easy BorderLayout painter with raw swing

src/lec05/glab/swing/Painter.java

 package lec05.glab.swing;
 
 import javax.swing.*;
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ChangeListener;
 import java.awt.*;
+import java.awt.event.MouseEvent;
+import java.awt.event.MouseMotionAdapter;
+import java.awt.event.MouseMotionListener;
 
 /**
  * Created by Adam on 11/2/2015.
  */
-public class Painter {
+public class Painter implements ChangeListener {
     //define a frame
     private JFrame frm;
+    private JPanel mPanelIndicator;
+    private JPanel mPanelCenter;
+    private JPanel mPanelSlider;
+
+    private JSlider mSliderRed;
+    private JSlider mSliderGreen;
+    private JSlider mSliderBlue;
+
+    private Color mColor;
+
+
 
     //creaete a main method that insantiates the ecnlosing object
     public static void main(String[] args) {
@@ -30,12 +46,73 @@ public class Painter {
         initialize();
     }
 
+    //use BorderLayout. this is the easiest one.
+    //https://docs.oracle.com/javase/tutorial/uiswing/layout/border.html
+
     //our init methhod
     private void initialize() {
         frm = new JFrame();
-        frm.setBounds(100, 100, 450, 476);
+        frm.setBounds(100, 100, 700, 476);
         frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+        //lay our componnets out
+        mPanelIndicator = new JPanel();
+
+        //http://stackoverflow.com/questions/17083657/make-bottom-panel-in-borderlayout-to-expand-like-center-panel
+        mPanelIndicator.setPreferredSize(new Dimension(frm.getWidth(), 50));
+
+        frm.getContentPane().add(mPanelIndicator, BorderLayout.NORTH);
+
+        mPanelCenter = new JPanel();
+        frm.getContentPane().add(mPanelCenter, BorderLayout.CENTER);
+
+
+        mSliderBlue = new JSlider(0,255);
+        mSliderGreen = new JSlider(0,255);
+        mSliderRed = new JSlider(0,255);
+
+
+        mPanelSlider = new JPanel();
+        mPanelSlider.add(mSliderRed);
+        mPanelSlider.add(mSliderGreen);
+        mPanelSlider.add(mSliderBlue);
+
+        frm.getContentPane().add(mPanelSlider, BorderLayout.SOUTH);
+
+
+        //add behavior
+        mColor = Color.GRAY;
+        mPanelIndicator.setBackground(mColor);
+
+        mSliderBlue.addChangeListener(this);
+        mSliderGreen.addChangeListener(this);
+        mSliderRed.addChangeListener(this);
+
+        mPanelCenter.addMouseMotionListener(new MouseMotionAdapter() {
+            @Override
+            public void mouseDragged(MouseEvent e) {
+                super.mouseDragged(e);
+              Graphics graphics =  mPanelCenter.getGraphics();
+
+                graphics.setColor(mColor);
+                graphics.fillOval(e.getX(), e.getY(), 20,20);
+            }
+        });
+
+//        frm.pack();
+//       // frm.setLocationRelativeTo(null);
+//        frm.setVisible(true);
+
     }
 
 
+    @Override
+    public void stateChanged(ChangeEvent e) {
+      mColor =  new Color(mSliderRed.getValue(),
+                mSliderGreen.getValue(),
+                mSliderBlue.getValue()
+
+        );
+        mPanelIndicator.setBackground(mColor);
+    }
 }