Is there a way to run part of the Pain() method once?

Question

I'm working on a paint program.
I'm using AWT and Applet supplied by Java, and in the Paint method I have it drawing the UI and checking to see if this or that has been clicked to change color. Problem is, the Paint method is always running, and so the UI is always being redrawn, and so the color is always black, which is the last color to be changed.
So, is there any way I can have it stop drawing the UI, and just checking the colors? Or is there another method to use to put the UI code in?
Here's the code:
// CiPaint
// Version 0.2
// Programmed and Designed by Paul Adamski
// This program is inflexible and exhibits poor design
// ZOMG!!
// TODO:     80% -      Changing colors
import java.awt.*;
import java.applet.*;
public class CiPaint extends Applet
     Rectangle red, green, blue, purple, black, white, yellow;
     Color backgroundColor, eraseColor, currentColor;
     int numColor;
     Image virtualMem;
     Graphics gBuffer;
     int oldX, oldY, newX, newY;
     int appletWidth;          
     int appletHeight;
     public void init()
          backgroundColor = Color.white;
          eraseColor = Color.black;
          red = new Rectangle(10,10,25,25);
          green = new Rectangle(40,10,25,25);
          blue = new Rectangle(70,10,25,25);
          purple = new Rectangle(100,10,25,25);
          yellow = new Rectangle(130,10,25,25);
          black = new Rectangle(160,10,25,25);
          white = new Rectangle(85,40,25,25);
          numColor = 0;
          appletWidth = getWidth();
          appletHeight = getHeight();     
          virtualMem = createImage(appletWidth,appletHeight);
          gBuffer = virtualMem.getGraphics();
          //gBuffer.setColor(Color.white); Makes screen flicker
          //gBuffer.setColor(Color.red); Makes whole right side of menu screen red
          gBuffer.fillRect(200,0,appletWidth-200,appletHeight);
     public void paint(Graphics g)
          // Draws the borders and UI     
          g.drawLine(200,0,200,600);
          g.drawLine(1,1,800,1);
          g.drawLine(800,1,800,600);
          g.drawLine(800,600,1,600);
          g.drawLine(1,600,1,1);
          g.setColor(Color.red);
          g.fillRect(10,10,25,25);
          g.setColor(Color.green);
          g.fillRect(40,10,25,25);
          g.setColor(Color.blue);
          g.fillRect(70,10,25,25);
          g.setColor(Color.magenta);
          g.fillRect(100,10,25,25);
          g.setColor(Color.yellow);
          g.fillRect(130,10,25,25);
          g.setColor(Color.black);     // This line unwantingly is the drawing color
          g.fillRect(160,10,25,25);     // This whole section is repeatidly called, it only should be called ONCE
          g.drawRect(85,40,25,25);
          // End Drawing
          switch (numColor)
               case 1:
                    g.setColor(Color.red);
                    currentColor = Color.red;
                    System.out.println("ITS RED NUBCAKE");
                    break;
               case 2:
                    g.setColor(Color.green);
                    currentColor = Color.green;
                    break;
               case 3:
                    g.setColor(Color.blue);
                    currentColor = Color.blue;
                    break;
               case 4:
                    g.setColor(Color.magenta);
                    currentColor = Color.magenta;
                    break;
               case 5:
                    g.setColor(Color.yellow);
                    currentColor = Color.yellow;
                    break;
               case 6:
                    g.setColor(Color.black);
                    currentColor = Color.black;
                    break;
               case 7:
                    g.setColor(Color.white);
                    currentColor = Color.white;
                    break;
               case 8:
                    break;
          // Works, but doesn't change color
          if (oldX > 200)
                    g.fillRect(oldX,oldY,2,2);
                    //g.drawImage(virtualMem,0,0,this);     
          /*UBER Flicker and doesn't even draw
          if (oldX > 200)
                    gBuffer.fillRect(oldX,oldY,2,2);
                    g.drawImage(virtualMem,0,0,this);     
     public boolean mouseDown(Event e, int x, int y)
          if(red.inside(x,y))
               numColor = 1;
          else if(green.inside(x,y))
               numColor = 2;
          else if(blue.inside(x,y))
               numColor = 3;
          else if(purple.inside(x,y))
               numColor = 4;
          else if(yellow.inside(x,y))
               numColor = 5;
          else if(black.inside(x,y))
               numColor = 6;
          else if(white.inside(x,y))
               numColor = 7;
          else
               numColor = 8;
          newX = x;
          newY = y;
          oldX = newX;
          oldY = newY;
          repaint();
          return true;
     public boolean mouseDrag(Event e, int x, int y)
          newX = x;
          newY = y;
          oldX = newX;
          oldY = newY;
          repaint();
          return true;
     public void update(Graphics g)
          paint(g);
}

Answer 1

You have only to move your switch block from paint method to mouseDown method: in this way you first assign correct value to currentColor variable.... then pain method will use the color you have already set.
Notice that methods mouseDown and mouseDrag are deprecated: you should better use processMouseEvent and processMouseMotionEvent methods (see documentation of class Component to more details.
Below the implementation I tried.
Bye
Diego
import java.awt.*;
import java.applet.*;
public class CiPaint extends Applet
     Rectangle red, green, blue, purple, black, white, yellow;
     Color backgroundColor, eraseColor, currentColor;
     int numColor;
     Image virtualMem;
     Graphics gBuffer;
     int oldX, oldY, newX, newY;
     int appletWidth;          
     int appletHeight;
     public void init()
          backgroundColor = Color.white;
          eraseColor = Color.black;
          red = new Rectangle(10,10,25,25);
          green = new Rectangle(40,10,25,25);
          blue = new Rectangle(70,10,25,25);
          purple = new Rectangle(100,10,25,25);
          yellow = new Rectangle(130,10,25,25);
          black = new Rectangle(160,10,25,25);
          white = new Rectangle(85,40,25,25);
          numColor = 0;
          appletWidth = getWidth();
          appletHeight = getHeight();     
          virtualMem = createImage(appletWidth,appletHeight);
          gBuffer = virtualMem.getGraphics();
          //gBuffer.setColor(Color.white); Makes screen flicker
          //gBuffer.setColor(Color.red); Makes whole right side of menu screen red
          gBuffer.fillRect(200,0,appletWidth-200,appletHeight);
     public void paint(Graphics g)
          // Draws the borders and UI     
          g.drawLine(200,0,200,600);
          g.drawLine(1,1,800,1);
          g.drawLine(800,1,800,600);
          g.drawLine(800,600,1,600);
          g.drawLine(1,600,1,1);
          g.setColor(Color.red);
          g.fillRect(10,10,25,25);
          g.setColor(Color.green);
          g.fillRect(40,10,25,25);
          g.setColor(Color.blue);
          g.fillRect(70,10,25,25);
          g.setColor(Color.magenta);
          g.fillRect(100,10,25,25);
          g.setColor(Color.yellow);
          g.fillRect(130,10,25,25);
          g.setColor(Color.black);     // This line unwantingly is the drawing color
          g.fillRect(160,10,25,25);     // This whole section is repeatidly called, it only should be called ONCE
          g.drawRect(85,40,25,25);
          // End Drawing
//          switch (numColor)
//               case 1:
//                    g.setColor(Color.red);
//                    currentColor = Color.red;
//                    System.out.println("ITS RED NUBCAKE");
//                    break;
//               case 2:
//                    g.setColor(Color.green);
//                    currentColor = Color.green;
//                    break;
//               case 3:
//                    g.setColor(Color.blue);
//                    currentColor = Color.blue;
//                    break;
//               case 4:
//                    g.setColor(Color.magenta);
//                    currentColor = Color.magenta;
//                    break;
//               case 5:
//                    g.setColor(Color.yellow);
//                    currentColor = Color.yellow;
//                    break;
//               case 6:
//                    g.setColor(Color.black);
//                    currentColor = Color.black;
//                    break;
//               case 7:
//                    g.setColor(Color.white);
//                    currentColor = Color.white;
//                    break;
//               case 8:
//                    break;
                g.setColor(currentColor);
          // Works, but doesn't change color
          if (oldX > 200)
                    g.fillRect(oldX,oldY,2,2);
                    //g.drawImage(virtualMem,0,0,this);     
          /*UBER Flicker and doesn't even draw
          if (oldX > 200)
                    gBuffer.fillRect(oldX,oldY,2,2);
                    g.drawImage(virtualMem,0,0,this);     
     public boolean mouseDown(Event e, int x, int y)
          if(red.inside(x,y))
               numColor = 1;
          else if(green.inside(x,y))
               numColor = 2;
          else if(blue.inside(x,y))
               numColor = 3;
          else if(purple.inside(x,y))
               numColor = 4;
          else if(yellow.inside(x,y))
               numColor = 5;
          else if(black.inside(x,y))
               numColor = 6;
          else if(white.inside(x,y))
               numColor = 7;
          else
               numColor = 8;
          newX = x;
          newY = y;
          oldX = newX;
          oldY = newY;
          switch (numColor)
               case 1:
                    currentColor = Color.red;
                    System.out.println("ITS RED NUBCAKE");
                    break;
               case 2:
                    currentColor = Color.green;
                    break;
               case 3:
                    currentColor = Color.blue;
                    break;
               case 4:
                    currentColor = Color.magenta;
                    break;
               case 5:
                    currentColor = Color.yellow;
                    break;
               case 6:
                    currentColor = Color.black;
                    break;
               case 7:
                    currentColor = Color.white;
                    break;
               case 8:
                    break;
          repaint();
          return true;
     public boolean mouseDrag(Event e, int x, int y)
          newX = x;
          newY = y;
          oldX = newX;
          oldY = newY;
          repaint();
          return true;
     public void update(Graphics g)
          paint(g);
}