package org.freehep.util.images;
import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.Point;
import java.awt.Toolkit;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Hashtable;
import javax.swing.Icon;
import javax.swing.ImageIcon;
/**
* A convenience class for handling images.
* Maintains a cache of images suitable for small icons which may be reused
* often.
*
* @author Tony Johnson
* @author Cal Loomis
* @version $Id: ImageHandler.java 8584 2006-08-10 23:06:37Z duns $
*/
public class ImageHandler
{
public static final Image brokenImage;
public static final Cursor brokenCursor;
public static final Icon brokenIcon;
private static String[] imageExtensions = { ".png", ".gif", ".jpeg", ".jpg" };
private static Hashtable imageCache = new Hashtable();
private static Hashtable cursorCache = new Hashtable();
private static Hashtable iconCache = new Hashtable();
// only static methods
protected ImageHandler()
{
}
static
{
Toolkit toolkit = Toolkit.getDefaultToolkit();
brokenImage = toolkit.getImage(ImageHandler.class.getResource("BrokenImage.gif"));
if (brokenImage == null)
{
throw new RuntimeException("Could not load BrokenIcon .. this looks bad!");
}
brokenIcon = new ImageIcon(brokenImage,"BrokenIcon");
Image brokenCursorImage = toolkit.getImage(ImageHandler.class.getResource("BrokenCursor.gif"));
if (GraphicsEnvironment.isHeadless()) {
// if run with headless option no custom cursors are available
brokenCursor = Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR);
} else if (brokenCursorImage != null) {
brokenCursor = toolkit.createCustomCursor(brokenCursorImage, new Point(0,0), "BrokenCursor");
} else {
brokenCursor = null;
}
if (brokenCursor == null)
{
throw new RuntimeException("Could not load BrokenCursor .. this looks bad!");
}
}
/**
* Load an image from a URL. Images are cached for efficiency. If the image cannot be found
* will return a brokenImage. No exceptions are thrown.
* @param url The url of the image to load.
* @return The image
*/
public static Image getImage(URL url)
{
Image image = null;
if (url!=null) {
image = (Image) imageCache.get(url);
} else {
image = brokenImage;
}
if (image==null && url!=null)
{
Toolkit toolkit = Toolkit.getDefaultToolkit();
// Note we dont use toolkit.createImage(url) since it returns an image
// even if the specified URL does not exist
try
{
InputStream in = url.openStream();
try
{
int length = in.available();
if (length == 0) length = 1000;
byte[] bytes = new byte[length];
for (int offset=0;;)
{
int rc = in.read(bytes,offset,length-offset);
if (rc<0) break;
if (rc>0) offset += rc;
else
{
length += 1000;
byte[] newBytes = new byte[length];
System.arraycopy(bytes,0,newBytes,0,offset);
bytes = newBytes;
}
}
image = toolkit.createImage(bytes);
}
finally
{
in.close();
}
}
catch (IOException x)
{
image = brokenImage;
}
// Note we SHOULD include brokenImage in the cache, otherwise repeated requests for
// the same non-existant url will be very slow
if (url!=null) imageCache.put(url, image);
}
return image;
}
/**
* Create the best cursor by reading from a URL, with hotspot (0,0).
*/
public static Cursor getBestCursor(String name, Class clazz, int width, int height) {
return getBestCursor(name, clazz, width, height, 0, 0);
}
/**
* Create the best cursor by reading from a URL, with hotspot (x, y).
* The best width and height are inserted into the URL in the spots with %width
* and %height. Example:
*
* getBestCursor("/org/freehep/swing/images/MyIcon%wx%h.png", 32 32);
*
* @param name URL of the cursor
* @param clazz Class to be used for getting resource
* @param width suggested width
* @param height suggested height
* @param x hotspot
* @param y hotspot
* @return The cursor, the default cursor if custom cursors are not supported
* or brokenCursor if the cursor cannot be found
*/
public static Cursor getBestCursor(String name, Class clazz, int width, int height, int x, int y) {
Toolkit toolkit = Toolkit.getDefaultToolkit();
Dimension dimension = toolkit.getBestCursorSize(width, height);
if ((dimension.width == 0) && (dimension.height == 0)) return Cursor.getDefaultCursor();
name = name.replaceAll("%w", Integer.toString(dimension.width));
name = name.replaceAll("%h", Integer.toString(dimension.height));
return getCursor(name, clazz, x, y);
}
/**
* Create a cursor by reading from a URL, with hotspot (0,0).
* @param url The URL to read
* @return The cursor, or brokenCursor if the cursor cannot be found
*/
public static Cursor getCursor(URL url) {
return getCursor(url, 0, 0);
}
/**
* Create a cursor by reading from a URL
* @param url The URL to read
* @param x x position of hotspot
* @param y y position of hotspot
* @return The cursor, or brokenCursor if the cursor cannot be found
*/
public static Cursor getCursor(URL url, int x, int y)
{
Cursor cursor = (url!=null) ? (Cursor) cursorCache.get(url) : null;
if (cursor == null)
{
Toolkit toolkit = Toolkit.getDefaultToolkit();
Image image = getImage(url);
if (image == brokenImage) cursor = brokenCursor;
else cursor = toolkit.createCustomCursor(image, new Point(x, y), url.getFile());
if (url != null) cursorCache.put(url, cursor);
}
return cursor;
}
/**
* Create an Icon by reading from a URL
* @param url The URL to read
* @return The icon, or brokenIcon if it cannot be loaded
*/
public static Icon getIcon(URL url)
{
Icon icon = (url!=null) ? (Icon) iconCache.get(url) : null;
if (icon == null)
{
Image image = getImage(url);
if (image == brokenImage) icon = brokenIcon;
else icon = new ImageIcon(image,url.getFile());
if (url != null) iconCache.put(url, icon);
}
return icon;
}
/**
* Convenience routine, equivalent to getImage(clazz.getResource(name));
* As an additional convenience, if the name does not contain an extension (eg .gif)
* then a list of common extensions will be tried.
* @param name The relative address of the image to load
* @param clazz The class from which the address is based
* @return The image, or brokenImage if no image is found.
*/
public static Image getImage(String name, Class clazz)
{
if (name.indexOf('.') >= 0) return getImage(clazz.getResource(name));
for (int i=0; i<imageExtensions.length; i++)
{
URL url = clazz.getResource(name+imageExtensions[i]);
if (url != null) return getImage(url);
}
return brokenImage;
}
/**
* Convenience routine, equivalent to getCursor(clazz.getResource(name));
* As an additional convenience, if the name does not contain an extension (eg .gif)
* then a list of common extensions will be tried.
* @param name The relative address of the cursor to load
* @param clazz The class from which the address is based
* @return The cursor, or brokenCursor if no cursor is found.
*/
public static Cursor getCursor(String name, Class clazz) {
return getCursor(name, clazz, 0, 0);
}
/**
* Convenience routine, equivalent to getCursor(clazz.getResource(name));
* As an additional convenience, if the name does not contain an extension (eg .gif)
* then a list of common extensions will be tried.
* @param name The relative address of the cursor to load
* @param clazz The class from which the address is based
* @param x hotspot
* @param y hotspot
* @return The cursor, or brokenCursor if no cursor is found.
*/
public static Cursor getCursor(String name, Class clazz, int x, int y)
{
if (name.indexOf('.') >= 0) return getCursor(clazz.getResource(name), x, y);
for (int i=0; i<imageExtensions.length; i++)
{
URL url = clazz.getResource(name+imageExtensions[i]);
if (url != null) return getCursor(url, x, y);
}
return brokenCursor;
}
/**
* Convenience routine, equivalent to getIcon(clazz.getResource(name));
* As an additional convenience, if the name does not contain an extension (eg .gif)
* then a list of common extensions will be tried.
* @param name The relative address of the icon to load
* @param clazz The class from which the address is based
* @return The icon, or brokenIcon if no icon is found.
*/
public static Icon getIcon(String name, Class clazz)
{
if (name.indexOf('.') >= 0) return getIcon(clazz.getResource(name));
for (int i=0; i<imageExtensions.length; i++)
{
URL url = clazz.getResource(name+imageExtensions[i]);
if (url != null) return getIcon(url);
}
return brokenIcon;
}
}