View transparency and Gesture handling - iphone

I am currently trying to create a View that would handle all the Gesture that could happened on my application.
I would like this view transparent in order to put other view below and they would still display (I don't want to make them subbiews of the handling view)
The Gesture handling works fine until I set the view color on "clearColor" from then, it is has the view disappear. Unless I stick subviews, in this case the gesture are only happening when hitting on subviews.
My question hence is: How could I manage to have the Gesture event happening on a transparent view?

Try something like this. This code adds two subviews to the main view "bottomView which is has a red background and then "testView" which is transparent an overlay on top of "bottomView" with a tap gesture recognizer. If you tap anyway in the "testView" it will print out the NSLog message. I hope that helps.
-(void)viewDidLoad
{
[super viewDidLoad];
UIView *bottomView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
[bottomView setBackgroundColor:[UIColor redColor]];
[self.view addSubview:bottomView];
UIView *testView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, 150)];
[testView setBackgroundColor:[UIColor clearColor]];
[self.view addSubview:testView];
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc]
initWithTarget:self
action:#selector(handleTap:)];
[tapRecognizer setNumberOfTapsRequired:1];
[tapRecognizer setDelegate:testView];
[testView addGestureRecognizer:tapRecognizer];
}
-(void)handleTap:(UITapGestureRecognizer *)sender
{
NSLog(#"Tapped Subview");
}

Related

UIActivityIndicatorView in an UIScrollview

I have a full screen UIScrollView to display my image. An UIActivityIndicatorView is added to the UIScrollView, it spinning well, but how could i make it always spinning in the middle of the screen while I am scrolling, zooming, rotating?
If you add the UIActivityIndicatorView directly to the scroll view it will scroll with the scroll view. But, if you add it to the parent of the scroll view it will remain where it was placed. So, the solution is to add it to the parent of the scroll view.
Notes:
I would recommend having a UIViewController in your window, and then adding these both to the UIViewController.
See the discussion here about adding views directly to your window:
View Controller being sent a message even though it has been deallocated
In ur .h file
UIView *primaryImage;
UIView *secondaryImage;
UIActivityIndicatorView *indicator;
In ur .m file
-(void)indicatorView
{
primaryImage = [[UIView alloc] initWithFrame:CGRectMake(0,0,320,480)];
primaryImage.backgroundColor = [UIColor blackColor];
primaryImage.alpha =0.5;
//[self.view.superview insertSubview:primaryImage aboveSubview:self.view.superview];
//[theTableView addSubview:primaryImage];
[self.view addSubview:primaryImage];
secondaryImage = [[UIView alloc] initWithFrame:CGRectMake(127.50,215,65,50)];
secondaryImage.backgroundColor = [UIColor blackColor];
secondaryImage.alpha = 0.9;
secondaryImage.layer.cornerRadius = 12;
[primaryImage addSubview:secondaryImage];
indicator = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(30, 25, 25, 25)];
indicator.center = CGPointMake(32, 25);
//[indicator hidesWhenStopped];
[indicator startAnimating];
[secondaryImage addSubview:indicator];
}
-(void)dismissCoverImageView {
[indicator stopAnimating];
[indicator removeFromSuperview];
[secondaryImage removeFromSuperview];
[primaryImage removeFromSuperview];
}
and after that you can call [self indicatorView];
and [self dismissCoverImageView];
Define the UIScrollViewDelegate of your UIScrollView. And in the delegate method –(void)scrollViewDidScroll:(UIScrollView *)scrollView change the frame of UIActivityIndicator object.

UIImageView is not Recognizing Second time Gesture

I have implemented UITapGestureRecognizer on UIImageView, It is working on first tap. On First Tap, I am hiding that image and starting animation. Once the animations are completed, i am showing the image again. But After setting setHidden:FALSE, I am not getting the Tap event of that UIImageView.
Following is the code I am using :
- (void)viewDidLoad{
[super viewDidLoad];
defaultDogView= [[UIImageView alloc] initWithFrame:CGRectMake(3, 270, 110, 210)];
[defaultDogView setImage:[UIImage imageNamed:#"dog1.png"]];
defaultDogView.userInteractionEnabled = YES;
[self addGestureRecognizersToPiece:defaultDogView];
[self.view addSubview:defaultDogView];
}
- (void)addGestureRecognizersToPiece:(UIImageView *)piece
{
NSLog(#"in Gesture");
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(singleTapPiece:)];
[tapGesture setDelegate:self];
[piece addGestureRecognizer:tapGesture];
[tapGesture release];
UILongPressGestureRecognizer *longPressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(longPressPiece:)];
[piece addGestureRecognizer:longPressGesture];
[longPressGesture release];
NSLog(#"%#", [piece gestureRecognizers]);
}
- (void)singleTapPiece:(UITapGestureRecognizer *)gestureRecognizer
{
NSLog(#"Image Tapped");
/** Hide the default Image and start the animation ***/
[defaultDogView setHidden:TRUE];
/***Animating the Dog***/
[dogArray addObject:[SpriteHelpers setupAnimatedDog:self.view numFrames:69 withFilePrefix:#"dog" withDuration:(12) ofType:#"png" withValue:0]];
dogView = [dogArray objectAtIndex:0];
//[self addGestureRecognizersToPiece:dogView];
[self performSelector:#selector(callBubbleUpdater) withObject:nil afterDelay:5.5];
}
-(void)showDogFrame{
NSLog(#"%#",[defaultDogView gestureRecognizers]);
[defaultDogView setHidden:FALSE];
defaultDogView.userInteractionEnabled = YES;
}
When view is hidden or its alpha component is zero that view won't receive any UIGestureRecognizers.
I can suggest to use next approach if you need to hide some view (let's name it touchableView) but want it to respond to gestures:
Create backgroundView with the same frame as touchableView:
UIView *backgroundView = [[UIView alloc] initWithFrame:touchableView.frame];
Set background color of backgroundView to clearColor:
backgroundView.backgroundColor = [UIColor clearColor];
Reset position of touchableView:
CGRect frame = touchableView.frame;
frame.origin.x = 0;
frame.origin.y = 0;
Disable user interaction of touchableView:
touchableView.userInteractionEnabled = NO;
Add touchableView as subview to backgroundView:
[backgroundView addSubview:touchableView];
Add appropriate gesture recognizers to backgroundView.
Add backgroundView to view that you want.
Now you can hide touchableView but you will still receive gesture recognizers.
I don't test this but I think it should work.
sure
when UIImageView is hidden. it does not receive any touch events
set alpha zero for uiimageview

Best Practice to Float a View over Another View?

I have a 320x460 view with a number of buttons, depending on the button pressed, a 280x280 view pops up over the 320x460 view (similar to the behavior of the UIAlertView) using code like this:
UIView *overlayView = [[UIView alloc] initWithFrame:CGRectMake(20, 200, 280, 280)];
overlayView.backgroundColor = [UIColor whiteColor];
[overlayView autorelease];
[overlayView addSubview:label]; // label declared elsewhere
[overlayView addSubview:backgroundImage]; // backgroundImage declared elsewhere
//... Add a bunch of other controls
[label release];
[backgroundImage release];
//... Release a bunch of other controls
[self.view addSubview:overlayView];
Everything works fine displaying the overlayView and all its controls.
The question I have is, how do I get rid of the overlayView once it's displayed? I want to make it not only not visible but to remove it completely, since the user will be popping up the overlayView repeatedly during use.
You need access to overlayView to remove it, I'd suggest adding this to the create side:
overlayView.tag = 5; // Or some other non-zero number
Then later you can use it like this:
-(void)removeOverlayView
{
UIView *overlayView = [self.view viewWithTag:5];
[overlayView removeFromSuperview];
}

UIScrollView with UITapGestureRecognizer and UIPageControl

I'm creating a horizontal scrolling tableview containing images. I have the swiping functionality working great, and am able to add the images to the scrollView as so in cellForRowAtIndexPath:
scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, tv.frame.size.width, 78)];
[scrollView setContentSize:CGSizeMake(700, 78)];
UIImage *footImage = [UIImage imageNamed:#"Foot.png"];
UIImageView *footImageView = [[UIImageView alloc] initWithImage:footImage];
footImageView.frame = CGRectMake(0, 0, 80, 78);
footImageView.userInteractionEnabled = YES;
[scrollView addSubview: footImageView];
UIImage *handImage = [UIImage imageNamed:#"Hand.png"];
UIImageView *handImageView = [[UIImageView alloc] initWithImage:handImage];
handImageView.frame = CGRectMake(90, 0, 80, 78);
handImageView.userInteractionEnabled = YES;
[scrollView addSubview: handImageView];
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(highlightImage)];
[scrollView addGestureRecognizer:tapGesture];
NSLog(#"tapGesture added to scrollView");
[[cell contentView] addSubview:scrollView];
pageControl = [[UIPageControl alloc] initWithFrame:CGRectMake(0, 50, tv.frame.size.width, 50)];
[pageControl setNumberOfPages:4];
[[cell contentView] addSubview:pageControl];
My tapGesture is registering with the selector, hightlightImage, and just logging that its calling this method correctly.
- (void) highlightImage
{
NSLog(#"tapping tapping");
}
What I REALLY am working for is the ability to highlight/select these images if tapped, and highlight/deselect them if tapped again. I will have another button on screen that will navigate to the next page (irrelevant here).
Am I going down the right path here? Obviously I will populate an NSArray of UIImages and populate the scrollView that way, but just spiking it out for now. If someone could give me some direction or an example of how to make each button separately selectable/de-selectable, that would be GREAT:)
Use UIButton instead of UIImageView.
It's got built-in selected functionality.
get rid of your gestures and add highlightImage as the action to every button.
make your highlightImage into highlightImage:(id)sender
sender should be a button so you can just do
[sender setSelected:YES];

Detecting taps in uiimageview inside uiscrollview

I have a UIScrollView with multiple UIImageViews in it created like this.
frame = [[UIImageView alloc] initWithImage:bg];
frame.frame = CGRectMake(FRAME_SEPARATOR + numPage*1024 + numColumn*(FRAME_SEPARATOR+230), 10 +numRow*(FRAME_SEPARATOR+145), 230, 145);
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imageTapped:)];
[frame addGestureRecognizer:tap];
[tap release];
[scroll addSubView:frame];
The problem is that imageTapped is not being called when tapping over an image.
If I add the gesture recognizer to the scrollview like this:
UITapGestureRecognizer *tap =
[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imageTapped:)];
[scroll addGestureRecognizer:tap];
[tap release];
imageTapped is called.
How can I detect the taps over the UIImageViews?
Thanks
Make sure userInteractionEnabled is set to YES on the UIImageView:
frame.userInteractionEnabled = YES;
I'd also recommend using a different name for the UIImageView variable (eg. imageView instead of frame). Otherwise, you can easily confuse it with the view's frame property.