Mask a view in Objective-C - ios

In ActionScript 3 we can apply a mask of to a visual object like this:
SomeVisualObject.mask = maskShapeObject;
How can I achieve similar result in Objective-C? Assume I have two UIImageView objects, I want something like this:
imageView1.mask = imageView2;
How can I use one UIImageView to mask, or clip the shape of, another?

CALayer *maskLayer = [CALayer layer];
UIImage *maskImage = [UIImage imageNamed:#"maskImage.png"];
maskLayer.contents = (id)maskImage.CGImage;
maskLayer.bounds = (CGRect){CGPointZero, maskImage.size};
UIImageView *imageViewToMask = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
imageViewToMask.image = [UIImage imageNamed:#"image2.png"];
imageViewToMask.layer.mask = maskLayer;

Related

CALayer remove transparent masking

I am working on an ios application and i have a issue using CALayer it has created a transparent mask on every image i put in the Layer.
Please have a look at the code below :
self.mask = [CALayer layer];
self.mask.contents = CFBridgingRelease(([UIImage imageNamed:#"launch screen.png"].CGImage));
self.mask.bounds = CGRectMake(0, 0, 200, 200);
self.mask.anchorPoint = CGPointMake(0.5, 0.5);
self.mask.position = CGPointMake(CGRectGetMidX(self.view.bounds), CGRectGetMidY(self.view.bounds));
self.imageView = _imageView;
self.view.layer.mask = self.mask;
Please Refer to this image for example :
http://31.media.tumblr.com/10cc0ba92377a2cba9fb35c9943fd2ca/tumblr_inline_n6zpokNxpC1qh9cw7.gif

Is it possible to add a UIImage to CPTGraph?

I'm trying to add an image to a graph using Core-Plot and I want the image to move along with the graph when it being dragged or pinched. I've tried the code below but it didn't work. Can anyone tell me how to do so?
CALayer *subLayer = [CALayer layer];
subLayer.contents = [UIImage imageNamed:#"image.png"];
subLayer.position = CGPointMake(100, 120);
[_graph addSublayer:subLayer];
Use a plot space annotation:
CPTBorderedLayer *imageLayer = [[CPTBorderedLayer alloc] initWithFrame:imageFrame];
imageLayer.fill = [CPTFill fillWithImage:[CPTImage imageNamed:#"image.png"]];
NSArray *plotPoint = #[xCoordinate, yCoordinate];
CPTPlotSpaceAnnotation *imageAnnotation = [[CPTPlotSpaceAnnotation alloc] initWithPlotSpace:plotSpace
anchorPlotPoint:plotPoint];
imageAnnotation.contentLayer = imageLayer;

CALayer Troubles when loading an image from a UIImagePicker

I have a UIViewController with a UIImageView (imageView), and I'm defining several layers that will be nested in the imageview as follows in viewDidLoad:
//container layer - the very top layer
CALayer *containerLayer = [CALayer layer];
containerLayer.opacity = 0;
containerLayer.bounds = [self.imageView.layer frame];
// Holder Layer
CALayer *holderLayer = [CALayer layer];
holderLayer.opacity = 0;
holderLayer.bounds = self.imageView.bounds;
// Hierarchy layers
[containerLayer setValue:holderLayer forKey:#"__holderLayer"];
[containerLayer addSublayer:holderLayer];
[self.imageView.layer addSublayer:containerLayer];
I have the following code that works when loading an image from a UIImagePicker :
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
UIImageView *newImgView = [[UIImageView alloc] initWithFrame:self.imageView.frame];
CGRect frame = self.imageView.frame;
newImgView.image = image;
frame.origin = CGPointMake(0, 0);
newImgView.layer.frame = frame;
newImgView.layer.opacity = .9;
newImgView.layer.contentsGravity = kCAGravityResizeAspectFill;
CALayer * containerLayer = self.imageView.layer.sublayers[0];
if (containerLayer != nil)
{
[containerLayer setValue:newImgView.layer forKey:#"__imageLayer"];
CALayer * holderLayer = [containerLayer valueForKey:#"__holderLayer"];
if (holderLayer != nil)
{
//!!!!!line below doesn't work!!!
//[holderLayer addSublayer:newImgView.layer];
//line below works!
[self.imageView.layer addSublayer:newImgView.layer];
}
}
[self.imageView setNeedsDisplay];
[self checkAndPrintLayers];
so the first nested layer is containerLayer, then holderLayer, and I'm expecting to add various images as sublayers to the holderLayer and then manipulate it. However, calling
[holderLayer addSublayer:newImgView.layer];
doesn't work; the imageView stays blank. However, calling
[self.imageView.layer addSublayer:newImgView.layer];
and adding a sublayer to the top layer works just dandy.
Am I missing something obvious here? Would love any suggestions.
thanks.
Because
holderLayer and containerLayer are transparent (holderLayer.opacity = 0 / containerLayer.opacity = 0),
Make it,
//container layer - the very top layer
CALayer *containerLayer = [CALayer layer];
containerLayer.opacity = 1.0;
containerLayer.bounds = [self.imageView.layer frame];
// Holder Layer
CALayer *holderLayer = [CALayer layer];
holderLayer.opacity = 1.0;
holderLayer.bounds = self.imageView.bounds;

CALayer hides the imageView

Hai all am using CALayer to mask the UIImage, when i add the layer on imageview it display only layer portion hides remanning all image with white color filled
CALayer *mask = [CALayer layer];
mask.contents = (id)[[UIImage imageNamed:#"mask.png"] CGImage];
mask.frame = CGRectMake(0, 0, mainImageWidth+30, mainImageHeight);
mask.shadowOffset = CGSizeMake(0, 3);
mask.shadowOpacity = 1.5;
mainImageView.layer.mask = mask;
[mainImageView.layer setMasksToBounds:NO];
it hides my image view except the layer portion. how do i solve this
Instead of create mask using image view i have added three mask for UIView now its working perfect
mainLayer.frame = CGRectMake(0, 0, mainImageWidth, mainImageHeight);
[self.view.layer addSublayer:mainLayer];
mainLayer.backgroundColor = [UIColor clearColor].CGColor;
secondLayer.frame = CGRectMake(gloss_x, gloss_y, gloss_w, gloss_h);
maskLayer = [CALayer layer];
UIImage *mask = [UIImage imageNamed:#"mask.png"];
maskLayer.contents = (id)mask.CGImage;
maskLayer.frame = maskRect;//CGRectMake(gloss_x, gloss_y-50, gloss_w, gloss_h);
secondLayer.contents = (id)s_glossImage.CGImage;
[mainLayer addSublayer:secondLayer];
mainLayer.mask = maskLayer;
[mainImageView.layer addSublayer:mainLayer];
Now its working fine.

How to add only right border to UIImageView

I want to add a white border to an UIImageView. I tried the following, but it didn't work:
UIImage *image = [UIImage imageNamed:imagePath];
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
CGRect rect = imageView.frame;
rect.size.width = rect.size.width + 1; // create white right border
[imageView setBackgroundColor:[UIColor whiteColor]];
imageView.frame = rect;
[myViewView addSubview:imageView];
I now did it like
CALayer *sublayer = [CALayer layer];
sublayer.backgroundColor = [UIColor whiteColor].CGColor;
sublayer.frame = CGRectMake(imageView.bounds.size.width, 0, 1, imageView.frame.size.height);
[imageView.layer addSublayer:sublayer];
You can create a UIView that is larger than the UIImage view, and set the image view's frame to be 0,0, width+1, height, and that will add the extra to the side.

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