ios - Creating a custom slider using Sprite Kit - how do I pass a @selector? -

a sprite kit game i'm working on uses custom slider act color picker (the color picked slider track graphic, uiimage containing gradient).

i looked using customised uislider, standard ios ui controls don't play sprite kit's scenes: they're difficult position relative rest of scene (as exist subview of main view rather part of skscene), pop existence (rather transitioning rest of scene) , must manually removed when exiting scene. in short, implementing them pain, , don't integrate seamlessly.

i've started implementing custom slider using skspritenodes, building on graf's excellent skbutton class, , have slider track , handle in place. handle sliding left , right along track, , setting value between 0 , 1 (just uislider). i've called class skslider.

what pass skslider @selector, in same way uislider, can define function inside skscene slider execute:

[myslider addtarget:self action:@selector(slidervaluechanged:) forcontrolevents:uicontroleventvaluechanged]; 

the function i'm trying invoke when slider's changed looks this:

-(uicolor*)getrgbafromimage:(uiimage*)image atx:(float)xp aty:(float)yp {     nsmutablearray *resultcolor = [nsmutablearray array];        cgimageref imageref = [image cgimage];     nsuinteger width = cgimagegetwidth(imageref);     nsuinteger height = cgimagegetheight(imageref);     cgcolorspaceref colorspace = cgcolorspacecreatedevicergb();      unsigned char *rawdata = (unsigned char*) calloc(height * width * 4, sizeof(unsigned char));      nsuinteger bytesperpixel = 4;     nsuinteger bytesperrow = bytesperpixel * width;     nsuinteger bitspercomponent = 8;      cgcontextref context = cgbitmapcontextcreate(rawdata, width, height,                                                  bitspercomponent, bytesperrow, colorspace,                                                  kcgimagealphapremultipliedlast | kcgbitmapbyteorder32big);      cgcolorspacerelease(colorspace);        cgcontextdrawimage(context, cgrectmake(0, 0, width, height), imageref);      cgcontextrelease(context);      // rawdata contains image data in rgba8888 pixel format.      int byteindex = (bytesperrow * yp) + xp * bytesperpixel;     cgfloat red   = (rawdata[byteindex]     * 1.0) /255.0;     cgfloat green = (rawdata[byteindex + 1] * 1.0)/255.0 ;     cgfloat blue  = (rawdata[byteindex + 2] * 1.0)/255.0 ;     cgfloat alpha = (rawdata[byteindex + 3] * 1.0) /255.0;      byteindex += 4;      uicolor *color = [uicolor colorwithred:red green:green blue:blue alpha:alpha];      [resultcolor addobject:color];      nslog(@"width:%i hight:%i color:%@",width,height,[color description]);      free(rawdata);      return color;         } 

(code found here, interested.)

but i'm not sure how should set in skslider's interface. point me in right direction?

just implement missing method in custom slider. add in interface:

- (void)addtarget:(id)target action:(sel)action forcontrolevents:(uicontrolevents)controlevents; 

and in implementation store target , action properties.

@property (nonatomic, strong) id target; @property (nonatomic) sel action;  - (void)addtarget:(id)target action:(sel)action forcontrolevents:(uicontrolevents)controlevents {     _target = target;     _action = action; } 

then call action on target when value changes:

objc_msgsend(_target, _action); 

remember import:

#import <objc/message.h> 

then updates slider create valuechanged method , add it:

- (void)valuechanged {     cgfloat value = _yourslider.value;     // value. }  [_yourslider addtarget:self action:@selector(valuechanged) forcontrolevents: uicontroleventvaluechanged];