class HScrollbar
{
  int swidth, sheight;    // width and height of bar
  int xpos, ypos;         // x and y position of bar
  float spos, newspos;    // x position of slider
  int sposMin, sposMax;   // max and min values of slider
  int loose;              // how loose/heavy
  boolean over;           // is the mouse over the slider?
  boolean locked;
  float ratio;

  HScrollbar (int xp, int yp, int sw, int sh, int l) {
    swidth = sw;
    sheight = sh;
    if(sw >= sh){
      int widthtoheight = sw - sh;
      ratio = (float)sw / (float)widthtoheight;
      xpos = xp;
      ypos = yp-sheight/2;
      spos = xpos + swidth/2 - sheight/2;
      newspos = spos;
      sposMin = xpos;
      sposMax = xpos + swidth - sheight;
    }
    else{
      int heighttowidth = sh - sw;
      ratio = (float)sh / (float)heighttowidth;
      xpos = xp - swidth/2;
      ypos = yp;
      spos = ypos + sheight/2 - swidth/2;
      newspos = spos;
      sposMin = ypos;
      sposMax = ypos - swidth + sheight;

    }

    loose = l;
  }

  void update() {
    if(over()) {
      over = true;
    } 
    else {
      over = false;
    }
    if(mousePressed && over) {
      locked = true;
    }
    if(!mousePressed) {
      locked = false;
    }
    if(locked) {
      if(swidth >=sheight)
        newspos = constrain(mouseX-sheight/2, sposMin, sposMax);
      else
        newspos = constrain(mouseY-swidth/2, sposMin, sposMax);
    }
    if(abs(newspos - spos) > 1) {
      spos = spos + (newspos-spos)/loose;
    }
  }

  int constrain(int val, int minv, int maxv) {
    return min(max(val, minv), maxv);
  }

  boolean over() {
    if(mouseX > xpos && mouseX < xpos+swidth &&
      mouseY > ypos && mouseY < ypos+sheight) {
      return true;
    } 
    else {
      return false;
    }
  }

  void display() {
    noStroke();
    rectMode(CORNER);
    fill(225,0);
    rect(xpos, ypos, swidth, sheight);
    stroke(1);
    if(over || locked) {
      fill(255);
    } 
    else {
      fill(102, 102, 102);
    }
    if(swidth >=sheight)
      rect(spos, ypos, sheight, 2*sheight);
    else{
      rectMode(CENTER);
      rect(xpos, spos,  2*swidth, swidth);
    }
  }

  float getPos() {
    // Convert spos to be values between
    // 0 and the total width of the scrollbar
    //if(swidth <=sheight)
  // println(spos+"\t"+ratio+"\n");
    return spos * ratio;
   
  }
}