Question

I am working in Xcode on a synthesizer application. I am using custom sliders and knobs. I want these to send control values to receivers in an embedded Pure Data patch (I am using libpd as a Pure Data library and wrapper).

I have multiple custom sliders and knobs on my interface. I want each one to send only their own control values independently of the other sliders/knobs.

I am using tags and a switch statement.
The problem is that only the first case is working and all of the sliders and knobs are sending control values to the same receiver.

- (void)viewDidLoad {
    [super viewDidLoad];

// Slider 1

    slider.tag = 0;
    slider = [[[DCSlider alloc] initWithDelegate:self] autorelease];
    slider.frame = CGRectMake(0,0,20,100);
    [self.sliderContainer addSubview: slider];


// Slider 2 

    slider2.tag = 1;    
    slider2 = [[[DCSlider alloc] initWithDelegate:self] autorelease];
    slider2.frame = CGRectMake(0,0,20,100); 
    [self.sliderContainer2 addSubview: slider2];    
}

and then I implement the method here…

- (void)controlValueDidChange:(float)value sender:(id)sender { 

    DCSlider *slidertag = (DCSlider *)sender;

    switch (slidertag.tag) 
    {
        case 0: 
        { 
            [PdBase sendFloat:value toReceiver:@"beatvol"];
        }
            break;
        case 1: 
        { 
            [PdBase sendFloat:value toReceiver:@"bassvol"];
        }
            break;
    }     
}

Can anyone help please? Thanks.

Answer 1

Geez, still at it?

You obviously need to assign a separate target for each slider!

Also, in your example, you assign the tag before you create the slider, no good. You should always place your init before setting any properties.

- (void)viewDidLoad 
{
    [super viewDidLoad];

    // Slider 1

    slider = [[[DCSlider alloc] initWithDelegate:self] autorelease];
    slider.tag = 0;
    slider.frame = CGRectMake(0,0,20,100);
    [slider addTarget:self action:@selector(controlBassValueDidChange:) forControlEvents:UIControlEventValueChanged];
    [self.sliderContainer addSubview: slider];

    // Slider 2 

    slider2 = [[[DCSlider alloc] initWithDelegate:self] autorelease];
    slider2.tag = 1;
    slider2.frame = CGRectMake(0,0,20,100); 
    [slider2 addTarget:self action:@selector(controlBeatValueDidChange:) forControlEvents:UIControlEventValueChanged];
    [self.sliderContainer2 addSubview: slider2];    
}

- (void)controlBassValueDidChange:(float)value sender:(id)sender 
{ 
    [PdBase sendFloat:value toReceiver:@"bassvol"];
}
- (void)controlBeatValueDidChange:(float)value sender:(id)sender 
{ 
    [PdBase sendFloat:value toReceiver:@"beatvol"];
}

And if you are going to use my answer to your other question, the least you could do is give it an upvote. ;—]