I want the effect like this:
When I scroll the word from "image1" to "image2" then the background also change, I just don't know how to set the word detection(the line).
#interface myViewController : UIViewController<UIScrollViewDelegate>
#end
- (void)viewDidLoad
{
[super viewDidLoad];
UIScrollView *myscrollView=[[UIScrollView alloc] initWithFrame: CGRectMake(0,0,320,460)];
myscrollView.delegate = self;
CGPoint position = CGPointMake(100, 150);
[myscrollView setContentOffset:position animated:YES];
}
-(void) scrollViewDidScroll:(UIScrollView *) scrollView{
}
-(void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView
{
}
Use the scrollViewDidScroll method, and inside call yourScrollView.contentOffset to check how much you scrolled; then make the necessary changes.
Another way, is by checking if the frame of the scrollView intersects the frame of the label, using CGRect's intersects function inside of scrollViewDidScroll. This might be the easier one.
Check the documentation for scrollViewDidScroll if you need more info.
In iOS 11 buttons and text field are unresponsive being subviews of UIToolBar. Comparing view hierarchy to iOS 10 we see there is a _UIToolBarContentView over all subview of UIToolBar.
For instance, this new layout of the UIToolBar breaks slacktextviewcontroller
https://github.com/slackhq/SlackTextViewController/issues/604
Need a solution working in iOS 10/11.
To solve the problem for iOS11 (compatible with lower versions) you only need
to make layoutSubview right after UIToolBar was added as a subview to UI hierarchy.
In this case _UIToolbarContentView lowers to the first subview of UIToolBar, and you can
add all your subviews higher as before.
For example in ObjC,
UIToolbar *toolbar = [UIToolbar new];
[self addSubview: toolbar];
[toolbar layoutIfNeeded];
<here one can add all subviews needed>
The same problem happens with slacktextviewcontroller
I have solved this problem in my case. I rewrite the layoutSubviews method in subclass of UIToobar and change the userInteractionEnable of _UIToolbarContentView into NO.
- (void)layoutSubviews {
[super layoutSubviews];
NSArray *subViewArray = [self subviews];
for (id view in subViewArray) {
if ([view isKindOfClass:(NSClassFromString(#"_UIToolbarContentView"))]) {
UIView *testView = view;
testView.userInteractionEnabled = NO;
}
}
}
You can just use the hitTest(_:with:) method.
First, create a property contentView in UIToolbar:
open private(set) var contentView: UIView = UIView()
Then, make the contentView's frame the same as the UIToolbar's. For example:
contentView.frame = bounds
contentView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
addSubview(contentView)
Finally, override the hitTest(_:with:) method:
open override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
if self.point(inside: point, with: event) {
if let hitTestView = contentView.hitTest(point, with: event) {
return hitTestView
} else {
return self
}
} else {
return nil
}
}
In this situation, if you want to customize a toolbar by simply adding additional views, you should add them to the contentView so they will be positioned appropriately.
The new UIToolbar object actively uses layout based on constraints, so it is better to override - (void)updateConstraints method. To present custom views over UIToolbar object it is better to subclass it and add custom container view:
- (UIView *)containerView
{
if (_containerView) {
return _containerView;
}
_containerView = [[UIView alloc] initWithFrame:self.bounds];
_containerView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
return _containerView;
}
Now you can safely add your custom views to the container view. To make the custom views responsive we need change the order of toolbar subviews after the constraints update:
- (void)updateConstraints
{
[super updateConstraints];
[self bringSubviewToFront:self.containerView];
}
Note, that if you are using UINavigationController with custom toolbar, you should force it to update its layout before adding your custom subviews.
In Swift with autolayout and code only, what worked for me was to do layout as malex mentions just before adding items, but after setting constraints.
Instantiate your toolbar
Add it to your view
Add constraints
toolbar.layoutIfNeeded()
toolbar.setItems([... (your items)], animated: true)
There is an odd way to do it.
[self.textInputbar sendSubviewToBack:[self.textInputbar.subviews lastObject]];
I have a PopupView that extends UIView. In PopupView I have a UITextView.
When the PopupView show, my UITextView doesn't start at first line (it scroll a little bit to bottom)
So I use the code below to scroll the UITextView to top after PopupView appears
- (void)layoutSubviews{
[super layoutSubviews];
[self.contentTextView setContentOffset:CGPointZero animated:NO];
}
It works well in iOS9 (both device and simulator) but it doesn't work in iOS8
Any idea to fix it.
Any help would be great appreciated
UPDATE
I found that drawRect get called after layoutSubviews and if I setContentOffset:CGPointZero inside it, it will work
-(void)drawRect:(CGRect)rect{
[self.contentTextView setContentOffset:CGPointZero];
}
But I found the purpose of drawRect:
drawRect: - Implement this method if your view draws custom content.
If your view does not do any custom drawing, avoid overriding this
method.
Is it good to use drawRect without layoutSubviews in my case?
According to #longpham instruction, the drawRect() will use GPU so it's not good. Here is the solution that solve my problem
-(void)awakeFromNib{
[super awakeFromNib];
[self layoutIfNeeded]; // call layoutIfNeeded here to make layoutSubviews get called whenever layout change
}
- (void)layoutSubviews{
...
[self.contentTextView setContentOffset:CGPointZero];
}
it worked for me
- (void)drawRect:(CGRect)rect {
self.textView=[[UITextView alloc] initWithFrame:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
[self addSubview:self.textView];
}
So I have a UIScrollView on my iPad app with a single child view (which itself is parent to all the controls). The scrolling all works fine on it. Rotating works fine (the whole view fits in portrait, scrolls on landscape). Once pushing a new screen on the UINavigationController, and then coming back breaks it.
It looks as if the frame of the scrollview's child has moved up, relative to the scroll position, but the scrollview has remained at the bottom (the entire child view has shifted upwards).
I've tried fighting the Constraints in storyboard, literally for hours, and cannot work out what could be causing this.
I had the same problem with scroll view and auto layouts (iOS 6 - doesn't work, iOS 7 - works fine), of course this is not perfect solution, but seems like it works. Hope it will help you:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self performSelector:#selector(content) withObject:nil afterDelay:0.0];
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
offset = self.scrollView.contentOffset;
}
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
self.scrollView.contentOffset = CGPointZero;
}
- (void)content
{
[self.scrollView setContentOffset:offset animated:NO];
}
Get the frame of the subview before it disappears then manually reset the frame of the subview every time the view appears in -(void)viewWillAppear:(BOOL)animated.
-(void)viewWillDisappear:(BOOL)animated{
[super viewWillDisappear:animated];
globalFrameVariable = subview.frame;
[subview removeFromSuperview];
}
-(void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
[subview setFrame:globalFrameVariable];
[scrollView addSubview:subview];
}
Here is a simple solution i found. (Assuming the parent view is meant to span the entire contentSize) Use this subclass of UIScrollView:
#interface BugFixScrollView : UIScrollView
#end
#implementation BugFixScrollView
-(void)layoutSubviews
{
[super layoutSubviews];
UIView *view=[self.subviews firstObject];
if(view)
{
CGRect rect=view.frame;
rect.origin=CGPointMake(0, 0);
view.frame=rect;
}
}
#end
It simply resets the origin every time auto-layout messes it up. this class can be used in InterfaceBuilder simply by changing the class name after placing the UIScrollView.
When a UITextField embedded in a UIScrollView becomes the first responder (for example, by the user typing in some character), the UIScrollView scrolls to that Field automatically. Is there any way to disable that?
Duplicate rdar://16538222
Building on Moshe's answer... Subclass UIScrollView and override the following method:
- (void)scrollRectToVisible:(CGRect)rect animated:(BOOL)animated
Leave it empty. Job done!
In Swift:
class CustomScrollView: UIScrollView {
override func scrollRectToVisible(_ rect: CGRect, animated: Bool) { }
}
I've been struggling with the same problem, and at last I've found a solution.
I've investigated how the auto-scroll is done by tracking the call-trace, and found that an internal [UIFieldEditor scrollSelectionToVisible] is called when a letter is typed into the UITextField. This method seems to act on the UIScrollView of the nearest ancestor of the UITextField.
So, on textFieldDidBeginEditing, by wrapping the UITextField with a new UIScrollView with the same size of it (that is, inserting the view in between the UITextField and it's superview), this will block the auto-scroll. Finally remove this wrapper on textFieldDidEndEditing.
The code goes like:
- (void)textFieldDidBeginEditing:(UITextField*)textField {
UIScrollView *wrap = [[[UIScrollView alloc] initWithFrame:textField.frame] autorelease];
[textField.superview addSubview:wrap];
[textField setFrame:CGRectMake(0, 0, textField.frame.size.width, textField.frame.size.height)];
[wrap addSubview: textField];
}
- (void)textFieldDidEndEditing:(UITextField*)textField {
UIScrollView *wrap = (UIScrollView *)textField.superview;
[textField setFrame:CGRectMake(wrap.frame.origin.x, wrap.frame.origin.y, wrap.frame.size.width, textField.frame.size.height)];
[wrap.superview addSubview:textField];
[wrap removeFromSuperview];
}
hope this helps!
I had the same issue with disabling auto-scrolling of a UITextView being a cell of UITableView. I was able to resolve it using the following approach:
#interface MyTableViewController : UITableViewController<UITextViewDelegate>
#implementation MyTableViewController {
BOOL preventScrolling;
// ...
}
// ... set self as the delegate of the text view
- (void)textViewDidBeginEditing:(UITextView *)textView {
preventScrolling = YES;
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (preventScrolling) {
[self.tableView setContentOffset:CGPointMake(0, -self.tableView.contentInset.top) animated:NO];
}
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
preventScrolling = NO;
}
Defining scrollViewWillBeginDragging is used for restoring the default scrolling behaviour, when the user himself initiates scrolling.
As Taketo mentioned, when a UITextField is made first responder, its first parent view that is of type UIScrollView (if one exists) is scrolled to make that UITextField visible. The easiest hack is to simply wrap each UITextField in a UIScrollView (or ideally, wrap all of them in a single dummy UIScrollView). This is very similar to Taketo's solution, but it should give you slightly better performance, and it will keep your code (or your interface in Interface Builder) much cleaner in my opinion.
Building on Luke's answer, to handle the issue that his solution completely disables auto-scroll, you can disable it selectively as follows:
// TextFieldScrollView
#import <UIKit/UIKit.h>
#interface TextFieldScrollView : UIScrollView
#property (assign, nonatomic) IBInspectable BOOL preventAutoScroll;
#end
#implementation TextFieldScrollView
- (void)scrollRectToVisible:(CGRect)rect animated:(BOOL)animated {
if (self.preventAutoScroll == NO) {
[super scrollRectToVisible:rect animated:animated];
}
}
#end
This way, you can completely set it up in Interface Builder to disable the auto-scroll, but have full control at any time to re-enable it (though why you'd want to is beyond me).
It looks like UIScrollview which contains UITextfield, auto adjusts its content offset; when textfield is going to become first responder.
This can be solved by adding textfield in scrollview of same size first, and then adding in to main scroll view. instead of directly adding in to main scrollview
// Swift
let rect = CGRect(x: 0, y: 0, width: 200, height: 50)
let txtfld = UITextField()
txtfld.frame = CGRect(x: 0, y: 0, width: rect.width, height: rect.height)
let txtFieldContainerScrollView = UIScrollView()
txtFieldContainerScrollView.frame = rect
txtFieldContainerScrollView.addSubview(txtfld)
// Now add this txtFieldContainerScrollView in desired UITableViewCell, UISCrollView.. etc
self.mainScrollView.addSubview(txtFieldContainerScrollView)
// Am33T
This is the way I do it:
It is very simple, you get to return your own contentOffset for any scrollRectToVisible.
This way you are not harming the normal behaviour and flow of things - just providing the same functionality in the same channel, with your own improvements.
#import <UIKit/UIKit.h>
#protocol ExtendedScrollViewDelegate <NSObject>
- (CGPoint)scrollView:(UIScrollView*)scrollView offsetForScrollingToVisibleRect:(CGRect)rect;
#end
#interface ExtendedScrollView : UIScrollView
#property (nonatomic, unsafe_unretained) id<ExtendedScrollViewDelegate> scrollToVisibleDelegate;
#end
#import "ExtendedScrollView.h"
#implementation ExtendedScrollView
- (void)scrollRectToVisible:(CGRect)rect animated:(BOOL)animated
{
if (_scrollToVisibleDelegate && [_scrollToVisibleDelegate respondsToSelector:#selector(scrollView:offsetForScrollingToVisibleRect:)])
{
[self setContentOffset:[_scrollToVisibleDelegate scrollView:self offsetForScrollingToVisibleRect:rect] animated:animated];
}
else
{
[super scrollRectToVisible:rect animated:animated];
}
}
#end
I've tried #TaketoSano's answer, but seems not works.. My case is that I don't have a scrollview, just a view with several text fields.
And finally, I got a workaround. There're two default notification names for keyboard that I need:
UIKeyboardDidShowNotification when the keyboard did show;
UIKeyboardWillHideNotification when the keyboard will hide.
Here's the sample code I used:
- (void)viewDidLoad {
[super viewDidLoad];
...
NSNotificationCenter * notificationCetner = [NSNotificationCenter defaultCenter];
[notificationCetner addObserver:self
selector:#selector(_keyboardWasShown:)
name:UIKeyboardDidShowNotification
object:nil];
[notificationCetner addObserver:self
selector:#selector(_keyboardWillHide:)
name:UIKeyboardWillHideNotification
object:nil];
}
- (void)_keyboardWasShown:(NSNotification *)note {
[self.view setFrame:(CGRect){{272.f, 55.f}, {480.f, 315.f}}];
}
- (void)_keyboardWillHide:(NSNotification *)note {
[self.view setFrame:(CGRect){{272.f, 226.5f}, {480.f, 315.f}}];
}
Here, the (CGRect){{272.f, 226.5f}, {480.f, 315.f}} is view's default frame when keyboard is hidden. And (CGRect){{272.f, 55.f}, {480.f, 315.f}} is view's frame when keyboard did show.
And b.t.w., the view's frame changing will be applied animation automatically, this's really perfect!
I have a collection view with a text field at the very top, mimicking the UITableView.tableHeaderView. This text field is located in the negative content offset space so that it doesn't interfere with the rest of the collection view. I basically am detecting whether or not the user is performing the scrolling in the scroll view and whether or not the text field is first responder and if the scroll view is being scrolled beyond the top of the scroll view's content inset. This exact code won't necessarily help anyone but they could manipulate it to fit their case.
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
// This is solving the issue where making the text field first responder
// automatically scrolls the scrollview down by the height of the search bar.
if (!scrollView.isDragging && !scrollView.isDecelerating &&
self.searchField.isFirstResponder &&
(scrollView.contentOffset.y < -scrollView.contentInset.top)) {
[scrollView setContentOffset:CGPointMake(scrollView.contentOffset.x, -scrollView.contentInset.top) animated:NO];
}
}
I don't know of any property of UIScrollView that would allow that. It would be poor user experience to be able to disable that, IMHO.
That said, it may be possible to subclass UIScrollView and override some of its methods to check that the UITextfield is not a first responder before scrolling.
An easier way to stop the scrollview scrolling when you select a textField is in your viewController::viewWillAppear() DO NOT call [super viewWillAppear];
You can then control the scroll as you wish.