imagerepository.java

这是一个基于java编写的torrent的P2P源码

					if (Constants.isWindows && bBig) {
						try {

							Class ehancerClass = Class.forName("org.gudy.azureus2.ui.swt.win32.Win32UIEnhancer");

							Method method = ehancerClass.getMethod("getBigImageData",
									new Class[] { String.class
									});
							imageData = (ImageData) method.invoke(null,
									new Object[] { ext
									});
							
						} catch (Exception e) {
							Debug.printStackTrace(e);
						}
					}

					if (imageData == null) {
						Program program = Program.findProgram(ext);
						if (program != null) {
							imageData = program.getImageData();
						}
					}

					if (imageData != null) {
						image = new Image(Display.getDefault(), imageData);
						images.put(id, image);
					}
			}
		} catch (Throwable e) {
			// seen exceptions thrown here, due to images.get failing in Program.hashCode
			// ignore and use default icon
		}

		if (image == null) {
			image = getImage("folder", true);
		}
		return image;
	}
  
  /**
   * @deprecated Does not account for custom or native folder icons
   * @see ImageRepository#getPathIcon(String)
   */
  public static Image
  getFolderImage()
  {
  	return getImage("folder", true);
  }

	public static Image getPathIcon(final String path) {
		return getPathIcon(path, false);
	}

    /**
	 * <p>Gets a small-sized iconic representation of the file or directory at the path</p>
	 * <p>For most platforms, the icon is a 16x16 image; weak-referencing caching is used to avoid abundant reallocation.</p>
	 * @param path Absolute path to the file or directory
	 * @return The image
	 */
	public static Image getPathIcon(final String path, boolean bBig) {
		if (path == null)
			return null;

		File file = null;
		boolean bDeleteFile = false;
		try {
			file = new File(path);

			// workaround for unsupported platforms
			// notes:
			// Mac OS X - Do not mix AWT with SWT (possible workaround: use IPC/Cocoa)

			String key;
			if (file.isDirectory()) {
				if (doNotUseAWTIcon)
					return getFolderImage();

				key = file.getPath();
			} else {
				final int lookIndex = file.getName().lastIndexOf(".");

				if (lookIndex == -1) {
					if (doNotUseAWTIcon)
						return getFolderImage();

					key = "?!blank";
				} else {
					final String ext = file.getName().substring(lookIndex);
					key = ext;

					if (doNotUseAWTIcon)
						return getIconFromExtension(ext, bBig);

					// case-insensitive file systems
					for (int i = 0; i < noCacheExtList.length; i++) {
						if (noCacheExtList[i].equalsIgnoreCase(ext)) {
							key = file.getPath();
							break;
						}
					}
				}
			}
			
			key += bBig ? "-big" : "";

			// this method mostly deals with incoming torrent files, so there's less concern for
			// custom icons (unless user sets a custom icon in a later session)

			// other platforms - try sun.awt
			Image image = (Image) registry.get(key);
			if (image != null) {
				return image;
			}
			

			bDeleteFile = !file.exists();
			if (bDeleteFile) {
				file = File.createTempFile("AZ_", FileUtil.getExtension(path));
			}

			java.awt.Image awtImage = null;
			
			final Class sfClass = Class.forName("sun.awt.shell.ShellFolder");
			if (sfClass != null && file != null) {
				Method method = sfClass.getMethod("getShellFolder",
						new Class[] { File.class });
				if (method != null) {
					Object sfInstance = method.invoke(null, new Object[] { file });

					if (sfInstance != null) {
						method = sfClass.getMethod("getIcon", new Class[] { Boolean.TYPE });
						if (method != null) {
							awtImage = (java.awt.Image) method.invoke(sfInstance,
									new Object[] { new Boolean(bBig) });
						}
					}
				}
			}

			if (awtImage != null) {
        final ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        ImageIO.write((BufferedImage)awtImage, "png", outStream);
        final ByteArrayInputStream inStream = new ByteArrayInputStream(outStream.toByteArray());

        image = new Image(Display.getDefault(), inStream);

				registry.put(key, image);

				return image;
			}
		} catch (Exception e) {
			//Debug.printStackTrace(e);
		}
		
		if (bDeleteFile && file != null && file.exists()) {
			file.delete();
		}

		// Possible scenario: Method call before file creation
		String ext = FileUtil.getExtension(path);
		if (ext.length() == 0) {
			return getFolderImage();
		}

		return getIconFromExtension(ext, bBig);
	}

    /**
     * <p>Gets an image with the specified canvas size</p>
     * <p>No scaling is performed on the original image, and a cached version will be used if found.</p>
     * @param name ImageRepository image resource name
     * @param canvasSize Size of image
     * @return The image
     */
    public static Image getImageWithSize(String name, Point canvasSize)
    {
        String key =
                new StringBuffer()
                    .append(name)
                    .append('.')
                    .append(canvasSize.x)
                    .append('.')
                    .append(canvasSize.y)
                .toString();

        Image newImage = (Image)images.get(key);

        if(newImage == null)
        {
            Image oldImage = getImage(name);

            if(oldImage == null)
                return null;

            newImage = new Image(Display.getCurrent(), canvasSize.x, canvasSize.y);
            GC gc = new GC(newImage);

            int x = Math.max(0, (canvasSize.x - oldImage.getBounds().width)/2);
            int y = Math.max(0, (canvasSize.y - oldImage.getBounds().height)/2);
            gc.drawImage(oldImage, x, y);

            gc.dispose();

            images.put(key, newImage);
        }

        return newImage;
    }
    
    public static void unloadImage(String name) {
      Image img = (Image) images.get(name);
      if(img != null) {
        images.remove(name);
        if(! img.isDisposed())
          img.dispose();        
      }
    }
    
    public static void unloadPathIcon(String path) {
     String key = getKey(path);
     Image img = (Image) registry.get(key);
     if(img != null) {
       registry.remove(key);
       if(! img.isDisposed())
         img.dispose();       
     }
    }
    
    private static String getKey(String path) {
      final File file = new File(path);

      String key;
      if(file.isDirectory())
      {
          key = file.getPath();
      }
      else
      {
          final int lookIndex = file.getName().lastIndexOf(".");
  
          if(lookIndex == -1)
          {
              key = "?!blank";
          }
          else
          {
              final String ext =  file.getName().substring(lookIndex);
              key = ext;
              
              // case-insensitive file systems
              for (int i = 0; i < noCacheExtList.length; i++)
              {
                  if(noCacheExtList[i].equalsIgnoreCase(ext))
                  {
                      key = file.getPath();
                  }
              }
          }
      } 
      
      return key;
    }
    
    public static void main(String[] args) {
			Display display = new Display();
			Shell shell = new Shell(display, SWT.SHELL_TRIM);
			shell.setLayout(new FillLayout(SWT.VERTICAL));
			
			final Label label = new Label(shell, SWT.BORDER);
			
			final Text text = new Text(shell, SWT.BORDER);
			text.addModifyListener(new ModifyListener() {
			
				public void modifyText(ModifyEvent e) {
					Image pathIcon = getPathIcon(text.getText(), false);
					label.setImage(pathIcon);
				}
			});
			
			
			shell.open();
			
			while (!shell.isDisposed()) {
				if (!display.readAndDispatch()) {
					display.sleep();
				}
			}
		}
}