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POImage won't paint to animation
 

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  1. POImage won't paint to animation
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    <p>Having problems loading/showing an image in a java applet. Not sure if I'm loading the image incorrectly or if I'm accessing it incorrectly. Here's the code that draws the ship and the background(it's an asteroid-like game). The background draws correctly but the ship doesn't. This is the main class method that I'm dealing with:</p> <pre><code>public void paintFrame(Graphics g) { Dimension d = size(); g.fillRect(0, 0, d.width, d.height); g.drawImage(ship.getImage(), d.width/2, d.height/2, null); } </code></pre> <p>I create an instance of the ship class at the beginning of the class. However, if I try to instantiate the ship class in a method (such as "Ship ship = new Ship();), it says the variable "ship" is never used.</p> <p>Here's the entire ship class:</p> <pre><code>public class Ship { private int dx; private int dy; private int x; private int y; private Image image; public Ship() { ImageIcon ii = new ImageIcon("ship1.png"); image = ii.getImage(); } public Image getImage() { return image; } } </code></pre> <p>If I run it as is, it runs without errors, but it doesn't display the ship. If I try to create the instance of the ship anywhere else except at the top, it gives me a NullPointerException.</p> <p><em>Update</em></p> <p>Here's my entire main class:</p> <pre><code>import java.applet.Applet; import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Image; public class RunGame extends Applet implements Runnable { int frame; int delay; Thread animator; Ship ship = new Ship(); Level level; Dimension offDimension; Image offImage; Graphics offGraphics; /** * Initialize the applet and compute the delay between frames. */ public void init() { String str = getParameter("fps"); int fps = (str != null) ? Integer.parseInt(str) : 10; delay = (fps &gt; 0) ? (1000 / fps) : 100; } /** * Method is called when the applet becomes visible on * the screen. */ public void start() { animator = new Thread(this); animator.start(); } /** * This method is called by the thread that was created in * the start method. It does the main animation. */ public void run() { // Remember the starting time long tm = System.currentTimeMillis(); while (Thread.currentThread() == animator) { // Display the next frame of animation. repaint(); // Delay depending on how far we are behind. try { tm += delay; Thread.sleep(Math.max(0, tm - System.currentTimeMillis())); } catch (InterruptedException e) { break; } // Advance the frame frame++; } } /** * This method is called when the applet is no longer * visible. Set the animator variable to null so that the * thread will exit before displaying the next frame. */ public void stop() { animator = null; offImage = null; offGraphics = null; } /** * Update a frame of animation. */ public void update(Graphics g) { Dimension d = size(); // Create the offscreen graphics context if ((offGraphics == null) || (d.width != offDimension.width) || (d.height != offDimension.height)) { offDimension = d; offImage = createImage(d.width, d.height); offGraphics = offImage.getGraphics(); } // Erase the previous image offGraphics.setColor(getBackground()); offGraphics.fillRect(0, 0, d.width, d.height); offGraphics.setColor(Color.black); // Paint the frame into the image paintFrame(offGraphics); // Paint the image onto the screen g.drawImage(offImage, 0, 0, null); } /** * Paint the previous frame (if any). */ public void paint(Graphics g) { if (offImage != null) { g.drawImage(offImage, 0, 0, null); } } /** * Paint a frame of animation. */ public void paintFrame(Graphics g) { Dimension d = size(); g.fillRect(0, 0, d.width, d.height); //g.drawImage(level.getImage(), 0, 0, null); g.drawImage(ship.getImage(), 400, 300, null); } } </code></pre>
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    1. COIs `paintFrame()` called from within a paintComponent method? Please have a look here: [Performing Custom Painting with Swing](http://docs.oracle.com/javase/tutorial/uiswing/painting/index.html).
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      1. USHovercraft Full Of Eels
    2. COYou should not read in images from within a drawing method to begin with -- read it in *once*, say in the class's constructor, and use `ImageIO.read(...)` to do this. Where is your NPE being thrown? Are you testing that the image is actually being read in? Is your image located within the user.dir? Or where exactly *is* the image file relative to everything?
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      1. USHovercraft Full Of Eels
    3. CO@HovercraftFullOfEels : Beg your pardon, but JApplets don't have `paintComponent(...)` method, seems like OP is using JApplet, as his question is saying "Having problems loading/showing an image in a java applet".
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      1. USnIcE cOw
 

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