class PSlider {
  float xpos, ypos;
  float x, y;
  float w, l;
  float delL ;
  float delS ;
  float  maxv, minv, ratio,  slv; 
  String label;
  boolean dragging = false;

  PSlider( float x1, float y1, float len1, float h1, String lab1, float minv1, float maxv1 ) {
    rectMode(CORNER); 
    xpos = x1;
    ypos = y1;
    w = h1; 
    l = len1;
    x = x1 + l/2.0 -w/2;
    y = y1;
    maxv = maxv1;
    minv = minv1;
    delS = (l-3*w)/(maxv- minv)/100;
    delL = delS*10;
    ratio =  (maxv - minv)/(l-3*w);
    slv = round(10000*(x-xpos - w)*ratio)/10000 + minv;
    label = lab1;
  }

  void initPos (float slv_init) {
    x =(slv_init -minv ) * (l-3.0*w)/(maxv - minv) +xpos +w ; 
  }

  boolean over(){ 
    boolean result = false; 
    if (mouseX>xpos && mouseX<xpos+l && mouseY>ypos && mouseY<ypos+w) 
      result = true;
    return result;
  }
  boolean overM(){ 
    boolean result = false; 
    if ( mouseX>xpos && mouseX<xpos+w && mouseY>y && mouseY<y+w) 
      result = true;
    return result;
  }
  boolean overP(){ 
    boolean result = false; 
    if ( mouseX>xpos+l-w && mouseX<xpos+l && mouseY>y && mouseY<y+w) 
      result = true;
    return result;
  }
  boolean overPTrack(){  
    boolean result = false; 
    if ( mouseX>x + w && mouseX<xpos+l-w && mouseY>y && mouseY<y+w) 
      result = true;
    return result;
  }
  boolean overMTrack(){  
    boolean result = false; 
    if ( mouseX>xpos+w && mouseX<x && mouseY>y && mouseY<y+w) 
      result = true;
    return result;
  }  

  boolean overThumb(){ 
    boolean result = false; 
    if (mouseX>x && mouseX<x+w && mouseY>y && mouseY<y+w) 
      result = true;
    return result;
  }
  void dragThumb(){
    dragging =  (overThumb() && mouseX>x &&  mouseX<x+w  && mousePressed) ;
  }
  void decByOneL(){
    if (x>xpos+w) x -= delL;  
    fill(200, 200,255);
    rect( xpos+w, y, x-xpos -w, w );
  }
  void incByOneL(){
    if (x<xpos+l-w) x += delL;  
    fill(200, 200,255); 
    rect( x+w, y, l + xpos- 2.0*w -x, w );
  }
  void decByOneS(){
    if (x>xpos+w+delS/10) x -= delS;  
    fill(200, 255, 200); 
    rect( xpos, y, w, w );
  }
  void incByOneS(){
    if (x<xpos+l-w-w-delS/10) x += delS;  
    fill(200, 255, 200); 
    rect( xpos + l-w, y, w, w );
  }      
  void changeValue(){
    if(overThumb())
      dragThumb();
    if(overP())
      incByOneS();
    if(overM())
      decByOneS();
    if(overMTrack())
      decByOneL();
    if(overPTrack())
      incByOneL();
  }    

  void display() {
    fill(255);
    rect(xpos+w, ypos, l-2*w, w);
    fill(150);
    rect(xpos, ypos, w,w);
    triangle(xpos+w, ypos, xpos, ypos+w/2, xpos+w, ypos+w);
    rect(xpos+l-w, ypos, w,w);
    triangle(xpos+l-w, ypos, xpos+l, ypos+w/2, xpos+l-w, ypos+w);
    if (dragging) { 
      x = constrain (mouseX-w/2,  xpos+w,  xpos+l-2*w); 
      fill(255, 200,200);
    } 
    else {
      fill(255);
    }
    rect( x, y, w, w );
    slv = (x-xpos - w)*ratio + minv;
    noStroke(); 
    fill(bkColor); 
    rect(xpos - 10, ypos -17,  100, 16);
    stroke(0);
    fill(255, 0, 0 );
    text(label+nfs(slv, 1,2), xpos, ypos-3);
    //     rectMode(CENTER); 
  }
}