// background color is set with setBackground
sclass JMultiColorBar > JComponentWithChangeListeners {
  class Entry {
    settable double value;
    settable Color color;
  }
  
  L<Entry> entries = notifyingList(l0 repaint);
  
  settableWithVar double max = 100;
  
  void addEntry(double value, Color color) {
    entries.add(new Entry().+value.+color);
  }
  
  *() {
    setForeground(Color.red);
    varMax().onChange(l0 repaint);
    jMinSize(50, 10, this);
  }

  public void paintComponent(Graphics g) {
    super.paintComponent(g); // paint background
    int w = getWidth(), h = getHeight();
    
    int x = 0;
    for (e : entries) {
      int x2 = main max(x, iround(w*clampZeroToOne(doubleRatio(e.value, max))));
      if (x2 > x)
        fillRect(g, x2+1, 0, x2-x, h, e.color);
      x = x2;
    }
  }
}