I have two UIImageView in a UIView in my application. And I need to Zoom, Rotate and Move the UIImageView which is at bottom of the top one, I don't need to do any thing with top one. I've already implemented the code for Move, Rotate and Zoom but the problem is I cant enable the touch to UIImageview in bottom.
How to solve this problem?
UIImageView's have userInteractionEnabled set to NO by default. You have to explicitly set this to YES for the image view you want to allow touch events to occur on.
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I have a UIViewController into which i added a UIImageView with CGRectMake(0,0,1024,704). (768-nav bar ht-status bar ht=704). I am working in landscape mode only. I added tap gesture to this UIImageView. But i want to restrict this tap area to the height to 604. This picture should make it a bit clear.
The area with red lines is the UIImageView and the are that has green and red lines is the area that does not need touch event.
Any idea how to go about doing this?
You can use the locationInView: method in UITabGestureRecognizer to know where the user tapped, and respond accordingly.
I have an UILabel. I want to glow the touch area in it. That is, when I click on a point in that UILabel, a small circular portion around the touch point should be presented with glowing effect. How can get this?
Well you can do that by creating a CALayer or a CAGradientLayer based on how you want your glow and add it as a sublayer to the label's layer at the location of the touch.
For enabling the touch on UILabel, look at userInteractionEnabled property. You will need to set it to YES.
Then you will need to attach a UITapGestureRecognizer to the label for getting the tap. Once you have the touch location, add the custom glow layer as a subview to the label's layer in an invisible state. Animate the glow layer in and out. You might want to repeat a few times before removing the glow layer as a sublayer at completion.
UILabels don't respond to touches.
Use a UIButton with a custom type and provide images for the normal state and the (glowing) highlighted state.
Gesture recognizers are nice, but if you want to do something that starts when the finger touches, stops when the finger stops touching, and moves around with the finger in between, then it's hard to think of a good gesture recognizer for that. I think in that case you'd be better off just using touchesBegan, touchesMoved, and touchesEnded (don't forget touchesCancelled).
You can either put those methods on your view controller or subclass UILabel. Either way, set userInteractionEnabled = YES on the label.
As for how to graphically make that effect, I don't have any clever ideas for it at the moment.
In My Application,i am having one scrollVIew containing multiple images.
and out of the scrollview i have one uiimageview.
i want to Drag any image from ScrollView and drop it on uiimageview which is out of the scrollview.
is it possible?
help And suggestions are appreciated
Thanks in advance.
gamozzii's reply is close to what you need to do, but there's one problem. An UIScrollView will eat touches, so tapping on an image will have no effect.
As a result you will have to subclass the UIScrollView
I have written a small functional app to illustrate dragging the image from a scroll view into an image view. You can download the project here.
Yes this should be possible, you will need to implement the touch/drag events directly.
Check out the touchesBegan, touchesMoved etc. delegate methods in UIResponder.
One approach would be to subclass imageview and implement touchesBegan, touchesMoved in it, and use this imageview subclass to display your images in the scroll view.
On the touchesBegan create a new image view and add it to the outer view and set its image to be the same as the one in the scroll view. You need to overlay it directly over your source image in the scroll view so adjust its frame origin to be relative to the outer view you will need to use the scrollview origin and also the content view size and offset of the source image view inside the content view in order to recalculate the new origin in the outer view.
Then on the touches moved, simply readjust the frame of this image in accordance with the coordinates from the touches moved so that the image follows the touch.
Do a boundary check against the frame of your target imageview - once the user drags it into this boundary, make that target imageviews image the same as the image in the view being dragged and remove the dragged image from the containing view and release it.
In case you're still interested in another solution (and for other users of course):
I did implement that behaviour before just like gamozzii recommended.
I set canCancelContentTouches = NO on the UIScrollView to make sure the subviews handle there touches on their own. If a subview (in your case an image) was touched, i moved the view out of the scrollview onto the superview and started tracking it's dragging. (You have to calculate the correct coordinates within the new superview, so it stays in place). After dragging finishes, i checked if the target area was reached, otherwise I moved it back into the scrollview.
The subviews are handling the dragging on there own via (touchesBegan:/Moved:/Ended:/Cancelled:).
If that's not detailed enough, here's my example code: Github: JDDroppableView
I'm adding a cameraOverlay to my UIImagePickerController, it shows and all but it doesn't register touches. I init a button in the viewDidLoad and a one via IB.
Is there some rule that prohibits me from adding a UIButton to a cameraOverlayView and register touches?
Thanks
I had a similar problem, and it turned out that my overlay UIView's frame was not large enough. The clipsToBounds property for a UIView is by default set to NO, which means its subviews are still visible even if they are outside the parent's frame.
So essentially, make sure your overlay's frame is large enough, or that your subviews of the overlay are positioned within its bounds.
I have two UIImageView objects inside my view (both 320x480 one above the other). The lower image view is inside a UIScrollView with scrolling and zooming enabled. Now I want to handle touches inside the other image view but it no longer detects any single taps.
I can understand that the UIScrollView handles all the touches which I do on it. But the touches on the image view above the scroll view are also not recognized.
Attached is an image with my view hierarchy. Can someone please tell me why the other image view's touches are also handled by the scrollview when it isn't a subview of scroll view?
And if the scrollview is bent on handling touches, how do I recognize touches on the other image view?
Thanks.
By default UIImageViews have userInteractionEnabled=NO;
Try setting it to YES (either in IB or in code).
I'm not sure, it might be that you need to set the frame size and/or content size of the scroll view properly. This page has a diagram of what I'm talking about.