I'm trying to detect a touch on a UISubview of a view being animated
Here's my detection code:
//simple but not very elegant way of getting correct frame
CGRect keepFrame = self.fishContainer.layer.frame;
self.fishContainer.layer.frame = [[self.fishContainer.layer presentationLayer] frame];
//get touch location, taking presentation layer into account. (See above)
CGPoint p = [sender locationInView:self.fishContainer];
CALayer *layer =[self.fishContainer.layer presentationLayer];
//apply relevant transform
p = CGPointApplyAffineTransform(p,layer.affineTransform);
EBLog(#"checking point %#",NSStringFromCGPoint(p));
UIView *vToRemove = nil;
//find topmost view containing touched point
for (UIView *v in self.parasites) {
EBLog(#"-BOUND %#",NSStringFromCGRect(v.frame));
if(CGRectContainsPoint(v.frame, p))
{
vToRemove = v;
}
}
//OK, we have a view. Let's remove it.
if(vToRemove)
{
EBLog(#"found one");
[vToRemove removeFromSuperview];
[self.parasites removeObject:vToRemove];
if ([self.parasites count] == 0) {
[self showWinnerScreen];
[self stopGame];
}
}
//restore view frame
self.fishContainer.layer.frame = keepFrame;
Everything works correctly as long as I don't animate parasiteArea parentview.
When I animate parasiteArea's parentview (A CAAnimation consisting of move of the view, scale of the view, and rotate of the view) , the touch is outside the bounds of the expected subview.
UPDATE
I manged to get the detection working in most cases (see code above), by using the presentationLayer property and CGPointApplyAffineTransform. There is however, still some cases where it dosnt work.
I guess I need to translate the touch point to the coordinate space of the CAAnimation.
Or something like that? any suggestions?
I ended up using UIView animateWithDuration instead of CAAninmation. For my purpose the limited animation possibles were enough.
Related
I am using a UIPangesture to move a imageview and this imageview is subview of of view of class, when I move imageview then it move outside its superview. I want to set the boundary of moving this imageview, means the imageview should move only inside its superview.
i guess in the selector that is called by the pan gesture you are setting the view's center or origin accordingly to the point of the pan.
this is how your code should look in order to solve your problem:
- (void)thePanSelector:(id)sender{
UIPanGestureRecognizer *recognizer = (UIPanGestureRecognizer *)sender;
CGPoint p = [recognizer locationInView:theSuperView];
float boundedX = MAX(0,MIN(theSuperView.frame.size.width,p.x));
float boundedY = MAX(0,MIN(theSuperView.frame.size.height,p.y));
CGPoint boundedPoint = CGPointMake(boundedX,boundedY);
view.center = p;
}
this code is untested so you may need to play a little with the values of boundedX and boundedY
What i'm trying to do is "navigating" into a bigger UIView with buttons and controls positioned in different places. I've made the size of the main UIView twice bigger than the usual. It is 640x480 instead of 320x480.
After clicking a button in the first part of the screen i've made a moving translation of -320px in the x-direction to show the second "hidden" part of the screen where other functions will reveals to the user. Everything works perfect apart the fact i can't get the UIView back to the original position. It seems that the button i use to get back to the original position and that is "outside the bounds" of the 320px, doesn't work.
My UIView is referenced as "introScreen", and the following is the function i call to translate the screen through the x direction:
- (void)secondPartOfTheScreen {
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.15];
introScreen.transform = CGAffineTransformMakeTranslation(-320, 0);
[UIView commitAnimations];
}
Calling this function my UIView moves correctly, but when my button appear in this part of the screen, it doesn't get any user interaction. If i move that button in the first part of the screen, it works correctly. It have something to do with the screen bounds? It is possibile to solve it?
Thanks in advance!
You should try to subclass your UIView and override its pointInside:withEvent: method so that also a point outside its bounds is recognized as belonging to the view. Otherwise, there is no chance that user interaction outside of the view bounds are handled as you would like to.
This is what the Event Handling Guide say:
In hit-testing, a window calls hitTest:withEvent: on the top-most view of the view hierarchy; this method proceeds by recursively calling pointInside:withEvent: on each view in the view hierarchy that returns YES, proceeding down the hierarchy until it finds the subview within whose bounds the touch took place. That view becomes the hit-test view.
You could use something like this in your custom UIView:
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
for (UIView* view in self.subviews) {
if (view.userInteractionEnabled && [view pointInside:[self convertPoint:point toView:view] withEvent:event]) {
return YES;
}
}
return NO;
}
You could do with this:
#interface MyView: UIView
#end
#implementation MyView
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
for (UIView* view in self.subviews) {
if (view.userInteractionEnabled && [view pointInside:[self convertPoint:point toView:view] withEvent:event]) {
return YES;
}
}
return NO;
}
#end
add this class definition to the beginning of the .m file where you are using the view. (You could also use separate .h/.m files, but for the sake of testing if everything works, it is enough). Then, replace UIView with MyView in the instantiation of your current UIView, and it should work.
You're not using the transform property properly, you should take into account the previous value of the property like this:
introScreen.transform = CGAffineTransformConcat(introScreen.transform, CGAffineTransformMakeTranslation(-320, 0));
Hope this helps, and check Apple's UIView documentation and CGAffineTransform documentation for more details.
2 things.
First why would you use transform when you are merely moving the object. You can set the frame just as easily.
CGRect frame = introScreen.frame;
frame.origin.x -= 320;
introScreen.frame = frame;
(Yes this will work inside an animation)
second, if you translate a view its contents should be within its bounds regardless of the size you want displayed in the first place.
therefore your container view (the one with the buttons) should be a size so that all contained pieces are within its bounds. Anything outside its bounds will not function. Having the main view twice its size is not as useful as having the contained view at twice its size.
Think of it like this.
Your table should be able to hold whatever your looking at. If you have a map you want to display you would slide it around on the table. the table does not need to be as big as the map but the map needs to be big enough to present you with all of its contents. if the map was say too short to display the poles and you would be without the information. No matter how much you transformed the map you would not be able to use the north or south poles..
To ensure the app reflects this you can turn on clip subviews on all the views in question, then if its outside the bounds it will not be visible.
To describe my project:
I have a rectangle UIImageView frame floating over a white layer. Inside the UIImageView, I'm successfully creating the illusion that it is showing a portion of a background image behind the white layer. You can drag the rectangle around, and it will "redraw" the image so that you can peer into what is behind the white. Its basically this code:
//whenever the frame is moved, updated the CGRect frameRect and run this:
self.newCroppedImage = CGImageCreateWithImageInRect([bgImage.image CGImage], frameRect);
frame.image = [UIImage imageWithCGImage:self.newCroppedImage];
Anyhow, I also have a rotation gesture recognizer that allows the user to rotate the frame (and consequentially rotates the image). This is because the CGRect sent to the CGImageCreateWithImageInRect is still oriented at its original rotation. This breaks the illusion that you're looking through a window because the image you see is rotated when only the frame should appear that way.
So ideally, I need to take the rotation of my frame and apply it to the image created from my bgImage. Does anyone have any clues or ideas on how I could apply this?
I suggest you take a different approach. Don't constantly create new images to put in your UIImageView. Instead, set up your view hierarchy like this:
White view
"Hole" view (just a regular UIView)
Image view
That is, the white view has the hole view as a subview. The hole view has the UIImageView as its subview.
The hole view must have its clipsToBounds property set to YES (you can set it with code or in your nib).
The image view should have its size set to the size of its image. This will of course be larger than the size of the hole view.
And this is very very important: the image view's center must be set to the hole view's center.
Here's the code I used in my test project to set things up. The white view is self.view. I start with the hole centered in the white view, and I set the image view's center to the hole view's center.
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:YES];
CGRect bounds = self.view.bounds;
self.holeView.center = CGPointMake(CGRectGetMidX(bounds), CGRectGetMidY(bounds));
self.holeView.clipsToBounds = YES;
bounds = self.holeView.bounds;
self.imageView.center = CGPointMake(CGRectGetMidX(bounds), CGRectGetMidY(bounds));
self.imageView.bounds = (CGRect){ CGPointZero, self.imageView.image.size };
}
I also set the image view's size to the size of its image. You might want to set it to the size of the white view.
To pan and rotate the hole, I'm going to set holeView.transform. I'm not going to change holeView.frame or holeView.center. I have two instance variables, _holeOffset and _holeRotation, that I use to compute the transform. The trick to making it seem like a hole through the white view, revealing the image view, is to apply the inverse transform to the image view, undoing the effects of the hole view's transform:
- (void)updateTransforms {
CGAffineTransform holeTransform = CGAffineTransformIdentity;
holeTransform = CGAffineTransformTranslate(holeTransform, _holeOffset.x, _holeOffset.y);
holeTransform = CGAffineTransformRotate(holeTransform, _holeRotation);
self.holeView.transform = holeTransform;
self.imageView.transform = CGAffineTransformInvert(holeTransform);
}
This trick of using the inverse transform on the subview only works if the center of the subview is at the center of its superview. (Technically the anchor points have to line up, but by default the anchor point of a view is its center.)
I put a UIPanGestureRecognizer on holeView. I configured it to send panGesture: to my view controller:
- (IBAction)panGesture:(UIPanGestureRecognizer *)sender {
CGPoint offset = [sender translationInView:self.view];
[sender setTranslation:CGPointZero inView:self.view];
_holeOffset.x += offset.x;
_holeOffset.y += offset.y;
[self updateTransforms];
}
I also put a UIRotationGestureRecognizer on holeView. I configured it to send rotationGesture: to my view controller:
- (IBAction)rotationGesture:(UIRotationGestureRecognizer *)sender {
_holeRotation += sender.rotation;
sender.rotation = 0;
[self updateTransforms];
}
I have a UIViewController that is detecting touch events with touchesBegan. There are moving UIImageView objects that float around the screen, and I need to see if the touch event landed on one of them. What I am trying:
UITouch* touch = [touches anyObject];
if ([arrayOfUIImageViewsOnScreen containsObject: [touch view]]) {
NSLog(#"UIImageView Touched!");
}
But this never happens. Also if I were to do something like this:
int h = [touch view].bounds.size.height;
NSLog([NSString stringWithFormat: #"%d", h]);
it outputs the height of the entire UIViewController (screen) everytime, even if I touch one of the UIImageViews, so clearly [touch view] is not giving me the UIImageView. How do I detect when only a UIImageView is pressed? Please do not suggest using UIButtons.
Thank you!
If you only want to detect when a UIImageView is pressed, check the class:
if (touch.view.class == [UIImageView class]) {
//do whatever
}
else {
//isnt a UIImageView so do whatever else
}
Edit----
You haven't set the userInteraction to enabled for the UIImageView have you?!
I know you said please do not suggest using UIButtons, but buttons sound like the best/easiest way to me.
You could try sending the hitTest message to the main view's CALayer with one of the touches - it'll return the CALayer furthest down the subview hierarchy that you touched.
You could then test to see if the layer you touched is a layer of one of the UIImageView's, and proceed from there.
This code uses a point generated from a UIGestureRecognizer.
CGPoint thePoint = [r locationInView:self.view];
thePoint = [self.view.layer convertPoint:thePoint toLayer:self.view.layer.superlayer];
selectedLayer = [self.view.layer hitTest:thePoint];
If you want to check the touch means use CGRectContainsPoint.
1.Capture the touch event and get the point where you touched,
2.Make a CGRect which bounds the object you want to check the touch event,
3.Use CGRectContainsPoint(CGRect , CGPoint) and catch the boolean return value.
http://developer.apple.com/library/ios/#DOCUMENTATION/GraphicsImaging/Reference/CGGeometry/Reference/reference.html
Here is the class reference for CGRect.
Forgot about this question- the problem was that I did not wait until viewDidLoad to set userInteractionEnabled on my UIImageView.
Alright this is a newbie question, so I apologize in advance. I have a UIView which I laid out in Interface Builder off-screen. When the user presses a button, I would like to animate this view on-screen. It works, but I can't interact with any buttons in the UIView. I have read that only the view is moved when you animate and that the actual objects retain their positions, so I have tried setting the position of the UIViews' layers, but it causes my UIView menu to display an extra 81 pixels to the left. When this happens, I can interact with the buttons, but I need it to be flush with the right of the screen. Here is my code in the IBAction on the openMenu button:
CABasicAnimation *moveView = [CABasicAnimation animationWithKeyPath:#"position"];
moveView.delegate = self;
moveView.duration=0.5;
// If the menu is displayed, close it!
CGPoint currentPosView = [[entirePage layer] position];
CGPoint destView;
[moveView setFromValue:[NSValue valueWithCGPoint:currentPosView]];
if (menuDisplayed) {
// Move right to our destination
destView.x = currentPosView.x;
destView.y = currentPosView.y + 81;
[moveView setToValue:[NSValue valueWithCGPoint:destView]];
// Otherwise, open it
} else {
// Move left to our destination
destView.x = currentPosView.x;
destView.y = currentPosView.y - 81;
[moveView setToValue:[NSValue valueWithCGPoint:destView]];
}
// Animate the view
[[entirePage layer] addAnimation:moveView forKey:#"move"];
// Set the final position of our layer
[[entirePage layer] setPosition:destView];
menuDisplayed = !menuDisplayed;
And then in the animationDidStop method:
CGPoint currentPosMenu = [[menuBar layer] position];
if (menuDisplayed) {
currentPosMenu.x -= 81;
} else {
currentPosMenu.x += 81;
}
[[menuBar layer] setPosition:currentPosMenu];
Help???
You shouldn't need to mess with the layers. You could probably achieve the effect you want by laying out the views in Interface Builder at the positions they will be in after they are animated into view. In other words, first lay things out in their final/correct positions. Don't do anything funky in IB.
In your code, after the app is launched or in a -viewDidAppear: method if you're using a UIViewController, you could offset the views by some amount and then restore them to their original position in an animation block:
myView.transform = CGAffineTransformMakeTranslation(0,81);
[UIView beginAnimations:#"slideUp" context:nil];
myView.transform = CGAffineTransformIdentity;
[UIView commitAnimations];
As for the lack of user interaction on your views, that could be a number of things. If all of your views are subviews of something like a UIImageView, UIImageView has userInteractionEnabled set to NO by default (at least if you build one in code - I'm not sure off hand what IB's default settings are for an image view). It could also mean that the superview of your views is actually too small and its frame does not contain the subviews. (If clipping was turned on for the superview, you wouldn't even be able to see subviews that are having this particular problem.)
EDIT:
I read things more carefully and see you want things to move in response to a button press, so in other words the views will need to be hidden from the start. In that case you could still lay everything out in IB in their final position, but just set them as hidden in IB. When you push the button, set the views visible (hidden=NO) before translating them. That should allow them to be laid out in their final/correct place in IB making sure that they are positioned on the proper superviews, etc while still getting the animation effect you want.
Forget about the animations for now; you should move your view by setting its frame property.
E.g.:
CGRect menuFrame = entirePage.frame;
if (menuDisplayed)
{
menuFrame.origin.x += 81;
}
else
{
menuFrame.origin.x -= 81;
}
entirePage.frame = menuFrame;
// Do your animation here, after the view has been moved
Don't worry about the animation until you've verified that your view is being placed in the correct location. Once you've verified that that code is working correctly, then do your animation after you set the frame property.
Note that you probably don't need to use the CoreAnimation API at all, unless you're doing something complex. UIKit can do animation on its own. E.g:
[UIView beginAnimations:#"MyAnimation" context:NULL];
myFirstView.frame = ...;
myOtherView.frame = ...;
[UIView commitAnimations];