Develop Reference

Changing the sizes of a coloured square after pressing a button

I have written this code however I am having trouble with one aspect I wish to code into it. I want to make the green square change size when I press one of the three buttons I have so when I press the button 'small' the square changes size to small e.g. 100 and when I press the button 'medium' it changes size to medium e.g. 400. This is my code so far:
package Lab2;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Main {
public static void main(String[] args) {
FilledFrame frame = new FilledFrame();
frame.setVisible( true );
}
}
class FilledFrame extends JFrame {
int size = 400;
public FilledFrame()
{
JButton butSmall = new JButton("Small");
JButton butMedium = new JButton("Medium");
JButton butLarge = new JButton("Large");
JButton butMessage = new JButton("Say Hi");
SquarePanel panel = new SquarePanel(this);
JPanel butPanel = new JPanel();
butPanel.add(butSmall);
butPanel.add(butMedium);
butPanel.add(butLarge);
butPanel.add(butMessage);
add(butPanel, BorderLayout.NORTH);
add(panel, BorderLayout.CENTER);
setSize( size+100, size+100 ); } }
class SquarePanel extends JPanel {
FilledFrame theApp;
SquarePanel(FilledFrame app)
{
theApp = app;
}
public void paintComponent ( Graphics g)
{
super.paintComponent(g);
g.setColor(Color.green);
g.fillRect(20, 20, theApp.size, theApp.size);
}
}
class buttonHandler implements ActionListener {
FilledFrame theApp;
int size;
public buttonHandler(FilledFrame app, int size) {
theApp = app;
this.size = size;
}
#Override
public void actionPerformed (ActionEvent e){
theApp.setSize(this.size, this.size);
}
}

As I don't see any event listeners for your buttons, I assume this is all the code you have. Your buttons will not do anything unless you tell them to do it. You need to add event listeners, and through that change the size and update the panel.
Example:
button.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
theApp.size = 200;
frame.getContentPane().repaint();
//OR frame.repaint();
}
});
EDIT:
The problem with using the button handler class is you would need to find which buttton was pressed, instead its easier to use the way I showed above. I edited the code above, try copy pasting to one of the buttons.

How can I switch between jpanels?

I'm still very new to java programming, so please help me to correct any mistakes I might have overlooked or give tips on how to improve this program.
Okay, so a lot of problems have been solved, and now I have a CardLayout, but I still have questions about how I should make my pipes show inside it.
When I tried to add in my refresh rate timer and my speed timer, I have problems about how I need to declare and initialize boolean variables.
Also, when I compile and run this game, I get files such as Game$1.class. Is there a way for me to clean this up, and could someone explain why this happens? Do these have an affect on the finished product? (When the game is compiled and packaged into a JAR.)
I want to set playerIsReady to true when the play button is clicked. And from there, when the if statement is true, then switch to a panel that displays the pipes, and start moving the pipe across the screen. Preferably 3 instances of that pipe, each starting at different times, but whatever you can help with is fine.
Some of this code needs work, so I have commented some parts out and left notes.
My other questions about this game can be found here.
This is my current code
Game.java
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.border.EmptyBorder;
import javax.swing.SwingUtilities;
public class Game {
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
// the GUI as seen by the user (without frame)
final CardLayout cl = new CardLayout();
final JPanel gui = new JPanel(cl);
// remove if no border is needed
gui.setBorder(new EmptyBorder(10,10,10,10));
JPanel menu = new JPanel(new GridBagLayout());
JButton playGame = new JButton("Play!");
ActionListener playGameListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
cl.show(gui, "game");
}
};
playGame.addActionListener(playGameListener);
Insets margin = new Insets(20, 50, 20, 50);
playGame.setMargin(margin);
menu.add(playGame);
gui.add(menu);
cl.addLayoutComponent(menu, "menu");
final JPanel pipes = new Pipes();
gui.add(pipes);
cl.addLayoutComponent(pipes, "game");
JFrame f = new JFrame("Pipes Game");
f.add(gui);
// Ensures JVM closes after frame(s) closed and
// all non-daemon threads are finished
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// See https://stackoverflow.com/a/7143398/418556 for demo.
f.setLocationByPlatform(true);
// ensures the frame is the minimum size it needs to be
// in order display the components within it
f.pack();
// should be done last, to avoid flickering, moving,
// resizing artifacts.
f.setVisible(true);
/*if (playerIsReady) {
Timer speed = new Timer(10, new ActionListener() { //pipe speed
#Override
public void actionPerformed(ActionEvent e) {
pipes.move();
}
});
speed.start();
Timer refresh = new Timer(30, new ActionListener() { //refresh rate
#Override
public void actionPerformed(ActionEvent e) {
pipes.repaint();
}
});
refresh.start();
}*/
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency
SwingUtilities.invokeLater(r);
}
}
Pipes.java
// What import(s) do I need for ArrayList?
public class Pipes {
List<Pipe> pipes = new ArrayList<Pipe>();
public Pipes() {
pipes.add(new Pipe(50, 100));
pipes.add(new Pipe(150, 100));
pipes.add(new Pipe(250, 100));
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for ( Pipe pipe : pipes ){
pipe.drawPipe(g);
}
}
}
PipeObject.java
import java.awt.Graphics;
public class PipeObject {
//Declare and initialiaze variables
int x1 = 754; //xVal start
int x2 = 75; //pipe width
//total width is 83
int y1 = -1; //yVal start
int y2 = setHeightVal(); //pipe height
int gap = 130; //gap height
public void drawPipe(Graphics g) {
g.clearRect(0,0,750,500); //Clear screen
g.drawRect(x1,y1,x2,y2); //Draw part 1
g.drawRect(x1-3,y2-1,x2+6,25); //Draw part 2
g.drawRect(x1-3,y2+25+gap,x2+6,25); //Draw part 3
g.drawRect(x1,y2+25+gap+25,x2,500-y2-49-gap); //Draw part 4
}
public void move() {
x1--;
}
public int getMyX() { //To determine where the pipe is horizontally
return x1-3;
}
public int getMyY() { //To determine where the pipe is vertically
return y2+25;
}
public int setHeightVal() { //Get a random number and select a preset height
int num = (int)(9*Math.random() + 1);
int val = 0;
if (num == 9)
{
val = 295;
}
else if (num == 8)
{
val = 246;
}
else if (num == 7)
{
val = 216;
}
else if (num == 6)
{
val = 185;
}
else if (num == 5)
{
val = 156;
}
else if (num == 4)
{
val = 125;
}
else if (num == 3)
{
val = 96;
}
else if (num == 2)
{
val = 66;
}
else
{
val = 25;
}
return val;
}
}

The best way to approach this is using a CardLayout.
Notes
A button with an ActionListener is far better than a MouseListener over a rectangle.
The button will show focus when the mouse is pointed at it, or the component is tabbed to via the keyboard.
The button is keyboard accessible.
The button has facility to support multiple icons built in (e.g. for 'initial look', focused, pressed etc.)
White space in the GUI is provided around the menu panel and game by adding an EmptyBorder
The button is made larger by setting a margin.
Adjust margins, borders and preferred size according to need. These sizes were set by me so as not to make the screenshots too large.
See more tips in the code comments.
Code
Here is the MCTaRE (Minimal Complete Tested and Readable Example) that produced the above screenshots.
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class PipesGame {
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
// the GUI as seen by the user (without frame)
final CardLayout cl = new CardLayout();
final JPanel gui = new JPanel(cl);
// remove if no border is needed
gui.setBorder(new EmptyBorder(10,10,10,10));
JPanel menu = new JPanel(new GridBagLayout());
JButton playGame = new JButton("Play!");
ActionListener playGameListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
cl.show(gui, "game");
}
};
playGame.addActionListener(playGameListener);
Insets margin = new Insets(20, 50, 20, 50);
playGame.setMargin(margin);
menu.add(playGame);
gui.add(menu);
cl.addLayoutComponent(menu, "menu");
JPanel pipes = new Pipes();
gui.add(pipes);
cl.addLayoutComponent(pipes, "game");
JFrame f = new JFrame("Pipes Game");
f.add(gui);
// Ensures JVM closes after frame(s) closed and
// all non-daemon threads are finished
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// See https://stackoverflow.com/a/7143398/418556 for demo.
f.setLocationByPlatform(true);
// ensures the frame is the minimum size it needs to be
// in order display the components within it
f.pack();
// should be done last, to avoid flickering, moving,
// resizing artifacts.
f.setVisible(true);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency
SwingUtilities.invokeLater(r);
}
}
class Pipes extends JPanel {
Pipes() {
setBackground(Color.BLACK);
setForeground(Color.WHITE);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawString("Pipes game appears here..", 170, 80);
}
#Override
public Dimension getPreferredSize() {
// adjust to need
return new Dimension(500,150);
}
}

"Is there a way for me to add my GameMenu jpanel to my jframe, and then replace it with the Pipes jpanel?"
As other have suggested, for this you want a CardLayout. It is very simple to you. Personally, I always wrap my CardLayout in a JPanel rather than the JFrame, just force of habit.
What you want to do is have a mainPanel that will have the CardLayout
CardLayout card = new CardLayout();
JPanel mainPanel = new JPanel();
Then you want to add your panels to the mainPanel. What the CardLyaout does is layer the panels, making just one visible at a time. The first one you add, will the in the foreground. Also when you add the panel, you'll also want to issue it a key it can be called from. The key, can be any String you like.
mainPanel.add(gameMenu, "menu");
mainPnael.add(pipes, "pipe");
Now gameMenu is the only panel shown. To show pipes, all you do is use this method
public void show(Container parent, String name) - Flips to the parent that was added to this layout with the specified name, using addLayoutComponent. If no such component exists, then nothing happens.
So you'd use, card.show(mainPanel, "pipes");
Whatever even you want to trigger the showing of pipes, just add that line in that event handler. You could add a button or something to the GameMenu that will allow movement to the Pipes panel.

This works with a mouse click on the menu. You can change it later, to a click on some button or whatever you want.
I added a MouseListener to the Game class. When the user presses the mouse on the menu JPanel, it adds the Pipes JPanel to JFrame and calls the pack method.
Game.java:
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Rectangle2D;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class Game {
GameMenu menu = new GameMenu();
Pipes game;
boolean start = false;
JFrame f;
Rectangle2D menuRect = new Rectangle2D.Double(20, 20, 60, 40);
public Game() {
f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(menu);
f.setTitle("Pipe Game");
f.setResizable(false);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
menu.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
Point click = new Point(e.getX(), e.getY());
System.out.println("Clicked on the Panel");
if(menuRect.contains(click))
{
System.out.println("Clicked inside the Rectangle.");
start = true;
menu.setVisible(false);
game = new Pipes();
f.add(game);
f.pack();
Timer timer = new Timer(10, new ActionListener() { //pipe speed
#Override
public void actionPerformed(ActionEvent e) {
game.move();
}
});
timer.start();
Timer refresh = new Timer(30, new ActionListener() { //refresh rate
#Override
public void actionPerformed(ActionEvent e) {
game.repaint();
}
});
refresh.start();
}
}
#Override
public void mouseReleased(MouseEvent e) {
}
});
}
public static void main(String args[]) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Game();
}
});
}
}

Using AWT Buttons and detecting if clicked

I just joined, and am glad to be here~ So, this morning (at like 2am, but thats besides the point :P ) I was doing a little bit of Java tests with JFrame and other GUI stuff. This is my first time working with GUIs. I was trying to make a little java app that would act as a dream journaller. However, my progress was frozen when I encountered a problem i could not solve. My code is as follows.
import java.awt.*;
import javax.swing.*;
import java.applet.*;
public class Display extends Canvas
{
static final int WIDTH = 600;
static final int HEIGHT = 400;
public static String defaultEntry = "Dreams...";
public static final String TITLE = "Dream Journal Testing";
Button erase;
public static void main(String[] args)
{
Display d = new Display();
d.create();
}
public void create()
{
JFrame frame = new JFrame();
System.out.println("Running");
Panel cardOne = new Panel();
Panel p1 = new Panel();
Panel p2 = new Panel();
Panel p3 = new Panel();
Panel grid = new Panel();
cardOne.setLayout(new BorderLayout());
p1.setLayout(new GridLayout(2,1,3,6));
TextArea textArea1 = new TextArea(defaultEntry);
/*Font f1 = new Font("Courier", Font.PLAIN, 16);
setFont(f1);*/
Label l1 = new Label("Welcome to the Dream Journal! :)");
Label l2 = new Label("Type your dream below:");
p1.add(l1);
p1.add(l2);
p2.add(textArea1);
p3.setLayout(new FlowLayout(FlowLayout.CENTER));
Button ok = new Button("Save");
erase = new Button("Erase");
p3.add(erase);
p3.add(ok);
cardOne.add("North",p1);
cardOne.add("Center",p2);
cardOne.add("South",p3);
frame.add(cardOne);
//frame.add(cardOne);
//frame.setLocationRelativeTo(null);
frame.pack();
frame.setTitle(TITLE);
frame.setSize(WIDTH, HEIGHT);
frame.setResizable(false);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
System.out.println(textArea1.getText());
}
/*public boolean handleEvent(Event evt)
{
if(evt.target == erase)
{
System.out.println("it works");
return true;
}
else return super.handleEvent(evt);
}
*/
public boolean action(Event evt, Object arg)
{
if("Erase".equals(arg))
{
System.out.println("hello");
//textArea1.setText("");
}
return true;
}
}
The problem i have is I am not able to figure out how to make it so if the "Erase" AWT button is pushed, the system will print a line (as a test). I have tried
public boolean action(Event evt, Object arg)
And
public boolean handleEvent, but neither worked. Anyone have any suggestions for the Java noob that is me? Thanks!! :)

One way is to add an action listener to the button (e.g. for Save). Another way is to create an Action (e.g. for Erase).
Don't mix Swing with AWT components unless it is necessary. It is not worth even learning how to use AWT components at this point in time, use Swing only for best results and best help.
Here is a version of the app. using all Swing components.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Display
{
static final int WIDTH = 600;
static final int HEIGHT = 400;
public static String defaultEntry = "Dreams...";
public static final String TITLE = "Dream Journal Testing";
JButton erase;
public static void main(String[] args)
{
Display d = new Display();
d.create();
}
public void create()
{
JFrame frame = new JFrame();
System.out.println("Running");
JPanel cardOne = new JPanel();
JPanel p1 = new JPanel();
JPanel p2 = new JPanel();
JPanel p3 = new JPanel();
cardOne.setLayout(new BorderLayout());
p1.setLayout(new GridLayout(2,1,3,6));
JTextArea textArea1 = new JTextArea(defaultEntry);
JLabel l1 = new JLabel("Welcome to the Dream Journal! :)");
JLabel l2 = new JLabel("Type your dream below:");
p1.add(l1);
p1.add(l2);
p2.add(textArea1);
p3.setLayout(new FlowLayout(FlowLayout.CENTER));
JButton ok = new JButton("Save");
ok.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent ae) {
System.out.println("Do " + ae.getActionCommand());
}
});
erase = new JButton(new EraseAction());
p3.add(erase);
p3.add(ok);
// Use the constants
cardOne.add(BorderLayout.PAGE_START,p1);
cardOne.add(BorderLayout.CENTER,p2);
cardOne.add(BorderLayout.PAGE_END,p3);
frame.add(cardOne);
frame.pack();
frame.setTitle(TITLE);
frame.setSize(WIDTH, HEIGHT);
frame.setResizable(false);
frame.setLocationByPlatform(true);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
System.out.println(textArea1.getText());
}
}
class EraseAction extends AbstractAction {
EraseAction() {
super("Erase");
}
#Override
public void actionPerformed(ActionEvent arg0) {
System.out.println("Do " + arg0.getActionCommand());
}
}

First let me explain you the Funda of Event Handler....
- First of all there are Event Source, when any action take place on the Event Source, an Event Object is thrown to the call back method.
- Call Back method is the method inside the Listener (Interface) which is needed to be implemented by the Class that implements this Listener.
- The statements inside this call back method will dictate whats needed to be done, when the action is done on the Event Source.
Eg:
Assume
Event Source - Button
When Clicked - Event object is thrown at the call back method
Call back method - actionPerformed(ActionEvent e) inside ActionListener.
Now your case :
Now this can be done in 2 ways.....
1. Let you Display class implements the ActionListener, then Register the button with
the ActionListener, and finally implement the abstract method actionPerformed() of ActionListener.
Eg:
public class Display extends Canvas implements ActionListener{
public Display(){
// Your code....
setComponent(); // Initializing the state of Components
}
public void setComponent(){
// Your code.........
Button b = new Button("Click");
b.addActionListener(this); // Registering the button.
// Your code..........
}
public void actionPerformed(ActionEvent event) {
// Do here whatever you want on the Button Click
}
}
2. Use Anonymous class.
- Anonymous class are declared and initialized simultaneously.
- Anonymous class must implement or extend to only one interface or class resp.
Your Display class will NOT implement ActionListener here....
public class Display extends Canvas {
public Display(){
// Your code....
setComponent(); // Initializing the state of Components
}
public void setComponent(){
// Your code.........
Button b = new Button("Click");
// Registering the button and Implementing it
b.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent event) {
// Do here whatever you want on the Button Click
}
});
// Your code..........
}
}

You need to implement ActionListner :
public class Display extends Canvas implements ActionListener
and add yourself to your button as such:
erase.addActionListener(this);
and then implement the required method:
public void actionPerformed(ActionEvent event) {
//do stuff
}
For more info, check out this tutorial on creating ActionListeners.
You'll find that this observable pattern is widely used the in Java GUI.
A couple high level critiques:
You are using many older AWT components (ie Button) when there are similar, but newer (read: more flexible) Swing components available (ie JButton). Take a look at this for a quick explanation on the difference.
The event model that you have implemented was revamped in 1997 to the observable pattern that I suggested above. If you would like to learn more, you can read this.

Base and extended windows in Java using inheritance

I've got one class called WindowTemplate that is the base for other (more complex) windows. It is an abstract class and then I'm trying to use the "extend" trick to add more stuff to the new window, keeping the original "skeleton". That is my problem though, because if I run WindowTemplate.createWindow(); or a_Welcome.createWindow(); (they should be point to the same thing), I get my "base" window. But when I run a_Welcome window = new a_Welcome(); (what should be the base + new stuff) I get only the extra bits that I added without the original features. Here is my code:
package windows;
import java.awt.*;
import javax.swing.*;
public abstract class WindowTemplate extends JFrame {
/**
* Create the GUI and show it. For thread safety, this method should be
* invoked from the event-dispatching thread.
*/
public static void createWindow() {
JFrame myFrame = new JFrame("My first window");
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
myFrame.setVisible(true);
myFrame.setSize(550, 450);
myFrame.setLocationRelativeTo(null);
// JLabel emptyLabel = new JLabel("");
// emptyLabel.setPreferredSize(new Dimension(550, 450));
// myFrame.getContentPane().setLayout(new CardLayout());
// myFrame.getContentPane().add(emptyLabel, BorderLayout.CENTER);
// myFrame.pack();
}
}
the class with new window and some extra stuff (ignore a_):
package windows;
import java.awt.*;
import javax.swing.*;
public class a_Welcome extends WindowTemplate {
public a_Welcome() {
JPanel area = new JPanel();
JLabel text = new JLabel("One line another line and another line"); // , JLabel.CENTER);
// text.setBounds(80, 400, 400, 50);
add(area);
// area.setLayout(null);
area.add(text, new CardLayout());
// area.add(text); // , BorderLayout.CENTER);
Font font = new Font("SansSerif", Font.BOLD, 30);
text.setFont(font);
text.setForeground(Color.green);
area.setBackground(Color.darkGray);
area.setSize(550, 450);
}
}
// timer-after 5 seconds-go to the next window (countdown in the bottom right corner)
and the main:
package windows;
public class Launcher {
public static void main(String[] args) {
// Schedule a job for the event-dispatching thread:
// creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
// WindowTemplate.createWindow();
// a_Welcome.createWindow();
a_Welcome window = new a_Welcome();
window.setVisible(true);
}
});
}
}
Thanks for your help!

Static method createWindow() always creates a new JFrame which is not a superclass of the WindowTemplate. Constructor of the a_Window is adding components to the WindowTemplate which hasn't been initialized since the static createWindow() creates an independent frame.
I would suggest you to change the static createWindow() into WindowTemplate constructor and try running main once again.
package windows;
import java.awt.*;
import javax.swing.*;
public abstract class WindowTemplate extends JFrame {
/**
* Create the GUI and show it. For thread safety, this method should be
* invoked from the event-dispatching thread.
*/
public WindowTemplate () {
JFrame myFrame = new JFrame("My first window");
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
myFrame.setVisible(true);
myFrame.setSize(550, 450);
myFrame.setLocationRelativeTo(null);
// JLabel emptyLabel = new JLabel("");
// emptyLabel.setPreferredSize(new Dimension(550, 450));
// myFrame.getContentPane().setLayout(new CardLayout());
// myFrame.getContentPane().add(emptyLabel, BorderLayout.CENTER);
// myFrame.pack();
}
}

You have another JFrame defined in the static createWindow() method. This means that you are adding the components to this frame that is scoped to the createWindow() method only and in the constructor you are adding to the a_Welcome instance.
You should do something like this
public class BaseWindow() {
//Constructor
public BaseWindow() {
init();
}
public void init() {
//add basic components
}
}
public class SubClassWindow() {
public SubClassWindow() {
super();
}
#Override
public void init() {
super.init(); //important so you get the base stuff
//add other components
}
}
Code not tested.

Another approach you might consider would be to have a JFrame that is just a wrapper and compose the window by adding a panel. Let's say you want a toolbar at the top of every window you're creating. Each window would have different buttons on the toolbar and a different set of components at the bottom. This way you are doing composition instead of inheritance, because inheritance can get ugly later on. (For discussions on that point, see this, this, and this for starters)
That would look something like:
public interface AppPanel {
List<JButton> getToolbarButtons();
boolean okToClose();
JPanel getGui();
}
public MyPanel extends JPanel implements AppPanel {
//standard swing components stuff set up here
public List<JButton> getToolbarButtons() {
//set up buttons and their actions
return buttonList;
}
public boolean okToClose() {
//ask user if they want to save, etc.
return true;
}
public JPanel getGui() {
return this;
}
}
public AppFrame extends JFrame {
private AppPanel panel;
public static AppFrame createFrame(AppPanel panel) {
AppFrame frame = new AppFrame(panel);
return frame;
}
public AppFrame(AppPanel panel) {
super();
this.panel = panel;
add(panel.getGui(), someLayoutConstraints);
panel.getToolbarButtons(); //do stuff with the buttons
//...
this.addWindowListener(new WindowAdapter() {
public void WindowClosing(WindowEvent e) {
if (panel.isOkToClose()) {
setVisible(false);
}
}
});
}
}

Calling awt Frame methods from subclass

This question is about Frames, Java and Processing.
This questions sounds pretty convoluted but its really not. I'll try keep this to a simple minimum. I'm creating a small ball in a maze game to get my head around physics and rendering. It's been a good experience so far but I've hit a bit of a brick wall.
The general layout I decided on was to contain PApplets within a AWT Frame and have the Frame close. The reason for this is because I was told that you should only have on instance of a Papplet at a time.
PApplet is the Applet class in Processing, a rendering library.
I have 3 classes here including the main
public class Menu extends PApplet
{
//images and buttons
PImage background, playbtn1, playbtn2, hsbtn1, hsbtn2, abbtn1, abbtn2, exbtn1, exbtn2;
FBox pBtn, hBtn, eBtn;
FWorld menu;
//simple constructor
public Menu()
{
}
public void setup()
{
size(600, 400);
smooth();
Fisica.init(this);
menu = new FWorld();
//loading and placing images
background = loadImage("MenuAlt.jpg");
System.out.println(background);
playbtn1 = loadImage("play1.gif");
playbtn2 = loadImage("play2.gif");
hsbtn1 = loadImage("high1.gif");
hsbtn2 = loadImage("high2.gif");
exbtn1 = loadImage("exit1.gif");
exbtn2 = loadImage("exit2.gif");
//loading and placing buttons
pBtn = new FBox(120, 150);
pBtn.setPosition(135, 215);
pBtn.setDrawable(false);
hBtn = new FBox(120, 150);
hBtn.setPosition(295, 215);
hBtn.setDrawable(false);
eBtn = new FBox(120, 150);
eBtn.setPosition(455, 215);
eBtn.setDrawable(false);
//add item to world
menu.add(pBtn);
menu.add(hBtn);
menu.add(eBtn);
}
public void draw()
{
image(background, 0, 0);
image(playbtn1, 80, 140);
image(hsbtn1, 237, 135);
image(exbtn1, 400, 140);
mouseOver();
menu.draw();
}
//close this frame an open a new level, high score or exit
//depending on what the use clicks
public void mousePressed()
{
FBody pressed = menu.getBody(mouseX, mouseY);
if (pressed == pBtn)
{
System.out.println("play game");
this.getParent().getParent().getParent().getParent().setVisible(false);
ExampleFrame x = new ExampleFrame(new Level("level1.txt"));
x.setLocation(this.getParent().getParent().getParent().getParent().getLocation());
}
if (pressed == hBtn)
{
System.out.println("high scores");
this.getParent().getParent().getParent().getParent().setVisible(false);
/* these are just for finding the parent
System.out.println(this.getName());
System.out.println(this.getParent().getName());
System.out.println(this.getParent().getParent().getName());
System.out.println(this.getParent().getParent().getParent().getName());
System.out.println(this.getParent().getParent().getParent().getParent().getName());
*/
ExampleFrame x = new ExampleFrame(new HighScores()); //for testing, you can change this to new menu()
x.setLocation(this.getParent().getParent().getParent().getParent().getLocation());
}
if (pressed == eBtn)
{
System.out.println("exit");
System.exit(0);
}
}
the exampleFrame class
public class ExampleFrame extends JFrame
{
PApplet app;
public ExampleFrame(PApplet emApp)
{
super("Ball Maze Game");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLocation(200, 200);
app = emApp;
setSize(615,438);
setVisible(true);
setLayout(new BorderLayout());
add(app, BorderLayout.CENTER);
app.init();
}
}
the main
public class Main
{
public static void main(String[] args)
{
ExampleFrame x = new ExampleFrame(new Menu());
}
}
What needs to happen when mousePressed == ebtn is all the stuff in the Frame will be removed and a Highscores Screen will be loaded. highscores is almost the same as menu. There is no need to post code as there is enough here.
The second class is the one which acts as a frame and holds the PApplet
Bottom line, has anyone have any idea how to call the Frame methods from the PApplet or another way to remove all PApplets contents and load another PApplet in?

What needs to happen when mousePressed == ebtn is all the stuff in the Frame will be removed and a Highscores Screen will be loaded
The demo. below of a nested CardLayout adds an ActionListener instead of a MouseListener. It reacts to both mouse and keyboard input.
There are a multitude of other ways to include more than one GUI element in the same screen space. Off the top of my head, JTabbedPane, JSplitPane, JDesktopPane/JInternalFrame, popping the high scores in a JDialog or JOptionPane..
Screenshots
CardLayoutDemo.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class CardLayoutDemo {
public static void main(String[] args) {
Runnable r = new Runnable () {
public void run() {
final JRadioButton game = new JRadioButton("Game", true);
JRadioButton highScores = new JRadioButton("High Scores");
ButtonGroup bg = new ButtonGroup();
bg.add( game );
bg.add( highScores );
JPanel buttons = new JPanel(new
FlowLayout(FlowLayout.CENTER, 5, 5));
buttons.add( game );
buttons.add( highScores );
JPanel gui = new JPanel(new BorderLayout(5,5));
gui.add(buttons, BorderLayout.SOUTH);
final CardLayout cl = new CardLayout();
final JPanel cards = new JPanel(cl);
gui.add(cards);
cards.add(new JLabel("Level 1"), "game");
cards.add(new JLabel("High Scores"), "scores");
ActionListener al = new ActionListener(){
public void actionPerformed(ActionEvent ae) {
if (game.isSelected()) {
cl.show(cards, "game");
} else {
cl.show(cards, "scores");
}
}
};
game.addActionListener(al);
highScores.addActionListener(al);
JOptionPane.showMessageDialog(null, gui);
}
};
SwingUtilities.invokeLater(r);
}
}

In order to answer How to call the Frame methods from the PApplet?, I have modified your code snippet to bare minimum. In this modified version when the user click mouse button a System.out is fired.
Now there are two ways in which you can access your Frame object. But before that let me state these two points:
When you create a PApplet like new ExampleFrame(new Menu()); and add it in your JFrame like this add(app, BorderLayout.CENTER); then a complex hierarchy of windows/panels are created.
Like this:
javax.swing.JPanel
javax.swing.JLayeredPane
javax.swing.JRootPane
test.ExampleFrame
PApplet provides a public field for setting and accessing your frame object. And amazingly it is called frame :). You can set it before calling app.init();
>>Code
** Checkout the comments in the code**
Modified ExampleFrame.java
import java.awt.BorderLayout;
import javax.swing.JFrame;
import processing.core.PApplet;
public class ExampleFrame extends JFrame
{
private static final long serialVersionUID = 4792534036194728580L;
PApplet app;
public ExampleFrame(PApplet emApp)
{
super("Ball Maze Game");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLocation(200, 200);
app = emApp;
setSize(615,438);
setVisible(true);
setLayout(new BorderLayout());
add(app, BorderLayout.CENTER);
// Setting my frame object
app.frame = this;
app.init();
}
// Sample Method
public void sampleMethod(String msg)
{
System.out.println("I think '"+ msg +"' called me !!");
}
}
Modified Menu.java
import java.awt.Container;
import processing.core.PApplet;
import processing.core.PImage;
public class Menu extends PApplet
{
private static final long serialVersionUID = -6557167654705489372L;
PImage background;
static String tab = "";
//simple constructor
public Menu()
{
}
public void setup()
{
size(600, 400);
smooth();
background = loadImage("C:/temp/background.jpg");
}
public void draw()
{
image(background, 0, 0);
}
public void mousePressed()
{
Container p = getParent();
tab = "";
// FIRST WAY OF ACCESSING PARENT FRAME
while(p != null)
{
//printParentTree(p);
if(p instanceof ExampleFrame)
{
ExampleFrame myframe = (ExampleFrame)p;
myframe.sampleMethod("First Way");
break;
}
p = p.getParent();
}
// SECOND WAY OF ACCESSING PARENT FRAME
if(frame != null && (frame instanceof ExampleFrame))
{
ExampleFrame myframe = (ExampleFrame)p;
myframe.sampleMethod("Second Way");
}
}
void printParentTree(Container p)
{
System.out.println(tab+p.getClass().getName());
tab +='\t';
}
}
Checkout the public void mousePressed() method.
For completeness, I am also including Main.java.
public class Main {
public static void main(String[] args){
new ExampleFrame(new Menu());
}
}
Now to answer Remove all PApplets contents and load another PApplet in
Well I have not tested it. But you can add a JPanel to your JApplet and do all your drawing on that i.e creating child controls etc. When feel like redrawing then call JPanel.removeAll(). Which as per javadoc:
Removes all the components from this
container. This method also notifies
the layout manager to remove the
components from this container's
layout via the removeLayoutComponent
method.
After this call repaint on the JPanel. Try it out, it might work :).