ADGame/ADGame/ScoreView.m
/* |
Copyright (C) 2015 Apple Inc. All Rights Reserved. |
See LICENSE.txt for this sample’s licensing information |
Abstract: |
A CAShapeLayer backed view to display the current score |
*/ |
#import "ScoreView.h" |
@import QuartzCore; |
// We use a subclass of CAShapeLayer so that the path will animate when changed. |
// Because UIView only allows certain animation keys to animate, we can't do this via |
// the other means usually reserved for doing this, such as the layer's actions dictionary |
// or the delegate's -actionForLayer:forKey: method. |
@interface MyCAShapeLayer : CAShapeLayer |
@end |
@implementation MyCAShapeLayer |
- (id<CAAction>)actionForKey:(NSString *)key { |
if ([key isEqualToString:@"path"]) { |
return [CABasicAnimation animationWithKeyPath:@"path"]; |
} |
else { |
return [super actionForKey:key]; |
} |
} |
@end |
@interface ScoreView () |
@property (weak, nonatomic, readonly) CAShapeLayer *shapeLayer; |
@end |
@implementation ScoreView |
CGGradientRef top; |
CGGradientRef left; |
CGGradientRef bottom; |
CGGradientRef right; |
+ (Class)layerClass { |
return [MyCAShapeLayer class]; |
} |
CGGradientRef CreateWhiteToColorGradient(CGFloat r, CGFloat g, CGFloat b) { |
CGFloat colors[] = { |
1.0, 1.0, 1.0, 1.0, |
r, g, b, 1.0, |
}; |
CGColorSpaceRef rgb = CGColorSpaceCreateDeviceRGB(); |
CGGradientRef gradient = CGGradientCreateWithColorComponents(rgb, colors, NULL, 2); |
CGColorSpaceRelease(rgb); |
return gradient; |
} |
- (void)commonInit { |
CAShapeLayer *shapeLayer = self.shapeLayer; |
shapeLayer.lineWidth = 3.0; |
shapeLayer.fillRule = kCAFillRuleEvenOdd; |
top = CreateWhiteToColorGradient(1.0, 0.0, 0.0); |
left = CreateWhiteToColorGradient(0.0, 0.0, 1.0); |
bottom = CreateWhiteToColorGradient(0.0, 1.0, 0.0); |
right = CreateWhiteToColorGradient(1.0, 0.625, 0.0); |
} |
- (instancetype)initWithFrame:(CGRect)frame { |
self = [super initWithFrame:frame]; |
if (self != nil) { |
[self commonInit]; |
} |
return self; |
} |
- (instancetype)initWithCoder:(NSCoder *)aDecoder { |
self = [super initWithCoder:aDecoder]; |
if (self != nil) { |
[self commonInit]; |
} |
return self; |
} |
- (void)drawRect:(CGRect)rect { |
CGContextRef context = UIGraphicsGetCurrentContext(); |
// First convert the coordinate system to a unit system. |
// This allows the radial gradients to be ovals if the view is not square. |
// Center will be 0,0, coordinates will be ±1 |
CGRect bounds = self.bounds; |
CGContextTranslateCTM(context, bounds.size.width / 2.0, bounds.size.height / 2.0); |
CGContextScaleCTM(context, bounds.size.width / 2.0, bounds.size.height / 2.0); |
// Top |
CGContextSaveGState(context); |
CGContextMoveToPoint(context, 0.0, 0.0); |
CGContextAddLineToPoint(context, -1.0, -1.0); |
CGContextAddLineToPoint(context, 1.0, -1.0); |
CGContextClip(context); |
CGContextDrawRadialGradient(context, top, CGPointZero, 0.0, CGPointZero, 1.0, kCGGradientDrawsBeforeStartLocation); |
CGContextRestoreGState(context); |
// Left |
CGContextSaveGState(context); |
CGContextMoveToPoint(context, 0.0, 0.0); |
CGContextAddLineToPoint(context, -1.0, -1.0); |
CGContextAddLineToPoint(context, -1.0, 1.0); |
CGContextClip(context); |
CGContextDrawRadialGradient(context, left, CGPointZero, 0.0, CGPointZero, 1.0, kCGGradientDrawsBeforeStartLocation); |
CGContextRestoreGState(context); |
// Bottom |
CGContextSaveGState(context); |
CGContextMoveToPoint(context, 0.0, 0.0); |
CGContextAddLineToPoint(context, -1.0, 1.0); |
CGContextAddLineToPoint(context, 1.0, 1.0); |
CGContextClip(context); |
CGContextDrawRadialGradient(context, bottom, CGPointZero, 0.0, CGPointZero, 1.0, kCGGradientDrawsBeforeStartLocation); |
CGContextRestoreGState(context); |
// Left |
CGContextSaveGState(context); |
CGContextMoveToPoint(context, 0.0, 0.0); |
CGContextAddLineToPoint(context, 1.0, -1.0); |
CGContextAddLineToPoint(context, 1.0, 1.0); |
CGContextClip(context); |
CGContextDrawRadialGradient(context, right, CGPointZero, 0.0, CGPointZero, 1.0, kCGGradientDrawsBeforeStartLocation); |
CGContextRestoreGState(context); |
} |
- (void)dealloc { |
CGGradientRelease(top); |
CGGradientRelease(left); |
CGGradientRelease(bottom); |
CGGradientRelease(right); |
} |
- (CAShapeLayer *)shapeLayer { |
return (CAShapeLayer *)self.layer; |
} |
- (UIBezierPath *)shape { |
return [UIBezierPath bezierPathWithCGPath:self.shapeLayer.path]; |
} |
- (void)setShape:(UIBezierPath *)shape { |
self.shapeLayer.path = shape.CGPath; |
} |
- (UIColor *)fillColor { |
return [UIColor colorWithCGColor:self.shapeLayer.fillColor]; |
} |
- (void)setFillColor:(UIColor *)fillColor { |
self.shapeLayer.fillColor = fillColor.CGColor; |
} |
- (UIColor *)strokeColor { |
return [UIColor colorWithCGColor:self.shapeLayer.strokeColor]; |
} |
- (void)setStrokeColor:(UIColor *)strokeColor; { |
self.shapeLayer.strokeColor = strokeColor.CGColor; |
} |
@end |
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