//****************************************************************************** // Demo.java: Applet // //****************************************************************************** import java.applet.*; import java.awt.*; import DemoFrame; //============================================================================== // Main Class for applet Demo // //============================================================================== public class Demo extends Applet implements Runnable { // THREAD SUPPORT: // m_Demo is the Thread object for the applet //-------------------------------------------------------------------------- Thread m_Demo = null; // ANIMATION SUPPORT: // m_Graphics used for storing the applet's Graphics context // m_Images[] the array of Image objects for the animation // m_nCurrImage the index of the next image to be displayed // m_ImgWidth width of each image // m_ImgHeight height of each image // m_fAllLoaded indicates whether all images have been loaded // NUM_IMAGES number of images used in the animation //-------------------------------------------------------------------------- private Graphics m_Graphics; private Image m_Images[]; private int m_nCurrImage; private int m_nImgWidth = 0; private int m_nImgHeight = 0; private boolean m_fAllLoaded = false; private final int NUM_IMAGES = 18; // STANDALONE APPLICATION SUPPORT: // m_fStandAlone will be set to true if applet is run standalone //-------------------------------------------------------------------------- boolean m_fStandAlone = false; // STANDALONE APPLICATION SUPPORT // The main() method acts as the applet's entry point when it is run // as a standalone application. It is ignored if the applet is run from // within an HTML page. //-------------------------------------------------------------------------- public static void main(String args[]) { // Create Toplevel Window to contain applet Demo //---------------------------------------------------------------------- DemoFrame frame = new DemoFrame("Demo"); // Must show Frame before we size it so insets() will return valid values //---------------------------------------------------------------------- frame.show(); frame.hide(); frame.resize(frame.insets().left + frame.insets().right + 320, frame.insets().top + frame.insets().bottom + 240); // The following code starts the applet running within the frame window. // It also calls GetParameters() to retrieve parameter values from the // command line, and sets m_fStandAlone to true to prevent init() from // trying to get them from the HTML page. //---------------------------------------------------------------------- Demo applet_Demo = new Demo(); frame.add("Center", applet_Demo); applet_Demo.m_fStandAlone = true; applet_Demo.init(); applet_Demo.start(); frame.show(); } // Demo Class Constructor //-------------------------------------------------------------------------- public Demo() { // TODO: Add constructor code here } // APPLET INFO SUPPORT: // The getAppletInfo() method returns a string describing the applet's // author, copyright date, or miscellaneous information. //-------------------------------------------------------------------------- public String getAppletInfo() { return "Name: Demo\r\n" + "Author: Richard Salter\r\n" + "Created with Microsoft Visual J++ Version 1.0"; } // The init() method is called by the AWT when an applet is first loaded or // reloaded. Override this method to perform whatever initialization your // applet needs, such as initializing data structures, loading images or // fonts, creating frame windows, setting the layout manager, or adding UI // components. //-------------------------------------------------------------------------- public void init() { // If you use a ResourceWizard-generated "control creator" class to // arrange controls in your applet, you may want to call its // CreateControls() method from within this method. Remove the following // call to resize() before adding the call to CreateControls(); // CreateControls() does its own resizing. //---------------------------------------------------------------------- resize(320, 240); // TODO: Place additional initialization code here } // Place additional applet clean up code here. destroy() is called when // when you applet is terminating and being unloaded. //------------------------------------------------------------------------- public void destroy() { // TODO: Place applet cleanup code here } // ANIMATION SUPPORT: // Draws the next image, if all images are currently loaded //-------------------------------------------------------------------------- private void displayImage(Graphics g) { if (!m_fAllLoaded) return; // Draw Image in center of applet //---------------------------------------------------------------------- g.drawImage(m_Images[m_nCurrImage], (size().width - m_nImgWidth) / 2, (size().height - m_nImgHeight) / 2, null); } // Demo Paint Handler //-------------------------------------------------------------------------- public void paint(Graphics g) { // ANIMATION SUPPORT: // The following code displays a status message until all the // images are loaded. Then it calls displayImage to display the current // image. //---------------------------------------------------------------------- if (m_fAllLoaded) { Rectangle r = g.getClipRect(); g.clearRect(r.x, r.y, r.width, r.height); displayImage(g); } else g.drawString("Loading images...", 10, 20); // TODO: Place additional applet Paint code here } // The start() method is called when the page containing the applet // first appears on the screen. The AppletWizard's initial implementation // of this method starts execution of the applet's thread. //-------------------------------------------------------------------------- public void start() { if (m_Demo == null) { m_Demo = new Thread(this); m_Demo.start(); } // TODO: Place additional applet start code here } // The stop() method is called when the page containing the applet is // no longer on the screen. The AppletWizard's initial implementation of // this method stops execution of the applet's thread. //-------------------------------------------------------------------------- public void stop() { if (m_Demo != null) { m_Demo.stop(); m_Demo = null; } // TODO: Place additional applet stop code here } // THREAD SUPPORT // The run() method is called when the applet's thread is started. If // your applet performs any ongoing activities without waiting for user // input, the code for implementing that behavior typically goes here. For // example, for an applet that performs animation, the run() method controls // the display of images. //-------------------------------------------------------------------------- public void run() { m_nCurrImage = 0; // If re-entering the page, then the images have already been loaded. // m_fAllLoaded == TRUE. //---------------------------------------------------------------------- if (!m_fAllLoaded) { repaint(); m_Graphics = getGraphics(); m_Images = new Image[NUM_IMAGES]; // Load in all the images //------------------------------------------------------------------ MediaTracker tracker = new MediaTracker(this); String strImage; // For each image in the animation, this method first constructs a // string containing the path to the image file; then it begins // loading the image into the m_Images array. Note that the call to // getImage will return before the image is completely loaded. //------------------------------------------------------------------ for (int i = 1; i <= NUM_IMAGES; i++) { // Build path to next image //-------------------------------------------------------------- strImage = "images/img00" + ((i < 10) ? "0" : "") + i + ".gif"; if (m_fStandAlone) m_Images[i-1] = Toolkit.getDefaultToolkit().getImage(strImage); else m_Images[i-1] = getImage(getDocumentBase(), strImage); tracker.addImage(m_Images[i-1], 0); } // Wait until all images are fully loaded //------------------------------------------------------------------ try { tracker.waitForAll(); m_fAllLoaded = !tracker.isErrorAny(); } catch (InterruptedException e) { // TODO: Place exception-handling code here in case an // InterruptedException is thrown by Thread.sleep(), // meaning that another thread has interrupted this one } if (!m_fAllLoaded) { stop(); m_Graphics.drawString("Error loading images!", 10, 40); return; } // Assuming all images are same width and height. //-------------------------------------------------------------- m_nImgWidth = m_Images[0].getWidth(this); m_nImgHeight = m_Images[0].getHeight(this); } repaint(); while (true) { try { // Draw next image in animation //-------------------------------------------------------------- displayImage(m_Graphics); m_nCurrImage++; if (m_nCurrImage == NUM_IMAGES) m_nCurrImage = 0; // TODO: Add additional thread-specific code here Thread.sleep(50); } catch (InterruptedException e) { // TODO: Place exception-handling code here in case an // InterruptedException is thrown by Thread.sleep(), // meaning that another thread has interrupted this one stop(); } } } // TODO: Place additional applet code here }