I'm using a UIScrollView for paging three different UIViewControllers. The pager initializes to display page 1 from start. So the user can swipe left or right from the beginning. When I present a modal view controller from the mid view controller, the UIScrollView temporarily scrolls to the first page during the animation of the presented view controller. When I dismiss the modal view controller everything's back to normal and the UIScrollView displays the center view controller.
I would expect (and want) the UIScrollView to keep it's position during the animation.
This is not a technical bug that causes a crash or something, it's just ugly.
Anyone ever had that before? Any idea how to fix it?
I've had this same problem, and after much investigation it appears to be a bug in UIKit relating to scrollviews and AutoLayout. Here's the 'fix'...
In viewDidDisappear:, save the current scrollview contentOffset to a property, and reset it to zero:
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
self.previousContentOffset = self.scrollView.contentOffset;
self.scrollView.contentOffset = CGPointZero;
}
Then, in viewWillAppear:, reset the content offset back to what it was previously. I had to dispatch this onto the main queue to get it to work correctly:
- (void)viewWillAppear:(BOOL)animated
{
if (!CGPointEqualToPoint(self.previousContentOffset, CGPointZero))
{
dispatch_async(dispatch_get_main_queue(), ^{
self.scrollView.contentOffset = self.previousContentOffset;
});
}
}
Related
I am using the new iOS8 viewWillTransitionToSize in my view controller like so:
-(void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator
{
[super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
__weak typeof(self) weakSelf = self;
[coordinator animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> context) {
[weakSelf handleOrientation:[UIApplication sharedApplication].statusBarOrientation];
} completion:^(id<UIViewControllerTransitionCoordinatorContext> context) {
}];
}
I am handling rotation changes in the transition block. This works fine.
But if I push another controller on. Rotate the device. Then navigate back using the swipe from the left of the screen pop gesture (interactivePopGestureRecognizer). The view is in the wrong orientation until the pop gesture is complete. If I just pop the controller using a button, the view is in the correct orientation. Also if I move the handle orientation into the completion block, this also works. But on normal rotation there is now no animation.
Here is a link to an example project
https://drive.google.com/file/d/0B_Fq1pK7MmAzWm5TUGRuX0R3Nlk
Steps:
Select an iOS 8 device
Push to the second view controller using the button
Rotate the device
Navigate back using the swipe gesture
The view will be orientated wrong.
Anyone encountered this problem before? It seems like a bug.
If you implement the popViewController:animated: method like this:
- (UIViewController *)popViewControllerAnimated:(BOOL)animated
{
return [super popViewControllerAnimated:NO];
}
on a navigation controller, the swipe back gesture only works one time. On the next swipe it won't do anything. Additionally, if you hit the back button then, the view controller will be popped with an animation.
Is this a bug or am I missing something?
Feel free to try this for yourself: https://github.com/mrmoneyboy/UINavigationController-Tests
Here's how the scroll views work: One scroll view is paging enabled in the horizontal direction. Each 'page' of this scroll view contains a vertically scrolling UITableView. Without modification, this works OK, but not perfectly.
The behaviour that's not right: When the user scrolls up and down on the table view, but then wants to flick over to the next page quickly, the horizontal flick/swipe will not work initially - it will not work until the table view is stationary (even if the swipe is very clearly horizontal).
How it should work: If the swipe is clearly horizontal, I'd like the page to change even if the table view is still scrolling/bouncing, as this is what the user will expect too.
How can I change this behaviour - what's the easiest or best way?
NOTE For various reasons, a UIPageViewController as stated in some answers will not work. How can I do this with cross directional UIScrollViews (/one is a table view, but you get the idea)? I've been banging my head against a wall for hours - if you think you can do this then I'll more than happily award a bounty.
According to my understanding of the question, it is only while the tableView is scrolling we want to change the default behaviour. All the other behaviour will be the same.
SubClass UITableView. UITableViews are subClass of UIScrollViews. On the UITableView subClass implement one UIScrollView's UIGestureRecognizer's delegate method
- (BOOL)gestureRecognizer:(UIPanGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UISwipeGestureRecognizer *)otherGestureRecognizer
{
//Edit 1
//return self.isDecelerating;
//return self.isDecelerating | self.bounces; //If we want to simultaneous gesture on bounce and scrolling
//Edit 2
return self.isDecelerating || self.contentOffset.y < 0 || self.contentOffset.y > MAX(0, self.contentSize.height - self.bounds.size.height); // #Jordan edited - we don't need to always enable simultaneous gesture for bounce enabled tableViews
}
As we only want to change the default gesture behaviour while the tableView is decelerating.
Now change all 'UITableView's class to your newly created tableViewSubClass and run the project, swipe should work while tableView is scrolling. :]
But the swipe looks a little too sensitive while tableView is scrolling. Let's make the swipe a little restrictive.
SubClass UIScrollView. On the UIScrollView subclass implement another UIGestureRecognizer's delegate method gestureRecognizerShouldBegin:
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
if ([gestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]]) {
CGPoint velocity = [(UIPanGestureRecognizer *)gestureRecognizer velocityInView:self];
if (abs(velocity.y) * 2 < abs(velocity.x)) {
return YES;
}
}
return NO;
}
We want to make the "swipe is clearly horizontal". Above code only permits gesture begin if the gesture velocity on x axis is double than on y axis. [Feel free to increase the hard coded value "2" if your like. The higher the value the swipe needs to be more horizontal.]
Now change the `UiScrollView' class (which has multiple TableViews) to your ScrollViewSubClass. Run the project. :]
I've made a project on gitHub https://github.com/rishi420/SwipeWhileScroll
Although apple doesn't like this method too much:
Important: You should not embed UIWebView or UITableView objects in UIScrollView objects. If you do so, unexpected behavior can result
because touch events for the two objects can be mixed up and wrongly
handled.
I've found a great way to accomplish this.
This is a complete solution for the problem. In order to scroll the UIScrollView while your UITableView is scrolling you'll need to disable the interaction you have it.
- (void)viewDidLoad
{
[super viewDidLoad];
_myScrollView.contentSize = CGSizeMake(2000, 0);
data = [[NSMutableArray alloc]init];
for(int i=0;i<30;i++)
{
[data addObject:[NSString stringWithFormat:#"%d",i]];
}
UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTap:)];
[self.view addGestureRecognizer:tap];
}
- (void)handleTap:(UITapGestureRecognizer *)recognizer
{
[_myTableView setContentOffset:_myTableView.contentOffset animated:NO];
}
- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView
{
scrollView.userInteractionEnabled = NO;
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
scrollView.userInteractionEnabled = YES;
}
To sum up the code above, if the UITableView is scrolling, set userInteractionEnabled to NO so the UIScrollView will detect the swipe. If the UITableView is scrolling and the user taps on the screen, userInteractionEnabled will be set to YES.
Instead of using UIScrollView as a container for these multiple table views, try using a UIPageViewController.
You can even integrate this into your existing view controller setup as a child view controller (directly replacing the UIScrollView).
In addition, you'll likely want to implement the required methods from UIPageViewControllerDataSource and possibly one or more of the methods from UIPageViewControllerDelegate.
Did you try the methods : directionalLockEnabled of both your table and scroll and set them up to horizontal for one and vertical for the other ?
Edit :
1)
What you want to do is very complicate since the touch wait some time (like 0.1s) to know what your movement will be. And if your table is moving, it will take your touch immediately whatever it is (because it's suppose to be reactive movement on it).
I don't see any other solution for you but to override touch movement from scratch to detect immediately the kind of mouvement you want (like if the movement will be horizontal) but it will be more than hard to do it good.
2)
Another solution I can advise you is to make your table have left and right margin, where you can touch the parent scroll (pages thing so) and then even if your table is scrolling, if you touch here, only your paging scroll will be touched. It's simpler, but could not fit with your design maybe...
Use UIPageViewController and in the -viewDidLoad method (or any other method what best suits your needs or design) get UIPageViewController's UIScrollView subview and assign a delegate to it. Keep in mind that, its delegate property won't be nil. So optionally, you can assign it to another reference, and then assign your object, which conforms to UIScrollViewDelegate, to it. For example:
id<UIScrollViewDelegate> originalPageScrollViewDelegate = ((UIScrollView *)[pageViewController.view.subviews objectAtIndex:0]).delegate;
[((UIScrollView *)[pageViewController.view.subviews objectAtIndex:0]) setDelegate:self];
So that you can implement UIScrollViewDelegate methods with ease. And your UIPageViewController will call your delegate's -scrollViewDidScroll: method.
By the way, you may be obliged to keep original delegate, and respond to delegate methods with that object. You can see an example implementation in ViewPagerController class on my UI control project here
I faced the same thing recently. My UIScrollview was on paging mode and every page contained a UITableView and like you described it worked but not as you'd expected it to work. This is how solved it.
First I disabled the scrolling of the UIScrollview
Then I added a UISwipeGestureRecognizer to the actual UITableView for left and right swipes.
The action for those swipes were:
[scroll setContentOffset:CGPointMake(currentPointX + 320, PointY) animated:YES];
//Or
[scroll setContentOffset:CGPointMake(currentPointX - 320 , PointY) animated:YES];
This works flawlessly, the only down side is that if the user drags his finger on the UITableVIew that will be considered as a swipe. He won't be able to see half of screen A and half of screen B on the same screen.
You could subclass your scroll view and your table views, and add this gesture recognizer delegate method to each of them...
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
shouldRecognizeSimultaneouslyWithGestureRecognizer:
(UIGestureRecognizer *)otherGestureRecognizer {
return YES;
}
I can't be sure this is exactly what you are after, but it may come close.
I have written a test iPad app which contains only a split view.
I used the storyboard for set the split view. I did not do any modification to the generated split view controller by the storyboard. But did some modifications to the master view controller and the detail view controller as follow,
Master View Controller:
- (void)viewDidLoad
{
[super viewDidLoad];
............
if ([self respondsToSelector:#selector(edgesForExtendedLayout)])
{
self.edgesForExtendedLayout = UIRectEdgeNone;
}
}
Detail View Controller:
- (void)viewDidLoad
{
.....................
if ([self respondsToSelector:#selector(edgesForExtendedLayout)])
{
self.edgesForExtendedLayout = UIRectEdgeNone;
}
[self.navigationController.navigationBar setBackgroundColor:[UIColor whiteColor]];
}
When launch the app, I noticed that the edges of the faded view appear on the navigation bar. This issue is not exist when I do not set edgesForExtendedLayout for the view controllers.
But it is needed to add.
Any Idea. Please help.
This is an example which has provided by the Apple documentation. This issue is exist with it too. https://developer.apple.com/LIBRARY/IOS/samplecode/Popovers/Introduction/Intro.html#//apple_ref/doc/uid/DTS40010436
I'm not sure, because I'm still learning iOS development but I'm searching for a way to removing the the default left, annoying, offset in a TableView when displaying cells. After googling, I found this answer https://stackoverflow.com/a/18986158/3022883 and if you unselect "Under Bottom Bars" the TabBar (bottom) stays grey. Each cell in a UITableViewController is reused every time you scroll, so since the space in the TabBar is not used to display a cell, I'm assuming that it's the background colour of the TableView.
I've hit a weird problem with UITabBarController on iOS7 and can't seem to find a workaround, so any help would be welcome!
Scenario:
Navigation-based app using landscape orientation on iPad.
App consists of a main view, and a second view which is a UITabBarController.
TabBarController has two tabs.
First view has two buttons - each button performs a segue to the tab bar controller and sets a different tab as selected. (i.e. button1 selects the first tab, and button2 selects the second tab).
Setting the tab is done in prepareForSegue by calling setSelectedIndex on the tab bar controller.
Outcome:
On iOS 7 I am finding that the view shown in the tab bar controller fails to register any touch events along the right-hand edge of the view! So in the storyboard shown above, the UISwitch on the right side of the screen cannot be tapped.
I've even attached a tap gesture recognizer to the views and used it to log the area of the screen that can be touched - it seems to register touch events up to about x=770 points across. The remaining 1/4 of the screen is 'untouchable'!
After the segue, if you manually switch to the other tab and switch back again, the touch events are 'fixed' and the full view responds to touches again.
This doesn't seem to be a problem on iOS 5 / 6.
Any help much appreciated as to:
What is causing this to happen in the first place (iOS7 bug / change?)
How else can I work around this? I've tried calling setSelectedViewController as well as using setSelectedIndex and this seems to be the same.
Thanks in advance.
I ended up raising this with Developer Tech Support, and it looks like a bug. This is the response I got back from Apple:
The container view that the tab bar controller sets up to contain your view controller is not being resized to account for the interface being in landscape orientation. It's dimensions at the time your view controller is displayed are 768 (width) x 1024 (height).
The view hierarchy looks like this when the selected tab's view is displayed:
UIWindow
/* Navigation Controller */
UILayoutContainerView
UINavigationTransitionView
UIViewControllerWrapperView
/* Tab bar controller */
UILayoutContainerView
UITransitionView
UIViewControllerWrapperView <-- Incorrectly sized.
/* MyViewController */
MyViewController.view
The incorrect size of UIViewControllerWrapperView does not cause a display problem because subviews are still displayed even if they are outside their superview's bounds. However, event routing is much more strict. Events on the right quarter of the screen are never routed to your view controller's view because the hit test fails at the wrongly-sized UIViewControllerWrapperView where the event falls outside UIViewControllerWrapperView's bounds.
As a workaround, I subclassed UITabBarController, and added the following in viewWillAppear:
#implementation FixedIOS7TabBarController
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
// Fix the frame of the UIViewControllerWrapperView
self.selectedViewController.view.superview.frame = self.view.bounds;
}
#end
Hope that helps someone else....
As explained in this answer,
The container view that the tab bar controller sets up to contain your
view controller is not being resized to account for the interface
being in landscape orientation. Its dimensions at the time your view
controller is displayed are 768 (width) x 1024 (height).
I was encountering this problem when the TabBarController was originally displayed in portrait mode. When the device was rotated into landscape mode, the view was unresponsive on the right hand side.
The solution proposed in that answer did not work for me, because viewWillAppear: is invoked only once. However, viewDidLayoutSubvews is invoked whenever the view changes, including rotations, so my solution was to subclass UITabBarController and perform the workaround in viewDidLayoutSubvews:
#implementation FixedIOS7TabBarController
- (void)viewDidLayoutSubviews
{
// fix for iOS7 bug in UITabBarController
self.selectedViewController.view.superview.frame = self.view.bounds;
}
#end
End up finding a workaround here:
self.view.autoresizesSubviews = YES;
self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
Right answer don't worked for me, cause user can change orientation; And it still not touchable in some area when change orientation.
So I create my own solution, I don't sure that is normal solution.
#implementation FixedIOS7TabBarController
- (UIView*)findInSubview:(UIView*)view className:(NSString*)className
{
for(UIView* v in view.subviews){
if([NSStringFromClass(v.class) isEqualToString:className])
return v;
UIView* finded = [self findInSubview:v className:className];
if(finded)
return finded;
}
return nil;
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
UIView* wraperView = [self findInSubview:self.view className:#"UIViewControllerWrapperView"];
wraperView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
}
#end
Works perfectly for me!
In the list of view controllers on the left hand side navigate to the views/view controllers affected, drag the view to underneath the first responder so that it is disassociated to the view controller's view.
Then go to the layout tab on the right hand side, select all 4 anchors and both sets of resizing arrows (horizontal + vertical).
Then drag the view back to where it was originally (just below the view controller).