PCProgressView.m

//
//  PCProgressView.m
//  PCProgressView
//
//  Created by Patrick Chamelo on 10/05/14.
//  Copyright (c) 2014 Patrick Chamelo. All rights reserved.
//
//  The MIT License (MIT)
//
//  Copyright (c) 2014 Patrick Chamelo
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in all
//  copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//  SOFTWARE.

#import "PCProgressView.h"

#import <QuartzCore/QuartzCore.h>

@implementation PCProgressView
{
	CGFloat _currentProgress;
	CAShapeLayer *_backgroundLineLayer;
	CAShapeLayer *_progressLineLayer;
}

#pragma mark - Initializers

- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]){
        [self setUp];
    }
    return self;
}


- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
    if (self = [super initWithCoder:aDecoder]){
        [self setUp];
    }
    return self;
}

#pragma mark - SetUp

- (void)setUp
{
    self.wantsLayer = YES;
    _currentProgress = 0.0;
    _duration = 0.4f;
    _progressLineWidth = 3.0f;
    _progressLineColor = [NSColor lightGrayColor];
    _backgroundLineWidth = 6.0f;
    _backgroundLineColor = [NSColor darkGrayColor];

    _backgroundLineLayer = [CAShapeLayer layer];
    [self.layer addSublayer:_backgroundLineLayer];
    _progressLineLayer = [CAShapeLayer layer];
    [self.layer addSublayer:_progressLineLayer];
}

#pragma mark - Exposed Methods

- (void)setProgress:(CGFloat)progress
{
    [self setProgress:progress animated:NO];
}

- (void)setProgress:(CGFloat)progress animated:(BOOL)animated
{
    // Boundry correctness
    progress = MIN(progress, 1.0);
    progress = MAX(progress, 0.0);
    
    _progress = progress;
    
    CGFloat borderWidth = MAX(_progressLineWidth, _backgroundLineWidth);
    CGFloat radius = (MIN(self.bounds.size.width, self.bounds.size.height) / 2.0) - borderWidth;
    CGFloat diameter = (radius * 2.0);
    CGRect cirlceRect = CGRectMake(NSMidX(self.bounds) - radius, NSMidY(self.bounds) - radius, diameter, diameter);
    CGPathRef path = [self _createCirclePathRefForRect:cirlceRect];
    
    _backgroundLineLayer.path = path;
    _backgroundLineLayer.fillColor = [NSColor clearColor].CGColor;
    _backgroundLineLayer.strokeColor = _backgroundLineColor.CGColor;
    _backgroundLineLayer.lineWidth = _backgroundLineWidth;
    
    _progressLineLayer.path = _backgroundLineLayer.path;
    _progressLineLayer.fillColor = [NSColor clearColor].CGColor;
    _progressLineLayer.strokeColor = _progressLineColor.CGColor;
    _progressLineLayer.lineWidth = _progressLineWidth;
    
    CFTimeInterval animationDuration = (animated ? _duration : 0.0);
    [_progressLineLayer addAnimation:[self _fillAnimationWithDuration:animationDuration] forKey:@"strokeEnd"];
    _currentProgress = _progress;

    CGPathRelease(path);
}

#pragma mark - Private Methods

- (CABasicAnimation *)_fillAnimationWithDuration:(CFTimeInterval)duration
{
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];    
    animation.duration = duration;
    animation.removedOnCompletion = NO;
    animation.fillMode = kCAFillModeBoth;
    animation.fromValue = @(_currentProgress);
    animation.toValue = @(_progress);
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    return animation;
}

- (CGPathRef)_createCirclePathRefForRect:(CGRect)rect
{
    /**
     CGPathAddEllipseInRect creates the path in an anticlockwise direction and
     the "strokeEnd" values/animation is reverted. By creating the path ourselfs we ensure
     that the direction is clockwise and the animation direction is correct.
    */
    CGFloat radius = (rect.size.width / 2);
    CGFloat minx = CGRectGetMinX(rect), midx = CGRectGetMidX(rect), maxx = CGRectGetMaxX(rect);
    CGFloat miny = CGRectGetMinY(rect), midy = CGRectGetMidY(rect), maxy = CGRectGetMaxY(rect);
    CGMutablePathRef path = CGPathCreateMutable();
    CGPathMoveToPoint(path, NULL, midx + 0.5, maxy + 0.5);
    CGPathAddArcToPoint(path, NULL, maxx + 0.5, maxy + 0.5, maxx + 0.5, midy + 0.5, radius);
    CGPathAddArcToPoint(path, NULL, maxx + 0.5, miny + 0.5, midx + 0.5, miny + 0.5, radius);
    CGPathAddArcToPoint(path, NULL, minx + 0.5, miny + 0.5, minx + 0.5, midy + 0.5, radius);
    CGPathAddArcToPoint(path, NULL, minx + 0.5, maxy + 0.5, midx + 0.5, maxy + 0.5, radius);
    CGPathCloseSubpath(path);
    return path;
}

@end