Category: Eclipse

Eclipse Application Export Error

While performing an Eclipse Product export, via wizard, the following error came up:

 Cannot complete the install because of a conflicting dependency.
 Software being installed: iCANgraph 1.0.0 (Lumina 1.0.0)
 Only one of the following can be installed at once:
 Cannot satisfy dependency:

Yes, the dependecy that could not be satisfied was not stated, so there was no clue about what was causing this export error…
There was absolutely no more error information. No export log was found, thus this useless error message was all that I had…
It took some time until I realise that the “Generate metadata repository” option was enabled, causing all this problems.
This option enables the “Provisioning platform“, commonly known as P2, which builds P2 repositories and products. It creates a plugins folders (repository\plugins) that contain the same plugins as the folders in the exported application.
My guess, since I was unnable to get suficient information to know for sure, is that the automatic resolution of dependencies between software components, one of P2 features, was not doing things properly, thus the error.

Since all that was needed was a product, the P2 information was unecessary and, obvisouly, redundant and a real trouble maker.
To solve this problem, all that was required was to disable the “Generate metadata repository” option and export the product again.

RCP Save Workbench Status

In Rich Client Platform (RCP) application, the workbench status can be easily saved and restored by simply including the snippet bellow in the ApplicationWorkbenchAdvisor class, that extends WorkbenchAdvisor.

@Override
public void initialize(IWorkbenchConfigurer configurer) {
super.initialize(configurer);

// tell eclipse to save workbench state when it quits
// (things like window size, view layout, etc.)
configurer.setSaveAndRestore(true);
}

This will automatically save the status of the workbench when the application is closed and will automatically restore that status when the application is executed again. The settings are saved on the [runtime-{your-product}]/.metadata/.plugins/org.eclipse.ui.workbench/workbench.xml file.

SWT File Dialog

During the development of an Rich Client Platform (RCP) it is common to develop a file browse dialog, here’s how to show a file dialog in SWT:

import org.eclipse.swt.widgets.FileDialog;

FileDialog dialog = new FileDialog(this.getShell(), SWT.NULL);
dialog.setFilterExtensions(new String[] { "*.txt", "*.*" });
dialog.setFilterNames(new String[] { "Text files", "All files" });
String path = dialog.open();
if (path != null) {
   File file = new File(path);
   if (file.isFile()) {
     System.out.println(file.toString());
   }
}

The snippet above filters by text files (*.txt) and all files (*.*) and it is easily applied to the click event of any button or file menu option.

Intenationalize RCP applications

To internationalize (i18n) and Rich Client Platform (RCP) application, also known as Eclipse Application, it’s not enough to download the language package. One also needs to download the language packs for the RCP core.

Here’s what it takes to i18n the core of an RCP application:

  1. Download the language packages from the Babel project using the Eclipse install/update mechanism.
  2. Open the RCP application “.product” file.
  3. Go to the “Configuration” section.
  4. Press “Add Required Plug-ins” button.

This last step is the “magical step”, it includes the i18n plugins to the RCP application.
You can identify the language plugins by their name. They come in the “<plugin>.nl_<language>” format. For instance, Portuguese JFace translation file is “org.eclipse.jface.nl_pt”.