class UIslider {  
  private int x0, y0, xW, yW;
  private float value, maxVal, minVal;
  private String[] label;

  UIslider(int _x0, int _y0, int _xW, int _yW, float _val,  float _minVal, float _maxVal, String _label){
    x0 = _x0;  
    y0 = _y0;
    xW = _xW;    
    yW = _yW;
    set(_val);
    minVal = _minVal;
    maxVal = _maxVal;
    label = split(_label,'\n');
  }

  public final void draw(){
    stroke(200);
    fill(160);
    line(x0,y0+yW/2,x0+xW,y0+yW/2);
    rect(x0+value, y0, 4, yW+1);
    fill(180);
    for (int l=0;l<label.length;l++){
      text(label[l],x0-30,y0+l*6+8);
    }
    text(get() ,x0+xW+4,y0+yW-2);
  }

  public final float get(){
    return value/xW*(maxVal-minVal)+minVal;
  }  

  public final void set(float val){
    value = constrain((val-minVal)/(maxVal-minVal),0,xW);
  }

  public final float mousePressed() {
    if (hover()){
      value = mouseX-x0;   
    }  
    return get();
  }

  private final boolean hover(){
    if (mouseX>x0 && mouseX<x0+xW && mouseY>y0 && mouseY<y0+yW ){
      return true;
    }
    return false;  
  }

  public final float mouseDragged(){
    if (hover()){
      value = mouseX-x0;
    }  
    return get();
  }
}