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I am working on Scroll View with gestures. I added a UIView in Scroll View whose size is equal to the ScrollView content size. I want to apply the pinch gesture and rotate gesture on the View which is subview of ScrollView. I have done the work of the pinch gesture by using zoom property and delegate of the ScrollView which give me same effect which I want. But Rotation Gesture is creating Problem. When I add rotation gesture on the view then zooming of the scroll view also get disturb.
So how can i apply the pinch gesture and Rotate gesture on the Scroll View's subview whose size must be equal to the content size of the ScrollView initially.
Can anybody give me the way to do this!
This is the code of .m file, when we rotate the view it become invisible
#import "ViewController.h"
#interface ViewController ()
{
UIView *backgroundView;
UIScrollView *scrollView;
CGFloat lastRotation;
}
#end
#implementation ViewController
-(void)loadView
{
[super loadView];
//Scroll View
scrollView = [[UIScrollView alloc] initWithFrame:self.view.frame];
scrollView.contentSize = self.view.frame.size;
scrollView.delegate = self;
scrollView.backgroundColor = [UIColor grayColor];
//Zooming factors of the Scroll View
scrollView.minimumZoomScale = 1.0;
scrollView.maximumZoomScale = 5.0f;
scrollView.zoomScale = 1.0;
[self.view addSubview:scrollView];
//Scroll View's subview
backgroundView = [[UIView alloc] initWithFrame:scrollView.frame];
[backgroundView setBackgroundColor:[UIColor orangeColor]];
[scrollView addSubview:backgroundView];
UIRotationGestureRecognizer *bgRotationGstr = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(rotateBackgroundView:)];
bgRotationGstr.delegate = self;
bgRotationGstr.cancelsTouchesInView = NO;
[backgroundView addGestureRecognizer:bgRotationGstr];
//Child of background view
UIView *childView = [[UIView alloc] initWithFrame:CGRectMake(20, 50, 100, 100)];
childView.backgroundColor = [UIColor grayColor];
[backgroundView addSubview:childView];
}
//Rotation of the background view
-(void)rotateBackgroundView:(UIRotationGestureRecognizer*)gesture
{
CGFloat rotation = 0.0 - (lastRotation - [(UIRotationGestureRecognizer*)gesture rotation]);
CGAffineTransform currentTransform = backgroundView.transform;
CGAffineTransform newTransform = CGAffineTransformRotate(currentTransform,rotation);
[backgroundView setTransform:newTransform];
lastRotation = [(UIRotationGestureRecognizer*)gesture rotation];
if (gesture.state == UIGestureRecognizerStateBegan || gesture.state == UIGestureRecognizerStateChanged)
{
scrollView.scrollEnabled = NO;
}
else if (gesture.state == UIGestureRecognizerStateEnded)
{
lastRotation = 0.0;
scrollView.scrollEnabled = YES;
return;
}
}
#pragma mark<UIScrollViewDelegate>
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return backgroundView;
}
#pragma mark<UIGetsureRecognizer>
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
return YES;
}
#end
After many days of struggling I found a definitive solution in order to use UIScrollView integrated zoom behavior together with UIRotationGestureRecognizer working like a charm. You have to add a container dummy view as subview of the scroll view, and put the UIImageView as subview of the container view. Afterthat, return the container view in the viewForZoomingInScrollView method and add the UIRotationGestureRecognizer to the scrollview, applying CGAffineTransformRotate to the UIImageView. Finally, return true in the shouldRecognizeSimultaneouslyWithGestureRecognizer method. In this way the scrollView will capture both the two fingers rotation gesture and the pinch to zoom gesture: the zoom will be applied to the dummy view and rotation to the uiimageview, without conflicts between transformations.
In code: let's think to have a UIViewController presenting a UIScrollView. We want to use scrollview's zoom behaviour out of the box together with UIImageView rotation.
1) The controller (or any other object) containing UIScrollView must conforms to UIGestureRecognizerDelegate protocol.
In myViewController.h
#interface myViewController : UIViewController < UIGestureRecognizerDelegate> {
}
2) Create a UIScrollView, add a dummy view as subview and finally add a UIImageView as subview of the dummy view.
In myViewController.m
//Scrollview
myScrollView=[[UIScrollView alloc] initWithFrame:CGRectMake(0,0, view.frame.size.width, view.frame.size.height)];
myScrollView.delegate=self;
[view addSubview:myScrollView];
//Dummy View
UIView *dummyView=[[UIView alloc] initWithFrame:CGRectMake(0, 0, myScrollView.frame.size.width, myScrollView.frame.size.height)];
[self addSubview:dummyView];
//ImageView
imageView=[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, dummyView.frame.size.width, dummyView.frame.size.height)];
imageView.contentMode=UIViewContentModeScaleAspectFit;
[dummyView addSubview:imageView];
//Add rotation gesture to the scrollView
rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(handleRotate:)];
[myScrollView addGestureRecognizer:_rotationGestureRecognizer];
//Set the controller as delegate of the recognizer
rotationGestureRecognizer.delegate=self;
[...]
#pragma UIScrollViewDelegate
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
//Set the dummy view (imageview's superview) as view for zooming
return imageView.superview;
}
[...]
#pragma Mark - UIGestureRecognizerDelegate
- (BOOL) gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
//Make it possibile to recognize simultaneously pinch and rotation gestures
return TRUE;
}
[...]
- (IBAction) handleRotate:(UIRotationGestureRecognizer*)recognizer {
//Apply the rotation to imageView
imageView.transform = CGAffineTransformRotate(imageView.transform, recognizer.rotation);
recognizer.rotation = 0;
}
For simplyfing purposes, I wrote everything in the same controller. You are free to subclass the UIScrollView. Remember that the tricks are:
1) returning the container dummy view as viewForZoomingInScrollView so zoom will affect the container view and rotation will affect the uiimageview.
2) set the viewcontroller containing the scrollview as delegate of the rotation gesture recognizer and return TRUE for shouldRecognizeSimultaneouslyWithGestureRecognizer.
Add this to your .m
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
return YES;
}
Also make sure you dont have exclusive touch enabled on any gesture recognizers.
Try to put you scalable/rotatable content in a subview of your content view. ( Maybe you must set the "clip content" property of your content view to true - not sure )
This way the scrollview is not concerned anymore by transformations, since its content view stays still.
If you have to display the clipped content ( if you rotate a square, for example, the corners go out the initial area), recompute your content view and update the scrollview.
Since you gave the code, I suggest to try:
//Scroll View's subview
backgroundViewHolder = [[UIView alloc] initWithFrame:scrollView.frame];
[backgroundViewHolder setBackgroundColor:[UIColor orangeColor]];
[scrollView backgroundViewHolder];
//Holder View's subview
backgroundView = [[UIView alloc] initWithFrame:backgroundViewHolder.bounds];
[backgroundViewHolder addSubview:backgroundView];
Everything else should remain the same. This is just an idea... Not sure it is the right answer.
Add this to your implement file, make it a UIGestureRecognizerDelegate.
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
return YES;
}
rotationGeustureRecognozier.delegate = self;// (the implement file)
I have a scroll view with some content. After loading the contents I am using the following code to move to the top of the scroll view
[scrollViewCustom setContentOffset:CGPointMake(0.0, 0.0) animated:NO];
It works. With one exception :
I have a UITextView. If I add some text to it, then the scroll view never goes back to the top with this code. I have to manually scroll to the top.
I have even tried to put the same code after adding text to the UITextView.
Can anyone kindly help out ? Thanks.
NB:So, heres the solution :
Basically UITextView derives from UIScrollView and as such, whenever there is some text there, it tries to scroll to make the text visible. I have replaced UITextView to UILabel and it works like a charm !
Instead of
[scrollViewCustom setContentOffset:CGPointMake(0.0, 0.0) animated:NO];
Use
[scroll scrollRectToVisible:CGRectMake(0,0, 100,100) animated:NO];
- (void)viewDidLoad{
scroll.contentSize=CGSizeMake(320, 400);
}
- (void)scrollViewToCenterOfScreen:(UIView *)theView {
CGFloat viewCenterY = theView.center.y;
CGRect applicationFrame = [[UIScreen mainScreen] applicationFrame];
CGFloat availableHeight;
availableHeight = applicationFrame.size.height - 300;
CGFloat z = viewCenterY - availableHeight / 2.0;
if (z < 0) {
z = 0;
}
[scroll setContentOffset:CGPointMake(0, z) animated:YES];
}
-(void)textViewDidBeginEditing:(UITextView *)textView{
[self scrollViewToCenterOfScreen:scroll];
}
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
if (range.length==0) {
[scroll setContentOffset:CGPointMake(0, 0) animated:YES];
return NO;
}
}
Just two steps:
// define the area that is initially visible
scrollViewCustom.frame = CGRectMake(0, 5, 354, 500);
// then define how much a user can scroll it
[scrollViewCustom setContentSize:CGSizeMake(354, 960)];
In addition,clear the background color of scroll view to show the text.
scrollViewCustom.backgroundColor = [UIColor clearColor];
I suppose it's not strictly in line with Apple guidelines but I guess it must be possible somehow. I'd like to change the height of navigation bar inside UINavigationController and the height of UIBarButtonItem elements inside that bar.
Using a trick from this question I managed to change the height of navigation bar but I can see no way of adjusting the height of bar button items.
If anyone knows how to change the size of bar button items, please help me out.
This is my solution. It works very well.
#interface UINavigationBar (CustomHeight)
#end
#implementation UINavigationBar (CustomHeight)
- (CGSize)sizeThatFits:(CGSize)size {
// Change navigation bar height. The height must be even, otherwise there will be a white line above the navigation bar.
CGSize newSize = CGSizeMake(self.frame.size.width, 40);
return newSize;
}
-(void)layoutSubviews {
[super layoutSubviews];
// Make items on navigation bar vertically centered.
int i = 0;
for (UIView *view in self.subviews) {
NSLog(#"%i. %#", i, [view description]);
i++;
if (i == 0)
continue;
float centerY = self.bounds.size.height / 2.0f;
CGPoint center = view.center;
center.y = centerY;
view.center = center;
}
}
Maybe this tutorial about a customized navbar will help you: Recreating the iBooks wood themed navigation bar
If you create a BarButtonItem with a UIImageView you can maybe change the framesize/boundsize of the custom UIImageView
UIImageView* imageView = [[[UIImageView alloc] initWithFrame:navigationController.navigationBar.frame] autorelease];
imageView.contentMode = UIViewContentModeLeft;
imageView.image = [UIImage imageNamed:#"NavBar-iPhone.png"];
[navigationController.navigationBar insertSubview:imageView atIndex:0];
So for your need you would give the -initWithFrame method appropriate values.
static CGFloat const CustomNavigationBarHeight = 74;
#implementation WTNavigationBar
- (CGSize)sizeThatFits:(CGSize)size{
size.width = 1024;
size.height = CustomNavigationBarHeight;
return size;
}
-(void)layoutSubviews {
[super layoutSubviews];
for (UIView *view in self.subviews) {
SFLog(#"view.class=%#",[view class]);
if ([view isKindOfClass:NSClassFromString(#"UINavigationItemButtonView")]) {
float centerY = self.bounds.size.height / 2.0f;
CGPoint center = view.center;
center.y = centerY;
view.center = center;
}
}
}
#end
in my iPad app,which has a fixed landscape orientation,I found I have to hardcode the size's width
I managed to do something similar by subclassing UINavigationBar and overriding -layoutSubviews. The code looks like:
-(void)layoutSubviews {
[super layoutSubviews];
int i = 0;
for (UIView *view in self.subviews) {
NSLog(#"%i. %#", i++, [view description]);
if ([view isKindOfClass:NSClassFromString(#"UINavigationButton")]) {
view.frame = CGRectMake(0, 0, 100, 50);
}
}
}
If you need to know how to subclass UINavigationBar, have a look at this very good answer.
I am not really sure about the NSClassFromString(#"UINavigationButton")] part. It works, but I did this as an experiment, and I'm not sure if this will get approved by Apple. I hope someone with a better knowledge might shed some light.
For the UINavigationbar
In iOS SDK 4.3 and beyond, there is a way (hack) to change the height of the UINavigationBar.
To change the height of UINavigationController, change its frame size in viewWillAppear:animated: function. Then, the height will stay customized throughout whole app.
For the UIBarButtonItems
I've actually run into this myself and the only thing I could come up with was leveraging initWithCustomView and passing in a UIButton with a defined frame.
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
/*
* Insert button styling
*/
button.frame = CGRectMake(0, 0, width, height);
UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc] initWithCustomView:button];
Otherwise UIBarButtonItem only has a width property that can be set but unfortunately not a height property. Another nifty thing I've done with initWithCustomView is to pass in a toolbar with a button and other things like activity indicators. Hope this helps.
How badly do you want this? And, how thin (or thick) do you want to make your navbar?
One approach would be to set the transform of the navbar to scale and translate it. If you scale it too much the title and button text will look wonky, but if you only need to shave a few pixels you might be allright.
Here's the result of scaling it to be 75% of full height (33 pixels tall):
And the code that produced this:
- (void)viewDidLoad
{
[super viewDidLoad];
self.navigationItem.title = #"Thin Navigation Bar";
self.navigationItem.rightBarButtonItem = [[[UIBarButtonItem alloc] initWithTitle: #"Press Me" style:UIBarButtonItemStyleBordered target: nil action: NULL ] autorelease];
CGFloat scale = .75;
CGFloat cy = 44.0 - ( 44.0 * scale );
self.navigationController.navigationBar.transform = CGAffineTransformScale( CGAffineTransformMakeTranslation( 0, -cy / 2.0 ), 1.0, scale ) ;
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
CGFloat scale = .75;
CGFloat cy = 44.0 - ( 44.0 * scale );
CGRect r = self.view.frame;
r.origin.y -= cy;
r.size.height += cy;
self.view.frame = r;
}
Now, this does have a number of problems, which may or may not be solvable. #1 is that you're fighting with the UINavigationController to size and position the navbar and the view-controller views. Animating between view controllers that use this technique is likely going to look weird.
I'd be curious if you could solve the related issues...
One last thought: If you dont use a UINavigationController then there really aren't a whole lot of issues with this other than squished text. Or, you could use a navigation controller but hide the default navbar, and add the thin navbar to each of your child-view controller views. You could even subclass UINavigationBar and set the transform from within:
#interface TSThinNavBar : UINavigationBar
{
}
#end
#implementation TSThinNavBar
// assuming we'll always be constructed from a nib
- (id) initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder: aDecoder];
if ( self != nil )
{
CGFloat scale = .75;
CGFloat cy = 44.0 - ( 44.0 * scale );
self.transform = CGAffineTransformScale( CGAffineTransformMakeTranslation( 0, -cy / 2.0 ), 1.0, scale ) ;
}
return self;
}
#end
I am using the example in the IOS Developer Library for managing the keyboard.
Text, Web and Edition Programming Guide
I have created a view using the IB. Its a simple UI that has a UIScrollView, UITextView, UIButton, and a UITextField. I placed the UIScrollView on my view and then added all the other controls as children of this scrollview. The scrollview is exposed to the viewcontroller via a IBOutlet "scrollView".
The follow code executes with the user sets focus to the textField but I never see a scrollbar appear and the scrollbar's contents are not moved. Should I be able to see the scrollbar by default? Can someone tell me what I'm missing?
-(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 application might not need or want this behavior.
CGRect aRect = self.view.frame;
aRect.size.height -= kbSize.height;
if (!CGRectContainsPoint(aRect, activeField.frame.origin) ) {
CGPoint scrollPoint = CGPointMake(0.0, activeField.frame.origin.y-kbSize.height);
[scrollView setContentOffset:scrollPoint animated:YES];
}
}
Again, I'm taking this code directly from the IOS Programming guide in the link. The UI layout looks like a basic chat window. I would like to move the "input" field up while the soft keyboard is visible. Thanks!
Update
It seems that I needed to add some padding to actually see the controls located at the bottom of the scrollview.
CGPoint scrollPoint = CGPointMake(0.0, (activeField.frame.origin.y - kbSize.height) + 10.0);
How come I don't see scrollbars?
IF YOU HAVE PARENT VIEW AS SCROLL THEN JUST USE : UITextFielddelegate and set the methods
-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
if(textField == self.txtUserName)
{
[self.txtPassword becomeFirstResponder];
}
else if(textField == self.txtPassword){
[self.txtPassword resignFirstResponder];
CGPoint bottomOffset = CGPointMake(0, 0);
[scrView setContentOffset:bottomOffset animated:YES];
[textField resignFirstResponder];
}
return YES;
}
-(void)textFieldDidBeginEditing:(UITextField *)textField
{
if (textField == self.txtUserName)
{
CGPoint bottomOffset = CGPointMake(0, 80);
[scrView setContentOffset:bottomOffset animated:YES];
}
if (textField == self.txtPassword)
{
CGPoint bottomOffset = CGPointMake(0, 135);
[scrView setContentOffset:bottomOffset animated:YES];
}
}
Scrollbars should show up only on user interaction. That's not the case here since your programmatically setting the inset of your scrollview.
If you want to show the scroll bars, i believe UIScrollView defines a flashScrollIndicators method, that should show the scroll bars.
I have 6 UITextFields on my UIScrollView. Now, I can scroll by user request. But when the keyboard appear, some textfields are hidden.
That is not user-friendly.
How scroll programmatically the view so I get sure the keyboard not hide the textfield?
Here's what worked for me. Having an instance variable that holds the value of the UIScrollView's offset before the view is adjusted for the keyboard so you can restore the previous state after the UITextField returns:
//header
#interface TheViewController : UIViewController <UITextFieldDelegate> {
CGPoint svos;
}
//implementation
- (void)textFieldDidBeginEditing:(UITextField *)textField {
svos = scrollView.contentOffset;
CGPoint pt;
CGRect rc = [textField bounds];
rc = [textField convertRect:rc toView:scrollView];
pt = rc.origin;
pt.x = 0;
pt.y -= 60;
[scrollView setContentOffset:pt animated:YES];
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
[scrollView setContentOffset:svos animated:YES];
[textField resignFirstResponder];
return YES;
}
Finally, a simple fix:
UIScrollView* v = (UIScrollView*) self.view ;
CGRect rc = [textField bounds];
rc = [textField convertRect:rc toView:v];
rc.origin.x = 0 ;
rc.origin.y -= 60 ;
rc.size.height = 400;
[self.scroll scrollRectToVisible:rc animated:YES];
Now I think is only combine this with the link above and is set!
I've put together a universal, drop-in UIScrollView and UITableView subclass that takes care of moving all text fields within it out of the way of the keyboard.
When the keyboard is about to appear, the subclass will find the subview that's about to be edited, and adjust its frame and content offset to make sure that view is visible, with an animation to match the keyboard pop-up. When the keyboard disappears, it restores its prior size.
It should work with basically any setup, either a UITableView-based interface, or one consisting of views placed manually.
Here it is.
(For google: TPKeyboardAvoiding, TPKeyboardAvoidingScrollView, TPKeyboardAvoidingCollectionView.)
Editor's note: TPKeyboardAvoiding seems to be continually updated and fresh, as of 2014.
If you set the delegate of your text fields to a controller object in your program, you can have that object implement the textFieldDidBeginEditing: and textFieldShouldReturn: methods. The first method can then be used to scroll to your text field and the second method can be used to scroll back.
You can find code I have used for this in my blog: Sliding UITextViews around to avoid the keyboard. I didn't test this code for text views in a UIScrollView but it should work.
simple and best
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
// self.scrlViewUI.contentOffset = CGPointMake(0, textField.frame.origin.y);
[_scrlViewUI setContentOffset:CGPointMake(0,textField.center.y-90) animated:YES];
tes=YES;
[self viewDidLayoutSubviews];
}
The answers posted so far didn't work for me as I've a quite deep nested structure of UIViews. Also, the I had the problem that some of those answers were working only on certain device orientations.
Here's my solution, which will hopefully make you waste some less time on this.
My UIViewTextView derives from UIView, is a UITextView delegate and adds a UITextView after having read some parameters from an XML file for that UITextView (that XML part is left out here for clarity).
Here's the private interface definition:
#import "UIViewTextView.h"
#import <CoreGraphics/CoreGraphics.h>
#import <CoreGraphics/CGColor.h>
#interface UIViewTextView (/**/) {
#private
UITextView *tf;
/*
* Current content scroll view
* position and frame
*/
CGFloat currentScrollViewPosition;
CGFloat currentScrollViewHeight;
CGFloat kbHeight;
CGFloat kbTop;
/*
* contentScrollView is the UIScrollView
* that contains ourselves.
*/
UIScrollView contentScrollView;
}
#end
In the init method I have to register the event handlers:
#implementation UIViewTextView
- (id) initWithScrollView:(UIScrollView*)scrollView {
self = [super init];
if (self) {
contentScrollView = scrollView;
// ...
tf = [[UITextView alloc] initWithFrame:CGRectMake(0, 0, 241, 31)];
// ... configure tf and fetch data for it ...
tf.delegate = self;
// ...
NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
[nc addObserver:self selector:#selector(keyboardWasShown:) name: UIKeyboardWillShowNotification object:nil];
[nc addObserver:self selector:#selector(keyboardWasHidden:) name: UIKeyboardWillHideNotification object:nil];
[self addSubview:tf];
}
return(self);
}
Once that's done, we need to handle the keyboard show event. This gets called before the textViewBeginEditing is called, so we can use it to find out some properties of the keyboard. In essence, we want to know the height of the keyboard. This, unfortunately, needs to be taken from its width property in landscape mode:
-(void)keyboardWasShown:(NSNotification*)aNotification {
NSDictionary* info = [aNotification userInfo];
CGRect kbRect = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue];
CGSize kbSize = kbRect.size;
CGRect screenRect = [[UIScreen mainScreen] bounds];
CGFloat sWidth = screenRect.size.width;
CGFloat sHeight = screenRect.size.height;
UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
if ((orientation == UIDeviceOrientationPortrait)
||(orientation == UIDeviceOrientationPortraitUpsideDown)) {
kbHeight = kbSize.height;
kbTop = sHeight - kbHeight;
} else {
//Note that the keyboard size is not oriented
//so use width property instead
kbHeight = kbSize.width;
kbTop = sWidth - kbHeight;
}
Next, we need to actually scroll around when we start editing. We do this here:
- (void) textViewDidBeginEditing:(UITextView *)textView {
/*
* Memorize the current scroll position
*/
currentScrollViewPosition = contentScrollView.contentOffset.y;
/*
* Memorize the current scroll view height
*/
currentScrollViewHeight = contentScrollView.frame.size.height;
// My top position
CGFloat myTop = [self convertPoint:self.bounds.origin toView:[UIApplication sharedApplication].keyWindow.rootViewController.view].y;
// My height
CGFloat myHeight = self.frame.size.height;
// My bottom
CGFloat myBottom = myTop + myHeight;
// Eventual overlap
CGFloat overlap = myBottom - kbTop;
/*
* If there's no overlap, there's nothing to do.
*/
if (overlap < 0) {
return;
}
/*
* Calculate the new height
*/
CGRect crect = contentScrollView.frame;
CGRect nrect = CGRectMake(crect.origin.x, crect.origin.y, crect.size.width, currentScrollViewHeight + overlap);
/*
* Set the new height
*/
[contentScrollView setFrame:nrect];
/*
* Set the new scroll position
*/
CGPoint npos;
npos.x = contentScrollView.contentOffset.x;
npos.y = contentScrollView.contentOffset.y + overlap;
[contentScrollView setContentOffset:npos animated:NO];
}
When we end editing, we do this to reset the scroll position:
- (void) textViewDidEndEditing:(UITextView *)textView {
/*
* Reset the scroll view position
*/
CGRect crect = contentScrollView.frame;
CGRect nrect = CGRectMake(crect.origin.x, crect.origin.y, crect.size.width, currentScrollViewHeight);
[contentScrollView setFrame:nrect];
/*
* Reset the scroll view height
*/
CGPoint npos;
npos.x = contentScrollView.contentOffset.x;
npos.y = currentScrollViewPosition;
[contentScrollView setContentOffset:npos animated:YES];
[tf resignFirstResponder];
// ... do something with your data ...
}
There's nothing left to do in the keyboard was hidden event handler; we leave it in anyway:
-(void)keyboardWasHidden:(NSNotification*)aNotification {
}
And that's it.
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
// Drawing code
}
*/
#end
I know this is old, but still none of the solutions above had all the fancy positioning stuff required for that "perfect" bug-free, backwards compatible and flicker-free animation.
Let me share my solution (assuming you have set up UIKeyboardWill(Show|Hide)Notification):
// Called when UIKeyboardWillShowNotification is sent
- (void)keyboardWillShow:(NSNotification*)notification
{
// if we have no view or are not visible in any window, we don't care
if (!self.isViewLoaded || !self.view.window) {
return;
}
NSDictionary *userInfo = [notification userInfo];
CGRect keyboardFrameInWindow;
[[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] getValue:&keyboardFrameInWindow];
// the keyboard frame is specified in window-level coordinates. this calculates the frame as if it were a subview of our view, making it a sibling of the scroll view
CGRect keyboardFrameInView = [self.view convertRect:keyboardFrameInWindow fromView:nil];
CGRect scrollViewKeyboardIntersection = CGRectIntersection(_scrollView.frame, keyboardFrameInView);
UIEdgeInsets newContentInsets = UIEdgeInsetsMake(0, 0, scrollViewKeyboardIntersection.size.height, 0);
// this is an old animation method, but the only one that retains compaitiblity between parameters (duration, curve) and the values contained in the userInfo-Dictionary.
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
[UIView setAnimationCurve:[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
_scrollView.contentInset = newContentInsets;
_scrollView.scrollIndicatorInsets = newContentInsets;
/*
* Depending on visual layout, _focusedControl should either be the input field (UITextField,..) or another element
* that should be visible, e.g. a purchase button below an amount text field
* it makes sense to set _focusedControl in delegates like -textFieldShouldBeginEditing: if you have multiple input fields
*/
if (_focusedControl) {
CGRect controlFrameInScrollView = [_scrollView convertRect:_focusedControl.bounds fromView:_focusedControl]; // if the control is a deep in the hierarchy below the scroll view, this will calculate the frame as if it were a direct subview
controlFrameInScrollView = CGRectInset(controlFrameInScrollView, 0, -10); // replace 10 with any nice visual offset between control and keyboard or control and top of the scroll view.
CGFloat controlVisualOffsetToTopOfScrollview = controlFrameInScrollView.origin.y - _scrollView.contentOffset.y;
CGFloat controlVisualBottom = controlVisualOffsetToTopOfScrollview + controlFrameInScrollView.size.height;
// this is the visible part of the scroll view that is not hidden by the keyboard
CGFloat scrollViewVisibleHeight = _scrollView.frame.size.height - scrollViewKeyboardIntersection.size.height;
if (controlVisualBottom > scrollViewVisibleHeight) { // check if the keyboard will hide the control in question
// scroll up until the control is in place
CGPoint newContentOffset = _scrollView.contentOffset;
newContentOffset.y += (controlVisualBottom - scrollViewVisibleHeight);
// make sure we don't set an impossible offset caused by the "nice visual offset"
// if a control is at the bottom of the scroll view, it will end up just above the keyboard to eliminate scrolling inconsistencies
newContentOffset.y = MIN(newContentOffset.y, _scrollView.contentSize.height - scrollViewVisibleHeight);
[_scrollView setContentOffset:newContentOffset animated:NO]; // animated:NO because we have created our own animation context around this code
} else if (controlFrameInScrollView.origin.y < _scrollView.contentOffset.y) {
// if the control is not fully visible, make it so (useful if the user taps on a partially visible input field
CGPoint newContentOffset = _scrollView.contentOffset;
newContentOffset.y = controlFrameInScrollView.origin.y;
[_scrollView setContentOffset:newContentOffset animated:NO]; // animated:NO because we have created our own animation context around this code
}
}
[UIView commitAnimations];
}
// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillHide:(NSNotification*)notification
{
// if we have no view or are not visible in any window, we don't care
if (!self.isViewLoaded || !self.view.window) {
return;
}
NSDictionary *userInfo = notification.userInfo;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:[[userInfo valueForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue]];
[UIView setAnimationCurve:[[userInfo valueForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]];
// undo all that keyboardWillShow-magic
// the scroll view will adjust its contentOffset apropriately
_scrollView.contentInset = UIEdgeInsetsZero;
_scrollView.scrollIndicatorInsets = UIEdgeInsetsZero;
[UIView commitAnimations];
}
You may check it out: https://github.com/michaeltyson/TPKeyboardAvoiding (I used that sample for my apps). It is working so well. I hope that helps you.
Actually, here's a full tutorial on using TPKeyboardAvoiding, which may help someone
(1) download the zip file from the github link. add these four files to your Xcode project:
(2) build your beautiful form in IB. add a UIScrollView. sit the form items INSIDE the scroll view. (Note - extremely useful tip regarding interface builder: https://stackoverflow.com/a/16952902/294884)
(3) click on the scroll view. then at the top right, third button, you'll see the word "UIScrollView". using copy and paste, change it to "TPKeyboardAvoidingScrollView"
(4) that's it. put the app in the app store, and bill your client.
(Also, just click on the Inspector tab of the scroll view. You may prefer to turn on or off bouncing and the scroll bars - your preference.)
Personal comment - I strongly recommend using scroll view (or collection view) for input forms, in almost all cases. do not use a table view. it's problematic for many reasons. and quite simply, it's incredibly easier to use a scroll view. just lay it out any way you want. it is 100% wysiwyg in interface builder. hope it helps
This is my code, hope it will help you. It work ok in case you have many textfield
CGPoint contentOffset;
bool isScroll;
- (void)textFieldDidBeginEditing:(UITextField *)textField {
contentOffset = self.myScroll.contentOffset;
CGPoint newOffset;
newOffset.x = contentOffset.x;
newOffset.y = contentOffset.y;
//check push return in keyboar
if(!isScroll){
//180 is height of keyboar
newOffset.y += 180;
isScroll=YES;
}
[self.myScroll setContentOffset:newOffset animated:YES];
}
- (BOOL)textFieldShouldReturn:(UITextField *)textField{
//reset offset of content
isScroll = NO;
[self.myScroll setContentOffset:contentOffset animated:YES];
[textField endEditing:true];
return true;
}
we have a point contentOffset to save contentoffset of scrollview before keyboar show. Then we will scroll content for y about 180 (height of keyboar). when you touch return in keyboar, we will scroll content to old point(it is contentOffset). If you have many textfield, you don't touch return in keyboar but you touch another textfield, it will +180 . So we have check touch return
Use any of these,
CGPoint bottomOffset = CGPointMake(0, self.MainScrollView.contentSize.height - self.MainScrollView.bounds.size.height);
[self.MainScrollView setContentOffset:bottomOffset animated:YES];
or
[self.MainScrollView scrollRectToVisible:CGRectMake(0, self.MainScrollView.contentSize.height - self.MainScrollView.bounds.size.height-30, MainScrollView.frame.size.width, MainScrollView.frame.size.height) animated:YES];
I think it's better use keyboard notifications because you don't know if the first responder (the control with focus on) is a textField or a textView (or whatever). So juste create a category to find the first responder :
#import "UIResponder+FirstResponder.h"
static __weak id currentFirstResponder;
#implementation UIResponder (FirstResponder)
+(id)currentFirstResponder {
currentFirstResponder = nil;
[[UIApplication sharedApplication] sendAction:#selector(findFirstResponder:) to:nil from:nil forEvent:nil];
return currentFirstResponder;
}
-(void)findFirstResponder:(id)sender {
currentFirstResponder = self;
}
#end
then
-(void)keyboardWillShowNotification:(NSNotification*)aNotification{
contentScrollView.delegate=nil;
contentScrollView.scrollEnabled=NO;
contentScrollViewOriginalOffset = contentScrollView.contentOffset;
UIResponder *lc_firstResponder = [UIResponder currentFirstResponder];
if([lc_firstResponder isKindOfClass:[UIView class]]){
UIView *lc_view = (UIView *)lc_firstResponder;
CGRect lc_frame = [lc_view convertRect:lc_view.bounds toView:contentScrollView];
CGPoint lc_point = CGPointMake(0, lc_frame.origin.y-lc_frame.size.height);
[contentScrollView setContentOffset:lc_point animated:YES];
}
}
Eventually disable the scroll and set the delegate to nil then restore it to avoid some actions during the edition of the first responder. Like james_womack said, keep the original offset to restore it in a keyboardWillHideNotification method.
-(void)keyboardWillHideNotification:(NSNotification*)aNotification{
contentScrollView.delegate=self;
contentScrollView.scrollEnabled=YES;
[contentScrollView setContentOffset:contentScrollViewOriginalOffset animated:YES];
}
In Swift 1.2+ do something like this:
class YourViewController: UIViewController, UITextFieldDelegate {
override func viewDidLoad() {
super.viewDidLoad()
_yourTextField.delegate = self //make sure you have the delegate set to this view controller for each of your textFields so textFieldDidBeginEditing can be called for each one
...
}
func textFieldDidBeginEditing(textField: UITextField) {
var point = textField.convertPoint(textField.frame.origin, toView: _yourScrollView)
point.x = 0.0 //if your textField does not have an origin at 0 for x and you don't want your scrollView to shift left and right but rather just up and down
_yourScrollView.setContentOffset(point, animated: true)
}
func textFieldDidEndEditing(textField: UITextField) {
//Reset scrollview once done editing
scrollView.setContentOffset(CGPoint.zero, animated: true)
}
}