Eclipse tips & tricks
Find project from configuration
IConfiguration config;
IProject project = (IProject) config.getManagedProject().getOwner();
Display a message box from a non-UI thread
The JFace MessageDialog is prefered over SWT MessageBox (which is extremely ugly on some platforms).
class ErrorMessageDialog implements Runnable {
public int retCode = 0;
@Override
public void run() {
String[] buttons = new String[] { "Retry", "Ignore", "Abort" };
MessageDialog dialog = new MessageDialog(shell,
"Read error", null, sourceUrl.toString() + "\n"
+ e.getMessage(), MessageDialog.ERROR,
buttons, 0);
retCode = dialog.open();
}
}
ErrorMessageDialog messageDialog = new ErrorMessageDialog();
Display.getDefault().syncExec(messageDialog);
if (messageDialog.retCode == 2) {
throw e; // Abort
} else if (messageDialog.retCode == 1) {
return false; // Ignore
}
Run code in UI thread
To schedule execution of a piece of code in the UI thread:
Display.getDefault().asyncExec(new Runnable() {
public void run() {
// Do something
}
});
Generate an unpacked plug-in
If you need to access files from another plug-in, you need to leave it unpacked:
For this add the following line to MANIFEST.MF file:
Eclipse-BundleShape: dir
Get the path of folder where Eclipse is installed
URL url = Platform.getInstallLocation().getURL();
IPath path = new Path(url.getPath());
Get the path of a resource in another plug-in
If you need to access files from another plug-in, you need to get the absolute path:
Bundle bundle = Platform.getBundle(bundleId);
URL url = FileLocator.find(bundle, new Path(relativePath), null);
String location;
try {
location = FileLocator.resolve(url).getPath();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Template shared defaults
value = SharedDefaults.getInstance().getSharedDefaultsMap().get(id);
The store requires an update action:
SharedDefaults.getInstance().updateShareDefaultsMap(SharedDefaults.getInstance().getSharedDefaultsMap());
The preferences are stored in a file name shareddefaults.xml located in the workspace:
workspace/.metadata/.plugins/org.eclipse.cdt.core/shareddefaults.xml
Custom default files
Deprecated: since this is not exactly standard and leads to many small files, it will be migrated to regular preferences.
The preferences are stored in separate files, stored in separate folders named after the plug-in ID:
eclipse/configuration/<plug-in-id>/name.prefs
URL url = Platform.getInstallLocation().getURL();
IPath path = new Path(url.getPath());
File file = path.append("configuration")
.append(Activator.PLUGIN_ID).append(TOOLCHAIN).toFile();
InputStream is = new FileInputStream(file);
Properties prop = new Properties();
prop.load(is);
...
return prop.getProperty(property, "").trim();
Global markers
To create a marker that has global scope (not associated with any specific resource), you can use the workspace root (IWorkspace.getRoot()) as the resource.
public static void reportInfo(String message) {
try {
IMarker marker = ResourcesPlugin.getWorkspace().getRoot()
.createMarker(IMarker.PROBLEM);
marker.setAttribute(IMarker.MESSAGE, message);
marker.setAttribute(IMarker.SEVERITY, IMarker.SEVERITY_INFO);
marker.setAttribute(IMarker.LOCATION, "-");
} catch (CoreException e) {
System.out.println(message);
}
}
Configuration folders within PDE
When PDE launches a new instance of Eclipse from a debug session, each launch configuration gets a configuration folder:
./metadata/.plugins/org.eclipse.pde.core/<launch-name>/
