This should resolve the problem.
Only remaining issue is the animation, whereby the cap is not animated.
The trick was to add the cap to the end of the gauge, and update it when the value of the gauge changed. To calculate the location, a little math magic was used. It needs to be under the gauge, so the cap is added in the trackCircleLayer
//
// CHCircleGaugeView.m
//
// Copyright (c) 2014 ChaiOne <http://www.chaione.com/>
//
// 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 "CHCircleGaugeView.h"
#import "CHCircleGaugeViewDebugMacros.h"
#import <CoreText/CoreText.h>
#import <QuartzCore/QuartzCore.h>
static CGFloat const CHKeyAnimationDuration = 0.5f;
static CGFloat const CHKeyDefaultValue = 0.0f;
static CGFloat const CHKeyDefaultFontSize = 32.0f;
static CGFloat const CHKeyDefaultTrackWidth = 0.5f;
static CGFloat const CHKeyDefaultGaugeWidth = 2.0f;
static NSString * const CHKeyDefaultNAText = @"n/a";
static NSString * const CHKeyDefaultNoAnswersText = @"%";
#define CHKeyDefaultTrackTintColor [UIColor blackColor]
#define CHKeyDefaultGaugeTintColor [UIColor blackColor]
#define CHKeyDefaultTextColor [UIColor blackColor]
@interface CHCircleGaugeView ()
@property (nonatomic, strong) CAShapeLayer *trackCircleLayer;
@property (nonatomic, strong) CAShapeLayer *gaugeCircleLayer;
// ADDED
@property (nonatomic, strong) CAShapeLayer *capLayer;
// END ADDED
@property (nonatomic, strong) UILabel *valueTextLabel;
@end
@implementation CHCircleGaugeView
#pragma mark - View Initialization
- (instancetype)init {
return [self initWithFrame:CGRectZero];
}
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
[self initSetup];
}
return self;
}
- (instancetype)initWithCoder:(NSCoder *)aDecoder {
self = [super initWithCoder:aDecoder];
if (self) {
[self initSetup];
}
return self;
}
- (void)initSetup {
_state = CHCircleGaugeViewStateNA;
_value = CHKeyDefaultValue;
_trackTintColor = CHKeyDefaultTrackTintColor;
_gaugeTintColor = CHKeyDefaultGaugeTintColor;
_textColor = CHKeyDefaultTextColor;
_font = [UIFont systemFontOfSize:CHKeyDefaultFontSize];
_trackWidth = CHKeyDefaultTrackWidth;
_gaugeWidth = CHKeyDefaultGaugeWidth;
_notApplicableString = CHKeyDefaultNAText;
_noDataString = CHKeyDefaultNoAnswersText;
[self createGauge];
}
- (void)createGauge {
[self.layer addSublayer:self.trackCircleLayer];
[self.layer addSublayer:self.gaugeCircleLayer];
[self addSubview:self.valueTextLabel];
[self setupConstraints];
}
- (void)setupConstraints {
NSDictionary *viewDictionary = @{@"valueText" : self.valueTextLabel};
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[valueText]|" options:0 metrics:nil views:viewDictionary]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[valueText]|" options:0 metrics:nil views:viewDictionary]];
}
#pragma mark - Property Setters
- (void)setState:(CHCircleGaugeViewState)state {
if (_state != state) {
_state = state;
switch (state) {
case CHCircleGaugeViewStateNA: {
[self updateGaugeWithValue:0 animated:NO];
break;
}
case CHCircleGaugeViewStatePercentSign: {
[self updateGaugeWithValue:0 animated:NO];
break;
}
case CHCircleGaugeViewStateScore: {
[self updateGaugeWithValue:self.value animated:NO];
break;
}
default: {
ALog(@"Missing gauge state.");
break;
}
}
}
}
- (void)setValue:(CGFloat)value {
[self setValue:value animated:NO];
}
- (void)setValue:(CGFloat)value animated:(BOOL)animated {
self.state = CHCircleGaugeViewStateScore;
if (value != _value) {
[self willChangeValueForKey:NSStringFromSelector(@selector(value))];
value = MIN(1.0f, MAX(0.0f, value));
[self updateGaugeWithValue:value animated:animated];
_value = value;
[self didChangeValueForKey:NSStringFromSelector(@selector(value))];
}
}
- (void)setUnitsString:(NSString *)unitsString {
if ([_unitsString isEqualToString:unitsString] == NO) {
_unitsString = [unitsString copy];
self.valueTextLabel.attributedText = [self formattedStringForValue:self.value];
}
}
- (void)updateGaugeWithValue:(CGFloat)value animated:(BOOL)animated {
self.valueTextLabel.attributedText = [self formattedStringForValue:value];
BOOL previousDisableActionsValue = [CATransaction disableActions];
[CATransaction setDisableActions:YES];
self.gaugeCircleLayer.strokeEnd = value;
// ADDED
_capLayer.path = [self capPathForValue:value].CGPath;
// END ADDED
if (animated) {
self.gaugeCircleLayer.strokeEnd = value;
CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
pathAnimation.duration = CHKeyAnimationDuration;
pathAnimation.fromValue = [NSNumber numberWithFloat:self.value];
pathAnimation.toValue = [NSNumber numberWithFloat:value];
pathAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
[self.gaugeCircleLayer addAnimation:pathAnimation forKey:@"strokeEndAnimation"];
}
[CATransaction setDisableActions:previousDisableActionsValue];
}
- (void)setTrackTintColor:(UIColor *)trackTintColor {
if (_trackTintColor != trackTintColor) {
_trackTintColor = trackTintColor;
self.trackCircleLayer.strokeColor = trackTintColor.CGColor;
}
}
- (void)setGaugeTintColor:(UIColor *)gaugeTintColor {
if (_gaugeTintColor != gaugeTintColor) {
_gaugeTintColor = gaugeTintColor;
self.gaugeCircleLayer.strokeColor = gaugeTintColor.CGColor;
// ADDED
self.capLayer.fillColor = gaugeTintColor.CGColor;
// END ADDED
}
}
- (void)setTrackWidth:(CGFloat)trackWidth {
if (_trackWidth != trackWidth) {
_trackWidth = trackWidth;
self.trackCircleLayer.lineWidth = trackWidth;
[self.layer layoutSublayers];
}
}
- (void)setGaugeWidth:(CGFloat)gaugeWidth {
if (_gaugeWidth != gaugeWidth) {
_gaugeWidth = gaugeWidth;
self.gaugeCircleLayer.lineWidth = gaugeWidth;
[self.layer layoutSublayers];
}
}
- (void)setTextColor:(UIColor *)textColor {
if (_textColor != textColor) {
_textColor = textColor;
self.valueTextLabel.textColor = textColor;
}
}
- (void)setFont:(UIFont *)font {
if (_font != font) {
_font = font;
self.valueTextLabel.font = font;
}
}
- (void)setGaugeStyle:(CHCircleGaugeStyle)gaugeStyle {
if (_gaugeStyle != gaugeStyle) {
_gaugeStyle = gaugeStyle;
[self.layer layoutSublayers];
}
}
#pragma mark - Circle Shapes
- (CAShapeLayer *)trackCircleLayer {
if (_trackCircleLayer == nil) {
_trackCircleLayer = [CAShapeLayer layer];
_trackCircleLayer.lineWidth = self.trackWidth;
_trackCircleLayer.fillColor = [UIColor clearColor].CGColor;
_trackCircleLayer.strokeColor = self.trackTintColor.CGColor;
_trackCircleLayer.path = [self insideCirclePath].CGPath;
// ADDED
_capLayer = [CAShapeLayer layer];
_capLayer.shadowColor = [UIColor blackColor].CGColor;
_capLayer.shadowRadius = 8.0;
_capLayer.shadowOpacity = 0.9;
_capLayer.shadowOffset = CGSizeMake(0, 0);
_capLayer.fillColor = self.gaugeTintColor.CGColor;
_capLayer.path = [self capPathForValue:self.value].CGPath;
[_trackCircleLayer addSublayer:_capLayer];
// END ADDED
}
return _trackCircleLayer;
}
- (CAShapeLayer *)gaugeCircleLayer {
if (_gaugeCircleLayer == nil) {
_gaugeCircleLayer = [CAShapeLayer layer];
_gaugeCircleLayer.lineWidth = self.gaugeWidth;
_gaugeCircleLayer.fillColor = [UIColor clearColor].CGColor;
_gaugeCircleLayer.strokeColor = self.gaugeTintColor.CGColor;
_gaugeCircleLayer.strokeStart = 0.0f;
_gaugeCircleLayer.strokeEnd = self.value;
_gaugeCircleLayer.path = [self circlPathForCurrentGaugeStyle].CGPath;
}
return _gaugeCircleLayer;
}
// ADDED
- (UIBezierPath *)capPathForValue:(float)value {
CGPoint arcCenter = CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds));
CGFloat radius = CGRectGetWidth(self.bounds) / 2.0f;
float angle = value * 360.0;
float x = radius * sin(angle*M_PI/180.0);
float y = radius * cos(angle*M_PI/180.0);
CGPoint capArcCenter = CGPointMake(arcCenter.x + x, arcCenter.y - y);
UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:capArcCenter
radius:self.gaugeWidth*_capLayer.shadowRadius / 2.0f
startAngle:(3.0f * M_PI_2)
endAngle:(3.0f * M_PI_2) + (2.0f * M_PI)
clockwise:YES];
return path;
}
// END ADDED
- (UIBezierPath *)circlPathForCurrentGaugeStyle {
switch (self.gaugeStyle) {
case CHCircleGaugeStyleInside: {
return [self insideCirclePath];
}
case CHCircleGaugeStyleOutside: {
return [self outsideCirclePath];
}
default: {
return nil;
}
}
}
- (UIBezierPath *)insideCirclePath {
CGPoint arcCenter = CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds));
UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:arcCenter
radius:CGRectGetWidth(self.bounds) / 2.0f
startAngle:(3.0f * M_PI_2)
endAngle:(3.0f * M_PI_2) + (2.0f * M_PI)
clockwise:YES];
return path;
}
- (UIBezierPath *)outsideCirclePath {
CGPoint arcCenter = CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMidY(self.bounds));
CGFloat radius = (CGRectGetWidth(self.bounds) / 2.0f) + (self.trackWidth / 2.0f) + (self.gaugeWidth / 2.0f);
UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:arcCenter
radius:radius
startAngle:(3.0f * M_PI_2)
endAngle:(3.0f * M_PI_2) + (2.0f * M_PI)
clockwise:YES];
return path;
}
#pragma mark - Text Label
- (UILabel *)valueTextLabel {
if (_valueTextLabel == nil) {
_valueTextLabel = [[UILabel alloc] init];
[_valueTextLabel setTranslatesAutoresizingMaskIntoConstraints:NO];
_valueTextLabel.textAlignment = NSTextAlignmentCenter;
_valueTextLabel.attributedText = [self formattedStringForValue:self.value];
}
return _valueTextLabel;
}
- (NSAttributedString *)formattedStringForValue:(CGFloat)value {
NSAttributedString *valueString;
NSDictionary *stringAttributes = @{
NSForegroundColorAttributeName : self.textColor,
NSFontAttributeName : self.font
};
switch (self.state) {
case CHCircleGaugeViewStateNA: {
valueString = [[NSAttributedString alloc] initWithString:self.notApplicableString attributes:stringAttributes];
break;
}
case CHCircleGaugeViewStatePercentSign: {
valueString = [[NSAttributedString alloc] initWithString:self.noDataString attributes:stringAttributes];
break;
}
case CHCircleGaugeViewStateScore: {
NSString *suffix = self.unitsString ? self.unitsString : @"";
valueString = [[NSAttributedString alloc] initWithString:[NSString stringWithFormat:@"%.0f %@", value * 100.0f, suffix]
attributes:stringAttributes];
break;
}
default: {
ALog(@"Missing gauge state.");
break;
}
}
return valueString;
}
#pragma mark - KVO
// Handling KVO notifications for the value property, since
// we're proxying with the setValue:animated: method.
+ (BOOL)automaticallyNotifiesObserversForKey:(NSString *)key {
if ([key isEqualToString:NSStringFromSelector(@selector(value))]) {
return NO;
} else {
return [super automaticallyNotifiesObserversForKey:key];
}
}
#pragma mark - CALayerDelegate
- (void)layoutSublayersOfLayer:(CALayer *)layer {
[super layoutSublayersOfLayer:layer];
if (layer == self.layer) {
self.trackCircleLayer.path = [self insideCirclePath].CGPath;
self.gaugeCircleLayer.path = [self circlPathForCurrentGaugeStyle].CGPath;
}
}
@end
