package slider;

import java.awt.*; 
import javax.swing.*; 
import slider.*;

public class Slider extends JComponent {
 // The h_spacing determines the amount of horizontal spacing between
 // the min and max labels and the slider. The v_spacing determines the
 // amount of vertical spacing between the label for the current value and
 // the indicator of the current value
 final int LABEL_H_SPACING = 10;
 final int LABEL_V_SPACING = 5;

 SliderModel model;
 public Slider (SliderModel m) { 
     model = m;
 } 

 public void valueChanged (int old_v) {repaint();} 
 public void titleChanged (String old_t) {repaint();} 
 public void paintComponent(Graphics g) { 
   // always call the superclass paintComponent method. It clears the 
   // the clipping region. If you forget to call the superclass 
   // paintComponent method then you may see ghosting.
   super.paintComponent(g);

  // Get model information for displaying the slider's label and its
  // current value
  int value = model.getValue();
  String title = model.getTitle();

  // Obtain dimensions of the canvas on which this slider is being drawn
  Dimension d = getSize();                               
  int sliderWidth = d.width * 3 / 4;                              
  int sliderHeight = sliderWidth / 20;                             
  int minValue = model.getMinValue();
  int maxValue = model.getMaxValue();

  // Draw the slider's horizontal line
  int lineX1 = (d.width - sliderWidth) / 2;                  
  int lineY1 = d.height / 2;                                
  g.drawLine(lineX1, lineY1, lineX1 + sliderWidth, lineY1);

  // Reset color temporarily
  // Obtain current Color instance
  Color colorHandle = g.getColor();
  g.setColor(Color.red);

  // Draw the slider's vertical indicator line
  int pointerPosition                                            
      = lineX1 + sliderWidth * (value - minValue) / (maxValue - minValue);    

  g.drawLine(pointerPosition, lineY1, pointerPosition, lineY1 - sliderHeight);  
  // restore color
  g.setColor(colorHandle);

  // Prepare font -- the font size should be a minimum of 12 pt but should
  // get bigger as the window gets bigger
  int fontSize = (d.width / 30 < 12 ? 12 : d.width / 30);
  g.setFont(new Font(Font.SANS_SERIF, Font.BOLD, fontSize)); 

  // Write title
  FontMetrics f = g.getFontMetrics();                    
  int stringWidth = f.stringWidth(title);

  // Center the title horizontally under the slider
  int textLeft = (d.width - stringWidth) / 2;  

  int textTop = lineY1 + (2 * f.getHeight());  
  g.drawString(title, textLeft, textTop);  

  // Display minimum and maximum values
  String minValueString = Integer.toString(minValue);
  String maxValueString = Integer.toString(maxValue);
  int minValueWidth = f.stringWidth(minValueString);
  int maxValueWidth = f.stringWidth(maxValueString);
  g.drawString(minValueString, lineX1 - minValueWidth - LABEL_H_SPACING,
	       lineY1 + f.getHeight() / 2);
  g.drawString(maxValueString, lineX1 + sliderWidth + LABEL_H_SPACING,
	       lineY1 + f.getHeight() / 2);

  // Display current value
  String currentValueString = Integer.toString(value);
  int currentValueWidth = f.stringWidth(currentValueString);
  g.drawString(currentValueString, pointerPosition - currentValueWidth / 2,
	       lineY1 - sliderHeight - LABEL_V_SPACING);  
 }
 public Dimension getMinimumSize() {return new Dimension(400, 100);}  
 public Dimension getPreferredSize() {return new Dimension(400, 100);}  
}