//

// MNEValueTrackingSlider

//

// Copyright 2012 Michael Neuwert

// "You can use the code in your own project and modify it as you like."

// http://blog.neuwert-media.com/2012/04/customized-uislider-with-visual-value-tracking/

//

#import "MNEValueTrackingSlider.h"

#pragma mark -

#pragma mark Private UIView subclass rendering the popup showing slider value

@interface SliderValuePopupView : UIView

@property (nonatomic, strong) UIFont *font;

@property (nonatomic, copy) NSString *text;

@property (nonatomic) float arrowOffset;

@end

@implementation SliderValuePopupView

@synthesize font = _font;

@synthesize text = _text;

@synthesize arrowOffset = _arrowOffset;

- (id)initWithFrame:(CGRect)frame {

    self = [super initWithFrame:frame];

    if (self) {

        self.font = [UIFont boldSystemFontOfSize:18];

    }

    return self;

}

- (void)drawRect:(CGRect)rect {

    // Create the path for the rounded rectangle

    CGRect roundedRect = CGRectMake(self.bounds.origin.x, self.bounds.origin.y, self.bounds.size.width, floorf(self.bounds.size.height * 0.8));

    UIBezierPath *roundedRectPath = [UIBezierPath bezierPathWithRoundedRect:roundedRect cornerRadius:6.0];

    roundedRectPath.lineWidth = 2.0f;

    // Create the arrow path

    UIBezierPath *arrowPath = [UIBezierPath bezierPath];

    /*

    // Make sure the arrow offset is nice

    if (-self.arrowOffset + 1 > CGRectGetMidX(self.bounds) / 2)

        self.arrowOffset = -CGRectGetMidX(self.bounds) / 2 + 1;

    if (self.arrowOffset > CGRectGetMidX(self.bounds) / 2)

        self.arrowOffset = CGRectGetMidX(self.bounds) / 2 -1;

     */

    CGFloat midX = CGRectGetMidX(self.bounds) + self.arrowOffset;

    CGPoint p0 = CGPointMake(midX, CGRectGetMaxY(self.bounds));

    [arrowPath moveToPoint:p0];

    [arrowPath addLineToPoint:CGPointMake((midX - 10.0), CGRectGetMaxY(roundedRect))];

    [arrowPath addLineToPoint:CGPointMake((midX + 10.0), CGRectGetMaxY(roundedRect))];

    [arrowPath closePath];

    // Attach the arrow path to the rounded rect

    [roundedRectPath appendPath:arrowPath];

    // Color various sections

    [[UIColor blackColor] setFill];

    [roundedRectPath fill];

    [[UIColor whiteColor] setStroke];

    [roundedRectPath stroke];

    [[UIColor whiteColor] setFill];

    [arrowPath fill];

    // Draw the text

    if (self.text) {

        [[UIColor lightYellowColor] set];

        CGSize s = [_text sizeWithFont:self.font];

        CGFloat yOffset = (roundedRect.size.height - s.height) / 2;

        CGRect textRect = CGRectMake(roundedRect.origin.x, yOffset, roundedRect.size.width, s.height);

        [_text drawInRect:textRect

                 withFont:self.font

            lineBreakMode:UILineBreakModeWordWrap

                alignment:NSTextAlignmentCenter];

    }

}

@end

#pragma mark -

#pragma mark MNEValueTrackingSlider implementations

@implementation MNEValueTrackingSlider

@synthesize thumbRect, textValue;

#pragma mark Private methods

- (void)_constructSlider {

    valuePopupView = [[SliderValuePopupView alloc] initWithFrame:CGRectZero];

    valuePopupView.backgroundColor = [UIColor clearColor];

    valuePopupView.alpha = 0.0;

    [self addSubview:valuePopupView];

}

- (void)_fadePopupViewInAndOut:(BOOL)aFadeIn {

    [UIView beginAnimations:nil context:NULL];

    [UIView setAnimationDuration:0.25];

    if (aFadeIn) {

        valuePopupView.alpha = 1.0;

    } else {

        valuePopupView.alpha = 0.0;

    }

    [UIView commitAnimations];

}

- (void)_positionAndUpdatePopupView {

    CGRect _thumbRect = self.thumbRect;

    CGRect popupRect = CGRectOffset(_thumbRect, 0, -floorf(_thumbRect.size.height * 1.5));

    // (-100, -15) determines the size of the the rect

    popupRect = CGRectInset(popupRect, -100, -15);

    // this prevents drawing the popup outside the slider view

    if (popupRect.origin.x < -self.frame.origin.x+5)

        popupRect.origin.x = -self.frame.origin.x+5;

    else if (popupRect.origin.x > self.superview.frame.size.width - popupRect.size.width - self.frame.origin.x - 5)

        popupRect.origin.x = self.superview.frame.size.width - popupRect.size.width - self.frame.origin.x - 5;

    //else if (CGRectGetMaxX(popupRect) > CGRectGetMaxX(self.superview.bounds))

    //    popupRect.origin.x = CGRectGetMaxX(self.superview.bounds) - CGRectGetWidth(popupRect) - 1.0;

    valuePopupView.arrowOffset = CGRectGetMidX(_thumbRect) - CGRectGetMidX(popupRect);

    valuePopupView.frame = popupRect;

    valuePopupView.text = self.textValue;

    [valuePopupView setNeedsDisplay];

}

#pragma mark Memory management

- (id)initWithFrame:(CGRect)frame {

    self = [super initWithFrame:frame];

    if (self) {

        [self _constructSlider];

    }

    return self;

}

- (id)initWithCoder:(NSCoder *)aDecoder {

    self = [super initWithCoder:aDecoder];

    if (self) {

        [self _constructSlider];

    }

    return self;

}

#pragma mark -

#pragma mark UIControl touch event tracking

- (BOOL)beginTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event {

    // Fade in and update the popup view

    CGPoint touchPoint = [touch locationInView:self];

    // Check if the knob is touched. Only in this case show the popup-view

    if(CGRectContainsPoint(CGRectInset(self.thumbRect, -14.0, -12.0), touchPoint)) {

        [self _positionAndUpdatePopupView];

        [self _fadePopupViewInAndOut:YES];

    }

    return [super beginTrackingWithTouch:touch withEvent:event];

}

- (BOOL)continueTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event {

    // Update the popup view as slider knob is being moved

    [self _positionAndUpdatePopupView];

    return [super continueTrackingWithTouch:touch withEvent:event];

}

- (void)cancelTrackingWithEvent:(UIEvent *)event {

    [super cancelTrackingWithEvent:event];

}

- (void)endTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event {

    // Fade out the popoup view

    [self _fadePopupViewInAndOut:NO];

    [super endTrackingWithTouch:touch withEvent:event];

}

#pragma mark -

#pragma mark Custom property accessors

    CGRect trackRect = [self trackRectForBounds:self.bounds];

    CGRect thumbR = [self thumbRectForBounds:self.bounds

                                         trackRect:trackRect

                                             value:self.value];

    return thumbR;

}

@end