IOS编程开发教程：ios双拉杆

IOS编程开发教程：ios双拉杆，有机会 我将 开源 android 同样的组件。

//
//  EFCircularSlider.m
//  Awake
//
//  Created by Eliot Fowler on 12/3/13.
//  Copyright (c) 2013 Eliot Fowler. All rights reserved.
//

#import "EFCircularSlider.h"
#import 
#import 

#define ToRad(deg) 		( (M_PI * (deg)) / 180.0 )
#define ToDeg(rad)		( (180.0 * (rad)) / M_PI )
#define SQR(x)			( (x) * (x) )

@implementation EFCircularSlider {
    CGFloat radius;
    int angle1;
    int angle2;
    int fixedAngle;
    NSMutableDictionary* labelsWithPercents;
    NSArray* labelsEvenSpacing;
}

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Defaults
        _maximumValue = 100.0f;
        _minimumValue = 0.0f;
        _currentValue1 = 0.0f;
        _lineWidth = 55;
        _unfilledColor = [UIColor redColor];
        _filledColor1 = [UIColor redColor];
        _filledColor2 = [UIColor orangeColor];
        _handleColor = [UIColor whiteColor];
        _handleInColor1=_filledColor1;
        _handleInColor2=_filledColor2;
        _labelFont = [UIFont systemFontOfSize:10.0f];
        _snapToLabels = NO;
        _handleType = semiTransparentWhiteCircle;
        _labelColor = [UIColor redColor];
        
//        angle1=360 - (360-165) - 15;
//        _currentValue1=100;
//        _currentValue2=100;
//        angle2=360-(360-30)-150;
        
        angle1= 0;
        _currentValue1=0;
        _currentValue2=0;
        angle2=0;

        
        radius = self.frame.size.height/2 - _lineWidth/2;
        
        self.backgroundColor = [UIColor clearColor];
    }
    return self;
}

-(void)layoutSubviews{
    [super layoutSubviews];
    
    int totalAngle1 = 360 -165 +15;
    
    int currentAngle1 =0;
    
    float percentAngle1 = totalAngle1 * (_currentValue1/_maximumValue);
    if (percentAngle1<=(360-165)) {
        currentAngle1 = 165 + percentAngle1;
    }else{
        currentAngle1 = percentAngle1 - (360-165);
    }
    
    angle1 = 360 - (360-165) - currentAngle1;
    
    int totalAngle2 = 150-30;
    int currentAngle2=0;
    float percentAngle2 = totalAngle2 * (_currentValue2/_maximumValue);
    currentAngle2 = 30+percentAngle2;
    
    angle2=360-(360-30)-currentAngle2;
    

}

#pragma mark - drawing methods

- (void)drawRect:(CGRect)rect
{
    [super drawRect:rect];
    
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    
    //Draw the unfilled circle
//    CGContextAddArc(ctx, self.frame.size.width/2, self.frame.size.height/2, radius, 0, M_PI *2, 0);
    CGContextAddArc(ctx, self.frame.size.width/2  , self.frame.size.height/2, radius, 165*M_PI/180, ToRad(15), 0);
    [_unfilledColor setStroke];
    CGContextSetLineWidth(ctx, _lineWidth);
    CGContextSetLineCap(ctx, kCGLineCapButt);
    CGContextDrawPath(ctx, kCGPathStroke);
    
    CGContextAddArc(ctx, self.frame.size.width/2  , self.frame.size.height/2, radius, M_PI/6,M_PI/6-ToRad(-120), 0);
    [_unfilledColor setStroke];
    CGContextSetLineWidth(ctx, _lineWidth);
    CGContextSetLineCap(ctx, kCGLineCapButt);
    CGContextDrawPath(ctx, kCGPathStroke);
    
    //Draw the filled circle
//    if((_handleType == doubleCircleWithClosedCenter || _handleType == doubleCircleWithOpenCenter) && fixedAngle > 5) {
////        CGContextAddArc(ctx, self.frame.size.width/2  , self.frame.size.height/2, radius, 3*M_PI/2, 3*M_PI/2-ToRad(angle+3), 0);
//        CGContextAddArc(ctx, self.frame.size.width/2  , self.frame.size.height/2, radius, 165*M_PI/180, 165*M_PI/180-ToRad(angle1+3), 0);
//        [_filledColor setStroke];
//        CGContextSetLineWidth(ctx, _lineWidth);
//        CGContextSetLineCap(ctx, kCGLineCapButt);
//        CGContextDrawPath(ctx, kCGPathStroke);
//        CGContextAddArc(ctx, self.frame.size.width/2, self.frame.size.height/2, radius,  M_PI/6, M_PI/6-ToRad(angle2+3), 0);
//        [_filledColor setStroke];
//        CGContextSetLineWidth(ctx, _lineWidth);
//        CGContextSetLineCap(ctx, kCGLineCapButt);
//        CGContextDrawPath(ctx, kCGPathStroke);
//    } else {
//        CGContextAddArc(ctx, self.frame.size.width/2  , self.frame.size.height/2, radius, 3*M_PI/2, 3*M_PI/2-ToRad(angle), 0);
        CGContextAddArc(ctx, self.frame.size.width/2  , self.frame.size.height/2, radius, 165*M_PI/180, 165*M_PI/180-ToRad(angle1), 0);
        [_filledColor1 setStroke];
        CGContextSetLineWidth(ctx, _lineWidth);
        CGContextSetLineCap(ctx, kCGLineCapButt);
        CGContextDrawPath(ctx, kCGPathStroke);
        CGContextAddArc(ctx, self.frame.size.width/2, self.frame.size.height/2, radius,  M_PI/6, M_PI/6-ToRad(angle2), 0);
        [_filledColor2 setStroke];
        CGContextSetLineWidth(ctx, _lineWidth);
        CGContextSetLineCap(ctx, kCGLineCapButt);
        CGContextDrawPath(ctx, kCGPathStroke);
//    }
   
//    CGContextDrawPath(ctx, kCGPathStroke);
    
    //Add the labels (if necessary)
    if(labelsEvenSpacing != nil) {
        [self drawLabels:ctx];
    }
    
    //The draggable part
    [self drawHandle:ctx];
}

-(void) drawHandle:(CGContextRef)ctx{
    CGContextSaveGState(ctx);
    CGPoint handleCenter =  [self pointFromAngle1: angle1];
//    if(_handleType == semiTransparentWhiteCircle) {
//        [[UIColor colorWithWhite:1.0 alpha:0.7] set];
//        CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter.x, handleCenter.y, _lineWidth, _lineWidth));
//    } else if(_handleType == semiTransparentBlackCircle) {
//        [[UIColor colorWithWhite:0.0 alpha:0.7] set];
//        CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter.x, handleCenter.y, _lineWidth, _lineWidth));
//    } else if(_handleType == doubleCircleWithClosedCenter) {
//        [_handleColor set];
//        CGContextAddArc(ctx, handleCenter.x + (_lineWidth)/2, handleCenter.y + (_lineWidth)/2, _lineWidth, 0, M_PI *2, 0);
//        CGContextSetLineWidth(ctx, 7);
//        CGContextSetLineCap(ctx, kCGLineCapButt);
//        CGContextDrawPath(ctx, kCGPathStroke);
//        CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter.x, handleCenter.y, _lineWidth-1, _lineWidth-1));
//    } else if(_handleType == doubleCircleWithOpenCenter) {
//        [_handleColor set];
//        CGContextAddArc(ctx, handleCenter.x + (_lineWidth)/2, handleCenter.y + (_lineWidth)/2, 8, 0, M_PI *2, 0);
//        CGContextSetLineWidth(ctx, 4);
//        CGContextSetLineCap(ctx, kCGLineCapButt);
//        CGContextDrawPath(ctx, kCGPathStroke);
//        
//        CGContextAddArc(ctx, handleCenter.x + _lineWidth/2, handleCenter.y + _lineWidth/2, _lineWidth/2, 0, M_PI *2, 0);
//        CGContextSetLineWidth(ctx, 2);
//        CGContextSetLineCap(ctx, kCGLineCapButt);
//        CGContextDrawPath(ctx, kCGPathStroke);
//    } else if(_handleType == bigCircle) {
//        [_handleColor set];
//        CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter.x-2.5, handleCenter.y-2.5, _lineWidth+5, _lineWidth+5));
//    }
    
//    [_handleColor set];
//    CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter.x-2.5, handleCenter.y-2.5, _lineWidth+5, _lineWidth+5));
//    [_handleInColor set];
    [_handleColor set];
    CGContextAddArc(ctx, handleCenter.x + (_lineWidth)/2, handleCenter.y + (_lineWidth)/2, 8, 0, M_PI *2, 0);
    CGContextSetLineWidth(ctx, 4);
    CGContextSetLineCap(ctx, kCGLineCapButt);
//    CGContextSetShadowWithColor(ctx, CGSizeMake(0, 0), _lineWidth/2, [UIColor blueColor].CGColor);
    CGContextDrawPath(ctx, kCGPathStroke);
    
   
    CGContextAddArc(ctx, handleCenter.x + _lineWidth/2, handleCenter.y + _lineWidth/2, _lineWidth/2, 0, M_PI *2, 0);
    [_handleInColor1 set];
//    [[UIColor redColor] set];
    CGContextSetLineWidth(ctx, 2);
    CGContextSetLineCap(ctx, kCGLineCapButt);
//    CGContextSetShadowWithColor(ctx, CGSizeMake(0, 0), _lineWidth, [UIColor blackColor].CGColor);
     CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter.x-2.5, handleCenter.y-2.5, _lineWidth+5, _lineWidth+5));
//    CGContextDrawPath(ctx, kCGPathStroke);
    CGContextRestoreGState(ctx);
    
    CGContextSaveGState(ctx);
    CGPoint handleCenter2 =  [self pointFromAngle2: angle2];
//    if(_handleType == semiTransparentWhiteCircle) {
//        [[UIColor colorWithWhite:1.0 alpha:0.7] set];
//        CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter.x, handleCenter.y, _lineWidth, _lineWidth));
//    } else if(_handleType == semiTransparentBlackCircle) {
//        [[UIColor colorWithWhite:0.0 alpha:0.7] set];
//        CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter.x, handleCenter.y, _lineWidth, _lineWidth));
//    } else if(_handleType == doubleCircleWithClosedCenter) {
//        [_handleColor set];
//        CGContextAddArc(ctx, handleCenter.x + (_lineWidth)/2, handleCenter.y + (_lineWidth)/2, _lineWidth, 0, M_PI *2, 0);
//        CGContextSetLineWidth(ctx, 7);
//        CGContextSetLineCap(ctx, kCGLineCapButt);
//        CGContextDrawPath(ctx, kCGPathStroke);
//        CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter.x, handleCenter.y, _lineWidth-1, _lineWidth-1));
//    } else if(_handleType == doubleCircleWithOpenCenter) {
//        [_handleColor set];
//        CGContextAddArc(ctx, handleCenter.x + (_lineWidth)/2, handleCenter.y + (_lineWidth)/2, 8, 0, M_PI *2, 0);
//        CGContextSetLineWidth(ctx, 4);
//        CGContextSetLineCap(ctx, kCGLineCapButt);
//        CGContextDrawPath(ctx, kCGPathStroke);
//        
//        CGContextAddArc(ctx, handleCenter.x + _lineWidth/2, handleCenter.y + _lineWidth/2, _lineWidth/2, 0, M_PI *2, 0);
//        CGContextSetLineWidth(ctx, 2);
//        CGContextSetLineCap(ctx, kCGLineCapButt);
//        CGContextDrawPath(ctx, kCGPathStroke);
//    } else if(_handleType == bigCircle) {
//        [_handleColor set];
//        CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter.x-2.5, handleCenter.y-2.5, _lineWidth+5, _lineWidth+5));
//    }
//    [_handleColor set];
//    CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter2.x-2.5, handleCenter2.y-2.5, _lineWidth+5, _lineWidth+5));

    [_handleColor set];
    CGContextAddArc(ctx, handleCenter2.x + (_lineWidth)/2, handleCenter2.y + (_lineWidth)/2, 8, 0, M_PI *2, 0);
    CGContextSetLineWidth(ctx, 4);
    CGContextSetLineCap(ctx, kCGLineCapButt);
    //    CGContextSetShadowWithColor(ctx, CGSizeMake(0, 0), _lineWidth/2, [UIColor blueColor].CGColor);
    CGContextDrawPath(ctx, kCGPathStroke);
    
    
    CGContextAddArc(ctx, handleCenter2.x + _lineWidth/2, handleCenter2.y + _lineWidth/2, _lineWidth/2, 0, M_PI *2, 0);
    [_handleInColor2 set];
    //    [[UIColor redColor] set];
    CGContextSetLineWidth(ctx, 2);
    CGContextSetLineCap(ctx, kCGLineCapButt);
    //    CGContextSetShadowWithColor(ctx, CGSizeMake(0, 0), _lineWidth, [UIColor blackColor].CGColor);
    CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter2.x-2.5, handleCenter2.y-2.5, _lineWidth+5, _lineWidth+5));
    
//    CGContextFillEllipseInRect(ctx, CGRectMake(handleCenter2.x-5, handleCenter2.y-5, _lineWidth+10, _lineWidth+10));
    
    //    CGContextDrawPath(ctx, kCGPathStroke);
    CGContextRestoreGState(ctx);
    
//    CGContextRestoreGState(ctx);
}

-(void) drawLabels:(CGContextRef)ctx {
    if(labelsEvenSpacing == nil || [labelsEvenSpacing count] == 0) {
        return;
    } else {
        NSDictionary *attributes = @{ NSFontAttributeName: _labelFont,
                                      NSForegroundColorAttributeName: _labelColor};
        int distanceToMove = -15;
        
        for (int i=0; i<[labelsEvenSpacing count]; i++) {
            NSString* label = [labelsEvenSpacing objectAtIndex:[labelsEvenSpacing count] - i - 1];
            CGFloat percentageAlongCircle = i/(float)[labelsEvenSpacing count];
            CGFloat degreesForLabel = percentageAlongCircle * 360;
            CGPoint closestPointOnCircleToLabel = [self pointFromAngle1:degreesForLabel];
            
            CGRect labelLocation = CGRectMake(closestPointOnCircleToLabel.x, closestPointOnCircleToLabel.y, [self widthOfString:label withFont:_labelFont], [self heightOfString:label withFont:_labelFont]);
            
            CGPoint centerPoint = CGPointMake(self.frame.size.width/2, self.frame.size.height/2);
            float radiansTowardsCenter = ToRad(AngleFromNorth(centerPoint, closestPointOnCircleToLabel, NO));
            labelLocation.origin.x =  (labelLocation.origin.x + distanceToMove * cos(radiansTowardsCenter)) - labelLocation.size.width/4;
            labelLocation.origin.y = (labelLocation.origin.y + distanceToMove * sin(radiansTowardsCenter))- labelLocation.size.height/4;
            [label drawInRect:labelLocation withAttributes:attributes];
        }
    }
}

#pragma mark - UIControl functions

-(BOOL) beginTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event {
    [super beginTrackingWithTouch:touch withEvent:event];
    
    return YES;
}

-(BOOL) continueTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event {
    [super continueTrackingWithTouch:touch withEvent:event];
    
    CGPoint lastPoint = [touch locationInView:self];
    [self moveHandle:lastPoint];
    [self sendActionsForControlEvents:UIControlEventValueChanged];
    
    return YES;
}

-(void)endTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event{
    [super endTrackingWithTouch:touch withEvent:event];
//    if(_snapToLabels && labelsEvenSpacing != nil) {
//        CGPoint bestGuessPoint;
//        float minDist = 360;
//        for (int i=0; i<[labelsEvenSpacing count]; i++) {
//            CGFloat percentageAlongCircle = i/(float)[labelsEvenSpacing count];
//            CGFloat degreesForLabel = percentageAlongCircle * 360;
//            if(abs(fixedAngle - degreesForLabel) < minDist) {
//                minDist = abs(fixedAngle - degreesForLabel);
//                bestGuessPoint = [self pointFromAngle:degreesForLabel + 90 + 180];
//            }
//        }
//        CGPoint centerPoint = CGPointMake(self.frame.size.width/2, self.frame.size.height/2);
//        angle = floor(AngleFromNorth(centerPoint, bestGuessPoint, NO));
//        _currentValue = [self valueFromAngle];
//        [self setNeedsDisplay];
//    }
}

-(void)moveHandle:(CGPoint)point {
    CGPoint centerPoint = CGPointMake(self.frame.size.width/2, self.frame.size.height/2);
    int currentAngle = floor(AngleFromNorth(centerPoint, point, NO));
    if ((currentAngle>=165&¤tAngle<=360)||(currentAngle>=0&¤tAngle<=15)) {
        angle1 = 360 - (360-165) - currentAngle;//148
    }else if(currentAngle>=30&¤tAngle<=150){
        angle2=360-(360-30)-currentAngle;
    }
//    NSLog(@"%d-angle1-",angle1);
//    NSLog(@"%d-angle2-",angle2);
    _currentValue1 = [self valueFromAngle1];
    _currentValue2 = [self valueFromAngle2];
    [self setNeedsDisplay];
}

#pragma mark - helper functions

-(CGPoint)pointFromAngle1:(int)angleInt{
    
    //Define the Circle center
    CGPoint centerPoint = CGPointMake(self.frame.size.width/2 - _lineWidth/2, self.frame.size.height/2 - _lineWidth/2);
    
    //Define The point position on the circumference
    CGPoint result;
    result.y = round(centerPoint.y + radius * sin(ToRad(-angleInt-(180+15)))) ;//90
    result.x = round(centerPoint.x + radius * cos(ToRad(-angleInt-(180+15))));
    
    return result;
}

-(CGPoint)pointFromAngle2:(int)angleInt{
    
    //Define the Circle center
    CGPoint centerPoint = CGPointMake(self.frame.size.width/2 - _lineWidth/2, self.frame.size.height/2 - _lineWidth/2);
    
    //Define The point position on the circumference
    CGPoint result;
    result.y = round(centerPoint.y + radius * sin(ToRad(-angleInt-(360-30)))) ;//90
    result.x = round(centerPoint.x + radius * cos(ToRad(-angleInt-(360-30))));
    
    return result;
}

static inline float AngleFromNorth(CGPoint p1, CGPoint p2, BOOL flipped) {
    CGPoint v = CGPointMake(p2.x-p1.x,p2.y-p1.y);
    float vmag = sqrt(SQR(v.x) + SQR(v.y)), result = 0;
    v.x /= vmag;
    v.y /= vmag;
    double radians = atan2(v.y,v.x);
    result = ToDeg(radians);
    return (result >=0  ? result : result + 360.0);
}

-(float) valueFromAngle1 {
    if(angle1 <=0) {
        _currentValue1 = -angle1;
    } else {
        _currentValue1 = 15+180+(165-angle1);
    }
    fixedAngle = _currentValue1;
    return (_currentValue1*(_maximumValue - _minimumValue))/210;
}

-(float) valueFromAngle2 {
    if(angle2 <0) {
        _currentValue2 = -angle2;
    }
    fixedAngle = _currentValue2;
    return (_currentValue2*(_maximumValue - _minimumValue))/120;
}

- (CGFloat) widthOfString:(NSString *)string withFont:(UIFont*)font {
    NSDictionary *attributes = [NSDictionary dictionaryWithObjectsAndKeys:font, NSFontAttributeName, nil];
    return [[[NSAttributedString alloc] initWithString:string attributes:attributes] size].width;
}

- (CGFloat) heightOfString:(NSString *)string withFont:(UIFont*)font {
    NSDictionary *attributes = [NSDictionary dictionaryWithObjectsAndKeys:font, NSFontAttributeName, nil];
    return [[[NSAttributedString alloc] initWithString:string attributes:attributes] size].height;
}

#pragma mark - public methods
-(void)setInnerMarkingLabels:(NSArray*)labels{
    labelsEvenSpacing = labels;
    [self setNeedsDisplay];
}

@end