How to animate scroll a view like "pull to refresh"? - ios

My app is showing the following:
'Sample 1' is just a view to display content. After I click up button, 'Sample 1' will scroll up and a new view 'Sample 2' will be showed from bottom, the final result is :
I think I should append the sample 2 view at the end of up button, and just adjust the frame of sample 1 and up button to show sample 2.
But I don't know the details how to implement it. Is there a easy way to implement this?

Just place your button and the 2 sample view's in the UIScrollview and set the contentsize of the scrollview to the total height of the button and the 2 sample view's.
Next, you could disable the scrolling on the UIScrollView and connect the button to a method scrolling the UIScrollView up.
Assuming you got your UIScrollView and the 'sample' view's as properties in your custom UIViewController class you could do something like this:
- (void)viewDidLoad
{
[super viewDidLoad];
//disable scrolling
self.scrollView.scrollEnabled = NO;
}
//connect this action to you button
- (IBAction)buttonPressed:(id)sender{
//if current position is top scroll down, otherwise scroll up.
if(self.scrollView.contentOffset.y < 1){
[self.scrollView setContentOffset:CGPointMake(0, self.sample1.frame.size.height) animated:YES];
}else{
[self.scrollView setContentOffset:CGPointMake(0, 0) animated:YES];
}
}

You can try the enormego (EGO). Refer to this question:
Pull to Refresh (ios)

you can implement this using scroll view. Add the views in a scroll view and when the up button is pressed just scroll to the respective position.

I've done this before and before I get say anything about it, you want to be careful because you're creating a view larger than the screen size and therefor you are technically rendering a larger than regular view all the time. Avoiding this (while not necessary) may let you unload a view from screen if you can.
That aside, have your main view appear in a UIScrollView so you can adjust the view's position.
The code may look like:
- (IBAction)upButtonPress:(id)sender
{
[UIView animateWithDuration:2.0 animations:^{
// Approximate frame origin difference
self.scrollView.contentOffset.y = self.view.frame.size.height - upButton.frame.size.height;
} completion:^(BOOL finished) {
// if necessary, do something when animation completes
}];
}

Related

UIButton created outside view not working

I have an application I'm making in storyboards. I want to have a tutorial-type of view. I decided to go with a freeform view controller and am filling it with 600x600 views that count as the pages. The problem I'm having is that when I have a UI button animate to the next page, the buttons that were created outside of the visible view don't seem to work. I even moved a view over so the button was half-visible and only half the button works when I move the view over.
Here's my next page code:
- (void)nextPage {
if (scrolling) return;
scrolling = YES;
[UIView animateWithDuration:0.3 animations:^{
CGRect frame = self.tutorialView.frame;
frame.origin.x -= 50; //frame.size.width;
[self.tutorialView setFrame:frame];
}];
scrolling = NO;
}
I currently have it moving only 50px instead of the whole page for testing purposes.
For testing purposes, I've started it half-way through and only half the button works. I've started it with the second view on top of the other one halfway visible and the same thing happens (only half the button works). Otherwise, when I tap the next button on the first view the buttons on the second view don't work (buttons created outside the initial view).
Views don't receive touch events where they're outside the bounds of their superview. You'll need to increase the button's superview's size.
You can visualize this behavior by setting clipsToBounds = YES - then you'll only see the touchable area of your button.
(You can override this behavior, but you probably shouldn't.)

How to reset my UIScrollView's position after returning from a modal transition?

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;
}

Hiding a toolbar element when UITableView scrolls (similar to Facebook's app?)

How I can achieve this effect?
This isn't immediately noticeable from your screenshots, but I believe you want the that header toolbar to slide up as the user scrolls, right? (I'd suggest clarifying on that part)
You can do this a few ways, and in all of them you will have to implement your own scrolling logic, meaning how much the header toolbar slides up depending on where you have scrolled. That said, here's how to do it:
1. If you're using UITableView, I assume you've got your view controller set as its delegate. Since UITableView is a subclass of UIScrollView already, just add the UIScrollViewDelegate to your view controller. That will give us scroll events as they happen. You'll want to do your logic in scrollViewDidScroll:.
2.. If you're simply using UIScrollView, just set your view controller as its delegate, implement UIScrollViewDelegate, and do your logic in scrollViewDidScroll:.
That said, your code might look something like this:
- (void) scrollViewDidScroll:(UIScrollView *)scrollView {
CGPoint scrollPos = scrollView.contentOffset;
if(scrollPos.y >= 40 /* or CGRectGetHeight(yourToolbar.frame) */){
// Fully hide your toolbar
} else {
// Slide it up incrementally, etc.
}
}
Anyway, hope I helped.
If you have properly set the delegate, your table will call scrollViewDidScroll: when scrolled.
So in your controller, you can add something like :
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (scrollView.contentOffset.y >0) //means that the user began to scroll down the table
{
[UIView animateWithDuration:0.4 animations:^{
//animations you want to perform
}];
}
}
Here i implemented code for UIView Hide / Show when tableview scrolling. When tableview scrolling down then UIView is hidden and when scrolling up then UIView show. I hope it's working for you...!
Step 1:- Make one property in .h file
#property (nonatomic) CGFloat previousContentOffset;
Step 2:- Write down this code in scrollViewDidScroll Method.
-(void)scrollViewDidScroll:(UIScrollView *)scrollView {
CGFloat currentContentOffset = scrollView.contentOffset.y;
if (currentContentOffset > self.previousContentOffset) {
// scrolling towards the bottom
[self.subButtonView setHidden:YES];
} else if (currentContentOffset < self.previousContentOffset) {
// scrolling towards the top
[self.subButtonView setHidden:NO];
}
self.previousContentOffset = currentContentOffset;
}
I create simple class for this effect:
UIHidingView is an iOS class that displays UIView element on top UITableView which is hiding when Table View is scrolling.
This will answer your question :
iPhone: Hide UITableView search bar by default
same concept, different control. You can put a UIView on top row of tableview or any other relevant control such as button.
Good luck.

uitableview with header like instagram user profile

I've been struggling with this for quite a while now.
I have to implement an user profile similar to what Instagram has in their ios app.
When clicking on the first to buttons on that tab bar like thing all the contents downwards from it changes. The tableview that is displayed on the bottom part has dynamic size so they keep account of that also.
I have something implemented where the top part is a UIView with 5 buttons and based on them the bottom part (witch is like a container view) changes content. And these two (top uiview and bottom container view) are part of UIScrollView. But this way I can't get information back in time on the size about the tableview's size that I want to display in the bottom part in order to modify the UIScrollView's size. And I have a feeling this is a flawed way to do it.
I would really appreciate any ideas oh how to implement this king of interaction. Thank you.
I believe it's a headerView on a UITableView or a UICollectionView, depending on which view mode you have selected. When you tap one of the buttons it changes out the UITableView to a UICollectionView or vice versa.
You want to keep track of the current contentOffset for whichever is being displayed (UICollectionView and UITableView are both subclasses of UIScrollView so you will be able to get this from both) and then set the contentOffset on the view you're switching to.
Setup an ivar for the UIView header subclass so you can easily re-use it.
This is what I have. My problem is that I'm mot getting back in useful time the tableview's frame height from the tableview controller to the UserProfileViewController in order to change the latter's scrollview size. I also feel that I'm somehow doing this backwards so any suggestions are more than welcome.
This view has two parts: an upper part and a lower part. The parent view is a scroll view. What I wanted to achieve with this is having a sort of tab bar in the upper part that will controll waht will appear in the lower part.
The upper part has a flip animation when the upper left button is pressed to reveal another view.
The way this is achieved is by having 2 views: a dummy view and the back view. The dummy view has the front view as a child. The front view is the one that containes all the buttons.
The code for this animation is achieved in this way:
- (IBAction)infoButtonPressed:(id)sender
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:1.0];
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.hoverView cache:YES];
if ([self.headerView superview]) {
[self.headerView removeFromSuperview];
[self.hoverView addSubview:self.backOfHeaderView];
[self.infoButton removeFromSuperview];
[self.backOfHeaderView addSubview:self.infoButton];
} else {
[self.backOfHeaderView removeFromSuperview];
[self.hoverView addSubview:self.headerView];
[self.infoButton removeFromSuperview];
[self.headerView addSubview:self.infoButton];
}
[UIView commitAnimations];
}
The lower part is made out of a container view that acts as a place holder.
When a button is pressed a different view controller is displayed in the container view.
Each view controller has a container view of it's own. The specific view of that view controller (tableview) is added to it's container view when the controller is loaded. It also makes sure that if the tableview is already added to the container view it will be removed. All this is done in each specific view controller.
In the view controller of the User Profile view there is an instance of the container view and one of a UIViewController that also acts as a placeholder(named currentViewController from now on). When a specific button is pressed it checks if the an instance of the view controller that we want to display already exists. If not it will make one and will set it's tableview's frame to the bounds of the container view. After that it will remove the currentViewController's view from the superview and the currentViewController itself from the parent viewcontroller to make sure that if there is something assigned to these they will not be there. Then it goes and assigns the desired viewcontroller to the currentViewController. It also assigns the desired viewcontroller's containerView instance to the containerview in the parent viewcontroller (the User Profile viewcontroller). At the end it will add the desired viewcontroller as a child to the main viewcontroller (the User Profile viewcontroller) and desired viewcontroller's view to the containerView of the main viewcontroller.
This is the code for one of the buttons:
//Check if there is an instance of the viewcontroller we want to display. If not make one and set it's tableview frame to the container's view bounds
if(!_userWallViewController) {
self.userWallViewController = [[WallViewController alloc] init];
// self.userWallViewController.activityFeedTableView.frame = self.containerView.bounds;
}
[self.userWallViewController.containerView addSubview:self.userWallViewController.activityFeedTableView];
//If the currentviewcontroller adn it's view are already added to the hierarchy remove them
[self.currentViewController.view removeFromSuperview];
[self.currentViewController removeFromParentViewController];
//Add the desired viewcontroller to the currentviewcontroller
self.currentViewController = self.userWallViewController;
//Pass the data needed for the desired viewcontroller to it's instances
self.userWallViewController.searchURLString = [NSString stringWithFormat:#"event/user/%#/", self.userID];
self.userWallViewController.sendCommentURLString = [NSString stringWithFormat:#"event/message/%#", self.userID];
self.userWallViewController.totalCellHeight = ^(float totalCellHeight){
self.userWallViewController.numberOfCells = ^(float numberOfCells){
NSLog(#"The total number of cells: %f", numberOfCells);
NSLog(#"The total cell height: %f", totalCellHeight);
self.scrollView.contentSize = CGSizeMake(320.0, totalCellHeight + 172.0 + 33.0);
CGRect newFrame = self.userWallViewController.containerView.frame;
newFrame.size.height = totalCellHeight + 33.0;
self.userWallViewController.containerView.frame = newFrame;
NSLog(#"Container view: %f", self.containerView.frame.size.height);
NSLog(#"Scroll view: %f",self.scrollView.contentSize.height );
};
};
//Add this containerview to the desired viewcontroller's containerView
self.userWallViewController.containerView = self.containerView;
//Add the needed viewcontroller and view to the parent viewcontroller and the containerview
[self addChildViewController:self.userWallViewController];
[self.containerView addSubview:self.userWallViewController.view];
[self performSelector:#selector(changeScrollView) withObject:self afterDelay:0.5];
//CLEAN UP THE CONTAINER VIEW BY REMOVING THE PREVIOUS ADDED TABLE VIEWS
[self.userFansViewController.userSimpleTableView removeFromSuperview];
[self.fanOfViewController.userSimpleTableView removeFromSuperview];
[self.userPublishedMovellaListViewController.gridView removeFromSuperview];
[self.userPublishedMovellaListViewController removeFromParentViewController];
self.userPublishedMovellaListViewController = nil;
}
I know this answer is over a year late, but I wanted to state my hypothesis on it...just incase it might help someone else later. Im implementing a similar view and came to this conclusion. Anyone is welcomed to correct me if I'm wrong.
I think that perhaps the top view is a header view and the two options that seem like a collection view and a table view are both collection views.
Because the layout of collection views can be fine tuned to the most minute details, I think the view that looks like a table view is just a really specifically designed collection view. And when switching between the views, the collection view's data and properties are being swapped and reloaded.

UIView animation while scrolling a table

I have a UITableView in an iPad, and its right half side is covered with a view.
What I want is: when the user scroll the UITableView, I want the covering view to slide (with an animation) to the right until its origin.x is at the end of the right side of the table, so the UITableView is clear to see (just like in the Twitter app for iPad).
The problem is: You can scroll the UITableView and animate a view at the same time. When I start scrolling, I use didStartDraging and even DidScroll to create a [UIView animate...] method, but this method stuck my scrolling.
I tired with block animation. I tried with Gestures. I tried with CABasicAnimation, and it goes quite OK, but somehow all the UISubview "Touch area" in my sliding view stay at the old place (what I mean is that the view gets its new frame, but I can scroll a UIScrollView, which is a UISubview of my view, even when my finger is out of the superviews frame S-:, even that there is no view at that point on screen.)
Any thoughts how can I make the animation without damaging the scroll of the table? (and I heard about the timer in the K and the runloop common modes. Not so helping)
Thanks.
scrollview Delegate methods will be invoked for tableView also ............
you can use following code it worked for me and hope will work for you also.......
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
[UIView animateWithDuration:0.3 animations:^{
[scrollView setFrame:CGRectMake(50, scrollView.frame.origin.y, scrollView.frame.size.width, scrollView.frame.size.height)];
}];
}
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
[UIView animateWithDuration:0.3 animations:^{
[scrollView setFrame:CGRectMake(100, scrollView.frame.origin.y, scrollView.frame.size.width, scrollView.frame.size.height)];
}];
}
set x position of scrollView(tableView) as your requirement......
Have a happy coding....

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