utils.java

这是一个基于java编写的torrent的P2P源码

				if (event.data instanceof URLTransfer.URLType) {
					if (((URLTransfer.URLType) event.data).linkURL != null)
						url.setText(((URLTransfer.URLType) event.data).linkURL);
				} else if (event.data instanceof String) {
					String sURL = UrlUtils.parseTextForURL((String) event.data, true);
					if (sURL != null) {
						url.setText(sURL);
					}
				}
			}
		}
	}

  /**
   * Force label to use more vertical space if wrapped and in a GridLayout
   * Place this listener on the _parent_ of the label
   * See Eclipse SWT Bug #9866 (GridLayout does not handle wrapped Label properly)
   * This workaround only works for labels who:
   *   - horizontally span their whole parent 
   *     (ie. the parent has 3 columns, the label must span 3 columns)
   *   - GridData style has GridData.FILL_HORIZONTAL
   *   - Label style has SWT.WRAP
   *
   * @author TuxPaper
   * @note Bug 9866 fixed in 3105 and later
   */
  public static class LabelWrapControlListener extends ControlAdapter{
  	public void controlResized(ControlEvent e){
  		if (SWT.getVersion() >= 3105)
  			return;
  	  Composite parent = (Composite)e.widget;
  	  Control children[] = parent.getChildren();

  	  if (children.length > 0) {
        GridLayout parentLayout = (GridLayout)parent.getLayout();
        if (parentLayout != null) {
    	    Point size;
          int marginWidth = parentLayout.marginWidth;
          
      	  Composite grandParent = parent.getParent();
      	  if (grandParent instanceof ScrolledComposite) {
      	    Composite greatGP = grandParent.getParent();
      	    if (greatGP != null) {
              size = greatGP.getSize();
  
              if (greatGP.getLayout() instanceof GridLayout) {
                marginWidth += ((GridLayout)greatGP.getLayout()).marginWidth;
              }
            } else {
              // not tested
              size = grandParent.getSize();
            }

            if (grandParent.getLayout() instanceof GridLayout) {
              marginWidth += ((GridLayout)grandParent.getLayout()).marginWidth;
            }

            ScrollBar sb = grandParent.getVerticalBar();
            if (sb != null) {
              // I don't know why, but we have to remove one
              size.x -= sb.getSize().x + 1;
            }
          } else
            size = parent.getSize();
         
          boolean oneChanged = false;
      	  for (int i = 0; i < children.length; i++) {
      	    if ((children[i] instanceof Label) &&
      	        (children[i].getStyle() & SWT.WRAP) == SWT.WRAP) {
      	      GridData gd = (GridData)children[i].getLayoutData();
      	      if (gd != null && 
      	          gd.horizontalAlignment == GridData.FILL) {
      	        if (gd.horizontalSpan == parentLayout.numColumns) {
        		      gd.widthHint = size.x - 2 * marginWidth;
        		      oneChanged = true;
        		    } else {
        		      Point pt = children[i].getLocation();
        		      gd.widthHint = size.x - pt.x - (2 * marginWidth);
        		      oneChanged = true;
        		    }
      		    }
      		  }
      		}
      		if (oneChanged) {
      		  parent.layout(true);
        	  if (grandParent instanceof ScrolledComposite) {
        	    ((ScrolledComposite)grandParent).setMinSize(parent.computeSize(SWT.DEFAULT, SWT.DEFAULT, true));
        	  }
          }
      	}
    	} // size
  	} // controlResized
  } // class

  public static void alternateRowBackground(TableItem item) {
  	if (Utils.TABLE_GRIDLINE_IS_ALTERNATING_COLOR) {
  		if (!item.getParent().getLinesVisible())
  			item.getParent().setLinesVisible(true);
  		return;
  	}

  	if (item == null || item.isDisposed())
  		return;
  	Color[] colors = { item.getDisplay().getSystemColor(SWT.COLOR_LIST_BACKGROUND),
        Colors.colorAltRow };
  	Color newColor = colors[ item.getParent().indexOf(item) % colors.length];
  	if (!item.getBackground().equals(newColor)) {
  		item.setBackground(newColor);
  	}
  }

  public static void alternateTableBackground(Table table) {
  	if (table == null || table.isDisposed())
  		return;

  	if (Utils.TABLE_GRIDLINE_IS_ALTERNATING_COLOR) {
  		if (!table.getLinesVisible())
  			table.setLinesVisible(true);
  		return;
  	}

  	int iTopIndex = table.getTopIndex();
  	int iBottomIndex = getTableBottomIndex(table, iTopIndex);

  	Color[] colors = { table.getDisplay().getSystemColor(SWT.COLOR_LIST_BACKGROUND),
        Colors.colorAltRow };
  	int iFixedIndex = iTopIndex;
    for (int i = iTopIndex; i <= iBottomIndex; i++) {
      TableItem row = table.getItem(i);
      // Rows can be disposed!
      if (!row.isDisposed()) {
      	Color newColor = colors[iFixedIndex % colors.length];
      	iFixedIndex++;
      	if (!row.getBackground().equals(newColor)) {
//        System.out.println("setting "+rows[i].getBackground() +" to " + newColor);
      		row.setBackground(newColor);
      	}
      }
    }
  }

  /**
   * <p>
   * Set a MenuItem's image with the given ImageRepository key. In compliance with platform
   * human interface guidelines, the images are not set under Mac OS X.
   * </p>
   * @param item SWT MenuItem
   * @param repoKey ImageRepository image key
   * @see <a href="http://developer.apple.com/documentation/UserExperience/Conceptual/OSXHIGuidelines/XHIGMenus/chapter_7_section_3.html#//apple_ref/doc/uid/TP30000356/TPXREF116">Apple HIG</a>
   */
  public static void setMenuItemImage(final MenuItem item, final String repoKey)
  {
      if(!Constants.isOSX)
          item.setImage(ImageRepository.getImage(repoKey));
  }

  public static void setMenuItemImage(final MenuItem item, final Image image)
  {
      if(!Constants.isOSX)
          item.setImage(image);
  }
  /**
   * Sets the shell's Icon(s) to the default Azureus icon.  OSX doesn't require
   * an icon, so they are skipped
   * 
   * @param shell
   */
  public static void setShellIcon(Shell shell) {
		final String[] sImageNames = { "azureus", "azureus32", "azureus64",
				"azureus128" };

		if (Constants.isOSX)
			return;

		try {
			ArrayList list = new ArrayList();
			Image[] images = new Image[] { ImageRepository.getImage("azureus"),
					ImageRepository.getImage("azureus32"),
					ImageRepository.getImage("azureus64"),
					ImageRepository.getImage("azureus128") };

			for (int i = 0; i < images.length; i++) {
				Image image = ImageRepository.getImage(sImageNames[i]);
				if (image != null)
					list.add(image);
			}

			if (list.size() == 0)
				return;

			shell.setImages((Image[]) list.toArray(new Image[0]));
		} catch (NoSuchMethodError e) {
			// SWT < 3.0
			Image image = ImageRepository.getImage(sImageNames[0]);
			if (image != null)
				shell.setImage(image);
		}
	}

  /**
   * Execute code in the Runnable object using SWT's thread.  If current
   * thread it already SWT's thread, the code will run immediately.  If the
   * current thread is not SWT's, code will be run either synchronously or 
   * asynchronously on SWT's thread at the next reasonable opportunity.
   * 
   * This method does not catch any exceptions.
   * 
   * @param code code to run
   * @param async true if SWT asyncExec, false if SWT syncExec
   * @return success
   */
  public static boolean execSWTThread(Runnable code,
			boolean async) {
  	
    SWTThread swt = SWTThread.getInstance();
    
    Display display;
    if (swt == null) {
    	display = Display.getDefault();
    	if (display == null) {
      	System.err.println("SWT Thread not started yet!");
      	return false;
    	}
    } else {
    	if (swt.isTerminated()) {
    		return false;
    	}
      display = swt.getDisplay();
    }
    

  	if (display == null || display.isDisposed() || code == null)
			return false;

		if (display.getThread() == Thread.currentThread()) {
			code.run();
		} else if (async) {
			try {
				display.asyncExec(code);
			} catch (NullPointerException e) {
				// If the display is being disposed of, asyncExec may give a null
				// pointer error
				return false;
			}
		} else {
			display.syncExec(code);
		}

		return true;
	}

  /**
   * Execute code in the Runnable object using SWT's thread.  If current
   * thread it already SWT's thread, the code will run immediately.  If the
   * current thread is not SWT's, code will be run asynchronously on SWT's 
   * thread at the next reasonable opportunity.
   * 
   * This method does not catch any exceptions.
   * 
   * @param code code to run
   * @return success
   */
	public static boolean execSWTThread(Runnable code) {
		return execSWTThread(code, true);
	}
	
	public static boolean isThisThreadSWT() {
    SWTThread swt = SWTThread.getInstance();
    
    if (swt == null) {
    	System.err.println("SWT Thread not started yet");
    	return false;
    }

    Display display = swt.getDisplay();

  	if (display == null || display.isDisposed())
			return false;

		return (display.getThread() == Thread.currentThread());
	}

	/** Open a messagebox using resource keys for title/text
	 * 
	 * @param parent Parent shell for messagebox
	 * @param style SWT styles for messagebox
	 * @param keyPrefix message bundle key prefix used to get title and text.  
	 *         Title will be keyPrefix + ".title", and text will be set to
	 *         keyPrefix + ".text"
	 * @param textParams any parameters for text
	 * 
	 * @return what the messagebox returns
	 */
	public static int openMessageBox(Shell parent, int style, String keyPrefix,
			String[] textParams) {
		MessageBox mb = new MessageBox(parent, style);
		mb.setMessage(MessageText.getString(keyPrefix + ".text", textParams));
		mb.setText(MessageText.getString(keyPrefix + ".title"));
		return mb.open();
	}

	/** Open a messagebox with actual title and text
	 * 
	 * @param parent
	 * @param style
	 * @param title
	 * @param text
	 * @return
	 */ 
	public static int openMessageBox(Shell parent, int style, String title,
			String text) {
		MessageBox mb = new MessageBox(parent, style);
		mb.setMessage(text);
		mb.setText(title);
		return mb.open();
	}
	
	/**
	 * Bottom Index may be negative
	 */ 
	public static int getTableBottomIndex(Table table, int iTopIndex) {
		// on Linux, getItemHeight is slow AND WRONG. so is getItem(x).getBounds().y 
		// getItem(Point) is slow on OSX

		int itemCount = table.getItemCount();
		if (!table.isVisible() || iTopIndex >= itemCount)
			return -1;
		
		if (Constants.isOSX) {
			try {
				TableItem item = table.getItem(iTopIndex);
				Rectangle bounds = item.getBounds();
				Rectangle clientArea = table.getClientArea();
	
				int itemHeight = table.getItemHeight();
				int iBottomIndex = Math.min(iTopIndex
						+ (clientArea.height + clientArea.y - bounds.y - 1) / itemHeight,
						itemCount - 1);
	
	//			System.out.println(bounds + ";" + clientArea + ";" + itemHeight + ";bi="
	//					+ iBottomIndex + ";ti=" + iTopIndex + ";"
	//					+ (clientArea.height + clientArea.y - bounds.y - 1));
				return iBottomIndex;
			} catch (NoSuchMethodError e) {
				// item.getBounds is 3.2
				return Math.min(iTopIndex
						+ ((table.getClientArea().height - table.getHeaderHeight() - 1) / 
								table.getItemHeight()) + 1, table.getItemCount() - 1);
			}
		}

		// getItem will return null if clientArea's height is smaller than
		// header height.
		int areaHeight = table.getClientArea().height;