JMenuBar with paint method

Question

I'm having trouble getting my JMenuBar to appear alongside my paint() method.

package Main;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;

public class Main extends JFrame{

int x, y; // axis position for oval

//JMenuBar Variables
JMenuBar menuBar;
JMenu file;
JMenuItem newGame;
JMenuItem checkScore;
JMenuItem exitGame;

// DOUBLE BUFFERING
private Image dbImage;
private Graphics dbGraphics;

Font font = new Font("Arial", Font.ITALIC, 30);

// KeyListener Class
public class KeyListener extends KeyAdapter {
    public void keyPressed(KeyEvent e){
        int keyCode = e.getKeyCode();
        if(keyCode == e.VK_LEFT){
            if(x <=0){ // FRAME COLLISION DETECTION 
                x=0;
            }else
            x += -5; //decrement position to the left 
        }
        if(keyCode == e.VK_RIGHT){
            if(x >= 380){
                x = 380;
            }else
            x += +5; //incrementing position to the right
        }
        if(keyCode == e.VK_UP){
            if (y <= 25){
                y = 25;
            }else
            y += -5; //decrementing position up
        }
        if(keyCode == e.VK_DOWN){
            if(y >= 380){
                y = 380;
            }else
            y += +5; //incrementing position down
        }
    }
}


// CONSTRUCTOR
public Main(){
// Window Properties
    addKeyListener(new KeyListener()); // creates instance of KeyListener class
    setTitle("Tower Defence");
    setSize(400, 400);
    setResizable(false);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    //setBackground(Color.CYAN);


// JMenuBar
    menuBar = new JMenuBar();
    file = new JMenu("File");
    newGame = new JMenuItem("New Game");
    checkScore = new JMenuItem("Check High Scores");
    exitGame = new JMenuItem("Close Game");

    menuBar.add(file);
    file.add(newGame);
    file.add(checkScore);
    file.addSeparator();
    file.add(exitGame);
    setJMenuBar(menuBar);

// Display frame after all components added
    setVisible(true);

// default position for oval
    x = 150;
    y = 150;

}


public void paint(Graphics g){
    dbImage = createImage(getWidth(), getHeight()); // creates image of screen
    dbGraphics = dbImage.getGraphics(); // gets graphics to be drawn in off screen image
    paintComponent(dbGraphics); // paints graphics
    g.drawImage(dbImage, 0, 0, this);  // draw image to the visible screen
}

    // PAINT GRAPHICS TO SCREEN
public void paintComponent(Graphics g){

    g.setFont(font);
    g.drawString("Hello World", 100, 200);

    g.setColor(Color.red);
    g.drawOval(x, y, 15, 15);
    g.fillOval(x, y, 15, 15);
    repaint();
}


// MAIN METHOD
public static void main(String[] args) {
    new Main();
}

}

I saw a different question where the solution was to override the paint method and add super.paint(g); when i tried this the JMenuBar appears but the frame keeps flickering constantly.

I suggest that you go through one of the graphics tutorials because it appears that you're guessing at some of this and are doing quite a few things wrong, including drawing directly on the JFrame, not calling the super method calling repaint() from within a paint method. Don't guess -- check out the tut's as they'll show you the proper way to do this. Please start here: [Lesson: Performing Custom Painting](http://docs.oracle.com/javase/tutorial/uiswing/painting/index.html) and then check this link here: [Painting in AWT and Swing](http://www.oracle.com/technetwork/java/painting-140037.html) — Hovercraft Full Of Eels, Dec 12 '12 at 18:08
I've been following tutorials on youtube, probably not the best idea.. — Sawyer05, Dec 12 '12 at 18:11
Please check my links. Also you don't want to do background/buffer painting in paint or paintComponent as it defeats the purpose of background painting. You should be drawing in a component that derives ultimately from JComponent such as a JPanel or JComponent itself, you should override paintComponent, not paint, you should call the super method,... — Hovercraft Full Of Eels, Dec 12 '12 at 18:11
Your flicker comes from your poor attempt at double buffering and that you're calling repaint from paint or paintComponent. Why not use a Swing Timer for the game loop and use Swing graphics of a JComponent's paintComponent method that has automatic double buffering? — Hovercraft Full Of Eels, Dec 12 '12 at 18:16
I was following TheJavaHub's beginners game development tutorials on youtube, im comfortable writing applications, with just buttons and text, etc but i don't know anything about Graphics, i will check out your links..Thanks for the info — Sawyer05, Dec 12 '12 at 18:23
again SO isn't code generator, did your read tutorials, tried code examples from tutorial, — mKorbel, Dec 12 '12 at 18:25
@mKorbel, at no point did i ask for a "code generator", I asked about a specific problem, which i researched beforehand and could not find the answer. perhaps you should go read the two first sections here http://stackoverflow.com/faq and tell me how my question does not fit the rules. — Sawyer05, Dec 13 '12 at 15:39

David Kroukamp · Answer 1 · 2012-12-12T19:40:14.263

Dont extend JFrame unnecessarily
Dont overide any paint method of JFrame unnecessarily rathe add Jpanel and override paintComponent
Dont call repaint(...) in paintComponent(...) as this will cause a loop i.e repaint will re-call paintComponent and the cycle will carry on
Create and manipulate Swing components on Event Dispatch Thread
Dont call setSize(..) on JFrame rather override getPreferredSize and return an appropriate size which fits all drawings and than call JFrame#pack() before setting JFrame visible
Dont use KeyListener/KeyAdapter for Swing components rather use KeyBindings

Here is your code fixed:

enter image description here

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;

public class Main extends JPanel {

    int x, y; // axis position for oval
    //JMenuBar Variables
    JMenuBar menuBar;
    JMenu file;
    JMenuItem newGame;
    JMenuItem checkScore;
    JMenuItem exitGame;
    Font font = new Font("Arial", Font.ITALIC, 30);

    // KeyBindings Class
    public class KeyBindings {

        public KeyBindings(final JComponent jc) {
            jc.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0, false), "Right");
            jc.getActionMap().put("Right", new AbstractAction() {
                @Override
                public void actionPerformed(ActionEvent ae) {
                    if (x >= 380) {
                        x = 380;
                    } else {
                        x += +5; //incrementing position to the right
                    }
                    jc.repaint();

                }
            });

            jc.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0, false), "Left");
            jc.getActionMap().put("Left", new AbstractAction() {
                @Override
                public void actionPerformed(ActionEvent ae) {
                    if (x <= 0) { // FRAME COLLISION DETECTION 
                        x = 0;
                    } else {
                        x += -5; //decrement position to the left 
                    }
                    jc.repaint();

                }
            });
            jc.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0, false), "Up");
            jc.getActionMap().put("Up", new AbstractAction() {
                @Override
                public void actionPerformed(ActionEvent ae) {
                    if (y <= 25) {
                        y = 25;
                    } else {
                        y += -5; //decrementing position up
                    }
                    jc.repaint();

                }
            });
            jc.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0, false), "Down");
            jc.getActionMap().put("Down", new AbstractAction() {
                @Override
                public void actionPerformed(ActionEvent ae) {
                    if (y >= 380) {
                        y = 380;
                    } else {
                        y += +5; //incrementing position down
                    }
                    jc.repaint();

                }
            });
        }
    }

    // CONSTRUCTOR
    public Main() {
        // Window Properties
        JFrame frame = new JFrame();
        frame.setTitle("Tower Defence");
        frame.setResizable(false);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //setBackground(Color.CYAN);


        // JMenuBar
        menuBar = new JMenuBar();
        file = new JMenu("File");
        newGame = new JMenuItem("New Game");
        checkScore = new JMenuItem("Check High Scores");
        exitGame = new JMenuItem("Close Game");

        menuBar.add(file);
        file.add(newGame);
        file.add(checkScore);
        file.addSeparator();
        file.add(exitGame);

        JPanel panel = new JPanel() {
            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                Graphics2D g2 = (Graphics2D) g;
                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
                g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);

                g.setFont(font);
                g.drawString("Hello World", 100, 200);

                g.setColor(Color.red);
                g.drawOval(x, y, 15, 15);
                g.fillOval(x, y, 15, 15);
            }

            @Override
            public Dimension getPreferredSize() {
                return new Dimension(400, 400);
            }
        };
        //add keybindings
        new KeyBindings(panel);

        frame.add(panel);

        frame.setJMenuBar(menuBar);

        frame.pack();
        // Display frame after all components added
        frame.setVisible(true);

        // default position for oval
        x = 150;
        y = 150;

    }

    // MAIN METHOD
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new Main();
            }
        });
    }
}

@Sawyer05 please see update code is now fully functional i.e ball moves on keypressed — David Kroukamp, Dec 12 '12 at 18:59

score 4 · Accepted Answer · answered Dec 12 '12 at 18:40

Heck, I'll throw my code in the ring. Recs as per my comments. Also, don't use KeyListeners but rather Key Bindings.

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.RenderingHints;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;

import javax.swing.*;

@SuppressWarnings("serial")
public class Main2 extends JPanel {
   private static final int PREF_W = 400;
   private static final int PREF_H = PREF_W;
   private static final int OVAL_W = 15;
   private int x = 150;
   private int y = 150;
   private JMenuBar menuBar;
   private JMenu file;
   private JMenuItem newGame;
   private JMenuItem checkScore;
   private JMenuItem exitGame;
   private Font font = new Font("Arial", Font.ITALIC, 30);

   public Main2() {      
      menuBar = new JMenuBar();
      file = new JMenu("File");
      newGame = new JMenuItem("New Game");
      checkScore = new JMenuItem("Check High Scores");
      exitGame = new JMenuItem("Close Game");

      menuBar.add(file);
      file.add(newGame);
      file.add(checkScore);
      file.addSeparator();
      file.add(exitGame);

      addKeyBinding();
   }

   public JMenuBar getMenuBar() {
      return menuBar;
   }

   @Override
   public Dimension getPreferredSize() {
      return new Dimension(PREF_W, PREF_H);
   }

   @Override
   protected void paintComponent(Graphics g) {
      super.paintComponent(g);
      Graphics2D g2 = (Graphics2D) g;
      g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
            RenderingHints.VALUE_ANTIALIAS_ON);
      g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, 
            RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
      g.setFont(font);
      g.drawString("Hello World", 100, 200);

      g.setColor(Color.red);
      g.drawOval(x, y, OVAL_W, OVAL_W);
      g.fillOval(x, y, OVAL_W, OVAL_W);
   }

   private void addKeyBinding() {
      int condition = WHEN_IN_FOCUSED_WINDOW;
      InputMap inputMap = getInputMap(condition);
      ActionMap actionMap = getActionMap();

      for (final MyDirection dir : MyDirection.values()) {
         KeyStroke keyStroke = KeyStroke.getKeyStroke(dir.getKeyCode(), 0);
         inputMap.put(keyStroke, dir.toString());
         actionMap.put(dir.toString(), new AbstractAction() {

            @Override
            public void actionPerformed(ActionEvent evt) {
               int newX = x + dir.getxTrans();
               int newY = y + dir.getyTrans();

               newX = Math.min(newX, PREF_W - 2 * OVAL_W);
               newX = Math.max(newX, OVAL_W);
               newY = Math.min(newY, PREF_H - 2 * OVAL_W);
               newY = Math.max(newY, OVAL_W);

               x = newX;
               y = newY;
               repaint();
            }
         });
      }
   }

   enum MyDirection {
      UP(KeyEvent.VK_UP, 0, -5), DOWN(KeyEvent.VK_DOWN, 0, 5), 
      LEFT(KeyEvent.VK_LEFT, -5, 0), RIGHT(KeyEvent.VK_RIGHT, 5, 0);

      private int keyCode;
      private int xTrans;
      private int yTrans;

      private MyDirection(int keyCode, int xTrans, int yTrans) {
         this.keyCode = keyCode;
         this.xTrans = xTrans;
         this.yTrans = yTrans;
      }

      public int getKeyCode() {
         return keyCode;
      }

      public int getxTrans() {
         return xTrans;
      }

      public int getyTrans() {
         return yTrans;
      }


   }

   private static void createAndShowGui() {
      Main2 main = new Main2();

      JFrame frame = new JFrame("Main2");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(main);
      frame.setJMenuBar(main.getMenuBar());
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}

+1 I saw OP never even used KeyListener yet so left that out. +1 for the extra mile — David Kroukamp, Dec 12 '12 at 18:44
Thanks Hovercraft, there's quite a bit of stuff thats completely new to me in there, just tested it and its working great for me, i'll have a look over it, thanks again for the help! — Sawyer05, Dec 12 '12 at 18:45
Using the KeyListener or the Key Bindings as the game loop isn't elegant. Better to use a Swing Timer and then change direction based on the key binding action. — Hovercraft Full Of Eels, Dec 12 '12 at 18:46
Is there a disadvantage to using KeyListener rather than Key Bindings? — Sawyer05, Dec 12 '12 at 18:48
@Sawyer05 `KeyListener` has know focus issues with Swing, thus you may not have focus when expected and thus no Key events are recieved — David Kroukamp, Dec 12 '12 at 18:50
Thanks for the info guys, im following the lessons on the oracle website and im slowly beginning to understand what all your code means! — Sawyer05, Dec 12 '12 at 18:55

JMenuBar with paint method

2 Answers2