Startup

Since PaintApp.java is a Frame and implements the WindowListener, MouseListener, and MouseMotionListener interfaces, the program must set the size of the applet, add event listeners, and make the applet visible on startup.

PaintApp.java -- Class Heading
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public class PaintApp extends Frame implements WindowListener, MouseListener, MouseMotionListener {
 
				public class PaintApp extends Frame implements WindowListener, MouseListener, MouseMotionListener {
PaintApp.java -- main() creates application framework
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public static void main(String args[]) {    // The main method handles the application's framework (such as event listeners) and makes the window visible
    PaintApp paintProgram = new PaintApp();
    paintProgram.addWindowListener(paintProgram);
    paintProgram.addMouseListener(paintProgram);
    paintProgram.addMouseMotionListener(paintProgram);
     
    paintProgram.appWidth = 761;
    paintProgram.appHeight = 380;
    paintProgram.setSize(paintProgram.appWidth, paintProgram.appHeight);
     
    paintProgram.setVisible(true);
    paintProgram.createApp();
}
 
				public static void main(String args[]) {    // The main method handles the application's framework (such as event listeners) and makes the window visible
					PaintApp paintProgram = new PaintApp();
					paintProgram.addWindowListener(paintProgram);
					paintProgram.addMouseListener(paintProgram);
					paintProgram.addMouseMotionListener(paintProgram);
					
					paintProgram.appWidth = 761;
					paintProgram.appHeight = 380;
					paintProgram.setSize(paintProgram.appWidth, paintProgram.appHeight);
					
					paintProgram.setVisible(true);
					paintProgram.createApp();
				}

When createApp() is called, the menu bar, canvas, layers array, and toolbar are created. The menu is "click-able" but cannot be viewed yet until paint() is called.

PaintApp.java -- Creates menu bar, canvas, layers array, and toolbar
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public void createApp() {   // Menu bar, canvas, layers array, and toolbar are created
    menuHeight = 75;
    createCanvas();
    layersArray = new Layers(this);
    // The menu bar's selection boxes are created but not the buttons that you can see; i.e. buttons are invisible
    menuBar = new Menu(this, layersArray);
    toolbar = new Tools(this, menuBar, layersArray);
    firstPaint = true;
}
 
				public void createApp() {   // Menu bar, canvas, layers array, and toolbar are created
					menuHeight = 75;
					createCanvas();
					layersArray = new Layers(this);
					// The menu bar's selection boxes are created but not the buttons that you can see; i.e. buttons are invisible
					menuBar = new Menu(this, layersArray);
					toolbar = new Tools(this, menuBar, layersArray);
					firstPaint = true;
				}

After the main() has finished executing, then paint() is automatically called. During the first call to paint(), the menu bar is drawn and layers are created.

PaintApp.java -- First paint() call
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public void paint(Graphics g) {     // Called after paintProgram became visible and whenever the graphical output needs to be updated or repainted
    g2Frame = (Graphics2D) g;       // The abstract Graphics2D class extends the abstract Graphics class
 
    if (firstPaint) {  
        menuBar.createMenu();       // Menu items are drawn onto the menu off-screen image
        g2Frame.drawImage(menuBar.menuImage, 0, 0, this);   // Off-screen image is drawn onto the application; menu becomes visible
         
        firstPaint = false;
        continuePaint = true;
    }
}
 
				public void paint(Graphics g) {     // Called after paintProgram became visible and whenever the graphical output needs to be updated or repainted
					g2Frame = (Graphics2D) g;       // The abstract Graphics2D class extends the abstract Graphics class

					if (firstPaint) {   
						menuBar.createMenu();       // Menu items are drawn onto the menu off-screen image
						g2Frame.drawImage(menuBar.menuImage, 0, 0, this);   // Off-screen image is drawn onto the application; menu becomes visible
						
						firstPaint = false;
						continuePaint = true;
					}
				}