HW 4

Due: Midnight SATURDAY the 14th (NOTE: In lecture, I announced due
Fri.  This made sense when I thought I could get this out well before
end of day today.  Since I didn't, please take an extra day.)


How to turn in: Send two pieces of email to your TA having THE EXACT subject
line and contents as specified below.

    Email #1:
		Subject: Item1.java
		
		Contents should be:
			 A new program that takes advantage of the
			 fact that the new and improved ViewColors class is
			 reusable.  The program should be invoked
			 with
				java Item1
				

     Email #2:
		Subject: ViewSliderPanel.java
		
		Contents should be:
			 A new version of ViewSliderPanel.java that doesn't
			 suffer from the structural problems we
			 discussed in class. This new version
			 should REPLACE the ViewSliderPanel.java
			 provided below.
			 

			 			 
			 

This a quick assignment just intended to exercise your ability to
make and leverage good code.


Grading Criterion:

2 points: Clearly demonstrates an ability to make and leverage good code.
1 points: Partially demonstrates an ability to make and leverage good
code.
0 points: No demonstration.





-------------------------------------


//
// Original ViewColors.java
// For information only. Revised version below.
//
// Principle problem: 
// 	     NOT REUSABLE: contains in a single file all
//	     the logic for building the frame, populating it with things, and
//	     dealing with Main.
//
//********************************************************************
//  ViewColors.java       Authors: Lewis/Loftus
//
//  Demonstrates the use slider components.
//********************************************************************

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

public class ViewColors
{
   public static void main (String[] args)
   {
      JFrame frame = new JFrame ("View Colors");
      frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);

      JPanel colorPanel = new JPanel();
      colorPanel.setPreferredSize (new Dimension (100, 100));
      colorPanel.setBackground (new Color (0, 0, 0));

      Container cp = frame.getContentPane();
      cp.setLayout (new FlowLayout());
      cp.add (new ViewSliderPanel(colorPanel));
      cp.add (colorPanel);

      frame.pack();
      frame.show();
   }
}

// END OF FILE





//---------------------------------------------------------------------
// Save up to next END OF FILE into a file called ViewColors.java 
//
// Revised ViewColors.demo
//


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

public class ViewColors extends JFrame
{
    public ViewColors() {
	getContentPane().add(new ViewColorsGUI(this));
    }


    public static void main (String[] args)
    {

	JFrame frame = new ViewColors();
	frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);

	frame.pack();
	frame.show();
    }
}


class ViewColorsGUI extends JPanel {
    public ViewColorsGUI(JFrame f) {
	setPreferredSize (new Dimension (100, 100));
	setBackground (new Color (0, 0, 0));

	Container cp = f.getContentPane();
	cp.setLayout (new FlowLayout());
	cp.add (new ViewSliderPanel(this));
	cp.add (this);
    }
}


// END OF FILE



//////////////////////////////////////////
// Original ViewSliderPanel.java
// Save this to ViewSliderPanel.java 
// Edit it to solve the problems describe above.
//
// Problems with ViewSliderPanel:
//
// 1. single constructor doesn't fit on a screen
// 2. lots of repeating code.
// 3. failure to express differences in terms of best available tools.
// 4. shows lots of details to client.
// 5. Combines layout and creation/construction.

//

//********************************************************************
//  ViewSliderPanel.java       Authors: Lewis/Loftus
//
//  Represents the slider control panel for the ViewColors program.
//********************************************************************

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

public class ViewSliderPanel extends JPanel
{
   private JPanel colorPanel;
   private JSlider rSlider, gSlider, bSlider;
   private JLabel rLabel, gLabel, bLabel;

   //-----------------------------------------------------------------
   //  Sets up the sliders and their labels, aligning them along
   //  their left edge using a box layout.
   //-----------------------------------------------------------------
   public ViewSliderPanel (JPanel panel)
   {
      colorPanel = panel;

      rSlider = new JSlider (JSlider.HORIZONTAL, 0, 255, 0);
      rSlider.setMajorTickSpacing (50);
      rSlider.setMinorTickSpacing (10);
      rSlider.setPaintTicks (true);
      rSlider.setPaintLabels (true);
      rSlider.setAlignmentX (Component.LEFT_ALIGNMENT);

      gSlider = new JSlider (JSlider.HORIZONTAL, 0, 255, 0);
      gSlider.setMajorTickSpacing (50);
      gSlider.setMinorTickSpacing (10);
      gSlider.setPaintTicks (true);
      gSlider.setPaintLabels (true);
      gSlider.setAlignmentX (Component.LEFT_ALIGNMENT);

      bSlider = new JSlider (JSlider.HORIZONTAL, 0, 255, 0);
      bSlider.setMajorTickSpacing (50);
      bSlider.setMinorTickSpacing (10);
      bSlider.setPaintTicks (true);
      bSlider.setPaintLabels (true);
      bSlider.setAlignmentX (Component.LEFT_ALIGNMENT);

      SliderListener listener = new SliderListener();
      rSlider.addChangeListener (listener);
      gSlider.addChangeListener (listener);
      bSlider.addChangeListener (listener);

      rLabel = new JLabel ("Red: 0");
      rLabel.setAlignmentX (Component.LEFT_ALIGNMENT);
      gLabel = new JLabel ("Green: 0");
      gLabel.setAlignmentX (Component.LEFT_ALIGNMENT);
      bLabel = new JLabel ("Blue: 0");
      bLabel.setAlignmentX (Component.LEFT_ALIGNMENT);

      setLayout (new BoxLayout (this, BoxLayout.Y_AXIS));
      add (rLabel);
      add (rSlider);
      add (Box.createRigidArea (new Dimension (0, 20)));
      add (gLabel);
      add (gSlider);
      add (Box.createRigidArea (new Dimension (0, 20)));
      add (bLabel);
      add (bSlider);
   }

   //*****************************************************************
   //  Represents the listener for all three sliders.
   //*****************************************************************
   private class SliderListener implements ChangeListener
   {
      //--------------------------------------------------------------
      //  Gets the value of each slider, then updates the labels and
      //  the color panel.
      //--------------------------------------------------------------
      public void stateChanged (ChangeEvent event)
      {
         int red, green, blue;

	 System.out.println(event);

         red = rSlider.getValue();
         green = gSlider.getValue();
         blue = bSlider.getValue();

         rLabel.setText ("Red: " + red);
         gLabel.setText ("Green: " + green);
         bLabel.setText ("Blue: " + blue);

         colorPanel.setBackground (new Color (red, green, blue));
      }
   }
}


// END OF FILE