I'm trying to draw a very simple circle. Here is my code:
CameraButtonView *buttonView = [[CameraButtonView alloc]initWithFrame:CGRectMake((self.view.frame.size.width / 2) - 45, self.view.frame.size.height * 0.8, 90, 90)];
buttonView.layer.cornerRadius = buttonView.frame.size.width / 2;
buttonView.layer.borderWidth = 2;
buttonView.backgroundColor = [UIColor clearColor];
buttonView.layer.borderColor = [UIColor greenColor].CGColor;
buttonView.clipsToBounds = YES;
[previewView addSubview:buttonView];
then, in drawRect:
UIBezierPath *path1 = [UIBezierPath bezierPath];
[path1 addArcWithCenter:self.center radius:(20) startAngle:0 endAngle:6.28 clockwise:YES];
[path1 setLineWidth:6];
[[UIColor redColor] setStroke];
[path1 stroke];
I have set the center and radius, specified a line width and stroke color, and called stroke. I have set breakpoints in drawRect to make sure the path is not nil, and it is indeed not. Just nothing is drawn.
The only thing I see on screen is a green circle from the code in the view controller where I set the corner radius. I tried calling [buttonView setNeedsDisplay]; as well, and that did not help. I've tried different initializations of the bezier path as well, such as initializing with the arc instead of creating the path and then calling addArcWithCenter.
what am I doing wrong?
Pay attention that a view center is not the center of the view itself, but is the center position of the view in superview coordinates. Probably you are drawing out of screen.
The center is specified within the coordinate system of its superview
and is measured in points. Setting this property changes the values of
the frame properties accordingly.
If you want to know the center of your view do this:
CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds))
Related
Is there a way to draw a UIView circle with a dotted line border? I want to have control over the spacing between the dots, and the size of the dots. I tried specifying my own pattern image, but when I make it into a circle it doesn't look good:
UIView *mainCircle = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
[mainCircle.layer setCornerRadius:100];
[mainCircle.layer setBorderWidth:5.0];
[mainCircle.layer setBorderColor:[[UIColor colorWithPatternImage:[UIImage imageNamed:#"dotted"]] CGColor]];
[self.view addSubview:mainCircle];
[mainCircle setCenter:self.view.center];
Following on from aksh1t's answer and rob's answer, you should use a round line cap, along with a dash pattern to do this.
The only thing I would add is that with the current code, you can end up with results like this:
Notice how at the top, you get an overlap of the dots. This is due to the fact that the circumference of the circle isn't entirely divisible by the number of dots.
You can fix this relatively easily by doing a simple bit of maths before. I wrote a few lines of code that'll allows you to provide an dot diameter value, along with an expected dot spacing - and it will try and approximate the nearest dot spacing that will result in an integral number of dots.
Also, I recommend you take an 100% layered approach, using CAShapeLayer to draw your circle. That way you can easily add animations to it without having to completely re-draw it for each frame.
Something like this should do the trick:
// your dot diameter.
CGFloat dotDiameter = 10.0;
// your 'expected' dot spacing. we'll try to get as closer value to this as possible.
CGFloat expDotSpacing = 20.0;
// the size of your view
CGSize s = self.view.frame.size;
// the radius of your circle, half the width or height (whichever is smaller) with the dot radius subtracted to account for stroking
CGFloat radius = (s.width < s.height) ? s.width*0.5-dotDiameter*0.5 : s.height*0.5-dotDiameter*0.5;
// the circumference of your circle
CGFloat circum = M_PI*radius*2.0;
// the number of dots to draw as given by the circumference divided by the diameter of the dot plus the expected dot spacing.
NSUInteger numberOfDots = round(circum/(dotDiameter+expDotSpacing));
// the calculated dot spacing, as given by the circumference divided by the number of dots, minus the dot diameter.
CGFloat dotSpacing = (circum/numberOfDots)-dotDiameter;
// your shape layer
CAShapeLayer* l = [CAShapeLayer layer];
l.frame = (CGRect){0, 0, s.width, s.height};
// set to the diameter of each dot
l.lineWidth = dotDiameter;
// your stroke color
l.strokeColor = [UIColor blackColor].CGColor;
// the circle path - given the center of the layer as the center and starting at the top of the arc.
UIBezierPath* p = [UIBezierPath bezierPathWithArcCenter:(CGPoint){s.width*0.5, s.height*0.5} radius:radius startAngle:-M_PI*0.5 endAngle:M_PI*1.5 clockwise:YES];
l.path = p.CGPath;
// prevent that layer from filling the area that the path occupies
l.fillColor = [UIColor clearColor].CGColor;
// round shape for your stroke
l.lineCap = kCALineCapRound;
// 0 length for the filled segment (radius calculated from the line width), dot diameter plus the dot spacing for the un-filled section
l.lineDashPattern = #[#(0), #(dotSpacing+dotDiameter)];
[self.view.layer addSublayer:l];
You'll now get the following output:
If you want to use this in a UIView, I would suggest subclassing it and adding the CAShapeLayer as a sublayer. You'll also want to add a masking layer in order to mask the view's contents to inside the border.
I have added an example of this in the full project below.
Full Project: https://github.com/hamishknight/Dotted-Circle-View
The best way to do what you are trying would be to draw a circle UIBezierPath, and set the path to a dotted style. The dotted style path code was taken from this answer.
UIBezierPath * path = [[UIBezierPath alloc] init];
[path addArcWithCenter:center radius:50 startAngle:0 endAngle:2 * M_PI clockwise:YES];
[path setLineWidth:8.0];
CGFloat dashes[] = { path.lineWidth, path.lineWidth * 2 };
[path setLineDash:dashes count:2 phase:0];
[path setLineCapStyle:kCGLineCapRound];
// After you have the path itself, you can either make
// an image and set it in a view or use the path directly
// in the layer of the view you want to.
// This is the code for the image option.
UIGraphicsBeginImageContextWithOptions(CGSizeMake(300, 20), false, 2);
[path stroke];
UIImage * image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
I have the following code to make the UIImageView in each of my UITableView's cells have rounded corners:
- (void)awakeFromNib
{
// Rounded corners.
[[cellImage layer] setCornerRadius:([cellImage frame].size.height / 2)];
[[cellImage layer] setMasksToBounds:YES];
[[cellImage layer] setBorderColor:[[UIColor whiteColor] CGColor]];
[[cellImage layer] setBorderWidth:3]; // Trouble!
}
I want the images to have a bit of a gap between them, and figured I could make use of the border width to make that happen. Below is an image of what actually happened:
It's that faint black border that I want to know how to get rid of. I'd like to think there's a way of doing it using border width. If not, the best approach might be just to resize the image itself and just set the border width to be 0.
Rather than using corner radius, you can create bezier path for the mask, create a shape layer for that path, and then specify that shape layer for the image view's layer's mask:
CGFloat margin = 3.0;
CGRect rect = CGRectInset(imageView.bounds, margin, margin);
UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(imageView.bounds.size.width/2, imageView.bounds.size.height/2) radius:radius startAngle:0 endAngle:M_PI*2 clockwise:NO];
CAShapeLayer *mask = [CAShapeLayer layer];
mask.path = path.CGPath;
imageView.layer.mask = mask;
What you are doing is, you are clipping the profile image and the border together, which is making the cell's profile image extending through the border.
You are missing this line:-
cellImage.clipsToBounds = YES;
I have this code that draws a simple zigzag line. The initial point onX axis is 0. The problem is that I am trying to offset the initial point by 20pts, but I just can't get it right.
I've tried both CGRectInset and CGRectOffSet, but didn't work..
Here's my code:
- (UIBezierPath *)pathFromDataInRect:(CGRect)rect {
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(0, CGRectGetMidY(rect))];
[path addLineToPoint:CGPointMake((CGRectGetWidth(rect)/3), CGRectGetMaxY(rect))];
[path addLineToPoint:CGPointMake((CGRectGetWidth(rect)/3)*2, CGRectGetMinY(rect))];
[path addLineToPoint:CGPointMake((CGRectGetWidth(rect)/3)*3, CGRectGetMidY(rect))];
UIColor *startColor = [UIColor redColor];
[startColor setStroke];
[path stroke];
return path;
}
- (CGRect)closingDataRect {
return CGRectMake(0, 150, 200, 100);
}
- (void)drawRect:(CGRect)rect
{
CGRect dataRect = [self closingDataRect];
CGRect dataRectOffset = CGRectOffset(dataRect, 20, 0);
[self pathFromDataInRect:dataRectOffset];
}
The first pic is what I have when I run the code and the second pic is what I want.
Your first moveToPoint call hard-codes the x position to 0. If you want to start at the right edge of your rectangle, shouldn't you change that first moveToPoint line to pass in your rect's origin.x as the starting point?
Then you also need to change any code that calculates points in your path purely from the width/height use width+origin.x or height+origin.y, so when you shift the origin of your rectangle, all the points in the rectangle shift as well.
Being a beginner in iOS drawing I wanted to draw a small tooltip container which consists of a rectangle with an indicator arrow.
I created 2 UIBezierPaths and joined them with "appendPath".
I thought this was the right way to go about this, but after struggling for 1 day, I had to ask for help.
Here's the screenshot of where I am right now:
As you can see the problem is simply that when I try to stroke the joined path, it doesn't gets stroked as a whole, but as separate pieces.
Maybe someone could point me in the right direction to solve this ?
Here's the code:
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
// create indicator path
UIBezierPath *indicator = [[UIBezierPath alloc] init];
// corner radius
CGFloat radius = self.cornerRadius;
// main path
UIBezierPath *path;
// format frame
rect = CGRectMake(rect.origin.x, rect.origin.y, rect.size.width, rect.size.height - self.indicatorSize.height);
// assign path
path = [UIBezierPath bezierPathWithRoundedRect: rect
byRoundingCorners:UIRectCornerAllCorners
cornerRadii:CGSizeMake(radius, radius)];
// x point
CGFloat x = (rect.size.width - self.indicatorSize.width) / 2;
[indicator moveToPoint:CGPointMake(x, rect.size.height)];
[indicator addLineToPoint:CGPointMake(x + self.indicatorSize.width / 2, rect.size.height + self.indicatorSize.height)];
[indicator addLineToPoint:CGPointMake(x + self.indicatorSize.width, rect.size.height)];
// close path
[indicator closePath];
// append indicator to main path
[path appendPath:indicator];
[[UIColor redColor] setStroke];
[path setLineWidth:2.0];
[path stroke];
[self.fillColor setFill];
[path fill];
// release indicator
[indicator release];
}
Thanks in advance
You need to draw it all as one path, because at the moment you're telling it you want to draw a whole rectangle, and then a triangle, and that's what it's doing.
From the Apple UIBezierPath documentation:
[appendPath:] adds the commands used to create the path in bezierPath to the end of the receiver’s path. This method does not explicitly try to connect the subpaths in the two objects, although the operations in bezierPath might still cause that effect.
So first it will draw your rectangle, and then it will draw your triangle without attempting to join them
I have a UIView. I need to make only it's top left and top right corners rounded and also to have a 1 point border width.
Any idea?
Thanks
Try this:
#import <QuartzCore/QuartzCore.h>
view.layer.cornerRadius = 8.0;
view.layer.borderWidth = 1.0;
view.layer.borderColor = [UIColor blueColor].CGColor;
however, it'll make all of your corners rounded. If you don't want this, there are two options:
Draw the rounded corner yourself using CoreGraphics (How to draw a rounded rectangle in Core Graphics / Quartz 2D?) or
Use a mask (CALayer's #property mask here: http://developer.apple.com/library/ios/#DOCUMENTATION/GraphicsImaging/Reference/CALayer_class/Introduction/Introduction.html)
UIView With top left,right rounded corners and shadow
#import <QuartzCore/QuartzCore.h>
backView.layer.shadowColor=[UIColor blackColor].CGColor;
backView.layer.masksToBounds = NO;
backView.layer.shadowOffset = CGSizeMake(0.0f, 1.0f);
backView.layer.shadowRadius = 3;
backView.layer.shadowOpacity = 0.8;
CGFloat radius = 20.0;
CGRect maskFrame = self.backView.bounds;
maskFrame.size.height += radius;
CALayer *maskLayer1 = [CALayer layer];
maskLayer1.cornerRadius = radius;
maskLayer1.backgroundColor = [UIColor blackColor].CGColor;
maskLayer1.frame = maskFrame;
self.backView.layer.mask = maskLayer1;
you can achieve this using beizer path like this -
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:self.bounds byRoundingCorners:UIRectCornerTopLeft | UIRectCornerTopRight cornerRadii:CGSizeMake(5.0, 5.0)];
[maskPath setLineWidth:1.0];
//to give stroke color
[[UIColor colorWithRed:186.0/255.0 green:186.0/255.0 blue:186.0/255.0 alpha:1.0] setStroke];
//to color your border
[[UIColor colorWithRed:242.0/255.0 green:240.0/255.0 blue:240.0/255.0 alpha:1.0] setFill];
[maskPath fill];
[maskPath stroke];
Use CALayer's and try this tutorial more more information. http://nachbaur.com/blog/rendering-views-using-calayer-part-1
A very simple and quick solution:
set the corner radius so that it draws all four corners rounded in the normal way
for each corner that you don't want rounded:
create a small square UIView with side equal to the corner radius
add it as subview of the main view (the one with the rounded corners)
position it so that it sits exactly over the corner
set its background color to be the same as the main view's background
Not necessarily the most elegant solution, but only takes a minute to code it up!