I have a UIView and a UIWebView.
The UIWebView is a child view of the UIView.
The UIWebView contains a youtube video and is set as to let the video fit to the UIWebView.
I have a UITapGesture associated with the parent UIView for single tap, say, if a user single tap the whole view, it will invoke A.
So, when the UIWebView loads the youtube video, there is a button on top of the video waiting for users to click to play. But now if I click the button, the youtube is played, but also the A is invoked too. This is what I don't want.
How should I solve it?
I thought the touch/tap event should be in a order and if the button is clicked, it should absorb the event and not give the UIView any more.
I also tried to add another UIView under the UIWebView, and attach that gesture to the underlying view. However, it still doesn't work.
How can I do to let the button over the youtube video independent?
thanks
Try add this code in your view's .m file (if you are using UIView, subclass it):
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
CGPoint p = [self convertPoint:point toView:webView];
if ([webView pointInside:p withEvent:event]) {
return [webView hitTest:p withEvent:event];
}
return [super hitTest:point withEvent:event];
}
Since I did not try this code, tell me if it doesn't work. There are still many ways to deal with the situation. :)
Related
I am new to iPhone Developer,
I want to detect touch in my webview so i tried this but this method is not getting fired,
in .h file
#interface EpubReaderViewController : UIViewController
in .m file
...
- (void)sendEvent:(UIEvent *)event{
NSLog(#"Touch detected") ;
}
...
Even i tried this also,
- (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event {
NSLog(#"Touches began");
}
Thanks In Advance !
User is going to zoom in and zoom out on the website, as well as touch to click hpyerlinks etc. That'w shy touch methods won't respond for UIWebView.
If you want to enable touch, you might need to subclass UIWebview while it is forbidded in developer docs, check following threads for more discussion-
Handling touches inside UIWebview
https://stackoverflow.com/questions/2122745/how-to-detect-touch-event-in-uiwebview
How to intercept touches events on a MKMapView or UIWebView objects?
Handling touches inside UIWebview
You can go through this tutorial as well -
http://mithin.in/2009/08/26/detecting-taps-and-events-on-uiwebview-the-right-way
I have tried various solutions provided on this site and others to implement touch events on uiwebview. But still I am not able to do this. Actually, i have created a article reader application. Here, I have added a uiwebview on the normal uiview. Now, I want to trace some user touch events on that particular webview.
When I do this on normal view, it works perfectly. But if I try it on webview. it stops working.
The solutions I tried before are
implementing touch methods like
touchbegan
touchended
touchmoved
touch cancelled
2 implementing uigesturerecognizer
3 implementing window touch events like send event
Now If anyone can help me or tell me where I am doing wrong or a new solution(other than this), then I will be thankful.
Put a transparent UIVIew on top of your UIWebView to capture touches. You can then act on them or optionally pass them down to the UIWebView using the touchesBegan deletage method.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[self.myUIWebView touchesBegan:touches withEvent:event];
}
Check this previous post for details: iOS - forward all touches through a view
I subclassed UIWebView and just "leeched" onto its gesture recognizers in subviews 2 levels deep (you could go recursively but thats enough for iOS6-7).
Then you can do whatever you want with the touch location and gesture recognizer's state.
for (UIView* view in self.subviews) {
for (UIGestureRecognizer* recognizer in view.gestureRecognizers) {
[recognizer addTarget:self action:#selector(touchEvent:)];
}
for (UIView* sview in view.subviews) {
for (UIGestureRecognizer* recognizer in sview.gestureRecognizers) {
[recognizer addTarget:self action:#selector(touchEvent:)];
}
}
}
I have a UIScrollview in my app and I populate it with LOTS of UIImageViews approx 900. They are all very small and consist of only two different images over and over again.
Now I am having a lot of trouble detecting a touch on one of these UIImageViews.
I have assigned them all a unique TAG so as to be able to distinguish between them but I am really struggling to detect the touch.
The goal is just to be able to change the image of the touched UIImageView.
Due to the large amount of views involved a simple loop checking touch coordinates against each UIImageViews frame is just hanging my app.
Does anyone have any suggestions?
Thanks in Advance.
Ben
In my case the easiest way to do it was adding a gesture recognizer:
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(singleTapGestureCaptured:)];
//Default value for cancelsTouchesInView is YES, which will prevent buttons to be clicked
singleTap.cancelsTouchesInView = NO;
[myScrollView addGestureRecognizer:singleTap];
Then use this method to capture the touch:
- (void)singleTapGestureCaptured:(UITapGestureRecognizer *)gesture
{
CGPoint touchPoint=[gesture locationInView:myScrollView];
}
UIImageView has touch processing turned off by default. To change that set userInteractionEnabled to YES (see the docs here http://developer.apple.com/library/ios/#DOCUMENTATION/UIKit/Reference/UIImageView_Class/Reference/Reference.html)
Also if you want to know which view was hit in a view hierarchy you can use hitTest:withEvent: (see docs in UIView) which will be much faster than you looping through the hierarchy.
On a wider note I don't think having 900 UIImageView's on the screen all at once is going to be a good long term strategy. Have you investigated drawing the screen's content via CoreGraphics?
The best way to solve this issue is to subclass UIScrollView, add touchesBegan etc methods to it.
#interface MyScroll : UIScrollView
{
}
You could easily implement this method on the UIImageView object:
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
if ([self pointInside:point withEvent:event]) {
//You clicked inside the object
}
return [super hitTest:point withEvent:event]
}
Use the return to tell the application the next touch responder (such as the uiimageview or the scrollview).
Can we call different actions / delegates in response to the two different events of
A tap on a UIButton
A tap-and-hold on a UIButton
?
Yes, it's reasonably easy to implement this using a UILongPressGestureRecognizer (on iPhone OS 3.2+). A long press will be handled by the gesture recognizer, and a short tap will pass through to the button's normal action.
For example, I subclassed UIButton and added the following method for specifying a long touch action to go along with a tap (longPressGestureRecognizer is an instance variable):
- (void)setLongTouchAction:(SEL)newValue
{
if (newValue == NULL)
{
[self removeGestureRecognizer:longPressGestureRecognizer];
[longPressGestureRecognizer release];
longPressGestureRecognizer = nil;
}
else
{
[longPressGestureRecognizer release];
longPressGestureRecognizer = nil;
longPressGestureRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:[[self allTargets] anyObject] action:newValue];
[self addGestureRecognizer:longPressGestureRecognizer];
}
}
I then could do the following to set both short tap and long press actions that will be handled by the same target:
[undoButton addTarget:self action:#selector(performUndo:) forControlEvents:UIControlEventTouchUpInside];
[undoButton setLongTouchAction:#selector(showUndoOptions:)];
As you can see, this is useful for the undo buttons you see in title bars of many iPad applications.
Brad Larson's answer looks pretty good but here's another one that might give you a bit more flexibility/control of what you want or might want to do.
You subclass UIButton, you override the touchesBegan and touchesEnded methods so that when the user starts a touch you call
[self performSelector:#selector(detecetedLongTap) withObject:nil afterDelay:1.0];
and in the touchesEnded you call:
[NSObject cancelPreviousPerformRequestsWithTarget:self selector:#selector(detecetedLongTap) object:nil];
to cancel the event if the finger was lifted too soon.
You can get full code for this in this blog post:
http://www.isignmeout.com/adding-long-tap-functionality-uibutton/
The best solution I can think of, is to create another class, and subclass UIButton. Then on Interface Builder (if that's what you're using), you can set the button's class to the custom class you just created.
So in this new class, you have to override a method called
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
This is basically telling you that someone pressed down on your button. The touches is an NSSet and it holds all the information for all the fingers that are pressing down on the screen. If you only are interested in the one that's pressing on the button itself, you'll probably have something like:
NSSet *myTouches = [event touchesForView:self.view];
So now that you have the touches that correspond to your button, you have to find out how many times the user tapped on that button. You do that with something like:
NSUInteger numTaps = [[myTouches anyObject] tapCount];
If this number is 2, that means the user just double tapped your button. Now comes the next part. How do you know if the user is holding that button? Well when the user lets go of the screen, another method gets called. You'll need to override that one as well:
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
This is where you know if the person has stopped touching the screen or if his finger is still on it. If his finger is still on it, then this event hasn't been called yet.
Now enough with the background
Here's my suggestion to you. I suggest you override the touchesBegan: method and check if the number of taps in the button is 2. If so, then start a timer that does what you need it to do, for as long as you need it to be done, and then on the touchesEnded: method, you'll go ahead and stop that timer, and this way you will have done whatever it is that you needed to do, for as long as you needed to do it OR as long as the user has held on to the button.
I hope this helps, obviously I didn't write the whole code for you, you'll have to experiment and research that stuff, but if you have any questions, I'll be happy to lend a helping hand :)
I have the MPMoviePlayerController set up to play a movie.I want to detect a touch on the movie for bringing up few buttons.I used the code :
// The movie's window is the one that is active
UIWindow* moviePlayerWindow = [[UIApplication sharedApplication] keyWindow];
// Now we create an invisible control with the same size as the window
UIControl* overlay = [[[UIControl alloc] initWithFrame:moviePlayerWindow.frame]autorelease];
// We want to get notified whenever the overlay control is touched
[overlay addTarget:self action:#selector(movieWindowTouched:) forControlEvents:UIControlEventTouchDown];
// Add the overlay to the window's subviews
[moviePlayerWindow addSubview:overlay];
but then the play back controllers doesn't appear , I guess because the player window doesn't get the touch.how can I keep the player controllers and still detects touches?
thanks
You have to create your own UIView's subclass and add it as overlay.
In the method -(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event you can do everything you want to do when the screen is touched.
I have done this in my project. I have implemented design of the VideoOverlay( the UIView's subclass) in Interface Builder. It is much easier when you have to add other elements that user have to interact with.