Java课程设计——报刊管理系统

package com.swtdesigner; import java.io.BufferedInputStream; import java.io.FileInputStream; import java.io.InputStream; import java.util.HashMap; import java.util.Iterator; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.*; import org.eclipse.swt.widgets.*; /** * Utility class for managing OS resources associated with SWT controls such as * colors, fonts, images, etc. * * !!! IMPORTANT !!! Application code must explicitly invoke the <code>dispose()</code> * method to release the operating system resources managed by cached objects * when those objects and OS resources are no longer needed (e.g. on * application shutdown) * * This class may be freely distributed as part of any application or plugin. * <p> * Copyright (c) 2003 - 2005, Instantiations, Inc. <br>All Rights Reserved * * @author scheglov_ke * @author Dan Rubel */ public class SWTResourceManager { /** * Dispose of cached objects and their underlying OS resources. This should * only be called when the cached objects are no longer needed (e.g. on * application shutdown) */ public static void dispose() { disposeColors(); disposeFonts(); disposeImages(); disposeCursors(); } ////////////////////////////// // Color support ////////////////////////////// /** * Maps RGB values to colors */ private static HashMap<RGB, Color> m_ColorMap = new HashMap<RGB, Color>(); /** * Returns the system color matching the specific ID * @param systemColorID int The ID value for the color * @return Color The system color matching the specific ID */ public static Color getColor(int systemColorID) { Display display = Display.getCurrent(); return display.getSystemColor(systemColorID); } /** * Returns a color given its red, green and blue component values * @param r int The red component of the color * @param g int The green component of the color * @param b int The blue component of the color * @return Color The color matching the given red, green and blue componet values */ public static Color getColor(int r, int g, int b) { return getColor(new RGB(r, g, b)); } /** * Returns a color given its RGB value * @param rgb RGB The RGB value of the color * @return Color The color matching the RGB value */ public static Color getColor(RGB rgb) { Color color = m_ColorMap.get(rgb); if (color == null) { Display display = Display.getCurrent(); color = new Color(display, rgb); m_ColorMap.put(rgb, color); } return color; } /** * Dispose of all the cached colors */ public static void disposeColors() { for (Iterator<Color> iter = m_ColorMap.values().iterator(); iter.hasNext();) iter.next().dispose(); m_ColorMap.clear(); } ////////////////////////////// // Image support ////////////////////////////// /** * Maps image names to images */ private static HashMap<String, Image> m_ClassImageMap = new HashMap<String, Image>(); /** * Maps images to image decorators */ private static HashMap<Image, HashMap<Image, Image>> m_ImageToDecoratorMap = new HashMap<Image, HashMap<Image, Image>>(); /** * Returns an image encoded by the specified input stream * @param is InputStream The input stream encoding the image data * @return Image The image encoded by the specified input stream */ protected static Image getImage(InputStream is) { Display display = Display.getCurrent(); ImageData data = new ImageData(is); if (data.transparentPixel > 0) return new Image(display, data, data.getTransparencyMask()); return new Image(display, data); } /** * Returns an image stored in the file at the specified path * @param path String The path to the image file * @return Image The image stored in the file at the specified path */ public static Image getImage(String path) { return getImage("default", path); //$NON-NLS-1$ } /** * Returns an image stored in the file at the specified path * @param section The section to which belongs specified image * @param path String The path to the image file * @return Image The image stored in the file at the specified path */ public static Image getImage(String section, String path) { String key = section + '|' + SWTResourceManager.class.getName() + '|' + path; Image image = m_ClassImageMap.get(key); if (image == null) { try { FileInputStream fis = new FileInputStream(path); image = getImage(fis); m_ClassImageMap.put(key, image); fis.close(); } catch (Exception e) { image = getMissingImage(); m_ClassImageMap.put(key, image); } } return image; } /** * Returns an image stored in the file at the specified path relative to the specified class * @param clazz Class The class relative to which to find the image * @param path String The path to the image file * @return Image The image stored in the file at the specified path */ public static Image getImage(Class<?> clazz, String path) { String key = clazz.getName() + '|' + path; Image image = m_ClassImageMap.get(key); if (image == null) { try { if (path.length() > 0 && path.charAt(0) == '/') { String newPath = path.substring(1, path.length()); image = getImage(new BufferedInputStream(clazz.getClassLoader().getResourceAsStream(newPath))); } else { image = getImage(clazz.getResourceAsStream(path)); } m_ClassImageMap.put(key, image); } catch (Exception e) { image = getMissingImage(); m_ClassImageMap.put(key, image); } } return image; } private static final int MISSING_IMAGE_SIZE = 10; private static Image getMissingImage() { Image image = new Image(Display.getCurrent(), MISSING_IMAGE_SIZE, MISSING_IMAGE_SIZE); // GC gc = new GC(image); gc.setBackground(getColor(SWT.COLOR_RED)); gc.fillRectangle(0, 0, MISSING_IMAGE_SIZE, MISSING_IMAGE_SIZE); gc.dispose(); // return image; } /** * Style constant for placing decorator image in top left corner of base image. */ public static final int TOP_LEFT = 1; /** * Style constant for placing decorator image in top right corner of base image. */ public static final int TOP_RIGHT = 2; /** * Style constant for placing decorator image in bottom left corner of base image. */ public static final int BOTTOM_LEFT = 3; /** * Style constant for placing decorator image in bottom right corner of base image. */ public static final int BOTTOM_RIGHT = 4; /** * Returns an image composed of a base image decorated by another image * @param baseImage Image The base image that should be decorated * @param decorator Image The image to decorate the base image * @return Image The resulting decorated image */ public static Image decorateImage(Image baseImage, Image decorator) { return decorateImage(baseImage, decorator, BOTTOM_RIGHT); } /** * Returns an image composed of a base image decorated by another image * @param baseImage Image The base image that should be decorated * @param decorator Image The image to decorate the base image * @param corner The corner to place decorator image * @return Image The resulting decorated image */ public static Image decorateImage(Image baseImage, Image decorator, int corner) { HashMap<Image, Image> decoratedMap = m_ImageToDecoratorMap.get(baseImage); if (decoratedMap