DevTut

# CAShapeLayer

# Draw Rectangle


CAShapeLayer *mask = [[CAShapeLayer alloc] init];

mask.frame = CGRectMake(50, 50, 100, 100);

CGFloat width = 100;

CGFloat height = 100;

CGMutablePathRef path = CGPathCreateMutable();

CGPathMoveToPoint(path, nil, 30, 30);

CGPathAddLineToPoint(path, nil, width, 30);

CGPathAddLineToPoint(path, nil, width, height);

CGPathAddLineToPoint(path, nil,30, height);

CGPathAddLineToPoint(path, nil, 30, 30);

CGPathCloseSubpath(path);


mask.path = path;

CGPathRelease(path);

self.view.layer.mask = mask;

Rectangle (opens new window)

# Draw Circle


CAShapeLayer *circle = [CAShapeLayer layer];
    
    [circle setPath:[[UIBezierPath bezierPathWithOvalInRect:CGRectMake(100, 100, 150, 150)] CGPath]];
    
    [circle setStrokeColor:[[UIColor blueColor] CGColor]];

    [circle setFillColor:[[UIColor clearColor] CGColor]];
    
    [[self.view layer] addSublayer:circle];

Circle (opens new window)

# CAShapeLayer Animation

CAShapeLayer *circle = [CAShapeLayer layer];

[circle setPath:[[UIBezierPath bezierPathWithOvalInRect:CGRectMake(100, 100, 150, 150)] CGPath]];

[circle setStrokeColor:[[UIColor blueColor] CGColor]];

[circle setFillColor:[[UIColor clearColor] CGColor]];

[[self.view layer] addSublayer:circle];


CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];

pathAnimation.duration = 1.5f;

pathAnimation.fromValue = [NSNumber numberWithFloat:0.0f];

pathAnimation.toValue = [NSNumber numberWithFloat:1.0f];

pathAnimation.repeatCount = 10;

pathAnimation.autoreverses = YES;

[circle addAnimation:pathAnimation
              forKey:@"strokeEnd"];

Animation (opens new window)

# Basic CAShapeLayer Operation

UIBezierPath using to create a circular path ShapeLayer

CAShapeLayer *circleLayer = [CAShapeLayer layer];
[circleLayer setPath:[[UIBezierPath bezierPathWithOvalInRect:
CGRectMake(50, 50, 100, 100)] CGPath]];
circleLayer.lineWidth = 2.0;
[circleLayer setStrokeColor:[[UIColor redColor] CGColor]];
[circleLayer setFillColor:[[UIColor clearColor] CGColor]];
circleLayer.lineJoin = kCALineJoinRound;  //4 types are available to create a line style
circleLayer.lineDashPattern = [NSArray arrayWithObjects:
[NSNumber numberWithInt:2],[NSNumber numberWithInt:3 ], nil];
// self.origImage is parentView
[[self.view layer] addSublayer:circleLayer];
self.currentShapeLayer = circleLayer;  // public value using to keep that reference of the shape Layer
self.view.layer.borderWidth = 1.0f;
self.view.layer.borderColor = [[UIColor blueColor]CGColor];  // that will plotted in the mainview

Remove ShapeLayer

Keep a reference to that shape layer. For example, you might have a property currentShapeLayer: Now that you have a reference, you can easily remove the layer:

Type 1:


[self.currentShapeLayer removeFromSuperlayer];

Type 2:


self.view.layer.sublayers = nil ;                //removed all earlier shapes

Other Operation


//Draw Square Shape

CAShapeLayer *squareLayer = [CAShapeLayer layer];
squareLayer.frame = CGRectMake(20, 20, 100, 100);
squareLayer.lineWidth = 2.0;
squareLayer.fillColor = nil;
squareLayer.strokeColor = [[UIColor redColor] CGColor];
squareLayer.path = [UIBezierPath bezierPathWithRect:squareLayer.bounds].CGPath;
[[self.view layer] addSublayer:squareLayer];


//Draw Circle Shape

CAShapeLayer *circleShape = [CAShapeLayer layer];
circleShape.frame = CGRectMake(160, 20, 120, 120);
circleShape.lineWidth = 2.0;
circleShape.fillColor = nil;
circleShape.strokeColor = [[UIColor redColor] CGColor];
circleShape.path = [UIBezierPath bezierPathWithOvalInRect:circleShape.bounds].CGPath;
[[self.view layer] addSublayer:circleShape];


//Subpaths
//UIBezierPath can have any number of “path segments” (or subpaths) so you can effectively draw as many shapes or lines as you want in a single path object

CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.frame = CGRectMake(20, 140, 200, 200);
shapeLayer.lineWidth = 2.0;
shapeLayer.fillColor = nil;
shapeLayer.strokeColor = [[UIColor redColor] CGColor];

CGMutablePathRef combinedPath= CGPathCreateMutableCopy(circleShape.path);
CGPathAddPath(combinedPath, NULL, squareLayer.path);

shapeLayer.path = combinedPath;
[[self.view layer] addSublayer:shapeLayer];

//Open Path
// Paths do not need to connect their end points back to their starting points. A path that connects back to its starting point is called a closed path, and one that does not is called an open path.

shapeLayer = [CAShapeLayer layer];
shapeLayer.frame = CGRectMake(160, 140, 300, 300);
shapeLayer.lineWidth = 2.0;
shapeLayer.fillColor = nil;
shapeLayer.strokeColor = [[UIColor redColor] CGColor];

UIBezierPath *linePath=[UIBezierPath bezierPath];
[linePath moveToPoint:CGPointZero];
[linePath addLineToPoint:CGPointMake(0 , 120)];
[linePath addLineToPoint:CGPointMake(120 , 120)];
[linePath addLineToPoint:CGPointMake(120 , 0)];
shapeLayer.path = linePath.CGPath;
[[self.view layer] addSublayer:shapeLayer];

Example Output (opens new window)

Fill Concepts //Fill Color

CAShapeLayer *squareLayer = [CAShapeLayer layer];
squareLayer.frame = CGRectMake(20, 30, 100, 100);
squareLayer.lineWidth = 2.0;
squareLayer.fillColor = [[UIColor yellowColor]CGColor];
squareLayer.strokeColor = [[UIColor redColor] CGColor];
squareLayer.path = [UIBezierPath bezierPathWithRect:squareLayer.bounds].CGPath;
[[self.view layer] addSublayer:squareLayer];

//Fill Pattern Color
//images.jpeg

squareLayer = [CAShapeLayer layer];
squareLayer.frame = CGRectMake(140, 30, 100, 100);
squareLayer.lineWidth = 2.0;
squareLayer.fillColor = [[UIColor colorWithPatternImage:[UIImage imageNamed:@"images.jpeg"]]CGColor];
squareLayer.strokeColor = [[UIColor redColor] CGColor];
squareLayer.path = [UIBezierPath bezierPathWithRect:squareLayer.bounds].CGPath;
[[self.view layer] addSublayer:squareLayer];


//Fill Rule

//Type 1: kCAFillRuleNonZero
squareLayer = [CAShapeLayer layer];
squareLayer.frame = CGRectMake(0, 140, 150, 150);
squareLayer.lineWidth = 2.0;
squareLayer.fillColor = [[UIColor yellowColor]CGColor];
squareLayer.fillRule = kCAFillRuleNonZero;   // indicate the rule type
squareLayer.strokeColor = [[UIColor redColor] CGColor];
UIBezierPath *outerPath = [UIBezierPath bezierPathWithRect:CGRectInset(squareLayer.bounds, 20.0, 20.0)];
UIBezierPath *innerPath = [UIBezierPath bezierPathWithRect:CGRectInset(squareLayer.bounds, 50.0, 50.0)];
CGMutablePathRef combinedPath= CGPathCreateMutableCopy(outerPath.CGPath);
CGPathAddPath(combinedPath, NULL, innerPath.CGPath);
squareLayer.path = combinedPath;
[[self.view layer] addSublayer:squareLayer];


//Type 2: kCAFillRuleEvenOdd
squareLayer = [CAShapeLayer layer];
squareLayer.frame = CGRectMake(140, 140, 150, 150);
squareLayer.lineWidth = 2.0;
squareLayer.fillColor = [[UIColor yellowColor]CGColor];
squareLayer.fillRule = kCAFillRuleEvenOdd;   // indicate the rule type
squareLayer.strokeColor = [[UIColor redColor] CGColor];
outerPath = [UIBezierPath bezierPathWithRect:CGRectInset(squareLayer.bounds, 20.0, 20.0)];
innerPath = [UIBezierPath bezierPathWithRect:CGRectInset(squareLayer.bounds, 50.0, 50.0)];
combinedPath= CGPathCreateMutableCopy(outerPath.CGPath);
CGPathAddPath(combinedPath, NULL, innerPath.CGPath);
squareLayer.path = combinedPath;
[[self.view layer] addSublayer:squareLayer];

Fill Example (opens new window)

Listed the accessing Style properties


  fillColor    
        Fill the color based on the drawed shape.

   fillRule
        Fill Rule the there are two rule is applied to draw the shape.
        1.  kCAFillRuleNonZero
        2.  kCAFillRuleEvenOdd

   lineCap
        Below type used to change the style of the line.
        1.  kCALineCapButt
        2.  kCALineCapRound
        3.  kCALineCapSquare

   lineDashPattern
        The dash pattern applied to the shape’s path when stroked.
        Create DashStyle while you will stroke the line.

   lineDashPhase
        The dash phase applied to the shape’s path when stroked. Animatable.
   lineJoin
        Line join style for the shape path.Below style use to draw the line join style.
        1.  kCALineJoinMiter
        2.  kCALineJoinRound
        3.  kCALineJoinBevel

   lineWidth
        Which using to set the line width.

   miterLimit
        The miter limit used when stroking the shape’s path. Animatable.

   strokeColor
        Set the stroke color based on the path of the line.

   strokeStart
        When the stroke will start.

   strokeEnd
       When the stroke will end.

# Syntax

  1. shapeLayer.fillColor
  2. shapeLayer.fillRule
  3. shapeLayer.lineCap
  4. shapeLayer.lineDashPattern
  5. shapeLayer.lineDashPhase
  6. shapeLayer.lineJoin

# Remarks

The CAShapeLayer class draws a cubic Bezier spline in its coordinate space. The shape is composited between the layer's contents and its first sublayer.

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