added event code, reorganized java demos

java/1-basics/Animals1.java

+// Simple class hierarchy
+// Demonstrates abstract classes, containment
+
+public class Animals1 {
+
+    // inner classes
+    // base class
+    abstract class Animal {
+        abstract String talk();
+    }
+
+    // derived classes
+    class Cat extends Animal {
+        String talk() { return "Meow!"; }
+    }
+
+    class Dog extends Animal {
+        String talk() { return "Woof!"; }
+    }
+
+    // container class methods
+    Animals1() {
+        speak(new Cat());
+        speak(new Dog()); 
+    }
+
+    void speak(Animal a) {
+        System.out.println( a.talk() );
+    }
+
+    // static main methods -- entry point
+    public static void main(String[] args) {
+        Animals1 a = new Animals1();
+    }
+}
+

java/1-basics/Animals2.java

+// Simple class hierarchy
+// Contrasts interface and abstract class implementations
+
+public class Animals2 {
+
+    // interface
+    interface Pet { 
+        String talk();
+    }
+
+    // inner classes
+    class Cat implements Pet {
+        public String talk() { return "Meow!"; }
+    }
+
+    class Dog implements Pet {
+        public String talk() { return "Woof!"; }
+    }
+
+    // container class methods
+    Animals2() {
+        speak(new Cat());
+        speak(new Dog()); 
+    }
+
+    void speak(Pet a) {
+        System.out.println( a.talk() );
+    }
+
+    // static main methods -- entry point
+    public static void main(String[] args) {
+        Animals2 a = new Animals2();
+    }
+}
+

java/1-basics/Bicycle.java

+
+class Bicycle { 
+    String owner = null;
+    int speed = 0;
+    int gear = 1;
+
+    // constructor
+    Bicycle() { }
+    Bicycle(String name) { owner = name; }
+
+    // methods
+    void changeSpeed(int newValue) { speed = newValue; }
+    void changeGear(int newValue) { gear = newValue; }
+    int  getSpeed() { return speed; }
+    int  getGear() { return gear; }
+    
+    // static entry point - main method
+    public static void main(String[] args) {
+
+        Bicycle adultBike = new Bicycle("Jeff");
+        adultBike.changeSpeed(20);
+        System.out.println("speed=" + adultBike.getSpeed());
+
+        Bicycle kidsBike = new Bicycle("Austin");
+        kidsBike.changeSpeed(15);
+        System.out.println("speed=" + kidsBike.getSpeed());
+    }    
+}
+
+

java/1-basics/Bikes1.java

+// Simple class hierarchy
+// Demonstrates abstract classes and containment.
+
+// Bike container class
+class Bikes1 {
+
+	// base class
+	abstract class Bike {
+		int wheels = 0;
+		int speed = 0;
+
+		void setWheels(int val) { wheels = val; }
+		void setSpeed(int val) { speed = val; }
+		void show() {
+			System.out.println("wheels  = " + wheels);
+		}
+	}
+
+	// derived two-wheel bike
+	class Bicycle extends Bike {
+		Bicycle() { 
+			setWheels(2); 
+		}
+	}
+
+	// derived two-wheel bike
+	class Tricycle extends Bike {
+		Tricycle() { 
+			setWheels(3); 
+		}
+	}
+	
+	// container class
+	Bikes1() {
+		Bicycle b = new Bicycle();
+		b.show();
+
+		Tricycle t = new Tricycle();
+		t.show();
+	}
+
+	// entry point
+	public static void main(String[] args) {
+		Bikes1 b = new Bikes1();
+	}
+}
\ No newline at end of file

java/1-basics/Bikes2.java

+// Simple class hierarchy + interface
+// Demonstrates abstract classes, containment, interfaces.
+
+// Bike container class
+class Bikes2 {
+
+	// base class
+	abstract class Bike {
+		int wheels = 0;
+		int speed = 0;
+
+		void setWheels(int val) { wheels = val; }
+		void setSpeed(int val) { speed = val; }
+		void show() { 
+			System.out.println("wheels  = " + wheels);
+			System.out.println("speed  = " + speed);
+		}
+	}
+
+	// interface for ANYTHING driveable
+	// could be applied to car, scooter etc.
+	interface Driveable {
+		void accelerate();
+		void brake();
+	}
+
+	// derived two-wheel bike
+	class Bicycle extends Bike implements Driveable {
+
+		Bicycle() { setWheels(2); }
+
+		// interface methods
+		// need to make public to match access level for interface (above)
+		public void accelerate() { setSpeed(speed += 5); }
+		public void brake() { setSpeed(speed -= 5); }
+	}
+
+	// derived two-wheel bike
+	class Tricycle extends Bike implements Driveable {
+		Tricycle() { setWheels(3); }
+
+		// interface methods
+		// need to make public to match access level for interface (above)
+		public void accelerate() { setSpeed(speed += 1); }
+		public void brake() { setSpeed(speed -= 1); }		
+	}
+	
+	// container class
+	Bikes2() {
+		Bicycle b = new Bicycle();
+		b.accelerate();
+		b.show();
+
+		Tricycle t = new Tricycle();
+		t.accelerate();
+		t.show();
+	}
+
+	// entry point
+	public static void main(String[] args) {
+		Bikes2 b = new Bikes2();
+	}
+}
\ No newline at end of file

java/2-java-gui/BasicForm1.java

+
+import javax.swing.*;
+
+// Create a simple form
+public class BasicForm1 {
+    public static void main(String[] args) {
+        // create a window
+        JFrame frame = new JFrame("Window Demo");
+        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+        // create a panel and add components
+        JPanel panel = new JPanel();
+        JButton button = new JButton("Ok");
+        panel.add(button);
+
+        // add panel to the window
+        frame.add(panel);
+
+        // set window behaviour and display it
+        frame.setResizable(false);
+        frame.setSize(200, 200);
+        // frame.pack();
+        frame.setVisible(true);
+    }
+}
+

java/2-java-gui/BasicForm2.java

+
+import javax.swing.*;
+import javax.swing.event.MouseInputListener;
+import java.awt.event.MouseEvent;
+
+// Create a simple form
+// Adds a listener
+public class BasicForm2 {
+
+    public static void main(String[] args) {
+        // create a window
+        JFrame frame = new JFrame("Window Demo");
+        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+        // create a panel and add components
+        JPanel panel = new JPanel();
+        JButton button = new JButton("Ok");
+        button.addMouseListener(new MyMouseListener());
+        panel.add(button);
+
+        // add panel to the window
+        frame.add(panel);
+
+        // set window behaviour and display it
+        frame.setResizable(false);
+        frame.setSize(200, 200);
+        // frame.pack();
+        frame.setVisible(true);
+    }
+
+    // create a custom listener for my ok button
+    static class MyMouseListener implements MouseInputListener  {
+        @Override
+        public void mouseClicked(MouseEvent e) {
+            System.exit(1);
+        }
+
+        @Override
+        public void mousePressed(MouseEvent e) { }
+
+        @Override
+        public void mouseReleased(MouseEvent e) { }
+
+        @Override
+        public void mouseEntered(MouseEvent e) { }
+
+        @Override
+        public void mouseExited(MouseEvent e) { }
+
+        @Override
+        public void mouseDragged(MouseEvent e) { }
+
+        @Override
+        public void mouseMoved(MouseEvent e) { }
+    }
+}
\ No newline at end of file

java/2-java-gui/BasicForm3.java

+
+import javax.swing.*;
+import javax.swing.event.MouseInputListener;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
+import java.awt.event.MouseMotionListener;
+
+// Create a simple form
+// Converts listener to adapter
+public class BasicForm3 {
+
+    public static void main(String[] args) {
+        // create a window
+        JFrame frame = new JFrame("Window Demo");
+        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+        // create a panel and add components
+        JPanel panel = new JPanel();
+        JButton button = new JButton("Ok");
+        button.addMouseListener(new MyMouseAdapter());
+        panel.add(button);
+
+        // add panel to the window
+        frame.add(panel);
+
+        // set window behaviour and display it
+        frame.setResizable(false);
+        frame.setSize(200, 200);
+        // frame.pack();
+        frame.setVisible(true);
+    }
+
+    // create a custom adapter from MouseAdapter base class
+    static class MyMouseAdapter extends MouseAdapter {
+        public void mouseClicked(MouseEvent e) {
+            System.exit(1);
+        }
+    }
+}
+

java/2-java-gui/BasicForm4.java

+
+import javax.swing.*;
+import javax.swing.event.MouseInputListener;
+import java.awt.event.MouseAdapter;
+import java.awt.event.MouseEvent;
+import java.awt.event.MouseMotionListener;
+
+// Create a simple form
+// Converts adapter to anonymous inner class
+public class BasicForm4 {
+
+    public static void main(String[] args) {
+        // create a window
+        JFrame frame = new JFrame("Window Demo");
+        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+
+        // create a panel and add components
+        JPanel panel = new JPanel();
+        JButton button = new JButton("Ok");
+        button.addMouseListener(new MouseAdapter() { 
+                public void mouseClicked(MouseEvent e) {
+            System.exit(1);
+        }});
+        panel.add(button);
+
+        // add panel to the window
+        frame.add(panel);
+
+        // set window behaviour and display it
+        frame.setResizable(false);
+        frame.setSize(200, 200);
+        // frame.pack();
+        frame.setVisible(true);
+    }
+
+    // create a custom adapter from MouseAdapter base class
+    static class MyMouseAdapter extends MouseAdapter {
+        public void mouseClicked(MouseEvent e) {
+            System.exit(1);
+        }
+    }
+}
+

java/2-java-gui/SimpleDraw.java

+
+import javax.swing.*;
+import java.awt.Color;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.BasicStroke;
+import java.awt.RenderingHints;
+
+// JComponent is a base class for custom components 
+public class SimpleDraw extends JComponent {
+
+    public static void main(String[] args) {
+        JFrame f = new JFrame("SimpleDraw"); // jframe is the app window
+        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        f.setSize(400, 400); // window size
+
+        SimpleDraw canvas = new SimpleDraw();
+        f.setContentPane(canvas); // add canvas to jframe
+
+        f.setVisible(true); // show the window
+    }
+
+    // Constructor for SimpleDraw
+    public SimpleDraw() {
+    }
+
+    // custom graphics drawing 
+    // this is a method that we overrode from the JComponent class
+    public void paintComponent(Graphics g) {
+        Graphics2D g2 = (Graphics2D) g;               // 2D drawing
+        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
+        					RenderingHints.VALUE_ANTIALIAS_ON);
+        g2.setStroke(new BasicStroke(32));           // 32 pixels wide
+        g2.setColor(Color.BLUE);                     // make it blue
+        g2.drawLine(0, 0, getWidth(), getHeight());  // draw line 
+        g2.setColor(Color.RED);
+        g2.drawLine(getWidth(), 0, 0, getHeight());  
+    }
+}
+

java/2-java-gui/SimpleDraw2.java

+import javax.swing.*;
+import java.awt.Color;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.BasicStroke;
+import java.awt.RenderingHints;
+import java.awt.event.*;
+
+// JComponent is a base class for custom components 
+public class SimpleDraw2 extends JComponent {
+
+    public static void main(String[] args) {
+        SimpleDraw2 canvas = new SimpleDraw2();
+        JFrame f = new JFrame("SimpleDraw"); // jframe is the app window
+        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        f.setSize(400, 400); // window size
+        f.setContentPane(canvas); // add canvas to jframe
+        f.setVisible(true); // show the window
+    }
+
+    // Object properties
+    private int mouseX;
+    private int mouseY;
+
+    // Constructor for SimpleDraw
+    public SimpleDraw2() {
+	   this.addMouseMotionListener( new MyMotionListener() );
+    }
+
+    // custom graphics drawing 
+    public void paintComponent(Graphics g) {
+        Graphics2D g2 = (Graphics2D) g; // cast to get 2D drawing methods
+        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,  // antialiasing look nicer
+        					RenderingHints.VALUE_ANTIALIAS_ON);
+        g2.setStroke(new BasicStroke(32)); // 32 pixel thick stroke
+        g2.setColor(Color.BLUE); // make it blue
+        g2.drawLine(0, 0, getWidth(), getHeight());  // draw line 
+        g2.setColor(Color.RED);
+        g2.drawLine(getWidth(), 0, 0, getHeight());  
+
+    	String label = "Mouse at (" + mouseX + ", " + mouseY + ")";
+        g2.setColor(Color.BLACK);
+        g2.drawString(label, 130, 40);
+    }
+
+    // Inner class for handling mouse motion events
+    private class MyMotionListener implements MouseMotionListener {
+        public void mouseMoved(MouseEvent e) {
+            mouseX = e.getX();
+            mouseY = e.getY();
+            repaint();
+        }
+
+        public void mouseDragged(MouseEvent e) {
+	    // Do nothing.
+	    // But we still need this method implemented because it's part of the interface
+        }
+    }
+}

java/2-java-gui/SimpleDraw3.java

+import javax.swing.*;
+import java.awt.Color;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.BasicStroke;
+import java.awt.RenderingHints;
+import java.awt.event.*;
+
+// JComponent is a base class for custom components 
+public class SimpleDraw3 extends JComponent {
+
+    public static void main(String[] args) {
+        SimpleDraw3 canvas = new SimpleDraw3();
+        JFrame f = new JFrame("SimpleDraw"); // jframe is the app window
+        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        f.setSize(400, 400); // window size
+        f.setContentPane(canvas); // add canvas to jframe
+        f.setVisible(true); // show the window
+    }
+
+    // Object properties
+    private int mouseX;
+    private int mouseY;
+
+    // Constructor for SimpleDraw
+    public SimpleDraw3() {
+	   this.addMouseMotionListener( new MyMotionListener() );
+    }
+
+    // custom graphics drawing 
+    public void paintComponent(Graphics g) {
+        Graphics2D g2 = (Graphics2D) g; // cast to get 2D drawing methods
+        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,  // antialiasing look nicer
+        					RenderingHints.VALUE_ANTIALIAS_ON);
+        g2.setStroke(new BasicStroke(32)); // 32 pixel thick stroke
+        g2.setColor(Color.BLUE); // make it blue
+        g2.drawLine(0, 0, getWidth(), getHeight());  // draw line 
+        g2.setColor(Color.RED);
+        g2.drawLine(getWidth(), 0, 0, getHeight());  
+
+	    String label = "Mouse at (" + mouseX + ", " + mouseY + ")";
+        g2.setColor(Color.BLACK);
+    	g2.drawString(label, 130, 40);
+    }
+
+    // Inner class for handling mouse motion events
+    private class MyMotionListener extends MouseMotionAdapter {
+        public void mouseMoved(MouseEvent e) {
+            mouseX = e.getX();
+            mouseY = e.getY();
+            repaint();
+        }
+
+        // Notice the difference? 
+        // We implemented the MotionListener using an adapter instead of an interface
+        // This allows is to ignore methods we don't want!
+
+        /*
+        public void mouseDragged(MouseEvent e) {
+	    // Do nothing.
+	    // But we still need this method implemented because it's part of the interface
+        }
+        */
+    }
+}

java/2-java-gui/SimpleDraw4.java

+import javax.swing.*;
+import java.awt.Color;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.BasicStroke;
+import java.awt.RenderingHints;
+import java.awt.event.*;
+import java.util.Vector;
+
+// JComponent is a base class for custom components 
+public class SimpleDraw4 extends JComponent {
+
+    public static void main(String[] args) {
+        SimpleDraw4 canvas = new SimpleDraw4();
+        JFrame f = new JFrame("SimpleDraw"); // jframe is the app window
+        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        f.setSize(400, 400); // window size
+        f.setContentPane(canvas); // add canvas to jframe
+        f.setVisible(true); // show the window
+    }
+
+    // Object properties
+    private int mouseX;
+    private int mouseY;
+
+    // Constructor for SimpleDraw
+    public SimpleDraw4() {
+
+        // this is an example of an anonymous inner class
+    	this.addMouseMotionListener( new MouseAdapter() {
+          public void mouseMoved(MouseEvent e) {
+            mouseX = e.getX();
+            mouseY = e.getY();
+            repaint();
+          }
+	});
+    }
+
+    // custom graphics drawing 
+    public void paintComponent(Graphics g) {
+        Graphics2D g2 = (Graphics2D) g; // cast to get 2D drawing methods
+        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,  // antialiasing look nicer
+        					RenderingHints.VALUE_ANTIALIAS_ON);
+        g2.setStroke(new BasicStroke(32)); // 32 pixel thick stroke
+        g2.setColor(Color.BLUE); // make it blue
+        g2.drawLine(0, 0, getWidth(), getHeight());  // draw line 
+        g2.setColor(Color.RED);
+        g2.drawLine(getWidth(), 0, 0, getHeight());  
+
+	    String label = "Mouse at (" + mouseX + ", " + mouseY + ")";
+        g2.setColor(Color.BLACK);
+	    g2.drawString(label, 130, 40);
+    }
+}

java/3-widgets/WidgetDemo.java

+import java.awt.*;