Solution 1:

Here's a simple version of what you're describing.

alt text

It is "simple" in the sense that I didn't bother trying to add the shading and other subtleties. But it's easy to construct and you can tweak it to draw in a more subtle way if you like. For example, you could make your own image and use it as the slider's thumb.

This is actually a UISlider subclass lying on top of a UIView subclass (MyTherm) that draws the thermometer, plus two UILabels that draw the numbers.

The UISlider subclass eliminates the built-in track, so that the thermometer behind it shows through. But the UISlider's thumb (knob) is still draggable in the normal way, and you can set it to a custom image, get the Value Changed event when the user drags it, and so on. Here is the code for the UISlider subclass that eliminates its own track:

- (CGRect)trackRectForBounds:(CGRect)bounds {
    CGRect result = [super trackRectForBounds:bounds];
    result.size.height = 0;
    return result;
}

The thermometer is an instance of a custom UIView subclass, MyTherm. I instantiated it in the nib and unchecked its Opaque and gave it a background color of Clear Color. It has a value property so it knows how much to fill the thermometer. Here's its drawRect: code:

- (void)drawRect:(CGRect)rect {
    CGContextRef c = UIGraphicsGetCurrentContext();
    [[UIColor whiteColor] set];
    CGFloat ins = 2.0;
    CGRect r = CGRectInset(self.bounds, ins, ins);
    CGFloat radius = r.size.height / 2.0;
    CGMutablePathRef path = CGPathCreateMutable();
    CGPathMoveToPoint(path, NULL, CGRectGetMaxX(r) - radius, ins);
    CGPathAddArc(path, NULL, radius+ins, radius+ins, radius, -M_PI/2.0, M_PI/2.0, true);
    CGPathAddArc(path, NULL, CGRectGetMaxX(r) - radius, radius+ins, radius, M_PI/2.0, -M_PI/2.0, true);
    CGPathCloseSubpath(path);
    CGContextAddPath(c, path);
    CGContextSetLineWidth(c, 2);
    CGContextStrokePath(c);
    CGContextAddPath(c, path);
    CGContextClip(c);
    CGContextFillRect(c, CGRectMake(r.origin.x, r.origin.y, r.size.width * self.value, r.size.height));
}

To change the thermometer value, change the MyTherm instance's value to a number between 0 and 1, and tell it to redraw itself with setNeedsDisplay.

Solution 2:

This is doable using the standard controls.

In Interface Builder place your UISlider immediately on top of your UIProgressView and make them the same size.

On a UISlider the background horizontal line is called the track, the trick is to make it invisible. We do this with a transparent PNG and the UISlider methods setMinimumTrackImage:forState: and setMaximumTrackImage:forState:.

In the viewDidLoad method of your view controller add:

[self.slider setMinimumTrackImage:[UIImage imageNamed:@"transparent.png"] forState:UIControlStateNormal];
[self.slider setMaximumTrackImage:[UIImage imageNamed:@"transparent.png"] forState:UIControlStateNormal];

where self.slider refers to your UISlider.

I've tested the code in Xcode, and this will give you a slider with an independent progress bar.

Solution 3:

Solution that suits my design:

class SliderBuffering:UISlider {
    let bufferProgress =  UIProgressView(progressViewStyle: .Default)

    override init (frame : CGRect) {
        super.init(frame : frame)
    }

    convenience init () {
        self.init(frame:CGRect.zero)
        setup()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setup()
    }

    func setup() {
        self.minimumTrackTintColor = UIColor.clearColor()
        self.maximumTrackTintColor = UIColor.clearColor()
        bufferProgress.backgroundColor = UIColor.clearColor()
        bufferProgress.userInteractionEnabled = false
        bufferProgress.progress = 0.0
        bufferProgress.progressTintColor = UIColor.lightGrayColor().colorWithAlphaComponent(0.5)
        bufferProgress.trackTintColor = UIColor.blackColor().colorWithAlphaComponent(0.5)
        self.addSubview(bufferProgress)
    }
} 

Solution 4:

Create a UISlider:

// 1
// Make the slider as a public propriety so you can access it
playerSlider = [[UISlider alloc] init];
[playerSlider setContinuous:YES];
[playerSlider setHighlighted:YES];
// remove the slider filling default blue color
[playerSlider setMaximumTrackTintColor:[UIColor clearColor]];
[playerSlider setMinimumTrackTintColor:[UIColor clearColor]];
// Chose your frame
playerSlider.frame = CGRectMake(--- , -- , yourSliderWith , ----);

// 2
// create a UIView that u can access and make it the shadow of your slider 
shadowSlider = [[UIView alloc] init];
shadowSlider.backgroundColor = [UIColor lightTextColor];
shadowSlider.frame = CGRectMake(playerSlider.frame.origin.x , playerSlider.frame.origin.y , playerSlider.frame.size.width , playerSlider.frame.origin.size.height);
shadowSlider.layer.cornerRadius = 4;
shadowSlider.layer.masksToBounds = YES;
[playerSlider addSubview:shadowSlider];
[playerSlider sendSubviewToBack:shadowSlider];


// 3
// Add a timer Update your slider and shadow slider programatically 
 [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(updateSlider) userInfo:nil repeats:YES];


-(void)updateSlider {

    // Update the slider about the music time
    playerSlider.value = audioPlayer.currentTime; // based on ur case 
    playerSlider.maximumValue = audioPlayer.duration;

    float smartWidth = 0.0;
    smartWidth = (yourSliderFullWidth * audioPlayer.duration ) / 100;
    shadowSlider.frame = CGRectMake( shadowSlider.frame.origin.x , shadowSlider.frame.origin.y , smartWidth , shadowSlider.frame.size.height);

   }

Enjoy! P.S. I might have some typos.