I'm creating an overlay which will cover all displaying views on screen. This overlay always appears even in case rootViewController changes, pushing or presenting.
My idea is
Create CustomWindow which is a subclass of UIWindow. After that replacing default window of UIApplication with CustomWindow, create a new rootViewController for my new window.
In CustomWindow, I have an overlay (is an UIView). Overlay have light gray color with an alpha and every event on overlay will be pass through to below view.
Whenever CustomWindow add a new subview, i will bring overlay to front. It's make sure overlay will be on the top in every case.
CustomWindow
#implementation CustomWindow
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
_overlay = [[UIView alloc] initWithFrame:self.bounds];
_overlay.userInteractionEnabled = NO;
_overlay.backgroundColor = [UIColor lightGrayColor];
_overlay.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
[self addSubview:_overlay];
}
return self;
}
- (void)didAddSubview:(UIView *)subview {
[super didAddSubview:subview];
[self bringSubviewToFront:_overlay];
}
#end
Everything works fine in every case even when pushing, presenting or changing rootViewController.
Problem
But when i show an UIActivityViewController, I can't click on any extensions which are displayed on UIActivityViewController.
Magically
When i click outside of UIActivityViewController or click on Cancel Button, UIActivityViewController is dismissed normally.
If i change color of overlay to clearColor, it works fine too.
My question is
How can i touch on extensions when i have overlay on window and overlay have a color ?
If i can't, can anyone tell me why it happens ? It's perfect when you can quote the reason from a document.
I'm pretty sure this doesn't relate to how i initialize UIActivityViewController or the way i show UIActivityViewController.
MORE
I found a problem quite similar to this problem on Android. But i'm not sure because i haven't seen any official document about it from Apple. One more thing is when changing color to clearColor can affect touch. So actually, i don't think they are same.
This is due to a UIRemoveView (private) in the hierarchy. As best I can determine, your app cannot forward events directly to remote views. I suspect this is a security measure to prevent you from presenting the share dialog and automatically sending a touch event to it to do an external action the user didn't request. Remote views don't run in your application's process. The "Copy" button is interacted with across an XPC link.
This all means that if the remote view is covered by one of your views, there's no way (at least that I've found) to interact with it. You have to ensure that you're not covering it.
Actually doing that is simple. The thing that holds the remote view is called a UITransitionView and is used for other OS-level things that you probably shouldn't be covering either. So don't:
- (void)didAddSubview:(UIView *)subview {
[super didAddSubview:subview];
if ([subview isKindOfClass:NSClassFromString(#"UITransitionView")]) {
// To raise it above your overlay;
// otherwise it's immediately above the view controller (below the overlay)
[self bringSubviewToFront:subview];
} else {
[self bringSubviewToFront:self.overlay];
}
}
But.... This requires you to talk about UITransitionView in your code. This is both fragile, and possibly a forbidden use of private APIs.
Otherwise you'll have to wrap your UIActivityViewController requests with some call/notification that tells the window not to cover views until we're done (which you'll have to clear in the completion handler).
In a UINavigation bar, there is a right custom share UIBarButtonItem and a back button in the left UIBarButtonItem. When simultaneously tapping on both buttons, the app produces a black view, possibly because both buttons are attempting to display a new view simultaneously - the share button presents a UIActivityViewController and the back button a VC from the prior screen.
In looking through similar questions here, I've tried the following solutions but neither prevented a black view from appearing on a simultaneous button touch:
Inserting exclusiveTouch into ViewDidLoad in the following 2 ways
a)
for(UIView *temp in self.navigationController.navigationBar.subviews)
{ [temp setExclusiveTouch:YES]; }
b) [self.navigationController.navigationBar setExclusiveTouch:YES];
Applying self.navigationController.navigationBar.userInteractionEnabled = NO; after a touch.
Are there other solutions?
Is this related to multi-threading?
In each touch event handler, add the following line:
[[UIApplication sharedApplication] beginIgnoringInteractionEvents];
When the handler has completed, execute the following:
[[UIApplication sharedApplication] endIgnoringInteractionEvents];
It's up to you to figure out what to consider the end of the handler. If you're pushing or popping view controllers, you might add that second line to the viewWillAppear of the relevant view controllers. If you're displaying a modal view controller, you can use the completion handler of -[UIViewController presentViewController:animated:completion:].
Pretty much simple you can use make use of ExclusiveTouch property in this case
[self.navigationController.navigationBar setExclusiveTouch:YES];
This is a Boolean value that indicates whether the receiver handles touch events exclusively.
Setting this property to YES causes the receiver to block the delivery of touch events to other views in the same window. The default value of this property is NO.
If you want only one button to respond to touches at a time, you need to set exclusiveTouch for that button, rather than for the parent view.
Put this just after you add your bar button items.
for(UIView *temp in self.navigationController.navigationBar.subviews)
{
[temp setExclusiveTouch:YES];
}
or you can set exclusiveTouch individually for each UIBarButton while creating them.
I have an idea for an ios5 navigation I'm doing on an app and I thought it wise to get some constructive criticism from SOF about my idea.
Idea:
UIView containing 6 or so buttons stacked vertically
UIButtons have a selected state.
Buttons static/global keeps track of last touched button and always resets the last touched button when a new UIButton is touched.
Question:
Can you read and access the children of the UIView?
eg. (pseudocode)
for (i in [myView children]) {
[[myView getChildAt:i] doSomethingToThisButton];
}
Thanks all!
Yes. Here's the non-pseudocode (well, mostly):
for (UIView *subview in [myView subviews]) {
[subview doSomethingToThisButton];
}
Or, if you prefer
for (int i = 0; i < [myView.subviews count]; i++) {
[[myView.subviews objectAtIndex:i] doSomethingToThisButton];
}
Don't make your last touched button a static variable because then you can only have one such control in your whole app. Make a UIView subclass to act as the container for your buttons, and have the last selected view be a property of that class.
You may also want to make your containing view a subclass of UIControl instead of UIView, then you can make it send events and bind to it using drag and drop in interface builder, just like a regular control (e.g. a button).
I have a UIWebView with some content and I need to make its scroll indicator visible for a short time (like [UIScrollView flashScrollIndicators]).
Any idea how to do this?
Starting iOS 5.0 onwards, one can now customize the scrolling behavior of UIWebView by accessing the 'scrollview' property to achieve the desired functionality:
[webView.scrollView flashScrollIndicators];
There's no real way of doing this via a published API, however I think that in this case it's OK to guess the UIScrollView subview, so long as you make sure your application doesn't crash if you can't find the UIScrollView:
UIView* scrollView = [webView.subviews objectAtIndex:0];
if ([scrollView isKindOfClass:[UIScrollView class]) {
[((UIScrollView*)scrollView) flashScrollIndicators];
} else {
// If Apple changes the view hierarchy you won't get
// a flash, but that doesn't matter too much
}
EDIT: The above will not work because the first subview of a UIWebView is a UIScroller, not a UIScrollView (my memory might be playing tricks on me). Perhaps try the following?
UIView* uiScroller = [webView.subviews objectAtIndex:0];
if ([uiScroller respondsToSelector:#selector(displayScrollerIndicators)]) {
[((UIScrollView*)uiScroller) performSelector:#selector(displayScrollerIndicators)];
} else {
// If Apple changes the view hierarchy you won't get
// a flash, but that doesn't matter too much
}
Does anyone know how to stop a UIWebView from bouncing vertically? I mean when a user touches their iphone screen, drags their finger downwards, and the webview shows a blank spot above the web page I had loaded?
I've looked at the following possible solutions, but none of them worked for me:
http://www.iphonedevsdk.com/forum/iphone-sdk-development/996-turn-off-scrolling-bounces-uiwebview.html
http://forums.macrumors.com/showthread.php?t=619534
How do I stop a UIScrollView from bouncing horizontally?
for (id subview in webView.subviews)
if ([[subview class] isSubclassOfClass: [UIScrollView class]])
((UIScrollView *)subview).bounces = NO;
...seems to work fine.
It'll be accepted to App Store as well.
Update: in iOS 5.x+ there's an easier way - UIWebView has scrollView property, so your code can look like this:
webView.scrollView.bounces = NO;
Same goes for WKWebView.
I was looking at a project that makes it easy to create web apps as full fledged installable applications on the iPhone called QuickConnect, and found a solution that works, if you don't want your screen to be scrollable at all, which in my case I didn't.
In the above mentioned project/blog post, they mention a javascript function you can add to turn off the bouncing, which essentially boils down to this:
document.ontouchmove = function(event){
event.preventDefault();
}
If you want to see more about how they implement it, simply download QuickConnect and check it out.... But basically all it does is call that javascript on page load... I tried just putting it in the head of my document, and it seems to work fine.
Well all I did to accomplish this is :
UIView *firstView = [webView.subviews firstObject];
if ([firstView isKindOfClass:[UIScrollView class]]) {
UIScrollView *scroll = (UIScrollView*)firstView;
[scroll setScrollEnabled:NO]; //to stop scrolling completely
[scroll setBounces:NO]; //to stop bouncing
}
Works fine for me...
Also, the ticked answer for this question is one that Apple will reject if you use it in
your iphone app.
In the iOS 5 SDK you can access the scroll view associated with a web view directly rather than iterating through its subviews.
So to disable 'bouncing' in the scroll view you can use:
myWebView.scrollView.bounces = NO;
See the UIWebView Class Reference.
(However if you need to support versions of the SDK before 5.0, you should follow Mirek Rusin's advice.)
Swift 3
webView.scrollView.bounces = false
Warning. I used setAllowsRubberBanding: in my app, and Apple rejected it, stating that non-public API functions are not allowed (cite: 3.3.1)
In Swift to disable bounces
webViewObj.scrollView.bounces = false
Brad's method worked for me. If you use it you might want to make it a little safer.
id scrollView = [yourWebView.subviews objectAtIndex:0];
if( [scrollView respondsToSelector:#selector(setAllowsRubberBanding:)] )
{
[scrollView performSelector:#selector(setAllowsRubberBanding:) withObject:NO];
}
If apple changes something then the bounce will come back - but at least your app won't crash.
On iOS5 only if you plan to let the users zoom the webview contents (e.i.: double tap) the bounce setting isn't enough. You need to set also alwaysBounceHorizontal and alwaysBounceVertical properties to NO, else when they zoom-out (another double tap...) to default it will bounce again.
I traversed the collection of UIWebView's subviews and set their backgrounds to [UIColor blackColor], the same color as the webpage background. The view will still bounce but it will not show that ugly dark grey background.
It looks to me like the UIWebView has a UIScrollView. You can use documented APIs for this, but bouncing is set for both directions, not individually. This is in the API docs.
UIScrollView has a bounce property, so something like this works (don't know if there's more than one scrollview):
NSArray *subviews = myWebView.subviews;
NSObject *obj = nil;
int i = 0;
for (; i < subviews.count ; i++)
{
obj = [subviews objectAtIndex:i];
if([[obj class] isSubclassOfClass:[UIScrollView class]] == YES)
{
((UIScrollView*)obj).bounces = NO;
}
}
I was annoyed to find out that UIWebView is not a scroll view, so I made a custom subclass to get at the web view's scroll view. This suclass contains a scroll view so you can customize the behavior of your web view. The punchlines of this class are:
#class CustomWebView : UIWebview
...
- (id) initWithFrame:(CGRect)frame{
self = [super initWithFrame:frame];
// WebViews are subclass of NSObject and not UIScrollView and therefore don't allow customization.
// However, a UIWebView is a UIScrollViewDelegate, so it must CONTAIN a ScrollView somewhere.
// To use a web view like a scroll view, let's traverse the view hierarchy to find the scroll view inside the web view.
for (UIView* v in self.subviews){
if ([v isKindOfClass:[UIScrollView class]]){
_scrollView = (UIScrollView*)v;
break;
}
}
return self;
}
Then, when you create a custom web view, you can disable bouncing with:
customWebView.scrollView.bounces = NO; //(or customWebView.scrollView.alwaysBounceVertically = NO)
This is a great general purpose way to make a web view with customizable scrolling behavior. There are just a few things to watch out for:
as with any view, you'll also need to override -(id)initWithCoder: if you use it in Interface Builder
when you initially create a web view, its content size is always the same as the size of the view's frame. After you scroll the web, the content size represents the size of the actual web contents inside the view. To get around this, I did something hacky - calling -setContentOffset:CGPointMake(0,1)animated:YES to force an unnoticeable change that will set the proper content size of the web view.
Came across this searching for an answer and I eventually just lucked on an answer of my own by messing about. I did
[[webview scrollView] setBounces:NO];
and it worked.
This worked for me, and beautifully too (I am using phonegap with webView)
[[webView.webView scrollView] setScrollEnabled:NO];
or
[[webView scrollView] setScrollEnabled:NO];
I tried a slightly different approach to prevent UIWebView objects from scrolling and bouncing: adding a gesture recognizer to override other gestures.
It seems, UIWebView or its scroller subview uses its own pan gesture recognizer to detect user scrolling. But according to Apple's documentation there is a legitimate way of overriding one gesture recognizer with another. UIGestureRecognizerDelegate protocol has a method gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer: - which allows to control the behavior of any colliding gesture recognizers.
So, what I did was
in the view controller's viewDidLoad method:
// Install a pan gesture recognizer // We ignore all the touches except the first and try to prevent other pan gestures
// by registering this object as the recognizer's delegate
UIPanGestureRecognizer *recognizer;
recognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePanFrom:)];
recognizer.delegate = self;
recognizer.maximumNumberOfTouches = 1;
[self.view addGestureRecognizer:recognizer];
self.panGestureFixer = recognizer;
[recognizer release];
then, the gesture override method:
// Control gestures precedence
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
// Prevent all panning gestures (which do nothing but scroll webViews, something we want to disable in
// the most painless way)
if ([otherGestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]])
{
// Just disable every other pan gesture recognizer right away
otherGestureRecognizer.enabled = FALSE;
}
return NO;
}
Of course, this delegate method can me more complex in a real application - we may disable other recognizers selectively, analyzing otherGestureRecognizer.view and making decision based on what view it is.
And, finally, for the sake of completeness, the method we registered as a pan handler:
- (void)handlePanFrom:(UIPanGestureRecognizer *)recognizer
{
// do nothing as of yet
}
it can be empty if all we want is to cancel web views' scrolling and bouncing, or it can contain our own code to implement the kind of pan motions and animations we really want...
So far I'm just experimenting with all this stuff, and it seems to be working more or less as I want it. I haven't tried to submit any apps to iStore yet, though. But I believe I haven't used anything undocumented so far... If anyone finds it otherwise, please inform me.
Here's two newer potential solutions. Apparently, you can use jqtouch or pastrykit to disable scrolling. However, I haven't got these to work. You might be more competent.
turning off vertical scrolling
digging into pastrykit
fixed positioning on mobile safari
This link helped me lot.....Its easy.. There is a demo..
(Xcode 5 iOS 7 SDK example) Here is a Universal App example using the scrollview setBounces function. It is an open source project / example located here: Link to SimpleWebView (Project Zip and Source Code Example)
One of the subviews of UIWebView should be a UIScrollView. Set its scrollEnabled property to NO and the web view will have scrolling disabled entirely.
Note: this is technically using a private API and thus your app could be rejected or crash in future OS releases. Use #try and respondsToSelector
Look into the bounces property of UIScrollView. Quoth the Apple docs:
If the value of the property is YES (the default), the scroll view bounces when it encounters a boundary of the content. Bouncing visually indicates that scrolling has reached an edge of the content. If the value is NO, scrolling stops immediately at the content boundary without bouncing.
Make sure you're using the right UIScrollView. I'm not sure what the hierarchy looks like for a UIWebView, but the scroll view could be a parent, not a child, of the UIWebView.
To disable UIWebView scrolling you could use the following line of code:
[ObjWebview setUserInteractionEnabled:FALSE];
In this example, ObjWebview is of type UIWebView.
webView.scrollView.scrollEnabled=NO;
webView.scrollView.bounces=NO;