* Supported file formats are JPEG and GIF. * PNG is supported since Java 1.3. * I have heard that XBM are supposedly loaded as well. * I don't know that format and haven't tested this functionality. *
* In addition, this class can also use JIU's built-in codecs from * this class. *
* RGB24Image rgbImage = ToolkitLoader.loadAsRgb24Image("flower.jpg");
*
* This will only load images from files in formats that are supported
* by Toolkit - normally, that only includes JPEG, GIF and since Java 1.3 PNG.
* A potential problem of this approach is that Toolkit always delivers RGB
* data, even if the image file only contains a black and white image.
* In order to get an image object of the "real" type, try
* JIU's {@link net.sourceforge.jiu.color.reduction.AutoDetectColorType} with
* rgbImage (if you follow the link you will get a usage example
* for that class as well).
*
* System.exit(0);.
* @author Marco Schmidt
*/
public class ToolkitLoader
{
private static Frame frame = null;
/**
* This class has only static methods and fields, so there is no need to instantiate it.
* That's why the empty constructor is hidden here.
*/
private ToolkitLoader()
{
}
/**
* Loads an image from a file using the AWT's built-in loader.
* Returns that image as an AWT {@link java.awt.Image} object.
* This method does nothing more than call {@link java.awt.Toolkit#getImage(String)},
* wait for it using a {@link java.awt.MediaTracker} and return
* the resulting image.
*
* @param fileName name of the image file
* @return the image as AWT image object
*/
public static Image load(String fileName)
{
Toolkit toolkit = Toolkit.getDefaultToolkit();
Image image = toolkit.getImage(fileName);
if (frame == null)
{
frame = new Frame();
}
MediaTracker mt = new MediaTracker(frame);
mt.addImage(image, 0);
try
{
mt.waitForID(0);
}
catch (InterruptedException e)
{
return null;
}
return image;
}
/**
* Loads an image from a file using the AWT's built-in loader and
* converts the image to a {@link net.sourceforge.jiu.data.RGB24Image}
* object.
* First calls {@link #load} with the filename, then converts
* the loaded image using {@link ImageCreator#convertImageToRGB24Image}.
* @param fileName name of the file from which the image is to be loaded
* @return loaded image as {@link net.sourceforge.jiu.data.RGB24Image}
*/
public static RGB24Image loadAsRgb24Image(String fileName)
{
return ImageCreator.convertImageToRGB24Image(load(fileName));
}
/**
* Attempts to load an image from a file given by its name,
* using both the JIU codecs and the image loading functionality in
* java.awt.Toolkit.
* First tries JIU's codecs, then java.awt.Toolkit.
* Simply calls loadViaToolkitOrCodecs(fileName, false);.
* @param fileName name of the image file
* @return image object or null on failure
*/
public static PixelImage loadViaToolkitOrCodecs(String fileName)
{
return loadViaToolkitOrCodecs(fileName, false, null);
}
/**
* Attempts to load an image from a file given by its name,
* using both the JIU codecs and the image loading functionality in
* java.awt.Toolkit.
* The second argument determines which method is tried first,
* Toolkit (true) or the JIU codecs (false).
* Uses {@link #loadAsRgb24Image} from this class for Toolkit loading
* and {@link net.sourceforge.jiu.codecs.ImageLoader} for JIU's codecs.
* @param fileName name of the image file
* @return image object or null on failure
*/
public static PixelImage loadViaToolkitOrCodecs(String fileName, boolean preferToolkit, Vector progressListeners)
{
PixelImage result = null;
try
{
if (preferToolkit)
{
result = loadAsRgb24Image(fileName);
if (result == null)
{
result = ImageLoader.load(fileName, progressListeners);
}
}
else
{
result = ImageLoader.load(fileName, progressListeners);
if (result == null)
{
result = loadAsRgb24Image(fileName);
}
}
}
catch (OperationFailedException ofe)
{
}
catch (IOException ioe)
{
}
return result;
}
}