PSActivityIndicator.m #1

//
//  PSActivityIndicator.m
//  Perforce
//
//  Created by Adam Czubernat on 07/11/2013.
//  Copyright (c) 2013 Perforce Software, Inc. All rights reserved.
//

#import "PSActivityIndicator.h"

#define PSActivityIndicatorFinsNumber 12

@interface PSActivityIndicator () {
	NSColor *color;
	CALayer *fin;
}
- (void)makeLayers;
- (void)makeAnimation;
@end

@implementation PSActivityIndicator

- (void)viewDidMoveToWindow {
	[fin removeAnimationForKey:@"finAnimation"];
	if (self.window)
		[self makeLayers];
}

- (void)viewDidHide {
	[fin removeAnimationForKey:@"finAnimation"];
}

- (void)viewDidUnhide {
	[fin removeAnimationForKey:@"finAnimation"];
	[self makeAnimation];
}

#pragma mark - Private

- (void)makeLayers {
	
	CAReplicatorLayer *replicator = [CAReplicatorLayer layer];
	self.layer = replicator;
	self.wantsLayer = YES;
	
	CGFloat size = fminf(self.bounds.size.width, self.bounds.size.height);
	CGFloat thickness = size * 0.08f;
	CGFloat deltaAngle = (2.0*M_PI)/(PSActivityIndicatorFinsNumber);
	
	fin = [CALayer layer];
	[fin setFrame:(CGRect) { (size - thickness) * 0.5f, 0.0f, thickness, size * 0.25f }];
	CGColorRef colorRef = CGColorCreateFromColor(color ?: [NSColor blackColor]);
	[fin setBackgroundColor:colorRef];
	CGColorRelease(colorRef);
	[fin setCornerRadius:thickness * 0.5f];
	[fin setOpacity:0.25f];

	[replicator setFrame:self.bounds];
	[replicator setAnchorPoint:(CGPoint) { 0.5f, 0.5f }];
	[replicator addSublayer:fin];
	[replicator setInstanceCount:PSActivityIndicatorFinsNumber];
	[replicator setInstanceTransform:CATransform3DMakeRotation(-deltaAngle, 0.0f, 0.0f, 1.0f)];
	[replicator setInstanceDelay:1.0f / PSActivityIndicatorFinsNumber];
	[replicator addSublayer:fin];
			
	[self makeAnimation];
}

- (void)makeAnimation {
	CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"opacity"];
	[animation setRemovedOnCompletion:NO];
	[animation setRepeatCount:HUGE_VALF];
	[animation setFromValue:[NSNumber numberWithFloat:1.0]];
	[animation setToValue:[NSNumber numberWithFloat:0.0]];
	[animation setDuration:1.0f];
	[fin addAnimation:animation forKey:@"finAnimation"];
}

#pragma mark - Public

- (void)setColor:(NSColor *)aColor {
	color = aColor ?: [NSColor blackColor];
	CGColorRef colorRef = CGColorCreateFromColor(color);
	[fin setBackgroundColor:colorRef];
	CGColorRelease(colorRef);	
}

- (NSColor *)color {
	return color;
}

@end