我目前正在开发一个Eclipse RCP应用程序，在其中我尝试实现一个自定义启动画面处理程序，支持进度条（类似于您可以在.product定义中定义的默认进度条）和多个循环背景图像。
编辑主应用程序插件的扩展方式如下：
[...]
<!-- install custom splash handler -->
<extension point="org.eclipse.ui.splashHandlers">
<splashHandler
class="com.example.application.splash.SlideShowSplashHandler"
id="splash.slideshow">
</splashHandler>
<splashHandlerProductBinding
productId="com.example.application.product"
splashId="com.example.application.splash.slideshow">
</splashHandlerProductBinding>
</extension>
<!-- define images (in plugin root directory) to be shown -->
<extension point="com.example.application.splashExtension">
<splashExtension id="01" image="01_Splash2Ag.bmp"></splashExtension>
<splashExtension id="02" image="02_Splash3Ag.bmp"></splashExtension>
<splashExtension id="00" image="00_Splash1Ag.bmp"></splashExtension>
</extension>
[...]
我正在尝试实现自定义启动画面处理程序类：
public class SlideShowSplashHandler extends AbstractSplashHandler {
private List<Image> fImageList;
private ProgressBar fBar;
private final static String F_SPLASH_EXTENSION_ID = "com.example.application.splashExtension"; //NON-NLS-1
private final static String F_ELEMENT_IMAGE = "image"; //NON-NLS-1
private int imageIdx = 0;
public SlideShowSplashHandler() {
fImageList = new ArrayList<Image>(5);
}
/* (non-Javadoc)
* @see org.eclipse.ui.splash.AbstractSplashHandler#init(org.eclipse.swt.widgets.Shell)
*/
public void init(Shell splash) {
// Store the shell
super.init(splash);
// Force shell to inherit the splash background
getSplash().setBackgroundMode(SWT.INHERIT_DEFAULT);
// Load all splash extensions
loadSplashExtensions();
// If no splash extensions were loaded abort the splash handler
if (hasSplashExtensions() == false) return;
// Create UI
createUI(splash);
}
private boolean hasSplashExtensions() {
if (fImageList.isEmpty()) {
return false;
} else {
return true;
}
}
@Override
public IProgressMonitor getBundleProgressMonitor() {
return new NullProgressMonitor() {
@Override
public void beginTask(String name, final int totalWork) {
getSplash().getDisplay().syncExec(new Runnable() {
public void run() {
fBar.setSelection(50);
}
});
}
@Override
public void subTask(String name) {
getSplash().getDisplay().syncExec(new Runnable() {
public void run() {
if (fBar.getSelection() < 100) fBar.setSelection(fBar.getSelection() + 10);
if (imageIdx >= fImageList.size()) imageIdx = 0;
Image image = fImageList.get(imageIdx++);
getSplash().setBackgroundImage(image);
getSplash().setRedraw(true);
getSplash().redraw();
}
});
}
};
}
private void createUI(Shell shell) {
Composite container = new Composite(shell, SWT.NONE);
container.setLayout(new GridLayout(1, false));
container.setLocation(5, 374);
container.setSize(480, 15);
/* Progress Bar */
fBar = new ProgressBar(container, SWT.HORIZONTAL);
fBar.setLayoutData(new GridData(SWT.FILL, SWT.BEGINNING, true, false));
((GridData) fBar.getLayoutData()).heightHint = 13;
fBar.setMaximum(100);
fBar.setSelection(25);
/* Version Label */
Label versionLabel = new Label(container, SWT.NONE);
versionLabel.setLayoutData(new GridData(SWT.END, SWT.BEGINNING, true, false));
//versionLabel.setFont(fVersionFont);
//versionLabel.setForeground(fVersionColor);
//versionLabel.setText(NLS.bind(Messages.SplashHandler_BUILD, "2.1 Nightly")); //$NON-NLS-1$
/* Layout All */
shell.layout(true, true);
}
private void loadSplashExtensions() {
// Get all splash handler extensions
IExtension[] extensions = Platform.getExtensionRegistry()
.getExtensionPoint(F_SPLASH_EXTENSION_ID).getExtensions();
// Process all splash handler extensions
for (int i = 0; i < extensions.length; i++) {
processSplashExtension(extensions[i]);
}
}
/**
* Parse the extension points with the images filename.
*/
private void processSplashExtension(IExtension extension) {
// Get all splash handler configuration elements
IConfigurationElement[] elements = extension.getConfigurationElements();
// Process all splash handler configuration elements
for (int j = 0; j < elements.length; j++) {
processSplashElements(elements[j]);
}
}
/**
* Create the images defined as extension points
*/
private void processSplashElements(IConfigurationElement configurationElement) {
String name = configurationElement.getAttribute(F_ELEMENT_IMAGE);
ImageDescriptor descriptor = Activator.getImageDescriptor("/"+name);
if (descriptor != null) {
Image image = descriptor.createImage();
if (image !=null) {
fImageList.add(image);
}
}
}
public void dispose() {
super.dispose();
// Check to see if any images were defined
if ((fImageList == null) ||
fImageList.isEmpty()) {
return;
}
// Dispose of all the images
Iterator<Image> iterator = fImageList.iterator();
while (iterator.hasNext()) {
Image image = iterator.next();
image.dispose();
}
}
}
问题在于进度条可以正常工作，但图片却没有显示出来。调试时我可以验证图片确实被找到和加载了，并且正确地设置在外壳中; 外壳似乎只是没有被重新绘制。我是否漏掉了什么？