I have to draw an oval shape button, i don't want to set the image in oval shape.
I have read that you can draw different shaper with UIBezierPath but i am unable to draw a proper oval shape.
Here is the code is am using to create a circular shape.
self.layer.borderWidth=1.0;
self.clipsToBounds = YES;
[self setTitleColor:ktextColor forState:UIControlStateNormal];
self.layer.cornerRadius = self.bounds.size.width/2;//half of the width
self.layer.borderColor=[[UIColor whiteColor]CGColor];
Any help is appreciated !!
You can set the delegate for your button's layer and implement the delegate method `displayLayer:'
-(void)displayLayer:(CALayer *)layer
{
UIGraphicsBeginImageContext(layer.frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
UIBezierPath* ovalPath = [UIBezierPath bezierPathWithOvalInRect: CGRectMake(0.0, 0.0, CGRectGetWidth(layer.frame), CGRectGetHeight(layer.frame))];
[[UIColor whiteColor] setFill];
[ovalPath fill];
[[UIColor blackColor] setStroke];
ovalPath.lineWidth = 1;
[ovalPath stroke];
UIImage *imageBuffer = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
layer.contents = (id)[imageBuffer CGImage];
}
You can also create a CAShapelayer and than add gesture to the layer as below:
-(void)generateOvalWithSize:(CGSize)size origin:(CGPoint)origin {
CAShapeLayer ovalLayer = [CAShapeLayer layer];
CGMutablePathRef ovalPath = CGPathCreateMutable();
CGPathAddEllipseInRect(ovalPath, NULL, CGRectMake(origin.x, origin.y, size.width, size.height));
CGPathCloseSubpath(ovalPath);
ovalLayer.path = ovalPath;
// Configure the apperence of the circle
ovalLayer.fillColor = [UIColor whiteColor].CGColor;
ovalLayer.strokeColor = [UIColor whiteColor].CGColor;
ovalLayer.lineWidth = 2;
// Add to parent layer
[[self layer] addSublayer:ovalLayer];
}
i have been using these two functions for a while, i haven't come across any issues yet, but if someone sees an issue please let me know.
you can pass anything that is a subclass of UIView (ie. UIButton, UICollectionViewCell, etc.)
+ (void)setCornerRadius:(CGFloat)radius forView:(UIView*)view
{
[view.layer setCornerRadius:radius];
[view.layer setMasksToBounds:YES];
}
+ (void)setBordersForView:(UIView*)view width:(CGFloat)width color:(UIColor*)color
{
view.layer.borderColor = color.CGColor;
view.layer.borderWidth = width;
}
the above yields me the effect below in a collection view:
the collection view cell has a single button which is bound all the way around the edges (auto layout) and takes up the full height and width of the cell.
then i pass in the entire cell (or self.viewForBaseLineLayout if calling from within the cell) as the view parameter in both functions listed above.
for the radius parameter i am passing 20.0f.
(but this value will vary depending on the size the view you are passing; you just have to play around with it)
i know this post is old, but maybe it will help someone new : )
You can use the OBShapedButton class Download Here
Related
I have two rectangles (two closed sub cgpaths).
Rectangle B is small and is present inside Rectangle A. All edges within it.
Is there a direct way to fill color area external to the rectangle B.
CAShapeLayer fillExternalColor something like that? If not a direct way, how to do this programmatically?
A - Purple color
B - Yellow color
So I tried drawing A and then drawing B. I wanted B to be of clear color (for now I put Yellow) but then I see purple color of A..
I found CGRectIntersection method that gives AnB and CGRectUnion method that gives AuB.
Is there a method that gives the rest of the area which is AuB - AnB?
You are using a CAShapeLayer. If your fillColor and your strokeColor are both opaque (alpha 1.0), you can simply set the layer's backgroundColor to fill those pixels that are within the layer's bounds but outside of its stroked and filled path.
My test code:
#implementation ViewController {
CAShapeLayer *layer;
}
- (void)viewDidLoad {
[super viewDidLoad];
layer = [CAShapeLayer layer];
layer.path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(50, 50, 250, 250)].CGPath;
layer.fillColor = [UIColor yellowColor].CGColor;
layer.strokeColor = [UIColor whiteColor].CGColor;
layer.lineWidth = 4;
layer.backgroundColor = [UIColor purpleColor].CGColor;
[self.view.layer addSublayer:layer];
}
- (void)viewDidLayoutSubviews {
layer.frame = self.view.bounds;
}
#end
Result:
I wanted to add red border inner rectangle on UIImage with masked outer part.
I came through this page. The following code is using CGContextEOFillPath can be helpful to others like me. (Some of the code is gathered from other pages.)
-(UIImage ) imageByDrawingBorderRectOnImage:(UIImage )image theRect:(CGRect)theRect
{
// begin a graphics context of sufficient size
UIGraphicsBeginImageContext(image.size);
// draw original image into the context
[image drawAtPoint:CGPointZero];
// get the context for CoreGraphics
CGContextRef ctx = UIGraphicsGetCurrentContext();
// set stroking color and to draw rect
[[UIColor redColor] setStroke];
// drawing with a red stroke color
CGContextSetRGBStrokeColor(ctx, 1.0, 0.0, 0.0, 1.0);
// the line width to 3
CGContextSetLineWidth(ctx, 3.0);
// Add Stroke Rectangle,
CGContextStrokeRect(ctx, theRect);
// Now draw fill outside part with partial alpha gray color
// drawing with a gray stroke color
CGMutablePathRef aPath = CGPathCreateMutable();
// outer rectangle
CGRect rectangle = CGRectMake( 0, 0, image.size.width, image.size.height);
CGPathAddRect(aPath, nil, rectangle);
// innter rectangle
CGPathAddRect(aPath, nil, theRect);
// set gray transparent color
CGContextSetFillColorWithColor(ctx, [UIColor colorWithRed:0.75 green:0.75 blue:0.75 alpha:0.5].CGColor);
// add the path to Context
CGContextAddPath(ctx, aPath);
// This method uses Even-Odd Method to draw in outer rectangle
CGContextEOFillPath(ctx);
// make image out of bitmap context
UIImage *retImage = UIGraphicsGetImageFromCurrentImageContext();
// free the context
UIGraphicsEndImageContext();
return retImage;
}
Regards.
Assuming A is the bigger shape, B is the smaller, inner shape, and bounds refers to the containing rect of A (probably the bounds of the view)
Clip shape B to the context (-addClip should do it)
CGContextClearRect the bounds
Fill shape A
Edit, found the source of this code
Given HoleView : UIView you must set:
self.opaque = NO;
self.backgroudColor = [UIColor clearColor];
and in drawRect:
[[UIColor purpleColor] setFill];
UIRectFill(A);
CGRect gapRectIntersection = CGRectIntersection(B, A);
[[UIColor clearColor] setFill];
UIRectFill(gapRectIntersection);
kCAFillRuleEvenOdd
Specifies the even-odd winding rule. Count the total number of path crossings. If the number of crossings is even, the point is outside the path. If the number of crossings is odd, the point is inside the path and the region containing it should be filled.
Available in OS X v10.6 and later.
Declared in CAShapeLayer.h.
Refer to :CAShapeLayer Class reference
I have a Master-Details project setup and running in XCode with no problems at all and everything works fine. However, when I attempt to round the top right and left corners of the NavigationBar it has a very strange effect. It basically, offsets the 'touch' response of the 'back' left button on the details view.
The button still works, but it seems that the iPhone can only pick up the user's touch when they click just below the NavigationBar and not the button itself.
The code I have is:
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
UIColor *color = [UIColor darkGrayColor];
UIImage *img = [UIImage imageNamed:#"nav-bar"];
[img drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
self.tintColor = color;
// Create mask to round corners
CGRect bounds = CGRectMake(0, 0, self.frame.size.width, self.frame.size.height);
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:bounds byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerTopRight) cornerRadii:CGSizeMake(10.0, 10.0)];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = bounds;
maskLayer.path = maskPath.CGPath;
// Apply mask to navigation bar
[self.layer addSublayer:maskLayer];
self.layer.mask = maskLayer;
// Apply logo to navigation bar
UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"logo"]];
self.topItem.titleView = imageView;
}
Here is a screen shot of what I mean, button only responses when I touch where the arrow is pointing:
--- UPDATE ---
After some testing I've worked out the problem is with the 'self.layer.mask = maskLayer' line. I have refactored the code and tested in another project that just uses xib files and not story boards, and dont have any problems, but its still not working in the current project.
CGRect bounds = CGRectMake(0, 0, navigationController.navigationBar.bounds.size.width,
navigationController.navigationBar.bounds.size.height);
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:bounds byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerTopRight) cornerRadii:CGSizeMake(10.0, 10.0)];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = bounds;
maskLayer.path = maskPath.CGPath;
// Apply mask to navigation bar
//navigationController.navigationBar.layer.mask = maskLayer;
[navigationController.navigationBar.layer addSublayer:maskLayer];
navigationController.navigationBar.layer.mask = maskLayer;
use self.bounds instead of self.frame. You probably want to draw relatively to your own coordinates system and not relatively to your own parent view.
I would like to create a CALayer bezier path in a circle shape. And I would like to set it like it was a UIImageView (to be able to move it with animation etc.) Is it possible? If so how can I do it? Thank you.
You could always add a CAShapeLayer to your view. During init, do something like (all untested):
CAShapeLayer *circle = [[CAShapeLayer alloc] init];
[self.layer addSublayer:circle];
Then, in drawRect, layoutSubViews, or some other place that seems appropriate to update the layout:
circle.fillColor = [[UIColor redColor].CGColor;
CGMutablePathRef p = CGPathCreateMutable();
CGPathAddEllipseInRect(p, NULL, self.bounds);
circle.path = p;
circle.bounds = self.bounds;
circle.position = CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds));
I'm not sure what you mean by a "CALayer bezier path" but you have a couple of options here:
Create a subclass of UIView, where you draw your circle using UIBezierPath methods in the drawRect:. This view can then be added to another view as a subview and animated using standard methods. However, you are warned that this may affect performance, (as it has to keep re-drawing) so if that does turn out to be a problem...
Create a graphics context and draw your circle in there. Take an image from this graphics context and set it as the image for a UIImageView. Animate as in answer (1). This way you aren't redrawing all the time so performance would be better, but try with option 1 first as it is simpler, and if you have simple drawing code it shouldn't affect you too much.
For option 2, you begin a graphics context using UIGraphicsBeginImageContextWithOptions - you then do your drawing, and extract the image using UIGraphicsGetImageFromCurrentImageContext, then end the context using UIGraphicsEndImageContext. Those functions are all documented here
Sample code to do this:
CGFloat radius = 50;
CGSize size = CGSizeMake(radius*2,radius*2);
CGPoint centre = CGPointMake(radius,radius);
UIGraphicsBeginImageContextWithOptions(size,NO, 0.0);
UIBezierPath * solidPath = [UIBezierPath bezierPathWithArcCenter:centre radius:edgeSize/20 startAngle:0 endAngle:2 * M_PI clockwise:YES];
[solidPath closePath];
[[UIColor whiteColor] set];
[solidPath fill];
UIImage *circle = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageView *imageView = [[UIImageView alloc] initWithImage:circle];
I am having a lot of trouble trying to find out how to draw a transparent circle on top of a UIImage within my UIImageView. Google-ing gives me clues, but I still can't find a working example.
Are there any examples that anyone knows of that demonstrate this?
Easiest way is simply to create a semi-transparent square UIView, then set the cornerRadius of its layer to be half of its width/height. Something like:
UIView *squareView = [[UIView alloc] initWithFrame:CGRectMake(0,0,100,100)];
squareView.alpha = 0.5;
squareView.layer.cornerRadius = 50;
...
[squareView release];
This has got to be the simplest solution:
CGFloat r = 150;
UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(0,0,1.5*r,1.5*r)];
lbl.text = #"●";
lbl.transform = CGAffineTransformMakeTranslation(0.0f, -r/6);
lbl.textAlignment = UITextAlignmentCenter;
lbl.backgroundColor = [UIColor clearColor];
lbl.textColor = [UIColor redColor];
lbl.font = [UIFont systemFontOfSize:2*r];
lbl.alpha = 0.5;
lbl.center = self.view.center;
[self.view addSubview:lbl];
One way would be to add a CAShapeLayer with a circular path, either directly to the layer of the UIImageView or as the layer of a new UIView that is added to the UIImageView.
If you actually want to modify the image, then create a mutable copy of it by drawing it into a CGBitmapContext then creating a new image from the modified bitmap.
CGPathRef circlePath = CGPathCreateMutable();
CGPathAddEllipseInRect( circlePath , NULL , CGRectMake( 0,0,20,20 ) );
CAShapeLayer *circle = [[CAShapeLayer alloc] init];
circle.path = circlePath;
circle.opacity = 0.5;
[myImageView.layer addSublayer:circle];
CGPathRelease( circlePath );
[circle release];
You can implement a custom sub-class of UIView that draws your image and then the circle in the drawRect method:
#interface CircleImageView : UIView {
UIImage * m_image;
CGRect m_viewRect;
// anything else you need in this view?
}
Implementation of drawRect:
- (void)drawRect:(CGRect)rect {
// first draw the image
[m_image drawInRect:m_viewRect blendMode:kCGBlendModeNormal alpha:1.0];
// then use quartz to draw the circle
CGContextRef context = UIGraphicsGetCurrentContext ()
// stroke and fill black with a 0.5 alpha
CGContextSetRGBStrokeColor(context, 1.0, 1.0, 1.0, 0.5);
CGContextSetRGBFillColor(context, 1.0, 1.0, 1.0, 0.5);
// now draw the circle
CGContextFillEllipseInRect (context, m_viewRect);
}
You will need to set up the m_viewRect and m_image member functions on init.
Maybe it's because it's late. Whatever the reason I can't figure out why I'm having trouble with a simple CSScrollLayer example I'm trying. I add a 50 pixel Eclipse icon to a view based project and in my initialize method (called from initWithNibName:bundle:) I have this:
-(void) initialize
{
CAScrollLayer *scrollLayer = [CAScrollLayer layer];
scrollLayer.backgroundColor = [[UIColor blackColor] CGColor];
CGRect bounds = self.view.bounds;
scrollLayer.bounds = CGRectMake(0, 0, bounds.size.width, bounds.size.height);
scrollLayer.contentsRect = CGRectMake(0, 0, bounds.size.width + 800, bounds.size.height + 800);
scrollLayer.borderWidth = 2.5;
scrollLayer.borderColor = [[UIColor redColor] CGColor];
scrollLayer.position = CGPointMake(self.view.center.x, self.view.center.y - 20);
scrollLayer.scrollMode = kCAScrollBoth;
[self.view.layer addSublayer:scrollLayer];
UIImage *image = [UIImage imageNamed:#"eclipse32.gif"];
for(int i=0; i<6; i++) {
layer = [CALayer layer];
layer.backgroundColor = [[UIColor blackColor] CGColor];
layer.bounds = CGRectMake(0, 0, 100, 100);
layer.contents = (id)[image CGImage];
layer.position = CGPointMake(layer.bounds.size.width * i, self.view.center.y);
[scrollLayer addSublayer:layer];
}
// [button removeFromSuperview];
// [self.view addSubview:button];
// self.view.userInteractionEnabled = YES;
[image release];
}
The scroll layer shows, the icon is repeated on the layer I have a border around the edge of the screen. Everything is lovely except I can't scroll the icons. I've tried with/without setting scroll mode. I've tried with a single stretched icon that falls off screen. I've tried everything. What am I doing wrong?
CAScrollLayer does not plug into the UIEvent chain so you need to manually add code to modify the scroll offsets on touch events. It is also very tricky to get the scrolling momentum like UIScrollView does. I would strongly recommend re-implementing with UIScrollView -- it will be remarkably simpler. The only other option is to do manual touch event handling, which is painful! I tried to get a nice scroller with CAScrollLayer and gave up after implementing a few awkward scrolling behaviors manually.
The general rule I follow with using CALayer or UIView's is to use CALayer objects when I don't need any user interaction. If the user is going to touch it, use the UIView, it's a very lightweight object so the overhead is negligible.
That said, I've found CAScrollLayer remarkably useless! Why not just use a CALayer and modify the bounds? There's probably some use to it, but it is no replacement for UIScrollView.
Try adding this to your example to scroll the layer programmatically:
- (void)scroll {
[scrollLayer scrollToPoint:scrollPoint];
scrollPoint.x += 10;
[self performSelector:_cmd withObject:nil afterDelay:0.1];
}
and add this at the end of the initialize method:
scrollPoint = CGPointMake(0, 0);
[self scroll];