Search Results

Search found 382 results on 16 pages for 'setvisible'.

Page 16/16 | < Previous Page | 12 13 14 15 16 

  • game speed problem

    - by Meko
    HI..I made a little game.But this game works on every computer with different speed.I think it is about resolution.I used every thing in paintcomponent.and If I change screen size the game goes slower or faster.And if i run this game on another computer wich has different resolution it also works different. This is my game http://rapidshare.com/files/364597095/ShooterGame.2.6.0.jar and here code public class Shooter extends JFrame implements KeyListener, Runnable { JFrame frame = new JFrame(); String player; Font startFont, startSubFont, timerFont,healthFont; Image img; Image backGround; Graphics dbi; URL url1 = this.getClass().getResource("Images/p2.gif"); URL url2 = this.getClass().getResource("Images/p3.gif"); URL url3 = this.getClass().getResource("Images/p1.gif"); URL url4 = this.getClass().getResource("Images/p4.gif"); URL urlMap = this.getClass().getResource("Images/zemin.jpg"); Player p1 = new Player(5, 150, 10, 40, Color.GREEN, url3); Computer p2 = new Computer(750, 150, 10, 40, Color.BLUE, url1); Computer p3 = new Computer(0, 0, 10, 40, Color.BLUE, url2); Computer p4 = new Computer(0, 0, 10, 40, Color.BLUE, url4); ArrayList<Bullets> b = new ArrayList<Bullets>(); ArrayList<CBullets> cb = new ArrayList<CBullets>(); Thread sheap; boolean a, d, w, s; boolean toUp, toDown; boolean GameOver; boolean Level2; boolean newGame, resart, pause; int S, E; int random; int cbSpeed = 0; long timeStart, timeEnd; int timeElapsed; long GameStart, GameEnd; int GameScore; int Timer = 0; int timerStart, timerEnd; public Shooter() { sheap = new Thread(this); sheap.start(); startFont = new Font("Tiresias PCFont Z", Font.BOLD + Font.ITALIC, 32); startSubFont = new Font("Tiresias PCFont Z", Font.BOLD + Font.ITALIC, 25); timerFont = new Font("Tiresias PCFont Z", Font.BOLD + Font.ITALIC, 16); healthFont = new Font("Tiresias PCFont Z", Font.BOLD + Font.ITALIC, 16); setTitle("Shooter 2.5.1"); setBounds(350, 250, 800, 600); // setResizable(false); setBackground(Color.black); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); addKeyListener(this); a = d = w = s = false; toUp = toDown = true; GameOver = true; newGame = true; Level2 = false; S = E = 0; setVisible(true); } public void paint(Graphics g) { img = createImage(getWidth(), getHeight()); dbi = img.getGraphics(); paintComponent(dbi); g.drawImage(img, 0, 0, this); } public void paintComponent(Graphics g) { repaint(); timeStart = System.currentTimeMillis(); backGround = Toolkit.getDefaultToolkit().getImage(urlMap); g.drawImage(backGround, 0, 0, null); g.setColor(Color.red); g.setFont(healthFont); g.drawString("" + player + " Health : " + p1.health, 30, 50); g.setColor(Color.red); g.drawString("Computer Health : " + (p2.health + p3.health + p4.health), 600, 50); g.setColor(Color.BLUE); g.setFont(timerFont); g.drawString("Time : " + Timer, 330, 50); if (newGame) { g.setColor(Color.LIGHT_GRAY); g.setFont(startFont); g.drawString("Well Come To Shoot Game", 200, 190); g.drawString("Press ENTER To Start", 250, 220); g.setColor(Color.LIGHT_GRAY); g.setFont(startSubFont); g.drawString("Use W,A,S,D and Space For Fire", 200, 250); g.drawString("GOOD LUCK", 250, 280); newGame(); } if (!GameOver) { for (Bullets b1 : b) { b1.draw(g); } for (CBullets b2 : cb) { b2.draw(g); } update(); // Here MOvements for Player and For Fires } if (p1.health <= 0) { g.setColor(p2.col); g.setFont(startFont); g.drawString("Computer Wins ", 200, 190); g.drawString("Press Key R to Restart ", 200, 220); GameOver = true; } else if (p2.health <= 0 && p3.health <= 0 && p4.health <= 0) { g.setColor(p1.col); g.setFont(startFont); g.drawString(""+player+" Wins ", 200, 190); g.drawString("Press Key R to Resart ", 200, 220); GameOver = true; g.setColor(Color.MAGENTA); g.drawString(""+player+"`s Score is " + Timer, 200, 120); } if (Level2) { if (p3.health >= 0) { p3.draw(g); for (CBullets b3 : cb) { b3.draw(g); } } else { p3.x = 1000; } if (p4.health >= 0) { p4.draw(g); for (CBullets b4 : cb) { b4.draw(g); } } else { p4.x = 1000; } } if (p1.health >= 0) { p1.draw(g); } if (p2.health >= 0) { p2.draw(g); } else { p2.x = 1000; } } public void update() { if (w && p1.y > 54) { p1.moveUp(); } if (s && p1.y < 547) { p1.moveDown(); } if (a && p1.x > 0) { p1.moveLeft(); } if (d && p1.x < 200) { p1.moveRight(); } random = 1 * (int) (Math.random() * 100); if (random > 96) { if (p2.health >= 0) { CBullets bo = p2.getCBull(); bo.xVel =-1-cbSpeed; cb.add(bo); } if (Level2) { if (p3.health >= 0) { CBullets bo1 = p3.getCBull(); bo1.xVel = -2-cbSpeed; cb.add(bo1); } if (p4.health >= 0) { CBullets bo2 = p4.getCBull(); bo2.xVel = -4-cbSpeed; cb.add(bo2); } } } if (S == 1) { if (p1.health >= 0) { Bullets bu = p1.getBull(); bu.xVel = 5; b.add(bu); S += 1; } } //Here Also Problem .. When COmputer have More fire then it gaves Array Exeption . Or Player have More Fire for (int i = cb.size() -1; i = 0 ; i--) { boolean bremoved = false; for (int j = b.size() -1 ; j =0 ; j--) { if (b.get(j).rect.intersects(cb.get(i).rect) || cb.get(i).rect.intersects(b.get(j).rect)) { bremoved = true; b.remove(j); } } if(bremoved) cb.remove(i); } for (int i = 0; i < b.size(); i++) { b.get(i).move(); if (b.get(i).rect.intersects(p2.rect)) { if (p2.health >= 0) { p2.health--; b.remove(i); // System.out.println("Hited P2"); i--; continue; } } if (b.get(i).rect.intersects(p3.rect)) { if (p3.health >= 0) { p3.health--; b.remove(i); // System.out.println("Hited P3"); i--; continue; } } if (b.get(i).rect.intersects(p4.rect)) { if (p4.health >= 0) { p4.health--; b.remove(i); // System.out.println("Hited P4"); i--; continue; } } if (b.get(i).rect.x > 790) { b.remove(i); } } for (int j = 0; j < cb.size(); j++) { cb.get(j).move(); if (cb.get(j).rect.intersects(p1.rect) && cb.get(j).xVel < 0) { p1.health--; cb.remove(j); j--; continue; } } timeEnd = System.currentTimeMillis(); timeElapsed = (int) (timeEnd - timeStart); } public void level2() { if (p2.health <= 10) { Level2 = true; cbSpeed = 4; p3.x = 750; p4.x = 750; p2.speed = 10; p3.speed = 20; p4.speed = 30; } } public void keyTyped(KeyEvent e) { } public void keyPressed(KeyEvent e) { switch (e.getKeyCode()) { case KeyEvent.VK_ENTER: newGame = false; break; case KeyEvent.VK_P: pause = true; break; case KeyEvent.VK_R: resart = true; break; case KeyEvent.VK_A: a = true; break; case KeyEvent.VK_D: d = true; break; case KeyEvent.VK_W: w = true; break; case KeyEvent.VK_S: s = true; break; case KeyEvent.VK_SPACE: S += 1; break; } } public void keyReleased(KeyEvent e) { switch (e.getKeyCode()) { case KeyEvent.VK_A: a = false; break; case KeyEvent.VK_D: d = false; break; case KeyEvent.VK_W: w = false; break; case KeyEvent.VK_S: s = false; break; case KeyEvent.VK_SPACE: S = 0; break; } } public void newGame() { p1.health = 20; p2.health = 20; p3.health = 20; p4.health = 20; p3.x = 0; p4.x = 0; p2.x = 750; Level2 = false; cbSpeed = 0; p2.speed = 9; b.removeAll(b); cb.removeAll(cb); timerStart = (int) System.currentTimeMillis(); GameOver = false; } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { public void run() { KeyListener k = new Shooter(); } }); } @Override public void run() { player = JOptionPane.showInputDialog(frame, "Enter Player Name", "New Player", JOptionPane.DEFAULT_OPTION); while (true) { timerEnd = (int) System.currentTimeMillis(); if (resart) { newGame(); resart = false; } if (pause) { Thread.currentThread().notify(); } try { if (!GameOver) { Timer = timerEnd - timerStart; level2(); if (p1.y < p2.y && p2.y60) { p2.moveUp(); } if (p1.y < p3.y && p3.y43) { p3.moveUp(); } if (p1.y < p4.y && p4.y43) { p4.moveUp(); } if (p1.y > p2.y && p2.y<535) { p2.moveDown(); } if (p1.y > p3.y && p3.y<535) { p3.moveDown(); } if (p1.y > p4.y && p4.y<530) { p4.moveDown(); } } if (timeElapsed < 125) { Thread.currentThread().sleep(125); } } catch (InterruptedException ex) { System.out.print("FInished"); } } } }

    Read the article

  • Why keylistener is not working here?

    - by swift
    i have implemented keylistener interface and implemented all the needed methods but when i press the key nothing happens here, why? package swing; import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.GridLayout; import java.awt.Point; import java.awt.RenderingHints; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import java.awt.event.KeyListener; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import java.awt.event.MouseMotionListener; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.awt.image.BufferedImage; import javax.swing.BorderFactory; import javax.swing.BoxLayout; import javax.swing.ImageIcon; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLayeredPane; import javax.swing.JPanel; import javax.swing.JTextArea; class Paper extends JPanel implements MouseListener,MouseMotionListener,ActionListener,KeyListener { static BufferedImage image; String shape; Color color=Color.black; Point start; Point end; Point mp; Button elipse=new Button("elipse"); int x[]=new int[50]; int y[]=new int[50]; Button rectangle=new Button("rect"); Button line=new Button("line"); Button roundrect=new Button("roundrect"); Button polygon=new Button("poly"); Button text=new Button("text"); ImageIcon erasericon=new ImageIcon("images/eraser.gif"); JButton erase=new JButton(erasericon); JButton[] colourbutton=new JButton[9]; String selected; Point label; String key; int ex,ey;//eraser //DatagramSocket dataSocket; JButton button = new JButton("test"); JLayeredPane layerpane; Point p=new Point(); int w,h; public Paper() { JFrame frame=new JFrame("Whiteboard"); frame.setVisible(true); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(640, 480); frame.setBackground(Color.black); layerpane=frame.getLayeredPane(); setWidth(539,444); setBounds(69,0,555,444); layerpane.add(this,new Integer(2)); layerpane.add(this.addButtons(),new Integer(0)); setLayout(null); setOpaque(false); addMouseListener(this); addMouseMotionListener(this); setFocusable(true); addKeyListener(this); System.out.println(isFocusable()); setBorder(BorderFactory.createLineBorder(Color.black)); } public void paintComponent(Graphics g) { try { super.paintComponent(g); g.drawImage(image, 0, 0, this); Graphics2D g2 = (Graphics2D)g; if(color!=null) g2.setPaint(color); if(start!=null && end!=null) { if(selected==("elipse")) g2.drawOval(start.x, start.y,(end.x-start.x),(end.y-start.y)); else if(selected==("rect")) g2.drawRect(start.x, start.y, (end.x-start.x),(end.y-start.y)); else if(selected==("rrect")) g2.drawRoundRect(start.x, start.y, (end.x-start.x),(end.y-start.y),11,11); else if(selected==("line")) g2.drawLine(start.x,start.y,end.x,end.y); else if(selected==("poly")) g2.drawPolygon(x,y,2); } } catch(Exception e) {} } //Function to draw the shape on image public void draw() { Graphics2D g2 = image.createGraphics(); g2.setPaint(color); if(start!=null && end!=null) { if(selected=="line") g2.drawLine(start.x, start.y, end.x, end.y); else if(selected=="elipse") g2.drawOval(start.x, start.y, (end.x-start.x),(end.y-start.y)); else if(selected=="rect") g2.drawRect(start.x, start.y, (end.x-start.x),(end.y-start.y)); else if(selected==("rrect")) g2.drawRoundRect(start.x, start.y, (end.x-start.x),(end.y-start.y),11,11); else if(selected==("poly")) g2.drawPolygon(x,y,2); } if(label!=null) { JTextArea textarea=new JTextArea(); if(selected==("text")) { textarea.setBounds(label.x, label.y, 50, 50); textarea.setMaximumSize(new Dimension(100,100)); textarea.setBackground(new Color(237,237,237)); add(textarea); g2.drawString("key",label.x,label.y); } } start=null; repaint(); g2.dispose(); } public void text() { System.out.println(label); } //Function which provides the erase functionality public void erase() { Graphics2D pic=(Graphics2D) image.getGraphics(); Color erasecolor=new Color(237,237,237); pic.setPaint(erasecolor); if(start!=null) pic.fillRect(start.x, start.y, 10, 10); } //To set the size of the image public void setWidth(int x,int y) { System.out.println("("+x+","+y+")"); w=x; h=y; image = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB); } //Function to add buttons into the panel, calling this function returns a panel public JPanel addButtons() { JPanel buttonpanel=new JPanel(); buttonpanel.setMaximumSize(new Dimension(70,70)); JPanel shape=new JPanel(); JPanel colourbox=new JPanel(); shape.setLayout(new GridLayout(4,2)); shape.setMaximumSize(new Dimension(70,140)); colourbox.setLayout(new GridLayout(3,3)); colourbox.setMaximumSize(new Dimension(70,70)); buttonpanel.setLayout(new BoxLayout(buttonpanel,BoxLayout.Y_AXIS)); elipse.addActionListener(this); elipse.setToolTipText("Elipse"); rectangle.addActionListener(this); rectangle.setToolTipText("Rectangle"); line.addActionListener( this); line.setToolTipText("Line"); erase.addActionListener(this); erase.setToolTipText("Eraser"); roundrect.addActionListener(this); roundrect.setToolTipText("Round rect"); polygon.addActionListener(this); polygon.setToolTipText("Polygon"); text.addActionListener(this); text.setToolTipText("Text"); shape.add(elipse); shape.add(rectangle); shape.add(line); shape.add(erase); shape.add(roundrect); shape.add(polygon); shape.add(text); buttonpanel.add(shape); for(int i=0;i<9;i++) { colourbutton[i]=new JButton(); colourbox.add(colourbutton[i]); if(i==0) colourbutton[0].setBackground(Color.black); else if(i==1) colourbutton[1].setBackground(Color.white); else if(i==2) colourbutton[2].setBackground(Color.red); else if(i==3) colourbutton[3].setBackground(Color.orange); else if(i==4) colourbutton[4].setBackground(Color.blue); else if(i==5) colourbutton[5].setBackground(Color.green); else if(i==6) colourbutton[6].setBackground(Color.pink); else if(i==7) colourbutton[7].setBackground(Color.magenta); else if(i==8) colourbutton[8].setBackground(Color.cyan); colourbutton[i].addActionListener(this); } buttonpanel.add(colourbox); buttonpanel.setBounds(0, 0, 70, 210); return buttonpanel; } public void mouseClicked(MouseEvent e) { if(selected=="text") { label=new Point(); label=e.getPoint(); draw(); } } @Override public void mouseEntered(MouseEvent arg0) { } public void mouseExited(MouseEvent arg0) { } public void mousePressed(MouseEvent e) { if(selected=="line"||selected=="erase"||selected=="text") { start=e.getPoint(); } else if(selected=="elipse"||selected=="rect"||selected=="rrect") { mp = e.getPoint(); } else if(selected=="poly") { x[0]=e.getX(); y[0]=e.getY(); } } public void mouseReleased(MouseEvent e) { if(start!=null) { if(selected=="line") { end=e.getPoint(); } else if(selected=="elipse"||selected=="rect"||selected=="rrect") { end.x = Math.max(mp.x,e.getX()); end.y = Math.max(mp.y,e.getY()); } else if(selected=="poly") { x[1]=e.getX(); y[1]=e.getY(); } draw(); } } public void mouseDragged(MouseEvent e) { if(end==null) end = new Point(); if(start==null) start = new Point(); if(selected=="line") { end=e.getPoint(); } else if(selected=="erase") { start=e.getPoint(); erase(); } else if(selected=="elipse"||selected=="rect"||selected=="rrect") { start.x = Math.min(mp.x,e.getX()); start.y = Math.min(mp.y,e.getY()); end.x = Math.max(mp.x,e.getX()); end.y = Math.max(mp.y,e.getY()); } else if(selected=="poly") { x[1]=e.getX(); y[1]=e.getY(); } repaint(); } public void mouseMoved(MouseEvent arg0) {} public void actionPerformed(ActionEvent e) { if(e.getSource()==elipse) selected="elipse"; else if(e.getSource()==line) selected="line"; else if(e.getSource()==rectangle) selected="rect"; else if(e.getSource()==erase) { selected="erase"; System.out.println(selected); erase(); } else if(e.getSource()==roundrect) selected="rrect"; else if(e.getSource()==polygon) selected="poly"; else if(e.getSource()==text) selected="text"; if(e.getSource()==colourbutton[0]) color=Color.black; else if(e.getSource()==colourbutton[1]) color=Color.white; else if(e.getSource()==colourbutton[2]) color=Color.red; else if(e.getSource()==colourbutton[3]) color=Color.orange; else if(e.getSource()==colourbutton[4]) color=Color.blue; else if(e.getSource()==colourbutton[5]) color=Color.green; else if(e.getSource()==colourbutton[6]) color=Color.pink; else if(e.getSource()==colourbutton[7]) color=Color.magenta; else if(e.getSource()==colourbutton[8]) color=Color.cyan; } @Override public void keyPressed(KeyEvent e) { System.out.println("pressed"); } @Override public void keyReleased(KeyEvent e) { System.out.println("key released"); } @Override public void keyTyped(KeyEvent e) { System.out.println("Typed"); } public static void main(String[] a) { new Paper(); } } class Button extends JButton { String name; public Button(String name) { this.name=name; } public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D)g; g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); //g2.setStroke(new BasicStroke(1.2f)); if (name == "line") g.drawLine(5,5,30,30); if (name == "elipse") g.drawOval(5,7,25,20); if (name== "rect") g.drawRect(5,5,25,23); if (name== "roundrect") g.drawRoundRect(5,5,25,23,10,10); int a[]=new int[]{20,9,20,23,20}; int b[]=new int[]{9,23,25,20,9}; if (name== "poly") g.drawPolyline(a, b, 5); if (name== "text") g.drawString("Text",5, 22); } }

    Read the article

  • I can''t figure out how to use the comboBox to remove radiobuttons

    - by user3576336
    import java.awt.EventQueue; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.border.EmptyBorder; import javax.swing.ButtonGroup; import javax.swing.JLabel; import javax.swing.JDesktopPane; import javax.swing.JRadioButton; import javax.swing.JComboBox; import java.awt.GridBagLayout; import java.awt.GridBagConstraints; import java.awt.Insets; import java.awt.Color; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; @SuppressWarnings("serial") public class Calendar1 extends JFrame implements ActionListener { private JPanel contentPane; String[] Months = { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" }; JDesktopPane desktopPane; ButtonGroup bG = new ButtonGroup(); JRadioButton radioButton, rdbtnNewRadioButton, radioButton_1, radioButton_2, radioButton_3, radioButton_4, radioButton_5, radioButton_6, radioButton_7, radioButton_8, radioButton_9, radioButton_10, radioButton_11, radioButton_12, radioButton_13, radioButton_14, radioButton_15, radioButton_16, radioButton_17, radioButton_18, radioButton_19, radioButton_20, radioButton_21, radioButton_22, radioButton_23, radioButton_24, radioButton_25, radioButton_26, radioButton_27, radioButton_28, radioButton_29; /** * Launch the application. */ public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { public void run() { try { Calendar1 frame = new Calendar1(); frame.setVisible(true); } catch (Exception e) { e.printStackTrace(); } } }); } /** * Create the frame. */ @SuppressWarnings("unchecked") public Calendar1() { setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setBounds(100, 100, 521, 300); contentPane = new JPanel(); contentPane.setBorder(new EmptyBorder(5, 5, 5, 5)); setContentPane(contentPane); contentPane.setLayout(null); JComboBox comboBox = new JComboBox(Months); comboBox.setBounds(28, 16, 132, 27); contentPane.add(comboBox); comboBox.setSelectedIndex(0); comboBox.addActionListener(this); JLabel label = new JLabel("2014"); label.setBounds(350, 20, 61, 16); contentPane.add(label); desktopPane = new JDesktopPane(); desktopPane.setBackground(new Color(30, 144, 255)); desktopPane.setBounds(0, 63, 495, 188); contentPane.add(desktopPane); GridBagLayout gbl_desktopPane = new GridBagLayout(); gbl_desktopPane.columnWidths = new int[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; gbl_desktopPane.rowHeights = new int[] { 0, 0, 0, 0, 0, 0, 0, 0 }; gbl_desktopPane.columnWeights = new double[] { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE }; gbl_desktopPane.rowWeights = new double[] { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, Double.MIN_VALUE }; desktopPane.setLayout(gbl_desktopPane); // JLabel lblSun = new JLabel("Sun"); // lblSun.setForeground(Color.RED); // // GridBagConstraints gbc_lblSun = new GridBagConstraints(); // gbc_lblSun.insets = new Insets(0, 0, 5, 5); // gbc_lblSun.gridx = 2; // gbc_lblSun.gridy = 0; // desktopPane.add(lblSun, gbc_lblSun); // // JLabel lblMon = new JLabel("Mon"); // GridBagConstraints gbc_lblMon = new GridBagConstraints(); // gbc_lblMon.insets = new Insets(0, 0, 5, 5); // gbc_lblMon.gridx = 4; // gbc_lblMon.gridy = 0; // desktopPane.add(lblMon, gbc_lblMon); // // JLabel lblTues = new JLabel("Tues"); // GridBagConstraints gbc_lblTues = new GridBagConstraints(); // gbc_lblTues.insets = new Insets(0, 0, 5, 5); // gbc_lblTues.gridx = 6; // gbc_lblTues.gridy = 0; // desktopPane.add(lblTues, gbc_lblTues); // // JLabel lblWed = new JLabel("Wed"); // GridBagConstraints gbc_lblWed = new GridBagConstraints(); // gbc_lblWed.insets = new Insets(0, 0, 5, 5); // gbc_lblWed.gridx = 8; // gbc_lblWed.gridy = 0; // desktopPane.add(lblWed, gbc_lblWed); // // JLabel lblThurs = new JLabel("Thurs"); // GridBagConstraints gbc_lblThurs = new GridBagConstraints(); // gbc_lblThurs.insets = new Insets(0, 0, 5, 5); // gbc_lblThurs.gridx = 10; // gbc_lblThurs.gridy = 0; // desktopPane.add(lblThurs, gbc_lblThurs); // // JLabel lblFri = new JLabel("Friday"); // GridBagConstraints gbc_lblFri = new GridBagConstraints(); // gbc_lblFri.insets = new Insets(0, 0, 5, 5); // gbc_lblFri.gridx = 12; // gbc_lblFri.gridy = 0; // desktopPane.add(lblFri, gbc_lblFri); // // JLabel lblSat = new JLabel("Sat"); // lblSat.setForeground(Color.RED); // GridBagConstraints gbc_lblSat = new GridBagConstraints(); // gbc_lblSat.insets = new Insets(0, 0, 5, 5); // gbc_lblSat.gridx = 14; // gbc_lblSat.gridy = 0; // desktopPane.add(lblSat, gbc_lblSat); radioButton = new JRadioButton("1"); GridBagConstraints gbc_radioButton = new GridBagConstraints(); gbc_radioButton.insets = new Insets(0, 0, 5, 5); gbc_radioButton.gridx = 8; gbc_radioButton.gridy = 1; desktopPane.add(radioButton, gbc_radioButton); bG.add(radioButton); rdbtnNewRadioButton = new JRadioButton("2"); GridBagConstraints gbc_rdbtnNewRadioButton = new GridBagConstraints(); gbc_rdbtnNewRadioButton.insets = new Insets(0, 0, 5, 5); gbc_rdbtnNewRadioButton.gridx = 10; gbc_rdbtnNewRadioButton.gridy = 1; desktopPane.add(rdbtnNewRadioButton, gbc_rdbtnNewRadioButton); bG.add(rdbtnNewRadioButton); radioButton_1 = new JRadioButton("3"); GridBagConstraints gbc_radioButton_1 = new GridBagConstraints(); gbc_radioButton_1.insets = new Insets(0, 0, 5, 5); gbc_radioButton_1.gridx = 12; gbc_radioButton_1.gridy = 1; desktopPane.add(radioButton_1, gbc_radioButton_1); bG.add(radioButton_1); radioButton_2 = new JRadioButton("4"); GridBagConstraints gbc_radioButton_2 = new GridBagConstraints(); gbc_radioButton_2.insets = new Insets(0, 0, 5, 5); gbc_radioButton_2.gridx = 14; gbc_radioButton_2.gridy = 1; desktopPane.add(radioButton_2, gbc_radioButton_2); bG.add(radioButton_2); radioButton_3 = new JRadioButton("5"); GridBagConstraints gbc_radioButton_3 = new GridBagConstraints(); gbc_radioButton_3.insets = new Insets(0, 0, 5, 5); gbc_radioButton_3.gridx = 2; gbc_radioButton_3.gridy = 2; desktopPane.add(radioButton_3, gbc_radioButton_3); bG.add(radioButton_3); radioButton_4 = new JRadioButton("6"); GridBagConstraints gbc_radioButton_4 = new GridBagConstraints(); gbc_radioButton_4.insets = new Insets(0, 0, 5, 5); gbc_radioButton_4.gridx = 4; gbc_radioButton_4.gridy = 2; desktopPane.add(radioButton_4, gbc_radioButton_4); bG.add(radioButton_4); radioButton_5 = new JRadioButton("7"); GridBagConstraints gbc_radioButton_5 = new GridBagConstraints(); gbc_radioButton_5.insets = new Insets(0, 0, 5, 5); gbc_radioButton_5.gridx = 6; gbc_radioButton_5.gridy = 2; desktopPane.add(radioButton_5, gbc_radioButton_5); bG.add(radioButton_5); radioButton_6 = new JRadioButton("8"); GridBagConstraints gbc_radioButton_6 = new GridBagConstraints(); gbc_radioButton_6.insets = new Insets(0, 0, 5, 5); gbc_radioButton_6.gridx = 8; gbc_radioButton_6.gridy = 2; desktopPane.add(radioButton_6, gbc_radioButton_6); bG.add(radioButton_6); radioButton_7 = new JRadioButton("9"); GridBagConstraints gbc_radioButton_7 = new GridBagConstraints(); gbc_radioButton_7.insets = new Insets(0, 0, 5, 5); gbc_radioButton_7.gridx = 10; gbc_radioButton_7.gridy = 2; desktopPane.add(radioButton_7, gbc_radioButton_7); bG.add(radioButton_7); radioButton_8 = new JRadioButton("10"); GridBagConstraints gbc_radioButton_8 = new GridBagConstraints(); gbc_radioButton_8.insets = new Insets(0, 0, 5, 5); gbc_radioButton_8.gridx = 12; gbc_radioButton_8.gridy = 2; desktopPane.add(radioButton_8, gbc_radioButton_8); bG.add(radioButton_8); radioButton_9 = new JRadioButton("11"); GridBagConstraints gbc_radioButton_9 = new GridBagConstraints(); gbc_radioButton_9.insets = new Insets(0, 0, 5, 5); gbc_radioButton_9.gridx = 14; gbc_radioButton_9.gridy = 2; desktopPane.add(radioButton_9, gbc_radioButton_9); bG.add(radioButton_9); radioButton_10 = new JRadioButton("12"); GridBagConstraints gbc_radioButton_10 = new GridBagConstraints(); gbc_radioButton_10.insets = new Insets(0, 0, 5, 5); gbc_radioButton_10.gridx = 2; gbc_radioButton_10.gridy = 3; desktopPane.add(radioButton_10, gbc_radioButton_10); bG.add(radioButton_10); radioButton_11 = new JRadioButton("13"); GridBagConstraints gbc_radioButton_11 = new GridBagConstraints(); gbc_radioButton_11.insets = new Insets(0, 0, 5, 5); gbc_radioButton_11.gridx = 4; gbc_radioButton_11.gridy = 3; desktopPane.add(radioButton_11, gbc_radioButton_11); bG.add(radioButton_11); radioButton_12 = new JRadioButton("14"); GridBagConstraints gbc_radioButton_12 = new GridBagConstraints(); gbc_radioButton_12.insets = new Insets(0, 0, 5, 5); gbc_radioButton_12.gridx = 6; gbc_radioButton_12.gridy = 3; desktopPane.add(radioButton_12, gbc_radioButton_12); bG.add(radioButton_12); radioButton_13 = new JRadioButton("15"); GridBagConstraints gbc_radioButton_13 = new GridBagConstraints(); gbc_radioButton_13.insets = new Insets(0, 0, 5, 5); gbc_radioButton_13.gridx = 8; gbc_radioButton_13.gridy = 3; desktopPane.add(radioButton_13, gbc_radioButton_13); bG.add(radioButton_13); radioButton_14 = new JRadioButton("16"); GridBagConstraints gbc_radioButton_14 = new GridBagConstraints(); gbc_radioButton_14.insets = new Insets(0, 0, 5, 5); gbc_radioButton_14.gridx = 10; gbc_radioButton_14.gridy = 3; desktopPane.add(radioButton_14, gbc_radioButton_14); bG.add(radioButton_14); radioButton_15 = new JRadioButton("17"); GridBagConstraints gbc_radioButton_15 = new GridBagConstraints(); gbc_radioButton_15.insets = new Insets(0, 0, 5, 5); gbc_radioButton_15.gridx = 12; gbc_radioButton_15.gridy = 3; desktopPane.add(radioButton_15, gbc_radioButton_15); bG.add(radioButton_15); radioButton_16 = new JRadioButton("18"); GridBagConstraints gbc_radioButton_16 = new GridBagConstraints(); gbc_radioButton_16.insets = new Insets(0, 0, 5, 5); gbc_radioButton_16.gridx = 14; gbc_radioButton_16.gridy = 3; desktopPane.add(radioButton_16, gbc_radioButton_16); bG.add(radioButton_16); radioButton_17 = new JRadioButton("19"); GridBagConstraints gbc_radioButton_17 = new GridBagConstraints(); gbc_radioButton_17.insets = new Insets(0, 0, 5, 5); gbc_radioButton_17.gridx = 2; gbc_radioButton_17.gridy = 4; desktopPane.add(radioButton_17, gbc_radioButton_17); bG.add(radioButton_17); radioButton_18 = new JRadioButton("20"); GridBagConstraints gbc_radioButton_18 = new GridBagConstraints(); gbc_radioButton_18.insets = new Insets(0, 0, 5, 5); gbc_radioButton_18.gridx = 4; gbc_radioButton_18.gridy = 4; desktopPane.add(radioButton_18, gbc_radioButton_18); bG.add(radioButton_18); radioButton_19 = new JRadioButton("21"); GridBagConstraints gbc_radioButton_19 = new GridBagConstraints(); gbc_radioButton_19.insets = new Insets(0, 0, 5, 5); gbc_radioButton_19.gridx = 6; gbc_radioButton_19.gridy = 4; desktopPane.add(radioButton_19, gbc_radioButton_19); bG.add(radioButton_19); radioButton_20 = new JRadioButton("22"); GridBagConstraints gbc_radioButton_20 = new GridBagConstraints(); gbc_radioButton_20.insets = new Insets(0, 0, 5, 5); gbc_radioButton_20.gridx = 8; gbc_radioButton_20.gridy = 4; desktopPane.add(radioButton_20, gbc_radioButton_20); bG.add(radioButton_20); radioButton_21 = new JRadioButton("23"); GridBagConstraints gbc_radioButton_21 = new GridBagConstraints(); gbc_radioButton_21.insets = new Insets(0, 0, 5, 5); gbc_radioButton_21.gridx = 10; gbc_radioButton_21.gridy = 4; desktopPane.add(radioButton_21, gbc_radioButton_21); bG.add(radioButton_21); radioButton_22 = new JRadioButton("24"); GridBagConstraints gbc_radioButton_22 = new GridBagConstraints(); gbc_radioButton_22.insets = new Insets(0, 0, 5, 5); gbc_radioButton_22.gridx = 12; gbc_radioButton_22.gridy = 4; desktopPane.add(radioButton_22, gbc_radioButton_22); bG.add(radioButton_22); radioButton_23 = new JRadioButton("25"); GridBagConstraints gbc_radioButton_23 = new GridBagConstraints(); gbc_radioButton_23.insets = new Insets(0, 0, 5, 5); gbc_radioButton_23.gridx = 14; gbc_radioButton_23.gridy = 4; desktopPane.add(radioButton_23, gbc_radioButton_23); bG.add(radioButton_23); radioButton_24 = new JRadioButton("26"); GridBagConstraints gbc_radioButton_24 = new GridBagConstraints(); gbc_radioButton_24.insets = new Insets(0, 0, 5, 5); gbc_radioButton_24.gridx = 2; gbc_radioButton_24.gridy = 5; desktopPane.add(radioButton_24, gbc_radioButton_24); bG.add(radioButton_24); radioButton_25 = new JRadioButton("27"); GridBagConstraints gbc_radioButton_25 = new GridBagConstraints(); gbc_radioButton_25.insets = new Insets(0, 0, 5, 5); gbc_radioButton_25.gridx = 4; gbc_radioButton_25.gridy = 5; desktopPane.add(radioButton_25, gbc_radioButton_25); bG.add(radioButton_25); radioButton_26 = new JRadioButton("28"); GridBagConstraints gbc_radioButton_26 = new GridBagConstraints(); gbc_radioButton_26.insets = new Insets(0, 0, 5, 5); gbc_radioButton_26.gridx = 6; gbc_radioButton_26.gridy = 5; desktopPane.add(radioButton_26, gbc_radioButton_26); bG.add(radioButton_26); radioButton_27 = new JRadioButton("29"); GridBagConstraints gbc_radioButton_27 = new GridBagConstraints(); gbc_radioButton_27.insets = new Insets(0, 0, 5, 5); gbc_radioButton_27.gridx = 8; gbc_radioButton_27.gridy = 5; desktopPane.add(radioButton_27, gbc_radioButton_27); bG.add(radioButton_27); radioButton_28 = new JRadioButton("30"); GridBagConstraints gbc_radioButton_28 = new GridBagConstraints(); gbc_radioButton_28.insets = new Insets(0, 0, 5, 5); gbc_radioButton_28.gridx = 10; gbc_radioButton_28.gridy = 5; desktopPane.add(radioButton_28, gbc_radioButton_28); bG.add(radioButton_28); radioButton_29 = new JRadioButton("31"); GridBagConstraints gbc_radioButton_29 = new GridBagConstraints(); gbc_radioButton_29.insets = new Insets(0, 0, 5, 5); gbc_radioButton_29.gridx = 12; gbc_radioButton_29.gridy = 5; desktopPane.add(radioButton_29, gbc_radioButton_29); bG.add(radioButton_29); } @Override public void actionPerformed(ActionEvent e) { JComboBox cb = (JComboBox) e.getSource(); String months = (String) cb.getSelectedItem(); if (months.equals("February")) { desktopPane.remove(radioButton_28); desktopPane.revalidate(); } } } I'm trying to use the combobox to remove radiobuttons in the actionperformed, but when I run the program, nothing happens, nor can I enable new buttons in the actionperformed. Thank you so much in advance for helping me out.

    Read the article

  • update jframe in java or revalidate/repaint/ panel

    - by user1516251
    How to update a java frame with changed content I want to update a frame or just the panel with updated content. What do I use for this Here is where i want to revalidate the frame or repaint mainpanel or whatever will work I have tried a number of things, but none of them have worked. public void actionPerformed(ActionEvent e) { //System.out.println(e.getActionCommand()); if (e.getActionCommand().equals("advance")) { multi--; // Revalidate update repaint here <<<<<<<<<<<<<<<<<<< } else if (e.getActionCommand().equals("reverse")) { multi++; // Revalidate update repaint here <<<<<<<<<<<<<<<<<<< } else { openURL(e.getActionCommand()); } } Here is the whole java file /* * * */ package build; import java.lang.reflect.Method; import javax.swing.JOptionPane; import java.util.Arrays; import java.util.*; import java.util.ArrayList; import javax.swing.*; import javax.swing.AbstractButton; import javax.swing.JScrollPane; import javax.swing.JButton; import javax.swing.JPanel; import javax.swing.JFrame; import javax.swing.ImageIcon; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; /* * ButtonDemo.java requires the following files: * images/right.gif * images/middle.gif * images/left.gif */ public class StockTable extends JPanel implements ActionListener { static int multi = 1; int roll = 0; static TextVars textvars = new TextVars(); static final String[] browsers = { "firefox", "opera", "konqueror", "epiphany", "seamonkey", "galeon", "kazehakase", "mozilla", "netscape" }; JFrame frame; JPanel mainpanel, panel1, panel2, panel3, panel4, panel2left, panel2center, panel2right; JButton stknames_btn[] = new JButton[textvars.getNumberOfStocks()]; JLabel label[] = new JLabel[textvars.getNumberOfStocks()]; JLabel headlabel, dayspan, namelabel; JRadioButton radioButton; JButton button; JScrollPane scrollpane; int wid = 825; public JPanel createContentPane() { mainpanel = new JPanel(); mainpanel.setPreferredSize(new Dimension(wid, 800)); mainpanel.setLayout(new GridBagLayout()); GridBagConstraints c = new GridBagConstraints(); panel1 = new JPanel(); panel1.setPreferredSize(new Dimension(wid, 25)); c.gridx = 0; c.gridy = 0; c.insets = new Insets(0,0,0,0); mainpanel.add(panel1, c); // Panel 2------------ panel2 = new JPanel(); panel2.setPreferredSize(new Dimension(wid, 51)); c.gridx = 0; c.gridy = 1; c.insets = new Insets(0,0,0,0); mainpanel.add(panel2, c); panel2left = new JPanel(); panel2left.setPreferredSize(new Dimension(270, 51)); c.gridx = 0; c.gridy = 1; c.insets = new Insets(0,0,0,0); panel2.add(panel2left, c); panel2center = new JPanel(); panel2center.setPreferredSize(new Dimension(258, 51)); c.gridx = 1; c.gridy = 1; c.insets = new Insets(0,0,0,0); panel2.add(panel2center, c); panel2right = new JPanel(); panel2right.setPreferredSize(new Dimension(270, 51)); c.gridx = 2; c.gridy = 1; c.insets = new Insets(0,0,0,0); panel2.add(panel2right, c); // ------------------ panel3 = new JPanel(); panel3.setLayout(new GridBagLayout()); scrollpane = new JScrollPane(panel3); scrollpane.setPreferredSize(new Dimension(wid, 675)); c.gridx = 0; c.gridy = 2; c.insets = new Insets(0,0,0,0); mainpanel.add(scrollpane, c); ImageIcon leftButtonIcon = createImageIcon("images/right.gif"); //b1 = new JButton("Disable middle button", leftButtonIcon); //b1.setVerticalTextPosition(AbstractButton.CENTER); //b1.setHorizontalTextPosition(AbstractButton.LEADING); //aka LEFT, for left-to-right locales //b1.setMnemonic(KeyEvent.VK_D); //b1.setActionCommand("disable"); //Listen for actions on buttons 1 //b1.addActionListener(this); //b1.setToolTipText("Click this button to disable the middle button."); //Add Components to this container, using the default FlowLayout. //add(b1); headlabel = new JLabel("hellorow1"); c.gridx = 0; c.gridy = 0; c.insets = new Insets(0, 0, 0, 0); panel1.add(headlabel, c); radioButton = new JRadioButton("Percentage"); c.gridx = 2; c.gridy = 0; c.insets = new Insets(0, 0, 0, 0); panel1.add(radioButton, c); radioButton = new JRadioButton("Days Range"); c.gridx = 3; c.gridy = 0; c.insets = new Insets(0, 0, 0, 0); panel1.add(radioButton, c); radioButton = new JRadioButton("Open / Close"); c.gridx = 4; c.gridy = 0; c.insets = new Insets(0, 0, 0,0 ); panel1.add(radioButton, c); button = new JButton("<<"); button.setPreferredSize(new Dimension(50, 50)); button.setActionCommand("reverse"); button.addActionListener(this); c.gridx = 0; c.gridy = 1; c.insets = new Insets(0, 0, 0, 0); panel2left.add(button, c); dayspan = new JLabel("hellorow2"); dayspan.setHorizontalAlignment(JLabel.CENTER); dayspan.setVerticalAlignment(JLabel.CENTER); dayspan.setPreferredSize(new Dimension(270, 50)); c.gridx = 1; c.gridy = 1; c.insets = new Insets(0, 0, 0, 0); panel2center.add(dayspan, c); button = new JButton(">>"); button.setPreferredSize(new Dimension(50, 50)); button.setActionCommand("advance"); button.addActionListener(this); if (multi == 0) { button.setEnabled(false); } else { button.setEnabled(true); } c.gridx = 2; c.gridy = 1; c.insets = new Insets(0, 0, 0, 0); panel2right.add(button, c); int availSpace_int = textvars.getStocks().size()-textvars.getNumberOfStocks()*7; ArrayList<String[]> stocknames = textvars.getStockNames(); ArrayList<String[]> stocks = textvars.getStocks(); for (int column = 0; column < 8; column++) { for (int row = 0; row < textvars.getNumberOfStocks(); row++) { if (column==0) { if (row==0) { namelabel = new JLabel(stocknames.get(0)[0]); namelabel.setVerticalAlignment(JLabel.CENTER); namelabel.setHorizontalAlignment(JLabel.CENTER); namelabel.setPreferredSize(new Dimension(100, 25)); c.gridx = column; c.gridy = row; c.insets = new Insets(0, 0, 0, 0); panel3.add(namelabel, c); } else { stknames_btn[row] = new JButton(stocknames.get(row)[0], leftButtonIcon); stknames_btn[row].setVerticalTextPosition(AbstractButton.CENTER); stknames_btn[row].setActionCommand(stocknames.get(row)[1]); stknames_btn[row].addActionListener(this); stknames_btn[row].setToolTipText("go to Google Finance "+stocknames.get(row)[0]); stknames_btn[row].setPreferredSize(new Dimension(100, 25)); c.gridx = column; c.gridy = row; c.insets = new Insets(0, 0, 0, 0); //scrollpane.add(stknames[row], c); panel3.add(stknames_btn[row], c); } } else { label[row]= new JLabel(textvars.getStocks().get(columnMulti(multi))[1]); label[row].setBorder(BorderFactory.createLineBorder(Color.black)); label[row].setVerticalAlignment(JLabel.CENTER); label[row].setHorizontalAlignment(JLabel.CENTER); label[row].setPreferredSize(new Dimension(100, 25)); c.gridx = column; c.gridy = row; c.insets = new Insets(0,0,0,0); panel3.add(label[row], c); } } } return mainpanel; } public void actionPerformed(ActionEvent e) { //System.out.println(e.getActionCommand()); if (e.getActionCommand().equals("advance")) { multi--; } else if (e.getActionCommand().equals("reverse")) { multi++; } else { openURL(e.getActionCommand()); } } /** Returns an ImageIcon, or null if the path was invalid. */ protected static ImageIcon createImageIcon(String path) { java.net.URL imgURL = StockTable.class.getResource(path); if (imgURL != null) { return new ImageIcon(imgURL); } else { System.err.println("Couldn't find file: " + path); return null; } } public static void openURL(String url) { String osName = System.getProperty("os.name"); try { if (osName.startsWith("Mac OS")) { Class<?> fileMgr = Class.forName("com.apple.eio.FileManager"); Method openURL = fileMgr.getDeclaredMethod("openURL", new Class[] {String.class}); openURL.invoke(null, new Object[] {url}); } else if (osName.startsWith("Windows")) { Runtime.getRuntime().exec("rundll32 url.dll,FileProtocolHandler " + url); } else { //assume Unix or Linux boolean found = false; for (String browser : browsers) if (!found) { found = Runtime.getRuntime().exec( new String[] {"which", browser}).waitFor() == 0; if (found) Runtime.getRuntime().exec(new String[] {browser, url}); } if (!found) throw new Exception(Arrays.toString(browsers)); } } catch (Exception e) { JOptionPane.showMessageDialog(null, "Error attempting to launch web browser\n" + e.toString()); } } int reit = 0; int start = textvars.getStocks().size()-((textvars.getNumberOfStocks()*5)*7)-1; public int columnMulti(int multi) { reit++; start++; if (reit == textvars.getNumberOfStocks()) { reit = 0; start=start+64; } //start = start - (multi*(textvars.getNumberOfStocks())); return start; } /** * Create the GUI and show it. For thread safety, * this method should be invoked from the * event-dispatching thread. */ private static void createAndShowGUI() { //Create and set up the window. JFrame frame = new JFrame("Stock Table"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane. StockTable newContentPane = new StockTable(); //newContentPane.setOpaque(true); //content panes must be opaque //frame.setContentPane(newContentPane); frame.setContentPane(newContentPane.createContentPane()); frame.setSize(800, 800); //Display the window. frame.pack(); frame.setVisible(true); } 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() { createAndShowGUI(); } }); } }

    Read the article

  • How to save image drawn on a JPanel?

    - by swift
    I have a panel with transparent background which i use to draw an image. now problem here is when i draw anything on panel and save the image as a JPEG file its saving the image with black background but i want it to be saved as same, as i draw on the panel. what should be done for this? plz guide me j Client.java public class Client extends Thread { static DatagramSocket datasocket; static DatagramSocket socket; Point point; Whiteboard board; Virtualboard virtualboard; JLayeredPane layerpane; BufferedImage image; public Client(DatagramSocket datasocket) { Client.datasocket=datasocket; } //This function is responsible to connect to the server public static void connect() { try { socket=new DatagramSocket (9000); //client connection socket port= 9000 datasocket=new DatagramSocket (9005); //client data socket port= 9002 ByteArrayOutputStream baos=new ByteArrayOutputStream(); DataOutputStream dos=new DataOutputStream(baos); //this is to tell server that this is a connection request dos.writeChar('c'); dos.close(); byte[]data=baos.toByteArray(); //Server IP address InetAddress ip=InetAddress.getByName("10.123.97.154"); //create the UDP packet DatagramPacket packet=new DatagramPacket(data, data.length,ip , 8000); socket.send(packet); Client client=new Client(datasocket); client.createFrame(); client.run(); } catch(Exception e) { e.printStackTrace(); } } //This function is to create the JFrame public void createFrame() { JFrame frame=new JFrame("Whiteboard"); frame.setVisible(true); frame.setBackground(Color.black); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(680,501); frame.addWindowListener(new WindowAdapter() { public void windowOpened(WindowEvent e) {} public void windowClosing(WindowEvent e) { close(); } }); layerpane=frame.getLayeredPane(); board= new Whiteboard(datasocket); image = new BufferedImage(590,463, BufferedImage.TYPE_INT_ARGB); board.setBounds(74,2,590,463); board.setImage(image); virtualboard=new Virtualboard(); virtualboard.setImage(image); virtualboard.setBounds(74,2,590,463); layerpane.add(virtualboard,new Integer(2));//Panel where remote user draws layerpane.add(board,new Integer(3)); layerpane.add(board.colourButtons(),new Integer(1)); layerpane.add(board.shapeButtons(),new Integer(0)); //frame.add(paper.addButtons(),BorderLayout.WEST); } /* * This function is overridden from the thread class * This function listens for incoming packets from the server * which contains the points drawn by the other client */ public void run () { while (true) { try { byte[] buffer = new byte[512]; DatagramPacket packet = new DatagramPacket(buffer, buffer.length); datasocket.receive(packet); InputStream in=new ByteArrayInputStream(packet.getData(), packet.getOffset(),packet.getLength()); DataInputStream din=new DataInputStream(in); int x=din.readInt(); int y=din.readInt(); String varname=din.readLine(); String var[]=varname.split("-",4); point=new Point(x,y); virtualboard.addPoint(point, var[0], var[1],var[2],var[3]); } catch (IOException ex) { ex.printStackTrace(); } } } //This function is to broadcast the newly drawn point to the server public void broadcast (Point p,String varname,String shape,String event, String color) { try { ByteArrayOutputStream baos=new ByteArrayOutputStream(); DataOutputStream dos=new DataOutputStream(baos); dos.writeInt(p.x); dos.writeInt(p.y); dos.writeBytes(varname); dos.writeBytes("-"); dos.writeBytes(shape); dos.writeBytes("-"); dos.writeBytes(event); dos.writeBytes("-"); dos.writeBytes(color); dos.close(); byte[]data=baos.toByteArray(); InetAddress ip=InetAddress.getByName("10.123.97.154"); DatagramPacket packet=new DatagramPacket(data, data.length,ip , 8002); datasocket.send(packet); } catch (Exception e) { e.printStackTrace(); } } //This function is to close the client's connection with the server public void close() { try { ByteArrayOutputStream baos=new ByteArrayOutputStream(); DataOutputStream dos=new DataOutputStream(baos); //This is to tell server that this is request to remove the client dos.writeChar('r'); dos.close(); byte[]data=baos.toByteArray(); //Server IP address InetAddress ip=InetAddress.getByName("10.123.97.154"); DatagramPacket packet=new DatagramPacket(data, data.length,ip , 8000); socket.send(packet); System.out.println("closed"); } catch(Exception e) { e.printStackTrace(); } } public static void main(String[] args) throws Exception { connect(); } } Whiteboard.java class Whiteboard extends JPanel implements MouseListener,MouseMotionListener,ActionListener,KeyListener { BufferedImage image; Boolean tooltip=false; int post; String shape; String selectedcolor="black"; Color color=Color.black; //Color color=Color.white; Point start; Point end; Point mp; Point tip; int keycode; String fillshape; Point fillstart=new Point(); Point fillend=new Point(); int noofside; Button r=new Button("rect"); Button rectangle=new Button("rect"); Button line=new Button("line"); Button roundrect=new Button("roundrect"); Button polygon=new Button("poly"); Button text=new Button("text"); JButton save=new JButton("Save"); Button elipse=new Button("elipse"); ImageIcon fillicon=new ImageIcon("images/fill.jpg"); JButton fill=new JButton(fillicon); ImageIcon erasericon=new ImageIcon("images/eraser.gif"); JButton erase=new JButton(erasericon); JButton[] colourbutton=new JButton[28]; String selected; Point label; String key=""; int ex,ey;//eraser DatagramSocket dataSocket; JButton button = new JButton("test"); Client client; Boolean first; int w,h; public Whiteboard(DatagramSocket dataSocket) { try { UIManager.setLookAndFeel( UIManager.getCrossPlatformLookAndFeelClassName()); } catch (Exception e) { e.printStackTrace(); } setLayout(null); setOpaque(false); setBackground(new Color(237,237,237)); this.dataSocket=dataSocket; client=new Client(dataSocket); addKeyListener(this); addMouseListener(this); addMouseMotionListener(this); setBorder(BorderFactory.createLineBorder(Color.black)); } public void paintComponent(Graphics g) { try { super.paintComponent(g); g.drawImage(image, 0, 0, this); Graphics2D g2 = (Graphics2D)g; if(color!=null) g2.setPaint(color); if(start!=null && end!=null) { if(selected==("elipse")) g2.drawOval(start.x, start.y,(end.x-start.x),(end.y-start.y)); else if(selected==("rect")) g2.drawRect(start.x, start.y, (end.x-start.x),(end.y-start.y)); else if(selected==("rrect")) g2.drawRoundRect(start.x, start.y, (end.x-start.x),(end.y-start.y),11,11); else if(selected==("line")) g2.drawLine(start.x,start.y,end.x,end.y); else if(selected==("poly")) { g2.drawLine(start.x,start.y,end.x,end.y); client.broadcast(start, "start", "poly", "drag", selectedcolor); client.broadcast(end, "end", "poly", "drag", selectedcolor); } } if(tooltip==true) { System.out.println(selected); if(selected=="text") { g2.drawString("|", tip.x, tip.y-5); g2.drawString("Click to add text", tip.x+10, tip.y+23); g2.drawString("__", label.x+post, label.y); } if(selected=="erase") { g2.setPaint(new Color(237,237,237)); g2.fillRect(tip.x-10,tip.y-10,10,10); g2.setPaint(color); g2.drawRect(tip.x-10,tip.y-10,10,10); } } } catch(Exception e) {} } //Function to draw the shape on image public void draw() { Graphics2D g2 = (Graphics2D) image.createGraphics(); Font font=new Font("Times New Roman",Font.PLAIN,14); g2.setFont(font); g2.setPaint(color); if(start!=null && end!=null) { if(selected=="line") g2.drawLine(start.x, start.y, end.x, end.y); else if(selected=="elipse") g2.drawOval(start.x, start.y, (end.x-start.x),(end.y-start.y)); else if(selected=="rect") g2.drawRect(start.x, start.y, (end.x-start.x),(end.y-start.y)); else if(selected==("rrect")) g2.drawRoundRect(start.x, start.y, (end.x-start.x),(end.y-start.y),11,11); else if(selected==("poly")) { g2.drawLine(start.x,start.y,end.x,end.y); client.broadcast(start, "start", "poly", "release", selectedcolor); client.broadcast(end, "end", "poly", "release", selectedcolor); } fillstart=start; fillend=end; fillshape=selected; } if(selected!="poly") { start=null; end=null; } if(label!=null) { if(selected==("text")) { g2.drawString(key,label.x,label.y); client.broadcast(label, key, "text", "release", selectedcolor); } } repaint(); g2.dispose(); } //Function which provides the erase functionality public void erase() { Graphics2D pic=(Graphics2D) image.createGraphics(); Color erasecolor=new Color(237,237,237); pic.setPaint(erasecolor); if(start!=null) pic.fillRect(start.x-10, start.y-10, 10, 10); } //To set the size of the image public void setImage(BufferedImage image) { this.image = image; } //Function to add buttons into the panel, calling this function returns a panel public JPanel shapeButtons() { JPanel shape=new JPanel(); shape.setBackground(new Color(181, 197, 210)); shape.setLayout(new GridLayout(5,2,2,4)); shape.setBounds(0, 2, 74, 166); rectangle.addActionListener(this); rectangle.setToolTipText("Rectangle"); line.addActionListener( this); line.setToolTipText("Line"); erase.addActionListener(this); erase.setToolTipText("Eraser"); roundrect.addActionListener(this); roundrect.setToolTipText("Round edge Rectangle"); polygon.addActionListener(this); polygon.setToolTipText("Polygon"); text.addActionListener(this); text.setToolTipText("Text"); fill.addActionListener(this); fill.setToolTipText("Fill with colour"); elipse.addActionListener(this); elipse.setToolTipText("Elipse"); save.addActionListener(this); shape.add(elipse); shape.add(rectangle); shape.add(roundrect); shape.add(polygon); shape.add(line); shape.add(text); shape.add(fill); shape.add(erase); shape.add(save); return shape; } public JPanel colourButtons() { JPanel colourbox=new JPanel(); colourbox.setBackground(new Color(181, 197, 210)); colourbox.setLayout(new GridLayout(8,2,8,8)); colourbox.setBounds(0,323,70,140); //colourbox.add(empty); for(int i=0;i<16;i++) { colourbutton[i]=new JButton(); colourbox.add(colourbutton[i]); if(i==0) colourbutton[0].setBackground(Color.black); else if(i==1) colourbutton[1].setBackground(Color.white); else if(i==2) colourbutton[2].setBackground(Color.red); else if(i==3) colourbutton[3].setBackground(Color.orange); else if(i==4) colourbutton[4].setBackground(Color.blue); else if(i==5) colourbutton[5].setBackground(Color.green); else if(i==6) colourbutton[6].setBackground(Color.pink); else if(i==7) colourbutton[7].setBackground(Color.magenta); else if(i==8) colourbutton[8].setBackground(Color.cyan); else if(i==9) colourbutton[9].setBackground(Color.black); else if(i==10) colourbutton[10].setBackground(Color.yellow); else if(i==11) colourbutton[11].setBackground(new Color(131,168,43)); else if(i==12) colourbutton[12].setBackground(new Color(132,0,210)); else if(i==13) colourbutton[13].setBackground(new Color(193,17,92)); else if(i==14) colourbutton[14].setBackground(new Color(129,82,50)); else if(i==15) colourbutton[15].setBackground(new Color(64,128,128)); colourbutton[i].addActionListener(this); } return colourbox; } public void fill() { if(selected=="fill") { Graphics2D g2 = (Graphics2D) image.getGraphics(); g2.setPaint(color); System.out.println("Fill"); if(fillshape=="elipse") g2.fillOval(fillstart.x, fillstart.y, (fillend.x-fillstart.x),(fillend.y-fillstart.y)); else if(fillshape=="rect") g2.fillRect(fillstart.x, fillstart.y, (fillend.x-fillstart.x),(fillend.y-fillstart.y)); else if(fillshape==("rrect")) g2.fillRoundRect(fillstart.x, fillstart.y, (fillend.x-fillstart.x),(fillend.y-fillstart.y),11,11); // else if(fillshape==("poly")) // g2.drawPolygon(x,y,2); } repaint(); } //To save the image drawn public void save() { try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(bos); JFileChooser fc = new JFileChooser(); fc.showSaveDialog(this); encoder.encode(image); byte[] jpgData = bos.toByteArray(); FileOutputStream fos = new FileOutputStream(fc.getSelectedFile()+".jpeg"); fos.write(jpgData); fos.close(); //add replce confirmation here } catch (IOException e) { System.out.println(e); } } public void mouseClicked(MouseEvent e) { } @Override public void mouseEntered(MouseEvent e) { } public void mouseExited(MouseEvent arg0) { } public void mousePressed(MouseEvent e) { if(selected=="line"||selected=="text") { start=e.getPoint(); client.broadcast(start,"start", selected,"press", selectedcolor); } else if(selected=="elipse"||selected=="rect"||selected=="rrect") mp = e.getPoint(); else if(selected=="poly") { if(first==true) { start=e.getPoint(); //client.broadcast(start,"start", selected,"press", selectedcolor); } else if(first==false) { end=e.getPoint(); repaint(); //client.broadcast(end,"end", selected,"press", selectedcolor); } } else if(selected=="erase") { start=e.getPoint(); erase(); } } public void mouseReleased(MouseEvent e) { if(selected=="text") { System.out.println("Reset"); key=""; post=0; label=new Point(); label=e.getPoint(); grabFocus(); } if(start!=null && end!=null) { if(selected=="line") { end=e.getPoint(); client.broadcast(end,"end", selected,"release", selectedcolor); draw(); } else if(selected=="elipse"||selected=="rect"||selected=="rrect") { end.x = Math.max(mp.x,e.getX()); end.y = Math.max(mp.y,e.getY()); client.broadcast(end,"end", selected,"release", selectedcolor); draw(); } else if(selected=="poly") { draw(); first=false; start=end; end=null; } } } public void mouseDragged(MouseEvent e) { if(end==null) end = new Point(); if(start==null) start = new Point(); if(selected=="line") { end=e.getPoint(); client.broadcast(end,"end", selected,"drag", selectedcolor); } else if(selected=="erase") { start=e.getPoint(); erase(); client.broadcast(start,"start", selected,"drag", selectedcolor); } else if(selected=="elipse"||selected=="rect"||selected=="rrect") { start.x = Math.min(mp.x,e.getX()); start.y = Math.min(mp.y,e.getY()); end.x = Math.max(mp.x,e.getX()); end.y = Math.max(mp.y,e.getY()); client.broadcast(start,"start", selected,"drag", selectedcolor); client.broadcast(end,"end", selected,"drag", selectedcolor); } else if(selected=="poly") end=e.getPoint(); System.out.println(tooltip); if(tooltip==true) { if(selected=="erase") { Graphics2D g2=(Graphics2D) getGraphics(); tip=e.getPoint(); g2.drawRect(tip.x-10,tip.y-10,10,10); } } repaint(); } public void mouseMoved(MouseEvent e) { if(selected=="text" ||selected=="erase") { tip=new Point(); tip=e.getPoint(); tooltip=true; repaint(); } } public void actionPerformed(ActionEvent e) { if(e.getSource()==elipse) selected="elipse"; else if(e.getSource()==line) selected="line"; else if(e.getSource()==rectangle) selected="rect"; else if(e.getSource()==erase) { selected="erase"; tooltip=true; System.out.println(selected); erase(); } else if(e.getSource()==roundrect) selected="rrect"; else if(e.getSource()==polygon) { selected="poly"; first=true; start=null; } else if(e.getSource()==text) { selected="text"; tooltip=true; } else if(e.getSource()==fill) { selected="fill"; fill(); } else if(e.getSource()==save) save(); if(e.getSource()==colourbutton[0]) { color=Color.black; selectedcolor="black"; } else if(e.getSource()==colourbutton[1]) { color=Color.white; selectedcolor="white"; } else if(e.getSource()==colourbutton[2]) { color=Color.red; selectedcolor="red"; } else if(e.getSource()==colourbutton[3]) { color=Color.orange; selectedcolor="orange"; } else if(e.getSource()==colourbutton[4]) { selectedcolor="blue"; color=Color.blue; } else if(e.getSource()==colourbutton[5]) { selectedcolor="green"; color=Color.green; } else if(e.getSource()==colourbutton[6]) { selectedcolor="pink"; color=Color.pink; } else if(e.getSource()==colourbutton[7]) { selectedcolor="magenta"; color=Color.magenta; } else if(e.getSource()==colourbutton[8]) { selectedcolor="cyan"; color=Color.cyan; } } @Override public void keyPressed(KeyEvent e) { //System.out.println(e.getKeyChar()+" : "+e.getKeyCode()); if(label!=null) { if(e.getKeyCode()==10) //Check for Enter key { label.y=label.y+14; key=""; post=0; repaint(); } else if(e.getKeyCode()==8) //Backspace { try{ Graphics2D g2 = (Graphics2D) image.getGraphics(); g2.setPaint(new Color(237,237,237)); g2.fillRect(label.x+post-7, label.y-13, 14, 17); if(post>0) post=post-6; keycode=0; key=key.substring(0, key.length()-1); System.out.println(key.substring(0, key.length())); repaint(); Point broadcastlabel=new Point(); broadcastlabel.x=label.x+post-7; broadcastlabel.y=label.y-13; client.broadcast(broadcastlabel, key, "text", "backspace", selectedcolor); } catch(Exception ex) {} } //Block invalid keys else if(!(e.getKeyCode()>=16 && e.getKeyCode()<=20 || e.getKeyCode()>=112 && e.getKeyCode()<=123 || e.getKeyCode()>=33 && e.getKeyCode()<=40 || e.getKeyCode()>=144 && e.getKeyCode()<=145 || e.getKeyCode()>=524 && e.getKeyCode()<=525 ||e.getKeyCode()==27||e.getKeyCode()==155 ||e.getKeyCode()==127)) { key=key+e.getKeyChar(); post=post+6; draw(); } } } @Override public void keyReleased(KeyEvent e) { } @Override public void keyTyped(KeyEvent e) { } } class Button extends JButton { String name; int i; public Button(String name) { this.name=name; try { UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel"); } catch (Exception e) { e.printStackTrace(); } } public Button(int i) { this.i=i; } public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D)g; g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); //g2.setStroke(new BasicStroke(1.2f)); if (name == "line") g.drawLine(5,5,30,30); if (name == "elipse") g.drawOval(5,7,25,20); if (name== "rect") g.drawRect(5,5,25,23); if (name== "roundrect") g.drawRoundRect(5,5,25,23,10,10); int a[]=new int[]{20,9,20,23,20}; int b[]=new int[]{9,23,25,20,9}; if (name== "poly") g.drawPolyline(a, b, 5); if (name== "text") g.drawString("Text",8, 24); } }

    Read the article

  • Thread not behaving correctly

    - by ivor
    Hello, I wonder if anyone can help me to understand where I could be going wrong with this code; Basically I'm working on a turorial and calling the class below from another class - and it is getting the following error; Exception in thread "Thread-1" java.lang.NullPointerException at org.newdawn.spaceinvaders.TCPChat.run(TCPChat.java:322) at java.lang.Thread.run(Unknown Source) I realise the error is beibg flagged in another class- but I have tested the other class with a small class which sets up a separate thread - and it works fine, but as soon as I try and implement a new thread in this class - it causes all sorts of problems. Am I setting up the thread correctly in this class? Basically I can set up a thread in this class, with a test loop and it's fine, but when I bring in the functionality of the rest of the game it sometimes hangs, or does not display at all. Any suggestions on where I could be going wrong would be greatly appreciated. Thanks for looking. package org.newdawn.spaceinvaders; import java.awt.BorderLayout; import java.awt.Canvas; import java.awt.Color; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.Graphics2D; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyAdapter; import java.awt.event.KeyEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.awt.image.BufferStrategy; import java.util.ArrayList; import java.util.Scanner; import java.awt.*;//maybe not needed import javax.swing.*;//maybenot needed import java.util.Random; //import java.io.*; /** * The main hook of our game. This class with both act as a manager * for the display and central mediator for the game logic. * * Display management will consist of a loop that cycles round all * entities in the game asking them to move and then drawing them * in the appropriate place. With the help of an inner class it * will also allow the player to control the main ship. * * As a mediator it will be informed when entities within our game * detect events (e.g. alient killed, played died) and will take * appropriate game actions. * * @author Kevin Glass */ public class Game extends Canvas implements Runnable{ /** The stragey that allows us to use accelerate page flipping */ private BufferStrategy strategy; /** True if the game is currently "running", i.e. the game loop is looping */ private boolean gameRunning = true; /** The list of all the entities that exist in our game */ private ArrayList entities = new ArrayList(); /** The list of entities that need to be removed from the game this loop */ private ArrayList removeList = new ArrayList(); /** The entity representing the player */ private Entity ship; /** The speed at which the player's ship should move (pixels/sec) */ private double moveSpeed = 300; /** The time at which last fired a shot */ private long lastFire = 0; /** The interval between our players shot (ms) */ private long firingInterval = 500; /** The number of aliens left on the screen */ private int alienCount; /** The number of levels progressed */ private double levelCount; /** high score for the user */ private int highScore; /** high score for the user */ private String player = "bob"; //private GetUserInput getPlayer; /** The list of entities that need to be removed from the game this loop */ /** The message to display which waiting for a key press */ private String message = ""; /** True if we're holding up game play until a key has been pressed */ private boolean waitingForKeyPress = true; /** True if the left cursor key is currently pressed */ private boolean leftPressed = false; /** True if the right cursor key is currently pressed */ private boolean rightPressed = false; /** True if we are firing */ private boolean firePressed = false; /** True if game logic needs to be applied this loop, normally as a result of a game event */ private boolean logicRequiredThisLoop = false; //private Thread cThread = new Thread(this); //public Thread t = new Thread(this); //private Thread g = new Thread(this); void setHighscore(int setHS) { highScore = setHS; } public int getHighscore() { return highScore; } public void setPlayer(String setPlayer) { player = setPlayer; } public String getPlayer() { return player; } public void run() { //setup(); System.out.println("hello im running bob"); /*int count = 1; do { System.out.println("Count is: " + count); count++; try{Thread.sleep(1);} catch(InterruptedException e){} } while (count <= 2000000);*/ //Game g =new Game(); //Game g = this; // Start the main game loop, note: this method will not // return until the game has finished running. Hence we are // using the actual main thread to run the game. //setup(); //this.gameLoop(); //try{thread.sleep(1);} //catch{InterruptedException e} } /** * Construct our game and set it running. */ public Game () { //Thread t = new Thread(this);//set up new thread for invaders game //t.run();//run the run method of the game //Game g =new Game(); //setup(); //Thread t = new Thread(this); //thread.start(); //SwingUtilities.invokeLater(this); Thread er = new Thread(this); er.start(); } public void setup(){ //initialise highscore setHighscore(0); // create a frame to contain our game JFrame container = new JFrame("Space Invaders 101"); // get hold the content of the frame and set up the resolution of the game JPanel panel = (JPanel) container.getContentPane(); panel.setPreferredSize(new Dimension(800,600)); //panel.setLayout(null); // setup our canvas size and put it into the content of the frame setBounds(0,0,800,600); panel.add(this); // Tell AWT not to bother repainting our canvas since we're // going to do that our self in accelerated mode setIgnoreRepaint(true); // finally make the window visible container.pack(); container.setResizable(false); container.setVisible(true); // add a listener to respond to the user closing the window. If they // do we'd like to exit the game container.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { //cThread.interrupt(); System.exit(0); } }); // add a key input system (defined below) to our canvas // so we can respond to key pressed addKeyListener(new KeyInputHandler()); // request the focus so key events come to us requestFocus(); // create the buffering strategy which will allow AWT // to manage our accelerated graphics createBufferStrategy(2); strategy = getBufferStrategy(); // initialise the entities in our game so there's something // to see at startup initEntities(); } /** * Start a fresh game, this should clear out any old data and * create a new set. */ private void startGame() { // clear out any existing entities and intialise a new set entities.clear(); initEntities(); //initialise highscore setHighscore(0); // blank out any keyboard settings we might currently have leftPressed = false; rightPressed = false; firePressed = false; } /** * Initialise the starting state of the entities (ship and aliens). Each * entitiy will be added to the overall list of entities in the game. */ //private void initEntities() { public void initEntities() { Random randomAlien = new Random(); // create the player ship and place it roughly in the center of the screen //ship = new ShipEntity(this,"sprites/ship.gif",370,550);//orignal ship = new ShipEntity(this,"sprites/ship.gif",700,300);//changed postioning to right hand side entities.add(ship); // create a block of aliens (5 rows, by 12 aliens, spaced evenly) alienCount = 0; levelCount = 1.02; for (int row=0;row<7;row++) {//altered number of rows for (int x=0;x<5;x++) { int r = randomAlien.nextInt(100);//loop added to produce random aliens if (r < 50){ //Entity alien = new AlienEntity(this,"sprites/alien.gif",/*100+*/(x*50),(50)+row*30); Entity alien = new AlienEntity(this,"sprites/alien.gif",100+(x*90),(12)+row*85); entities.add(alien); alienCount++; } } } } //private void initEntities() { public void initAlienEntities() { Random randomAlien = new Random(); // create the player ship and place it roughly in the center of the screen //ship = new ShipEntity(this,"sprites/ship.gif",370,550);//orignal //ship = new ShipEntity(this,"sprites/ship.gif",700,300);//changed postioning to right hand side //entities.add(ship); // create a block of aliens (5 rows, by 12 aliens, spaced evenly) alienCount = 0; levelCount = levelCount + 0.10;//this increases the speed on every level for (int row=0;row<7;row++) {//altered number of rows for (int x=0;x<5;x++) { int r = randomAlien.nextInt(100);//loop added to produce random aliens if (r < 50){//randome check to show alien //Entity alien = new AlienEntity(this,"sprites/alien.gif",/*100+*/(x*50),(50)+row*30); Entity alien = new AlienEntity(this,"sprites/alien.gif",-250+(x*90),(12)+row*85); entities.add(alien); alienCount++; } } } advanceAlienSpeed(levelCount); } /** * Notification from a game entity that the logic of the game * should be run at the next opportunity (normally as a result of some * game event) */ public void updateLogic() { logicRequiredThisLoop = true; } /** * Remove an entity from the game. The entity removed will * no longer move or be drawn. * * @param entity The entity that should be removed */ public void removeEntity(Entity entity) { removeList.add(entity); } /** * Notification that the player has died. */ public void notifyDeath() { message = "Oh no! They got you, try again?"; waitingForKeyPress = true; } /** * Notification that the player has won since all the aliens * are dead. */ public void notifyWin() { message = "Well done! You Win!"; waitingForKeyPress = true; } /** * Notification that an alien has been killed */ public void notifyAlienKilled() { // reduce the alient count, if there are none left, the player has won! alienCount--; if (alienCount == 0) { //notifyWin();win not relevant here... this.initAlienEntities();//call fresh batch of aliens } // if there are still some aliens left then they all need to get faster, so // speed up all the existing aliens advanceAlienSpeed(1.30); } public void advanceAlienSpeed(double speed) { // if there are still some aliens left then they all need to get faster, so // speed up all the existing aliens for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); if (entity instanceof AlienEntity) { // speed up by 2% entity.setHorizontalMovement(entity.getHorizontalMovement() * speed); //entity.setVerticalMovement(entity.getVerticalMovement() * 1.02); } } } /** * Attempt to fire a shot from the player. Its called "try" * since we must first check that the player can fire at this * point, i.e. has he/she waited long enough between shots */ public void tryToFire() { // check that we have waiting long enough to fire if (System.currentTimeMillis() - lastFire < firingInterval) { return; } // if we waited long enough, create the shot entity, and record the time. lastFire = System.currentTimeMillis(); ShotEntity shot = new ShotEntity(this,"sprites/shot.gif",ship.getX()+10,ship.getY()-30); entities.add(shot); } /** * The main game loop. This loop is running during all game * play as is responsible for the following activities: * <p> * - Working out the speed of the game loop to update moves * - Moving the game entities * - Drawing the screen contents (entities, text) * - Updating game events * - Checking Input * <p> */ public void gameLoop() { long lastLoopTime = System.currentTimeMillis(); // keep looping round til the game ends while (gameRunning) { // work out how long its been since the last update, this // will be used to calculate how far the entities should // move this loop long delta = System.currentTimeMillis() - lastLoopTime; lastLoopTime = System.currentTimeMillis(); // Get hold of a graphics context for the accelerated // surface and blank it out Graphics2D g = (Graphics2D) strategy.getDrawGraphics(); g.setColor(Color.black); g.fillRect(0,0,800,600); // cycle round asking each entity to move itself if (!waitingForKeyPress) { for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.move(delta); } } // cycle round drawing all the entities we have in the game for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.draw(g); } // brute force collisions, compare every entity against // every other entity. If any of them collide notify // both entities that the collision has occured for (int p=0;p<entities.size();p++) { for (int s=p+1;s<entities.size();s++) { Entity me = (Entity) entities.get(p); Entity him = (Entity) entities.get(s); if (me.collidesWith(him)) { me.collidedWith(him); him.collidedWith(me); } } } // remove any entity that has been marked for clear up entities.removeAll(removeList); removeList.clear(); // if a game event has indicated that game logic should // be resolved, cycle round every entity requesting that // their personal logic should be considered. if (logicRequiredThisLoop) { //g.drawString("Press any key",(800-g.getFontMetrics().stringWidth("Press any key"))/2,300); for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.doLogic(); } logicRequiredThisLoop = false; } // if we're waiting for an "any key" press then draw the // current message //show highscore at top of screen //show name at top of screen g.setColor(Color.white); g.drawString("Player : "+getPlayer()+" : Score : "+getHighscore(),20,20); if (waitingForKeyPress) { g.setColor(Color.white); g.drawString(message,(800-g.getFontMetrics().stringWidth(message))/2,250); g.drawString("Press any key",(800-g.getFontMetrics().stringWidth("Press any key"))/2,300); } // finally, we've completed drawing so clear up the graphics // and flip the buffer over g.dispose(); strategy.show(); // resolve the movement of the ship. First assume the ship // isn't moving. If either cursor key is pressed then // update the movement appropraitely ship.setVerticalMovement(0);//set to vertical movement if ((leftPressed) && (!rightPressed)) { ship.setVerticalMovement(-moveSpeed);//**took out setHorizaontalMOvement } else if ((rightPressed) && (!leftPressed)) { ship.setVerticalMovement(moveSpeed);//**took out setHorizaontalMOvement } // if we're pressing fire, attempt to fire if (firePressed) { tryToFire(); } // finally pause for a bit. Note: this should run us at about // 100 fps but on windows this might vary each loop due to // a bad implementation of timer try { Thread.sleep(10); } catch (Exception e) {} } } /** * A class to handle keyboard input from the user. The class * handles both dynamic input during game play, i.e. left/right * and shoot, and more static type input (i.e. press any key to * continue) * * This has been implemented as an inner class more through * habbit then anything else. Its perfectly normal to implement * this as seperate class if slight less convienient. * * @author Kevin Glass */ private class KeyInputHandler extends KeyAdapter { /** The number of key presses we've had while waiting for an "any key" press */ private int pressCount = 1; /** * Notification from AWT that a key has been pressed. Note that * a key being pressed is equal to being pushed down but *NOT* * released. Thats where keyTyped() comes in. * * @param e The details of the key that was pressed */ public void keyPressed(KeyEvent e) { // if we're waiting for an "any key" typed then we don't // want to do anything with just a "press" if (waitingForKeyPress) { return; } // if (e.getKeyCode() == KeyEvent.VK_LEFT) { ////leftPressed = true; ///} //// if (e.getKeyCode() == KeyEvent.VK_RIGHT) { //rightPressed = true; if (e.getKeyCode() == KeyEvent.VK_UP) { leftPressed = true; } if (e.getKeyCode() == KeyEvent.VK_DOWN) { rightPressed = true; } if (e.getKeyCode() == KeyEvent.VK_SPACE) { firePressed = true; } } /** * Notification from AWT that a key has been released. * * @param e The details of the key that was released */ public void keyReleased(KeyEvent e) { // if we're waiting for an "any key" typed then we don't // want to do anything with just a "released" if (waitingForKeyPress) { return; } if (e.getKeyCode() == KeyEvent.VK_UP) {//changed from VK_LEFT leftPressed = false; } if (e.getKeyCode() == KeyEvent.VK_DOWN) {//changed from VK_RIGHT rightPressed = false; } if (e.getKeyCode() == KeyEvent.VK_SPACE) { firePressed = false; } } /** * Notification from AWT that a key has been typed. Note that * typing a key means to both press and then release it. * * @param e The details of the key that was typed. */ public void keyTyped(KeyEvent e) { // if we're waiting for a "any key" type then // check if we've recieved any recently. We may // have had a keyType() event from the user releasing // the shoot or move keys, hence the use of the "pressCount" // counter. if (waitingForKeyPress) { if (pressCount == 1) { // since we've now recieved our key typed // event we can mark it as such and start // our new game waitingForKeyPress = false; startGame(); pressCount = 0; } else { pressCount++; } } // if we hit escape, then quit the game if (e.getKeyChar() == 27) { //cThread.interrupt(); System.exit(0); } } } /** * The entry point into the game. We'll simply create an * instance of class which will start the display and game * loop. * * @param argv The arguments that are passed into our game */ //public static void main(String argv[]) { //Game g =new Game(); // Start the main game loop, note: this method will not // return until the game has finished running. Hence we are // using the actual main thread to run the game. //g.gameLoop(); //} }

    Read the article

  • NullPointerException when linking to Service that uses ContentProvider

    - by Danny Chia
    H.i everyone, this is my first post here! Anyways, I'm trying to write a "todo list" application. It stores the data in a ContentProvider, which is accessed via a Service. However, my app crashes at launch. My code is below: Manifest file: <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.examples.todolist" android:versionCode="1" android:versionName="1.0"> <application android:icon="@drawable/icon" android:label="@string/app_name" android:debuggable="True"> <activity android:name=".ToDoList" android:label="@string/app_name" android:theme="@style/ToDoTheme"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <service android:name="TodoService"/> <provider android:name="TodoProvider" android:authorities="com.examples.provider.todolist" /> </application> <uses-sdk android:minSdkVersion="7" /> </manifest> ToDoList.java: package com.examples.todolist; import com.examples.todolist.TodoService.LocalBinder; import java.util.ArrayList; import java.util.Date; import android.app.Activity; import android.content.SharedPreferences; import android.database.Cursor; import android.os.AsyncTask; import android.os.Bundle; import android.view.ContextMenu; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.ServiceConnection; import android.os.IBinder; import android.view.KeyEvent; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.View.OnKeyListener; import android.widget.AdapterView; import android.widget.EditText; import android.widget.ListView; import android.widget.Toast; public class ToDoList extends Activity { static final private int ADD_NEW_TODO = Menu.FIRST; static final private int REMOVE_TODO = Menu.FIRST + 1; private static final String TEXT_ENTRY_KEY = "TEXT_ENTRY_KEY"; private static final String ADDING_ITEM_KEY = "ADDING_ITEM_KEY"; private static final String SELECTED_INDEX_KEY = "SELECTED_INDEX_KEY"; private boolean addingNew = false; private ArrayList<ToDoItem> todoItems; private ListView myListView; private EditText myEditText; private ToDoItemAdapter aa; int entries = 0; int notifs = 0; //ToDoDBAdapter toDoDBAdapter; Cursor toDoListCursor; TodoService mService; boolean mBound = false; /** Called when the activity is first created. */ public void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.main); myListView = (ListView)findViewById(R.id.myListView); myEditText = (EditText)findViewById(R.id.myEditText); todoItems = new ArrayList<ToDoItem>(); int resID = R.layout.todolist_item; aa = new ToDoItemAdapter(this, resID, todoItems); myListView.setAdapter(aa); myEditText.setOnKeyListener(new OnKeyListener() { public boolean onKey(View v, int keyCode, KeyEvent event) { if (event.getAction() == KeyEvent.ACTION_DOWN) if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) { ToDoItem newItem = new ToDoItem(myEditText.getText().toString(), 0); mService.insertTask(newItem); updateArray(); myEditText.setText(""); entries++; Toast.makeText(ToDoList.this, "Entry added", Toast.LENGTH_SHORT).show(); aa.notifyDataSetChanged(); cancelAdd(); return true; } return false; } }); registerForContextMenu(myListView); restoreUIState(); populateTodoList(); } private void populateTodoList() { // Get all the todo list items from the database. toDoListCursor = mService. getAllToDoItemsCursor(); startManagingCursor(toDoListCursor); // Update the array. updateArray(); Toast.makeText(this, "Todo list retrieved", Toast.LENGTH_SHORT).show(); } private void updateArray() { toDoListCursor.requery(); todoItems.clear(); if (toDoListCursor.moveToFirst()) do { String task = toDoListCursor.getString(toDoListCursor.getColumnIndex(ToDoDBAdapter.KEY_TASK)); long created = toDoListCursor.getLong(toDoListCursor.getColumnIndex(ToDoDBAdapter.KEY_CREATION_DATE)); int taskid = toDoListCursor.getInt(toDoListCursor.getColumnIndex(ToDoDBAdapter.KEY_ID)); ToDoItem newItem = new ToDoItem(task, new Date(created), taskid); todoItems.add(0, newItem); } while(toDoListCursor.moveToNext()); aa.notifyDataSetChanged(); } private void restoreUIState() { // Get the activity preferences object. SharedPreferences settings = getPreferences(0); // Read the UI state values, specifying default values. String text = settings.getString(TEXT_ENTRY_KEY, ""); Boolean adding = settings.getBoolean(ADDING_ITEM_KEY, false); // Restore the UI to the previous state. if (adding) { addNewItem(); myEditText.setText(text); } } @Override public void onSaveInstanceState(Bundle outState) { outState.putInt(SELECTED_INDEX_KEY, myListView.getSelectedItemPosition()); super.onSaveInstanceState(outState); } @Override public void onRestoreInstanceState(Bundle savedInstanceState) { int pos = -1; if (savedInstanceState != null) if (savedInstanceState.containsKey(SELECTED_INDEX_KEY)) pos = savedInstanceState.getInt(SELECTED_INDEX_KEY, -1); myListView.setSelection(pos); } @Override protected void onPause() { super.onPause(); // Get the activity preferences object. SharedPreferences uiState = getPreferences(0); // Get the preferences editor. SharedPreferences.Editor editor = uiState.edit(); // Add the UI state preference values. editor.putString(TEXT_ENTRY_KEY, myEditText.getText().toString()); editor.putBoolean(ADDING_ITEM_KEY, addingNew); // Commit the preferences. editor.commit(); } @Override public boolean onCreateOptionsMenu(Menu menu) { super.onCreateOptionsMenu(menu); // Create and add new menu items. MenuItem itemAdd = menu.add(0, ADD_NEW_TODO, Menu.NONE, R.string.add_new); MenuItem itemRem = menu.add(0, REMOVE_TODO, Menu.NONE, R.string.remove); // Assign icons itemAdd.setIcon(R.drawable.add_new_item); itemRem.setIcon(R.drawable.remove_item); // Allocate shortcuts to each of them. itemAdd.setShortcut('0', 'a'); itemRem.setShortcut('1', 'r'); return true; } @Override public boolean onPrepareOptionsMenu(Menu menu) { super.onPrepareOptionsMenu(menu); int idx = myListView.getSelectedItemPosition(); String removeTitle = getString(addingNew ? R.string.cancel : R.string.remove); MenuItem removeItem = menu.findItem(REMOVE_TODO); removeItem.setTitle(removeTitle); removeItem.setVisible(addingNew || idx > -1); return true; } @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) { super.onCreateContextMenu(menu, v, menuInfo); menu.setHeaderTitle("Selected To Do Item"); menu.add(0, REMOVE_TODO, Menu.NONE, R.string.remove); } @Override public boolean onOptionsItemSelected(MenuItem item) { super.onOptionsItemSelected(item); int index = myListView.getSelectedItemPosition(); switch (item.getItemId()) { case (REMOVE_TODO): { if (addingNew) { cancelAdd(); } else { removeItem(index); } return true; } case (ADD_NEW_TODO): { addNewItem(); return true; } } return false; } @Override public boolean onContextItemSelected(MenuItem item) { super.onContextItemSelected(item); switch (item.getItemId()) { case (REMOVE_TODO): { AdapterView.AdapterContextMenuInfo menuInfo; menuInfo =(AdapterView.AdapterContextMenuInfo)item.getMenuInfo(); int index = menuInfo.position; removeItem(index); return true; } } return false; } @Override public void onDestroy() { super.onDestroy(); } private void cancelAdd() { addingNew = false; myEditText.setVisibility(View.GONE); } private void addNewItem() { addingNew = true; myEditText.setVisibility(View.VISIBLE); myEditText.requestFocus(); } private void removeItem(int _index) { // Items are added to the listview in reverse order, so invert the index. //toDoDBAdapter.removeTask(todoItems.size()-_index); ToDoItem item = todoItems.get(_index); final long selectedId = item.getTaskId(); mService.removeTask(selectedId); entries--; Toast.makeText(this, "Entry deleted", Toast.LENGTH_SHORT).show(); updateArray(); } @Override protected void onStart() { super.onStart(); Intent intent = new Intent(this, TodoService.class); bindService(intent, mConnection, Context.BIND_AUTO_CREATE); } @Override protected void onStop() { super.onStop(); // Unbind from the service if (mBound) { unbindService(mConnection); mBound = false; } } private ServiceConnection mConnection = new ServiceConnection() { public void onServiceConnected(ComponentName className, IBinder service) { LocalBinder binder = (LocalBinder) service; mService = binder.getService(); mBound = true; } public void onServiceDisconnected(ComponentName arg0) { mBound = false; } }; public class TimedToast extends AsyncTask<Long, Integer, Integer> { @Override protected Integer doInBackground(Long... arg0) { if (notifs < 15) { try { Toast.makeText(ToDoList.this, entries + " entries left", Toast.LENGTH_SHORT).show(); notifs++; Thread.sleep(20000); } catch (InterruptedException e) { } } return 0; } } } TodoService.java: package com.examples.todolist; import android.app.Service; import android.content.ContentResolver; import android.content.ContentValues; import android.content.Intent; import android.database.Cursor; import android.os.Binder; import android.os.IBinder; public class TodoService extends Service { private final IBinder mBinder = new LocalBinder(); @Override public IBinder onBind(Intent arg0) { return mBinder; } public class LocalBinder extends Binder { TodoService getService() { return TodoService.this; } } public void insertTask(ToDoItem _task) { ContentResolver cr = getContentResolver(); ContentValues values = new ContentValues(); values.put(TodoProvider.KEY_CREATION_DATE, _task.getCreated().getTime()); values.put(TodoProvider.KEY_TASK, _task.getTask()); cr.insert(TodoProvider.CONTENT_URI, values); } public void updateTask(ToDoItem _task) { long tid = _task.getTaskId(); ContentResolver cr = getContentResolver(); ContentValues values = new ContentValues(); values.put(TodoProvider.KEY_TASK, _task.getTask()); cr.update(TodoProvider.CONTENT_URI, values, TodoProvider.KEY_ID + "=" + tid, null); } public void removeTask(long tid) { ContentResolver cr = getContentResolver(); cr.delete(TodoProvider.CONTENT_URI, TodoProvider.KEY_ID + "=" + tid, null); } public Cursor getAllToDoItemsCursor() { ContentResolver cr = getContentResolver(); return cr.query(TodoProvider.CONTENT_URI, null, null, null, null); } } TodoProvider.java: package com.examples.todolist; import android.content.*; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteOpenHelper; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteQueryBuilder; import android.database.sqlite.SQLiteDatabase.CursorFactory; import android.net.Uri; import android.text.TextUtils; import android.util.Log; public class TodoProvider extends ContentProvider { public static final Uri CONTENT_URI = Uri.parse("content://com.examples.provider.todolist/todo"); @Override public boolean onCreate() { Context context = getContext(); todoHelper dbHelper = new todoHelper(context, DATABASE_NAME, null, DATABASE_VERSION); todoDB = dbHelper.getWritableDatabase(); return (todoDB == null) ? false : true; } @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sort) { SQLiteQueryBuilder tb = new SQLiteQueryBuilder(); tb.setTables(TODO_TABLE); // If this is a row query, limit the result set to the passed in row. switch (uriMatcher.match(uri)) { case TASK_ID: tb.appendWhere(KEY_ID + "=" + uri.getPathSegments().get(1)); break; default: break; } // If no sort order is specified sort by date / time String orderBy; if (TextUtils.isEmpty(sort)) { orderBy = KEY_ID; } else { orderBy = sort; } // Apply the query to the underlying database. Cursor c = tb.query(todoDB, projection, selection, selectionArgs, null, null, orderBy); // Register the contexts ContentResolver to be notified if // the cursor result set changes. c.setNotificationUri(getContext().getContentResolver(), uri); // Return a cursor to the query result. return c; } @Override public Uri insert(Uri _uri, ContentValues _initialValues) { // Insert the new row, will return the row number if // successful. long rowID = todoDB.insert(TODO_TABLE, "task", _initialValues); // Return a URI to the newly inserted row on success. if (rowID > 0) { Uri uri = ContentUris.withAppendedId(CONTENT_URI, rowID); getContext().getContentResolver().notifyChange(uri, null); return uri; } throw new SQLException("Failed to insert row into " + _uri); } @Override public int delete(Uri uri, String where, String[] whereArgs) { int count; switch (uriMatcher.match(uri)) { case TASKS: count = todoDB.delete(TODO_TABLE, where, whereArgs); break; case TASK_ID: String segment = uri.getPathSegments().get(1); count = todoDB.delete(TODO_TABLE, KEY_ID + "=" + segment + (!TextUtils.isEmpty(where) ? " AND (" + where + ')' : ""), whereArgs); break; default: throw new IllegalArgumentException("Unsupported URI: " + uri); } getContext().getContentResolver().notifyChange(uri, null); return count; } @Override public int update(Uri uri, ContentValues values, String where, String[] whereArgs) { int count; switch (uriMatcher.match(uri)) { case TASKS: count = todoDB.update(TODO_TABLE, values, where, whereArgs); break; case TASK_ID: String segment = uri.getPathSegments().get(1); count = todoDB.update(TODO_TABLE, values, KEY_ID + "=" + segment + (!TextUtils.isEmpty(where) ? " AND (" + where + ')' : ""), whereArgs); break; default: throw new IllegalArgumentException("Unknown URI " + uri); } getContext().getContentResolver().notifyChange(uri, null); return count; } @Override public String getType(Uri uri) { switch (uriMatcher.match(uri)) { case TASKS: return "vnd.android.cursor.dir/vnd.examples.task"; case TASK_ID: return "vnd.android.cursor.item/vnd.examples.task"; default: throw new IllegalArgumentException("Unsupported URI: " + uri); } } // Create the constants used to differentiate between the different URI // requests. private static final int TASKS = 1; private static final int TASK_ID = 2; private static final UriMatcher uriMatcher; // Allocate the UriMatcher object, where a URI ending in 'tasks' will // correspond to a request for all tasks, and 'tasks' with a // trailing '/[rowID]' will represent a single task row. static { uriMatcher = new UriMatcher(UriMatcher.NO_MATCH); uriMatcher.addURI("com.examples.provider.Todolist", "tasks", TASKS); uriMatcher.addURI("com.examples.provider.Todolist", "tasks/#", TASK_ID); } //The underlying database private SQLiteDatabase todoDB; private static final String TAG = "TodoProvider"; private static final String DATABASE_NAME = "todolist.db"; private static final int DATABASE_VERSION = 1; private static final String TODO_TABLE = "todolist"; // Column Names public static final String KEY_ID = "_id"; public static final String KEY_TASK = "task"; public static final String KEY_CREATION_DATE = "date"; public long insertTask(ToDoItem _task) { // Create a new row of values to insert. ContentValues newTaskValues = new ContentValues(); // Assign values for each row. newTaskValues.put(KEY_TASK, _task.getTask()); newTaskValues.put(KEY_CREATION_DATE, _task.getCreated().getTime()); // Insert the row. return todoDB.insert(TODO_TABLE, null, newTaskValues); } public boolean updateTask(long _rowIndex, String _task) { ContentValues newValue = new ContentValues(); newValue.put(KEY_TASK, _task); return todoDB.update(TODO_TABLE, newValue, KEY_ID + "=" + _rowIndex, null) > 0; } public boolean removeTask(long _rowIndex) { return todoDB.delete(TODO_TABLE, KEY_ID + "=" + _rowIndex, null) > 0; } // Helper class for opening, creating, and managing database version control private static class todoHelper extends SQLiteOpenHelper { private static final String DATABASE_CREATE = "create table " + TODO_TABLE + " (" + KEY_ID + " integer primary key autoincrement, " + KEY_TASK + " TEXT, " + KEY_CREATION_DATE + " INTEGER);"; public todoHelper(Context cn, String name, CursorFactory cf, int ver) { super(cn, name, cf, ver); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL(DATABASE_CREATE); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { Log.w(TAG, "Upgrading database from version " + oldVersion + " to " + newVersion + ", which will destroy all old data"); db.execSQL("DROP TABLE IF EXISTS " + TODO_TABLE); onCreate(db); } } } I've omitted the other files as I'm sure they are correct. When I run the program, LogCat shows that the NullPointerException occurs in populateTodoList(), at toDoListCursor = mService.getAllToDoItemsCursor(). mService is the Cursor object returned by TodoService. I've added the service to the Manifest file, but I still cannot find out why it's causing an exception. Thanks in advance.

    Read the article

< Previous Page | 12 13 14 15 16