I have a UIImageView which is basically a mole. I want this mole to pop out of a hole. So actually what I have in mind is that I will create a mole some points below the hole and have a mask over it so and then animate up the image view so it looks like its popping out of hole. So following the thought , I had made written down this code :
CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
CGRect maskRect = _moleIcon.frame;
CGPathRef path = CGPathCreateWithRect(maskRect, NULL);
maskLayer.path = path;
CGPathRelease(path);
_moleIcon.layer.mask = maskLayer;
[UIView animateWithDuration:2.0 animations:^(void){
_moleIcon.transform=CGAffineTransformMakeTranslation(0, 50);
}];
but the problem, is that it seems that the mask itself is moving with the actual UIImageView. Any help would be highly appreciated.
try to use 2 UIViews, just maskView should be bring to front:
[superview bringSubviewToFront:maskView];
and set background color and alpha property for mask view,
maskView.backgroundColor = [UIColor blackColor];
maskView.alpha = 0.8;
and now you can move 2 view directly.
but better is to add 2 view to other view - container, and rotate this one view.
Related
I need to add mask on top and buttom of the screen like this.
How can I achieve this ?
if (!UIAccessibilityIsReduceTransparencyEnabled()) {
self.BlurView.backgroundColor = [UIColor clearColor];
UIBlurEffect *blurEffect = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];
UIVisualEffectView *blurEffectView = [[UIVisualEffectView alloc] initWithEffect:blurEffect];
blurEffectView.frame = self.view.bounds;
[blurEffectView setAlpha:1.0];
[self.BlurView addSubview:blurEffectView];
}
Where self.BlurView is type of UIView .
You can keep this for your upper and bottom view . And can adjust frame blurEffectView.frame according to your upper and bottom dimensions .
Hope this will help you.
Set up UIImageView with your background image.
Add UIVisualEffectView over the top:
UIVisualEffectView * vs = [[UIVisualEffectView alloc] initWithEffect:[UIBlurEffect effectWithStyle:UIBlurEffectStyleDark]];
vs.frame = self.view.bounds;
[self.view addSubview:vs];
Add a UIView over the top, and put your UITableView (or whatever) in that.
Add this code:
CAGradientLayer * layer = [CAGradientLayer layer];
layer.frame = tableHolder.bounds;
layer.colors = [NSArray arrayWithObjects:(id)[UIColor blackColor].CGColor, (id)[UIColor clearColor].CGColor, (id)[UIColor clearColor].CGColor, nil];
layer.locations = #[#0.90,#0.99,#1.0];
layer.startPoint = CGPointMake(0.0, 1.0f);
layer.endPoint = CGPointMake(0.0f, 0.0f);
tableHolder.layer.mask = layer;
tableHolder.layer.masksToBounds = true;
[tableHolder.layer insertSublayer:layer atIndex:0];
Adjust the variables for your own needs, you'll have to change the locations.
You're not 'blurring' the tops and bottoms, but gradually masking them out via the gradient layer.
I can think of a way to achieve this effect. But what you need is not a blur mask, you need to use a clipping mask.
1- present a modal view controller with a view that contains a UIVisualEffectView in the back, and a scrollview/tableview/collection view in the front that is offset 40px (or however much you want) from the top and bottom.
2- Add a mask to the scroll view using a black and white image tailored to the task, you can add the mask using the following code:
var maskImage = UIImage(name: "yourMask")
var maskLayer = CALayer()
maskLayer.frame = scrollView.bounds()
maskLayer.contents = maskImage.CGImage
scrollview.layer.mask = maskLayer
3- Alternatively, you can also use CAGradientLayer to achieve the same effect (this would work better with scaling as well). There's plenty of solutions on stack overflow on how to create a gradient layer, like this one: Create gradient image programmatically in iOS
Having said that I don't understand why your question is down voted. I think it's a perfectly good question to make.
Hope this helps!
I can create a mask like this:
CALayer *mask = [CALayer layer];
mask.contents = (id)[[UIImage imageNamed:#"mask.png"] CGImage];
mask.frame = CGRectMake(0, 0, 10, 10);
self.content.layer.mask = mask;
And this will correctly reveal the top left 10 pixels of my content (because mask.png is just a black image). However I want to animate the mask to reveal the rest of the content:
[UIView animateWithDuration:3.0
animations:^{
mask.frame = self.content.bounds;
}
completion:^(BOOL finished){
}];
The problem is that there's no animation. The entire content gets displayed immediately. Why does this happen, and how can I animate the mask so that the content is revealed from the upper left?
The frame is a derived property of various other properties, such as the position, bounds, anchorPoint, and any transform it has applied to it. It's not recommended to animate this property directly, especially when dealing with lower level CoreAnimation layers.
In this case, I would assume you want to animate the bounds. You can use the UIView animation method above, but when dealing with CALayers directly I prefer to use the CoreAnimation methods of animation.
CGRect oldBounds = mask.bounds;
CGRect newBounds = self.content.bounds;
CABasicAnimation* revealAnimation = [CABasicAnimation animationWithKeyPath:#"bounds"];
revealAnimation.fromValue = [NSValue valueWithCGRect:oldBounds];
revealAnimation.toValue = [NSValue valueWithCGRect:newBounds];
revealAnimation.duration = 3.0;
// Update the bounds so the layer doesn't snap back when the animation completes.
mask.bounds = newBounds;
[mask addAnimation:revealAnimation forKey:#"revealAnimation"];
I can add shadow to imageView layer using the following code.
self.imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"test.png"]];
self.imageView.center = self.view.center;
CALayer *containerLayer= [CALayer layer];
containerLayer.shadowColor = [UIColor blackColor].CGColor;
containerLayer.shadowRadius = 10.0f;
containerLayer.shadowOffset = CGSizeMake(10.0f, 5.0f);
containerLayer.shadowOpacity = .8f;
[containerLayer addSublayer:self.imageView.layer];
[self.view.layer addSublayer:containerLayer];
1 . The problem is that I don't know why I have to add imageView.layer to containerLayer to get the imageView shadow effect. However, if I add containerLayer to imageView.layer, there's no shadow in imageView, why?
The error code is:
self.imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"test.png"]];
self.imageView.center = self.view.center;
CALayer *containerLayer= [CALayer layer];
/*same as before*/
[self.imageView.layer addSublayer:containerLayer];
[self.view.layer addSublayer:self.imageView.layer];
Question2: the containerLayer's(used to provide shadow to imageView) frame = {{0, 0}, {0, 0}}, but the final position is in the center of screen. why?
A layer needs something opaque inside it to create a shadow around (unless you've specified a shadowPath explicitly). So your first version of the code works because the containerLayer has the imageView's layer as a sublayer. But, as you noticed from Question #2, the containerLayer's frame indicates that it is actually located in the upper left corner with a size of (0,0). The reason you can still see the image is that containerLayer is not masking to its bounds. Add this line to your first version, and the image disappears:
[containerLayer setMasksToBounds: YES]; // kitten (and shadow) is gone
Your version #2 of the code does not display a shadow because, in part, the containerLayer does not "contain" anything. If you use version #2 but give the containerLayer a new frame and an opaque background color, a shadow appears. (But this obviously isn't a solution, because the image is covered up...) Also note that there is no shadow when the layer's background is [UIColor clearColor].
[self.imageView.layer addSublayer:containerLayer];
containerLayer.frame = self.imageView.layer.bounds;
containerLayer.backgroundColor = [UIColor yellowColor].CGColor; // yellow box w/shadow
// containerLayer.backgroundColor = [UIColor clearColor].CGColor; // no shadow here
If you wanted to have a container with a shadow that houses the UIImageView, you could do something like this:
UIView * shadowView = [[UIView alloc] initWithFrame: self.imageView.frame];
shadowView.layer.shadowColor = [UIColor blackColor].CGColor;
shadowView.layer.shadowRadius = 10.0f;
shadowView.layer.shadowOffset = CGSizeMake(10.0f, 5.0f);
shadowView.layer.shadowOpacity = .8f;
[self.view addSubview: shadowView];
self.imageView.frame = (CGRect) { CGPointZero, self.imageView.frame.size };
[shadowView addSubview: self.imageView];
A CALayer could be used instead of a UIView in a similar way. Or you could apply shadow attributes to the imageView's layer directly, making sure that neither the view nor the layer is clipping/masking to bounds.
If you want to add a shadow over the imageview just change the alpha value (0.0 min - 1.0 max) of that imageview. This will give you the shadow effect and whenever you want to remove the shadow just restore the alpha value to 1.0.
For ex:
self.imageview.alpha = 0.5 // shadow state
self.imageview.alpha = 1.0 // original state
I know I can change a border's object with
item.layer.cornerRadius = floatValue;
item.layer.borderWidth = intValue;
item.layer.borderColor = colorValue;
But how can I only change top, left and right borders ?
Thank you for your advices.
I don't think you can do that directly.
There are a couple of responses to this question that might help, including one that links to some open source code that solves the problem.
You could use another layer to mask away the corners that you don't want to see. This has the downside that you:
can't have a shadow
can't have another mask (if you don't do them together)
will loose half the border width since the border is stroked on the center of your border
If that is okay with you, here is a sample code that should get you started
CGFloat borderWidth = 4.0;
[[myView layer] setBorderWidth:borderWidth];
CALayer *mask = [CALayer layer];
// The mask needs to be filled to mask
[mask setBackgroundColor:[[UIColor blackColor] CGColor]];
// Make the masks frame smaller in height
CGRect maskFrame = CGRectInset([myView bounds], 0, borderWidth);
// Move the maskFrame to the top
maskFrame.origin.y = 0;
[mask setFrame:maskFrame];
[[myView layer] setMask:mask];
I have a collection of CALayers. Each layer is a sublayer of the same parent CALayer, and each has a shadow applied to it. The layers are positioned dynamically, and there are many of them, so I can't predict how they'll be arranged ahead of time.
If the layers are adjacent to each other (close enough that they are almost touching) the shadow of one of the CALayers is rendered on top of the other CALayer. That's probably the desired effect in most cases, but I want my layers to exist in the same z-plane. (An example of this is the way CSS3 shadows are applied to block elements in web design.)
Is this possible? How can I achieve this?
(I had this idea: Adding a 'shadow' sublayer to each CALayer with my own shadow image, and setting the z-position to a lower value. But doesn't the layer-tree make this impossible? Z-positions in one layer's coordinate system are independent from z-positions in another layer's coordinate system, right?)
If all of the shadowed layers have the same shadow settings, put them into a container layer and set the shadow on the container layer. Example:
- (void)viewDidLoad
{
[super viewDidLoad];
CALayer *containerLayer = [CALayer layer];
containerLayer.frame = self.view.bounds;
containerLayer.shadowRadius = 10;
containerLayer.shadowOpacity = 1;
[self.view.layer addSublayer:containerLayer];
CAShapeLayer *layer1 = [CAShapeLayer layer];
layer1.bounds = CGRectMake(0, 0, 200, 200);
layer1.position = CGPointMake(130, 130);
layer1.path = [UIBezierPath bezierPathWithOvalInRect:layer1.bounds].CGPath;
layer1.fillColor = [UIColor redColor].CGColor;
[containerLayer addSublayer:layer1];
CAShapeLayer *layer2 = [CAShapeLayer layer];
layer2.bounds = CGRectMake(0, 0, 200, 200);
layer2.position = CGPointMake(170, 200);
layer2.path = [UIBezierPath bezierPathWithOvalInRect:layer2.bounds].CGPath;
layer2.fillColor = [UIColor blueColor].CGColor;
[containerLayer addSublayer:layer2];
}
Output: