Posted on 2009-07-31 13:51
eric_xu 閱讀(716)
評論(1) 編輯 收藏 所屬分類:
Eclipse Plugin
Image對象是一個包裝了本地資源的Java結構，不能被Java的垃圾回收器管理。加載圖像而不卸載，會導致內存泄漏。
Eclipse使用ImageDescriptor來描述Image，ImageDescriptor可以通過getImageDescriptor()方法來獲得。
ImageCache類為一個專門管理圖像的類。
package com.plugindev.addressbook.util;
import java.util.HashMap;
import java.util.Iterator;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.graphics.Image;
public class ImageCache {
private final static HashMap<ImageDescriptor, Image> imageMap = new HashMap<ImageDescriptor, Image>();
private static ImageCache instance;
//單例，獲得ImageCache的唯一實例
public static ImageCache getInstance() {
if (instance == null)
instance = new ImageCache();
return instance;
}
//保證每個圖像資源只有唯一的創建操作
public Image getImage(ImageDescriptor descriptor) {
if (descriptor == null)
return null;
Image image = (Image) imageMap.get(descriptor);
if (image == null) {
image = descriptor.createImage();
imageMap.put(descriptor, image);
}
return image;
}
//卸載圖像資源
public void dispose() {
Iterator iter = imageMap.values().iterator();
while (iter.hasNext())
((Image) iter.next()).dispose();
imageMap.clear();
}
}
ImageKey保存所有圖像路徑字符串描述符
package com.plugindev.addressbook.util;
import org.eclipse.jface.resource.ImageDescriptor;
import com.plugindev.addressbook.Activator;
public final class ImageKeys {
public static final String IMAGE_CATEGORY = "icons/category.gif";
public static final String IMAGE_PEOPLE = "icons/people.gif";
//類別圖像
public static final String IMG_CAT_BUSINESS = "icons/category/business.gif";
public static final String IMG_CAT_FAMILY = "icons/category/family.gif";
public static final String IMG_CAT_FRIENDS = "icons/category/friends.gif";
public static final String IMG_CAT_LOVER = "icons/category/lover.gif";
public static final String IMG_CAT_MATE = "icons/category/mate.gif";
public static final String IMG_CAT_ORDINARY = "icons/category/ordinary.gif";
public static final String IMG_CAT_VIP = "icons/category/vip.gif";
public static final String IMG_CAT_UNKNOWN = "icons/category/unknown.gif";
public static final String IMG_CAT_TEACHER = "icons/category/teacher.gif";
//操作圖像
public static final String IMG_TOOL_ADD = "icons/actions/add.gif";
public static final String IMG_TOOL_DELETE = "icons/actions/delete.gif";
public static final String IMG_TOOL_DISABLEDELETE = "icons/actions/delete_dis.gif";
public static final String IMG_TOOL_FILTER = "icons/actions/filter.gif";
//編輯器相關
public static final String IMG_FORM_BG = "icons/editors/form_banner.gif"; //$NON-NLS-1$
public static final String IMG_HORIZONTAL = "icons/editors/th_horizontal.gif"; //$NON-NLS-1$
public static final String IMG_VERTICAL = "icons/editors/th_vertical.gif"; //$NON-NLS-1$
//ScrollBlock圖標
public static final String IMG_SCROL_BASIC = "icons/editors/basic.gif";
public static final String IMG_SCROL_PHONE = "icons/editors/phone.gif";
public static final String IMG_SCROL_AREA = "icons/editors/area.gif";
public static final String IMG_SCROL_CONTACT = "icons/editors/contact.gif";
//向導相關
public static final String IMG_WIZARD_NEW = "icons/wizards/new_wiz.gif";
//幫助相關
public static final String IMG_HELP = "icons/help/help.gif";
public static ImageDescriptor getImageDescriptor(String path)
{
return Activator.getImageDescriptor(path);
}
}