utils.java

这是一个基于java编写的torrent的P2P源码

		if (areaHeight <= table.getHeaderHeight())
			return -1;

		// 2 offset to be on the safe side
		TableItem bottomItem = table.getItem(new Point(2,
				table.getClientArea().height - 1));
  	int iBottomIndex = (bottomItem != null) ? table.indexOf(bottomItem) :
			itemCount - 1;
  	return iBottomIndex;
	}
	
  public static void launch(String sFile) {
		if (sFile == null) {
			return;
		}

		if (SWT.getVersion() >= 3315 || SWT.getVersion() < 3300
				|| UrlUtils.isURL(sFile) || sFile.startsWith("mailto:")) {
			Program.launch(sFile);
		} else {
			if (Constants.isOSX) {
				Program.launch("file://" + sFile.replaceAll(" ", "%20"));
			} else {
				Program.launch(sFile);
			}
		}
	}
	
	/**
	 * Sets the checkbox in a Virtual Table while inside a SWT.SetData listener
	 * trigger.  SWT 3.1 has an OSX bug that needs working around.
	 * 
	 * @param item
	 * @param checked
	 */
	public static void setCheckedInSetData(final TableItem item,
			final boolean checked) {
		if (DIRECT_SETCHECKED) {
			item.setChecked(checked);
		} else {
			item.setChecked(!checked);
			item.getDisplay().asyncExec(new AERunnable() {
				public void runSupport() {
					item.setChecked(checked);
				}
			});
		}

		if (Constants.isWindowsXP || isGTK) {
			Rectangle r = item.getBounds(0);
			Table table = item.getParent();
			Rectangle rTable = table.getClientArea();
			
			r.y += VerticalAligner.getTableAdjustVerticalBy(table);
			table.redraw(0, r.y, rTable.width, r.height, true);
		}
	}
	
	
	public static boolean linkShellMetricsToConfig(final Shell shell,
			final String sConfigPrefix) {
		String windowRectangle = COConfigurationManager.getStringParameter(
				sConfigPrefix + ".rectangle", null);
		boolean bDidResize = false;
		if (null != windowRectangle) {
			int i = 0;
			int[] values = new int[4];
			StringTokenizer st = new StringTokenizer(windowRectangle, ",");
			try {
				while (st.hasMoreTokens() && i < 4) {
					values[i++] = Integer.valueOf(st.nextToken()).intValue();
				}
				if (i == 4) {
					Rectangle shellBounds = new Rectangle(values[0], values[1],
							values[2], values[3]);
					shell.setBounds(shellBounds);
					verifyShellRect(shell, true);
					bDidResize = true;
				}
			} catch (Exception e) {
			}
		}

		boolean isMaximized = COConfigurationManager.getBooleanParameter(
				sConfigPrefix + ".maximized", false);
		shell.setMaximized(isMaximized);

		new ShellMetricsResizeListener(shell, sConfigPrefix);
		
		return bDidResize;
	}
	
	private static class ShellMetricsResizeListener implements Listener {
		private int state = -1;

		private String sConfigPrefix;

		private Rectangle bounds = null;

		ShellMetricsResizeListener(Shell shell, String sConfigPrefix) {
			this.sConfigPrefix = sConfigPrefix;
			state = calcState(shell);
			if (state == SWT.NONE)
				bounds = shell.getBounds();
			
			shell.addListener(SWT.Resize, this);
			shell.addListener(SWT.Move, this);
			shell.addListener(SWT.Dispose, this);
		}

		private int calcState(Shell shell) {
			return shell.getMinimized() ? SWT.MIN : shell.getMaximized() ? SWT.MAX
					: SWT.NONE;
		}

		private void saveMetrics() {
			COConfigurationManager.setParameter(sConfigPrefix + ".maximized",
					state == SWT.MAX);

			if (bounds == null)
				return;

			COConfigurationManager.setParameter(sConfigPrefix + ".rectangle",
					bounds.x + "," + bounds.y + "," + bounds.width + "," + bounds.height);
		}

		public void handleEvent(Event event) {
			Shell shell = (Shell) event.widget;
			state = calcState(shell);

			if (event.type != SWT.Dispose && state == SWT.NONE)
				bounds = shell.getBounds();

			if (event.type == SWT.Dispose)
				saveMetrics();
		}
	}

	public static GridData setGridData(Composite composite, int gridStyle,
			Control ctrlBestSize, int maxHeight) {
		GridData gridData = new GridData(gridStyle);
		gridData.heightHint = ctrlBestSize.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
		if (gridData.heightHint > maxHeight && maxHeight > 0)
			gridData.heightHint = maxHeight;
		composite.setLayoutData(gridData);

		return gridData;
	}
	
	public static FormData getFilledFormData() {
		FormData formData = new FormData();
		formData.top = new FormAttachment(0, 0);
		formData.left = new FormAttachment(0, 0);
		formData.right = new FormAttachment(100, 0);
		formData.bottom = new FormAttachment(100, 0);
		
		return formData;
	}
	
	public static int pixelsToPoint(int pixels, int dpi) {
    int ret = (int) Math.round((pixels * 72.0) / dpi);
    return isGTK ? ret - 2 : ret;
	}
	
	public static int pixelsToPoint(double pixels, int dpi) {
    int ret = (int) Math.round((pixels * 72.0) / dpi);
    return isGTK ? ret - 2 : ret;
	}

	public static boolean drawImage(GC gc, Image image, Rectangle dstRect,
			Rectangle clipping, int hOffset, int vOffset, boolean clearArea)
	{
		return drawImage(gc, image, new Point(0, 0), dstRect, clipping, hOffset,
				vOffset, clearArea);
	}

	public static boolean drawImage(GC gc, Image image, Rectangle dstRect,
			Rectangle clipping, int hOffset, int vOffset)
	{
		return drawImage(gc, image, new Point(0, 0), dstRect, clipping, hOffset,
				vOffset, false);
	}

	public static boolean drawImage(GC gc, Image image, Point srcStart,
			Rectangle dstRect, Rectangle clipping, int hOffset, int vOffset,
			boolean clearArea)
	{
		Rectangle srcRect;
		Point dstAdj;

		if (clipping == null) {
			dstAdj = new Point(0, 0);
			srcRect = new Rectangle(srcStart.x, srcStart.y, dstRect.width,
					dstRect.height);
		} else {
			if (!dstRect.intersects(clipping)) {
				return false;
			}

			dstAdj = new Point(Math.max(0, clipping.x - dstRect.x), Math.max(0,
					clipping.y - dstRect.y));

			srcRect = new Rectangle(0, 0, 0, 0);
			srcRect.x = srcStart.x + dstAdj.x;
			srcRect.y = srcStart.y + dstAdj.y;
			srcRect.width = Math.min(dstRect.width - dstAdj.x, clipping.x
					+ clipping.width - dstRect.x);
			srcRect.height = Math.min(dstRect.height - dstAdj.y, clipping.y
					+ clipping.height - dstRect.y);
		}

		if (!srcRect.isEmpty()) {
			try {
				if (clearArea) {
					gc.fillRectangle(dstRect.x + dstAdj.x + hOffset, dstRect.y + dstAdj.y
							+ vOffset, srcRect.width, srcRect.height);
				}
				gc.drawImage(image, srcRect.x, srcRect.y, srcRect.width,
						srcRect.height, dstRect.x + dstAdj.x + hOffset, dstRect.y
								+ dstAdj.y + vOffset, srcRect.width, srcRect.height);
			} catch (Exception e) {
				System.out.println("drawImage: " + e.getMessage() + ": " + image + ", " + srcRect
						+ ", " + (dstRect.x + dstAdj.y + hOffset) + ","
						+ (dstRect.y + dstAdj.y + vOffset) + "," + srcRect.width + ","
						+ srcRect.height + "; imageBounds = " + image.getBounds());
			}
		}

		return true;
	}

	/**
	 * @param area
	 * @param event id
	 * @param listener
	 */
	public static void addListenerAndChildren(Composite area, int event,
			Listener listener)
	{
		area.addListener(event, listener);
		Control[] children = area.getChildren();
		for (int i = 0; i < children.length; i++) {
			Control child = children[i];
			if (child instanceof Composite) {
				addListenerAndChildren((Composite)child, event, listener);
			} else {
				child.addListener(event, listener);
			}
		}
	}
	
	public static Shell findAnyShell() {
		// Pick the main shell if we can
		UIFunctionsSWT uiFunctions = UIFunctionsManagerSWT.getUIFunctionsSWT();
		if (uiFunctions != null) {
			Shell shell = uiFunctions.getMainShell();
			if (shell != null && shell.isDisposed()) {
				return shell;
			}
		}

		// Get active shell from current display if we can
		Display current = Display.getCurrent();
		if (current == null) {
			return null;
		}
		Shell shell = current.getActiveShell();
		if (shell != null && !shell.isDisposed()) {
			return shell;
		}
		
		// Get first shell of current display if we can
		Shell[] shells = current.getShells();
		if (shells.length == 0) {
			return null;
		}
		
		if (shells[0] != null && !shells[0].isDisposed()) {
			return shells[0];
		}
		
		return null;
	}

	/**
	 * @param listener
	 */
	public static boolean verifyShellRect(Shell shell, boolean bAdjustIfInvalid) {
		boolean bMetricsOk;
		try {
			bMetricsOk = false;
			Point ptTopLeft = shell.getLocation();

			Monitor[] monitors = shell.getDisplay().getMonitors();
			for (int j = 0; j < monitors.length && !bMetricsOk; j++) {
				Rectangle bounds = monitors[j].getBounds();
				bMetricsOk = bounds.contains(ptTopLeft);
			}
		} catch (NoSuchMethodError e) {
			Rectangle bounds = shell.getDisplay().getBounds();
			bMetricsOk = shell.getBounds().intersects(bounds);
		}
		if (!bMetricsOk && bAdjustIfInvalid) {
			centreWindow(shell);
		}
		return bMetricsOk;
	}

	/**
	 * Relayout all composites up from control until there's enough room for the
	 * control to fit
	 * 
	 * @param control Control that had it's sized changed and needs more room
	 */
	public static void relayout(Control control) {
		if (control == null || control.isDisposed()) {
			return;
		}

		Point size = control.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
		Composite parent = control.getParent();
		while (parent != null) {
			parent.layout(true);
			parent = parent.getParent();

			Point newSize = control.getSize();
			
			if (newSize.y >= size.y && newSize.x >= size.x) {
				break;
			}
		}
		
		if (parent != null) {
			parent.layout();
		}
	}

	/**
	 * 
	 */
	public static void beep() {
		execSWTThread(new AERunnable() {
			public void runSupport() {
				Display display = Display.getDefault();
				if (display != null) {
					display.beep();
				}
			}
		});
	}
}