardRect);
self.duration = [userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
[self animateSizeChange];
}
- (void)keyboardWillHide:(NSNotification *)notification
{
self.desiredHeight = 0.0f;
[self animateSizeChange];
}
- (CGSize)intrinsicContentSize
{
return CGSizeMake(UIViewNoIntrinsicMetric, self.desiredHeight);
}
- (void)animateSizeChange
{
[self invalidateIntrinsicContentSize];
// Animate transition
[UIView animateWithDuration:self.duration animations:^{
[self.superview layoutIfNeeded];
}];
}
The nice thing about letting this particular view handle its resizing is that you can let the view controller ignore it, and you can also re-use this view any place in your app you want to shift everything up.
The full file is here:
https://gist.github.com/shepting/6025439
I´m working on an ipad app for a comic but i can´t get my scroll view to work. I need it to do:
Pinch zoom
Rotation
Double tap and move by comic strip
Here´s an example of what i want to get http://vimeo.com/16073699 (Second 35 +-)
Right now i have pinch zoom but i can get the scroll view to rotate and center image.
Here´s my controller code:
#define ZOOM_VIEW_TAG 100
#define ZOOM_STEP 2
#define PAGE_TIME 10
- (void)viewDidLoad{
[super loadView];
self.myImage.image = [UIImage imageNamed:#"Tira01.jpg"];
[self.myImage setTag:ZOOM_VIEW_TAG];
UISwipeGestureRecognizer *recognizer;
recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(Tap)];
[(UITapGestureRecognizer *)recognizer setNumberOfTouchesRequired:1];
[(UITapGestureRecognizer *)drecognizer setNumberOfTapsRequired:1];
[[self myImage] addGestureRecognizer:recognizer];
[recognizer release];
self.drecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleDoubleTap:)];
[(UITapGestureRecognizer *)drecognizer setNumberOfTouchesRequired:1];
[(UITapGestureRecognizer *)drecognizer setNumberOfTapsRequired:2];
[[self myImage] addGestureRecognizer:drecognizer];
[drecognizer release];
}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return [myScrollView viewWithTag:ZOOM_VIEW_TAG];
}
- (void)handleDoubleTap:(UIGestureRecognizer *)gestureRecognizer {
UIInterfaceOrientation currentOrientation = [[UIDevice currentDevice] orientation];
if(!self.zoomed)
{
// double tap zooms in
float newScale = [self.myScrollView zoomScale] * ZOOM_STEP;
CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]];
[self.myScrollView zoomToRect:zoomRect animated:YES];
self.zoomed = YES;
}
else {
float newScale = [self.myScrollView zoomScale] / ZOOM_STEP;
CGRect zoomRect = [self zoomRectForScale:newScale withCenter:[gestureRecognizer locationInView:gestureRecognizer.view]];
[self.myScrollView zoomToRect:zoomRect animated:YES];
self.zoomed = NO;
}
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{
return YES;
}
- (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.myScrollView frame].size.height / scale;
zoomRect.size.width = [self.myScrollView 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;
}
In interface builder i have:
-> UIView(ScaleToFill mode)
--> UIScrollView (ScaleToFill mode)
---> UIImageView (AspectFit mode)
I don´t know what i´m doing wrong but i´m going crazy with that :(
Regarding the UIScrollView centering the content, I might be wrong here, but the UIScrollView doesn't automatically do that.
In my app i'm manually doing it by actually moving the content in the scrollView so that it is centered.
Just as a quick explanation for the code below, if the content (image) frame is smaller than the bounds of the scroll view, then adjust the position of the content horizontally and vertically.
The code below is from my class derived from UIScrollView. If you're using the default UIScrollView, you can use this code in the parent UIView.
- (void)layoutSubviews
{
[super layoutSubviews];
if (![self centersContent])
{
return;
}
// center the image as it becomes smaller than the size of the screen
CGSize boundsSize = self.bounds.size;
CGRect frameToCenter = imageView.frame;
// center horizontally
if (frameToCenter.size.width < boundsSize.width)
frameToCenter.origin.x = (boundsSize.width - frameToCenter.size.width) / 2;
else
frameToCenter.origin.x = 0;
// center vertically
if (frameToCenter.size.height < boundsSize.height)
frameToCenter.origin.y = (boundsSize.height - frameToCenter.size.height) / 2;
else
frameToCenter.origin.y = 0;
imageView.frame = frameToCenter;
}