Packageing Image Encoders *
To package your image encoder, create an uncompressed zip file with the file name * cpXXX.zip, where XXX can be anything you want. (It has to be unique, so use * your company name, or the plugin name, or something like that.) * Put all your classes into that .zip file. At the top level of the .zip archive, * add a file called "netscape_plugin_composer.ini". *
Format of the "netscape_plugin_composer.ini" file. *
It is in standard java "Properties" file format. * The following properties are 'well known', and are used by the composer plugin * framework: *
* netscape.plugin.composer.imageEncoder.factory - a single classname of a Factory class. * netscape.plugin.composer.imageEncoder.classes - a colon-separated list of the classnames of the plugins in * this archive. **
Your encoder's class name should be listed as the value of the * netscape.plugin.composer.imageEncoder.classes * property. You can place several encoders in the same plugin file. All the encoder names should be * listed in the netscape.plugin.composer.imageEncoder.classes property. *
Alternatively, you can use a factory class to create your image encoders at runtime. *
*
Installing the Image Encoder package. *
Put that .zip file in the Netscape Plugins directory (or a subdirectory.) Then restart the * Composer application. * @see netscape.plugin.composer.Plugin * @see netscape.plugin.composer.ImageEncoderFactory * */ public class ImageEncoder { /** The default constructor for an image encoder. If you have a default constructor, it must be public. * so that your image encoder can be instantiated by name. (Also, your image encoder class must be a public * class so that it can be instantiated by name.) */ public ImageEncoder() {} /** Get the human readable name of the image encoder. Defaults to the name of the image encoder class. This * text will show up as the text of a menu item. * @return the human readable name of the image encoder. */ public String getName() { return getClass().getName(); } /** Get the human readable hint text for the image encoder. This is a one-sentence description of * what the image encoder does. Defaults to the name of the image encoder class. This text will * show up in the status line as the user moves the mouse over the plug-in's menu item. * @return the human readable hint for the image encoder. */ public String getHint() { return getClass().getName(); } /** Get the standard file extension of the image format. Defaults to the * empty string. Does not include the period. * @return the human readable category of the image encoder. */ public String getFileExtension() { return new String(); } /** Get the Macintosh FileType of the image format. Defaults to '????'. * @param type - a 4 byte array to be filled in with the FileType of the image format. */ public void getFileType(byte[] type) { type[0] = '?'; type[1] = '?'; type[2] = '?'; type[3] = '?'; } /** Does the source image have to be quantized? If this method returns true, * then the source image will be quantized (by some method) to contain * 256 or fewer distinct colors. If you want to use a specific quantization * technique, or if you want to interact with the user to optionally quantize, * then you will have to return false from this method, and supply your own * quantization code. *
Returns false by default. * @return true if the source image must be quantized before it is passed to encode(). */ public boolean needsQuantizedSource(){ return false; } /** Encode the image. * Override this method to perform the bulk of your work. * This is where your image encoder reads the image information out of the * image source, interacts * with the user, and writes the encoded information to the output stream. *
* The rest of the composer user interface is held in a modal state while your image encoder * is executing. So either finish quickly, or display a progress dialog, or otherwise * let the user know what's going on. *
* By default this method returns false. * @param source the image to encode. * @param destination the output stream to write the encoded information to. * @return true if the encoding should be permenent. False if the * encoding should be cancled. (Return false if the user Cancels the operation.) */ public boolean encode(ImageProducer source, OutputStream output) throws IOException { return false; } /** Used to register an encoder with the system. Registered encoders are * available for any program to use. * @param encoder An encoder to be register. */ public static void register(ImageEncoder encoder) { encoders_.addElement(encoder); } /* Returns the registered encoders. */ public static Enumeration encoders() { return encoders_.elements(); } private static Vector encoders_ = new Vector(); }