I have a Scrollview, it's properties are set in viewDidAppear.
Now when I get to the Scrollview first time there isn't any problem. However I have buttons that are assigned to UINavigationController. So when I press into one of them UINavigationController opens up, when I close the navigation controller, ScrollView does not restore properly. It basically aligns the centre of the screen as previously pressed button location. So if I try to scroll up it does not.
I have tried using this in my viewDidAppear:
scrollView.center = CGPointMake(scrollView.contentOffset.x, scrollView.contentOffset.y);
Which did not quite work. How can I solve this? I am using iOS6.1
Actually I found the answer here:
UIScrollview Autolayout Issue
The exact code that I used is:
- (void)viewDidDisappear:(BOOL)animated {
[super viewDidDisappear:animated];
//save the current offset
previousPoint = scrollView.contentOffset;
//set current view to the beginning point
self.scrollView.contentOffset = CGPointZero;
}
- (void)viewDidLayoutSubviews {
[super viewDidLayoutSubviews];
//retrieve the previous offset
self.scrollView.contentOffset = previousPoint;
}
previousPoint is nothing but a CGPoint variable declared on the implementation.
I've had this problem before too. This answer shows how to overcome this issue.
Basically, you need to set the scrollview's contentOffset appropriately in viewWillAppear: and viewDidDisappear:.
EDIT: Here's another related question that you might find useful, UIScrollview Autolayout Issue.
Related
I created new Xcode single view project. In interface builder, I added a UIScrollView to cover complete view. Over this scrollview, I added a UITextField. The resulting UI looked like this:
Note that the scrollview does not scroll at this point as the content takes only the size of view and not greater than it.
Now for bringing UITextField on top of keyboard while editing, I followed the way described by Apple on Managing The Keyboard page. After doing this, it gave me expected behavior which brought the text field right above keyboard on editing begin as shown in following screenshot:
Now, after calling [textfield endEditing:YES], the keyboard hides itself, but the textfield does not return to its original place. It return to the place just little above its original place and now the scroll view becomes scrollable as if little height was added to it:
Notice the scroll bar in the above screenshot!
I want help in bring back the original behavior of the view after editing ends (when keyboard hides) i.e. the textField to return to exact same place and scroll should be happening as it was not happening before editing begin.
Project URL: - https://github.com/therohansanap/keyboard.git
You need adjust scrollview contentOffset textFieldDidBeginEditing and textFieldDidEndEditing.
or
One controller is available for scrollview auto scroll.
https://github.com/simonbs/BSKeyboardControls
I think the official way specified by Apple here is easiest and best way to keep this functionality working.
You can do something similar without Using Keyboard notifications as well. As you may know that we have TextField delegate methods , we can use those to set scrollView contentOffset and acquire the same behaviour
- (void)textFieldDidBeginEditing:(UITextField *)textField{
scrollView.contentOffset = CGPointMake(0, textField.center.y-80); // you can change 80 to whatever which fits your needs
}
the above method sets contentOffset Value of scroll view and your textFiled moves up, while the textField resignFirstResponder the below delegate method gets called, where you can set back the contentOffset value
- (void)textFieldDidEndEditing:(UITextField *)textField{
scrollView.contentOffset = CGPointMake(0,-80);
}
Note: you need to make every text field in your view to have their delegate as your UIViewController instance. You also need need your UIViewController to adopt UITextFieldDelegate
Took a look at your code, you dont need to change the content insets etc when trying to position the scroll view. You just need to modify the content offset property.
Here is the modified code :
#interface ViewController () {
UITextField *activeField;
CGPoint scrollViewOldPosition;
}
Modify the keyboardWasShow as follows :
// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWasShown:(NSNotification*)aNotification
{
NSDictionary* info = [aNotification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
CGFloat someSpaceBetweenKeyBoardAndField = 20.0;
scrollViewOldPosition = self.scrollView.contentOffset;
self.scrollView.contentOffset = CGPointMake(0, kbSize.height - (self.view.frame.size.height - activeField.frame.origin.y - activeField.frame.size.height) + someSpaceBetweenKeyBoardAndField);
}
Keyboard will be hidden method :
// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
self.scrollView.contentOffset = scrollViewOldPosition;
}
Not the best code ever but it have some more features u can use, anything with _ is global variable
//Handle notification when keyboard appear
- (void)keyboardOnScreen:(NSNotification *)notification
{
if (_isKeyboardShow) {
return; //If keyboard is showing then return
}
_keyboardHeight = [[notification.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size.height;
[self animateTextFieldUp: YES];
_isKeyboardShow = YES;
}
//Handle notification when keyboard hide
- (void)keyboardOffScreen:(NSNotification *)notification
{
if(!_isKeyboardShow) return;
[self animateTextFieldUp: NO];
_isKeyboardShow = NO;//Missed this line
}
//Push view up with animation when keyboard show
- (void) animateTextFieldUp: (BOOL) up
{
UITextField *textfield = [UIResponder currentFirstResponder];
CGPoint windowPoint = [textfield convertPoint:textfield.bounds.origin toView:self.view];
int movementDistance;
CGPoint point = [_mainScrollView contentOffset];
//Push up only when blocked by keyboard
if (windowPoint.y + textfield.frame.size.height >= self.view.frame.size.height - _keyboardHeight) {
movementDistance = windowPoint.y - (self.view.frame.size.height - _keyboardHeight) + textfield.frame.size.height + 10;
_oldMovementDistance = movementDistance;
int movement = (up ? -movementDistance : movementDistance);
[_mainScrollView setContentOffset:CGPointMake(0, point.y - movement) animated:YES];
}
else { //Push view down the same amount
int movement = (up ? -movementDistance : _oldMovementDistance);
[_mainScrollView setContentOffset:CGPointMake(0, point.y - movement) animated:YES];
_oldMovementDistance = 0;
}
}
move UITextField and UITextView out of the way of the keyboard during editing:
For non-UITableViewControllers, drop the TPKeyboardAvoidingScrollView.m and TPKeyboardAvoidingScrollView.h source files into your project, pop a UIScrollView into your view controller's xib or storyboard, set the scroll view's class to TPKeyboardAvoidingScrollView, and put all your controls within that scroll view. You can also create it programmatically, without using a xib - just use the TPKeyboardAvoidingScrollView as your top-level view.
For use with UITableViewController classes, drop TPKeyboardAvoidingTableView.m and TPKeyboardAvoidingTableView.h into your project, and make your UITableView a TPKeyboardAvoidingTableView in the xib. If you're not using a xib with your controller, I know of no easy way to make its UITableView a custom class: The path of least resistance is to create a xib for it.
You can get reference from here.
Hope this helps.
I am trying to develop a new custom UIView (to allow for horizontal date selection). I want to do all the UI design in XIB files.
The custom UI view contains a scrollview and then two 'week' views. The idea is that as the scrolling occurs, I will move the two 'week' views in place and reconfigure them to the right dates to create an 'infinite' scroll for date selections.
I can load the UIView, which then loads scrollview and week views (all designed in a XIB).
My DatePickerView class, derived from the UIView class does an addSubview of the scroll view (which contains the two week views). The scroll view is 320 wide and the contentSize is set to 640 wide. UserInteraction is enabled. Horizonal Scrolling is enabled.
This all works and displays on the screen. The week views each contain 7 buttons. I can press them and they get the touch. However, the scrollview does not seem to want to scroll.
I set my custom view to be a UIScrollViewDelegate. No calls occur to scrollViewDidScroll.
For each of the week views, I have a 'container' view and then the buttons. I added the following to the container view (again derived from a UIView).
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
DDLogInfo(#"Began. Next Responder: %#", self.nextResponder);
[self.nextResponder touchesBegan:touches withEvent:event];
}
(and comparable ones for the other touch events, touchesMoved, touchesEnded, touchesCancelled),
I print out the nextResponder, which is the UIScrollView, so I know that I am sending the touch to the view, but I never see the scrollview want to scroll.
Is my method of passing the touchEvents up the responder chain correct?
Is there anything else I need to configure to get the scrolling to work?
Any help is appreciated.
Charlie
If I understand correctly, you want infinite scroll with just three pages of scroll view. I achieved it with similar effects in my calendar view project.
You can checkout from here DPCalendar
In a nutshell, I created a view like
#interface DPCalendarMonthlyView : UIScrollView
And initial it like this
self.showsHorizontalScrollIndicator = NO;
self.clipsToBounds = YES;
self.contentInset = UIEdgeInsetsZero;
self.pagingEnabled = YES;
self.delegate = self;
I create three views like this
[self.pagingViews addObject:[self singleMonthViewInFrame:self.bounds]];
[self.pagingViews addObject:[self singleMonthViewInFrame:CGRectMake(self.bounds.size.width, 0, self.bounds.size.width, self.bounds.size.height)]];
[self.pagingViews addObject:[self singleMonthViewInFrame:CGRectMake(self.bounds.size.width * 2, 0, self.bounds.size.width, self.bounds.size.height)]];
Then I set the content size and also scroll it to the middle
[self setContentSize:CGSizeMake(self.bounds.size.width * 3, self.bounds.size.height)];
[self scrollRectToVisible:((UIView *)[self.pagingViews objectAtIndex:1]).frame animated:NO];
In the scrollview delegate function, i need to do
- (void)scrollViewDidEndDecelerating:(UIScrollView *)sender
{
//If scroll right
if(self.contentOffset.x > self.frame.size.width)
{
//do something if scroll right
} else if(self.contentOffset.x < self.frame.size.width)
{
//do something else if scroll left
} else {
return;
}
//scroll back to the middle
[self scrollRectToVisible:((UICollectionView *)[self.pagingViews objectAtIndex:1]).frame animated:NO];
}
Hopefully it is useful to you.
For those that follow down this path, I figured this out and it was a silly error. I forgot to turn off AutoLayout. I keep forgetting that Apple put autoLayout as an enable/disable option under the 'document'-level of a NIB (so I forget to look there).
Turned it off and it works as designed. Looks like autoLayout was causing the views to be rearranged to not need to be scrolled, or something equivalent.
I have a simple view containing a long view with many buttons, with the whole thing being in a UIScrollView. The scroller works well, and I can scroll to the bottom and click a button. Every button triggers a modal seque to another view. That new view is then dismissed by user interaction, causing the original UIScrollView's view to load again.
Here's the problem: If I click on a button toward the top of the UIScrollView, I enter the modal segue, dismiss the new view, and return to the UIScrollView's view without a problem. But, if I click on one of the buttons toward the bottom of the UIScrollView, when I return seque out and then transition back, my scrolling is all messed up. I can only see the area beneath my scroller, and can't scroll back up to the top anymore!
I'm pretty sure there must be some way to reset the UIScrollView's starting and ending points upon ViewWillAppear, but I can't figure it out. Any help is appreciated!
Also, FYI, I simply added the UIScrollView through interface builder, and haven't implemented or synthesized it anywhere yet.
try this code:
- (void)viewWillAppear:(BOOL)animated
{
[yourscrollview setContentOffset:CGPointZero animated:YES];
}
Please note: the bug this question and answer is about appears to be fixed in iOS 7. The rest of this answer is only relevant to iOS 6 (and probably earlier).
The behaviour being exhibited here is a bug in the UIScrollView class. As noted by the OP, after returning from a modally presented UIViewController to a scene containing a UIScrollView, the UIScrollView takes whatever point it's currently scrolled to and starts behaving as though that is its origin. That means that if you'd scrolled down your scroll view before modally presenting another View Controller, you can't scroll back up upon returning to the scene with the scroll view.
The same thing happens when you remove the Scroll View from the view hierarchy and re-add it, even without changing its window.
You can work around this by setting the contentOffset of the scroll view back to {0,0} before it gets displayed again after dismissing the modal View Controller. If you actually want to preserve the point the user had scrolled to before they triggered the modal, then after the UIScrollView is redisplayed you can set the contentOffset back to whatever it was before you reset it.
Here's a UIScrollView subclass that fixes the bug without resetting the scroll view to the top whenever you return from a modal:
#interface NonBuggedScrollView : UIScrollView
#end
#implementation NonBuggedScrollView {
CGPoint oldOffset;
}
-(void)willMoveToWindow:(UIWindow *)newWindow {
oldOffset = self.contentOffset;
self.contentOffset = CGPointMake(0,0);
}
-(void)willMoveToSuperview:(UIView *)newSuperview {
oldOffset = self.contentOffset;
self.contentOffset = CGPointMake(0,0);
}
-(void)didMoveToWindow {
self.contentOffset = oldOffset;
}
-(void)didMoveToSuperview {
self.contentOffset = oldOffset;
}
#end
If you'd rather do this in a UIViewController than in a UIScrollView subclass, change the content offset in the viewWillAppear: and viewDidAppear methods.
If you don't want to preserve where the user's scroll position when they return from a modal, and just want to scroll the UIScrollView back to the top, as the OP asked for, then all you need is the even simpler:
#interface NonBuggedScrollView : UIScrollView
#end
#implementation NonBuggedScrollView
-(void)willMoveToWindow:(UIWindow *)newWindow {
self.contentOffset = CGPointMake(0,0);
}
-(void)willMoveToSuperview:(UIView *)newSuperview {
self.contentOffset = CGPointMake(0,0);
}
#end
First, thanks for the approved answer above. Someone mentioned that it was no longer applicable but I have a scrolling view inside of table view cell and it needs to be reset when the cell is reused.
Here is the solution in Swift.
#IBOutlet var scrollView: UIScrollView!
// many lines of code later inside a function of some sort...
scrollView.setContentOffset(CGPointMake(0.0, 0.0), animated: false)
To solve this problem i use this code:
-(void) viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
[self.scrollview scrollRectToVisible:CGRectMake(0, 0, 1, 1)
animated:NO];
}
You can change the starting and ending points by calling scrollRectToVisible:animated:. But I'm not sure if this fixes your problem.
Use below code snippet to restore the scroll position for a UIScrollview
Declare "scrollPosition" variable as CGPoint type.
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
//get the current offset
scrollPosition = scrollView.contentOffset;
//set current view to the beginning point
self.scrollView.contentOffset = CGPointZero;
}
- (void)viewDidLayoutSubviews
{
[super viewDidLayoutSubviews];
//retrieve the previous offset
self.scrollView.contentOffset = scrollPosition;
}
I have a UIPopover with a UIScrollViewinside it that contains a UITextView at the bottom. When the keyboard shows, the popover is resized as the text view begins to be edited. I want the code below to ensure the text view is visible:
- (void)textViewDidBeginEditing:(UITextView *)textView {
CGRect visRect = textView.frame;
[self.scrollView scrollRectToVisible:visRect animated:NO];
}
The problem is that the code does not make the entire text view visible. Instead, only the text view up to the bottom of the cursor is shown, as shown below:
How can I show the entire text view/ scroll the scrollview to the bottom? I have tried this:
CGPoint bottomOffset = CGPointMake(0, self.scrollView.contentSize.height - self.scrollView.bounds.size.height);
[self.scrollView setContentOffset:bottomOffset animated:YES];
as explained in this answer but nothing works.
In addition, my scrollview is scrolled to the position shown AFTER the keyboard is moved into place. Ideally I'd like the scrolling to happen before or during the keyboard movement.
Any help would be great.
#hey Dave
This By default Case in of UIPopOverController, whenever we used UIPopOverControler to display any PopUpView and in suppose that PopUpView height as large as can be covered by KeyBoard then in that case that PopOverView Automatically gets Shrink itself.as you resign keyboard that PopUpView will expand itself automatically.I have faced same case.
This is just my opinion , you can change the origin of CurrentView(parentView of PopUpView) as keyboard going to display/hide so that PopUpView could display itself properly from and could get the appropriate space.
See Below Are the Delegate methods of UITextView Responds Back as editing start and end.
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView
{
//chnage the OriginY of PopUpView's SUperView
}
- (void)textViewDidBeginEditing:(UITextView *)textView
{
//re Adjust the OriginY of PopUpView's SUperView
}
I hope it may helpful to you.
I found the solution:
- (void)keyboardDidShow:(NSNotification *)notification {
NSLog(#"Notification: %s", __PRETTY_FUNCTION__ );
//
CGFloat textviewBottom = CGRectGetMaxY(self.commentsTextView.frame);
CGRect belowTextViewRect = CGRectMake(0, textviewBottom, 350.f, self.scrollView.contentSize.height - textviewBottom);
// NB! This works ONLY: 1) keyboardDidShow 2) Non-animated;
// Does NOT work: 1) animated, 2) keyboardWillShow, 3) textViewDidBeginEditing
[self.scrollView scrollRectToVisible:belowTextViewRect animated:NO];
}
I add a custom view to my UIViewController dynamically. It adds perfectly now, no exception.But the screen is stuck. My scrollview is not functional. I got this problem earlier and people suggested use setContentSize. I did that and it worked fine. Now I have a new scenario.I have 2 screens.In screen A i save values .Then i click a bar button item on screen A and go to screen B. Here in screen B (it's a tableviewcontroller) I select one row and go back to screen A and fill the values accordingly (basically load the saved values that I saved in the beginning of the app). I fill them correctly and also add the scroll view but it is stuck.It doesn't move neither up/down. I have this code written for adding the subview and setting the scroll-view size and frame size.
ITMCustomView *cView = [[ITMCustomView alloc] initWithFrame:CGRectMake(187, 660, 400, 400)
andOrderedItem:#"New"
andTag:self.tagNumber
withFoldArray:self.foldTypeArray
withRollArray:self.rollTypeArray];
cView.tag =self.tagNumber;
NSLog(#"Assigned tag is %d",cView.tag);
cView.delegate = self;
CGPoint scrollPoint = CGPointMake(0.0, (cView.frame.origin.y/500)*400);
[self.scrollView setContentOffset:scrollPoint animated:YES];
[self.scrollView addSubview:cView];
CGFloat scrollViewHeight = 0.0f;
for (UIView *view in self.scrollView.subviews)
{
scrollViewHeight += view.frame.size.height;
}
CGSize newSize = CGSizeMake(320,scrollViewHeight);
[self.scrollView setContentSize:newSize];
NSLog(#"947 the tag number is %d",self.tagNumber);
I check the value of scrollViewHeight..its 3254.000..I changed it to say 4000 as someone suggested increasing height worked. So what am i doing wrong. This question follows another question of mine Navigating back to UIViewController from TableViewController using NSNotifications
If you need more info please ask.Thanks.
Got mine working after I used did appear instead of will appear.
- (void) viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
self.scrollView.contentSize = self.viewMain.bounds.size;
}
Check the scrollingEnabled property on the scroll view. Unsurprisingly, it needs to be set to YES. If this is the case and it still doesn't work, check if the view (and its superviews) has userInteractionEnabled set to YES as well. In the debugger, you can do po [self.view recursiveDescription] to get the view hierarchy back, that may give you some helpful information as well.