Tag: code

Five buttons arranged by FlowLayout

FlowTest.java ************* FlowTest.java Five buttons arranged by FlowLayout By default, FlowLayout arranges components in rows, left to right, and centered. /././././././././././././ import java.applet.Applet; import java.awt.*; /** FlowLayout puts components in rows.  *  ************************************ public class FlowTest extends Applet {   public void init() {     for(int i=1; i<6; i++) {       add(new Button(“Button ” + …

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A Frame that lets you draw circles with mouse clicks

SavedFrame.java **************** A Frame that lets you draw circles with mouse clicks //************** import java.awt.*; import java.awt.event.*; import java.io.*; /** A Frame that lets you draw circles with mouse clicks  *  and then save the Frame and all circles to disk.  * public class SavedFrame extends CloseableFrame                         implements ActionListener {     /** If …

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FrameExample1.java and 2

****************** # FrameExample1.java ****************** import java.awt.*; /**  */ public class FrameExample1 {   public static void main(String[] args) {     Frame f = new Frame(“Frame Example 1”);     f.setSize(400, 300);     f.setVisible(true);   } } ********************* # FrameExample2.java ********************* import java.awt.*; /**  */ public class FrameExample2 extends Frame {   public static void main(String[] args) …

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ThreadedRSAKey.java Illustrates converting a method in an existing class from a single-threaded method to a multi-threaded method.

ThreadedRSAKey.java  Illustrates converting a method in an existing class from a single-threaded method to a multi-threaded method. In this example, RSAKey  computes an RSA public-private key pair, where the key size has a specified number of digits. As large prime numbers require considerable CPU time, ThreadedRSAKey converts the original computeKey method in RSAKey  to a …

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Eight ungrouped buttons in an Applet using FlowLayout

mport java.applet.Applet; import java.awt. *; ************************** /** Eight ungrouped buttons in an Applet using FlowLayout. * */ public class ButtonTest1 extends Applet { public void init() { String[] labelPrefixes = { “Start”, “Stop”, “Pause”, “Resume” }; for (int i=0; i<4; i++) { add(new Button(labelPrefixes[i] + ” Thread1″)); } for (int i=0; i<4; i++) { add(new …

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A Circle component built using a Canvas

import java.awt.*; /** A Circle component built using a Canvas.  *   */ public class Circle extends Canvas {   private int width, height;                    public Circle(Color foreground, int radius) {     setForeground(foreground);     width = 2*radius;     height = 2*radius;     setSize(width, height);   }   public void paint(Graphics g) { …

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Simplifies the setting of native look and feel

WindowUtilities.java Simplifies the setting of native look and feel. #################### import javax.swing.*; import java.awt.*;   // For Color and Container classes. /** A few utilities that simplify using windows in Swing.  * ################### public class WindowUtilities {   /** Tell system to use native look and feel, as in previous    *  releases. Metal (Java) LAF …

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Using the this reference in class Ship3

/./././././././././. // Give Ship3 a constructor to let the instance variables // be specified when the object is created. /./././././././././ class Ship3 {   public double x, y, speed, direction;   public String name;   public Ship3(double x, double y, double speed,                double direction, String name) {     this.x = x; // “this” differentiates …

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DashedStrokeExample.java Draws a circle with a dashed line segment (border). Inherits from FontExample.java.

>>>>>>>>>>>>>>>>> import java.awt.*; /** An example of creating a custom dashed line for drawing.  *  ********************* public class DashedStrokeExample extends FontExample {   public void paintComponent(Graphics g) {     clear(g);     Graphics2D g2d = (Graphics2D)g;     drawGradientCircle(g2d);     drawBigString(g2d);     drawDashedCircleOutline(g2d);   }   protected void drawDashedCircleOutline(Graphics2D g2d) {     g2d.setPaint(Color.blue);     // 30-pixel line, …

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draws a circle wherever mouse was pressed

CircleListener.java A subclass of MouseAdapter that draws a circle wherever mouse was pressed. Illustrates first approach to event-handling with listeners: attaching a separate listener *********** import java.applet.Applet; import java.awt.*; import java.awt.event.*; /** The listener used by CircleDrawer1. Note call  *  to getSource to obtain reference to the applet.  *    *************** public class CircleListener extends …

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