Bug 5571 JAR Packager: Reveal first checked project
If the list of projects in the JAR Packager is long it is possible that the shown projects are not checked even though there are checked projects (due to current selection). ==> reveal the first checked project.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/CheckboxTreeAndListGroup.java
Object rootObject,
			ITreeContentProvider treeContentProvider,
			ILabelProvider treeLabelProvider,
			IStructuredContentProvider listContentProvider,
			ILabelProvider listLabelProvider,
			int style,
			int width,
			int height) {
		fRoot= rootObject;
		fTreeContentProvider= treeContentProvider;
		fListContentProvider= listContentProvider;
		fTreeLabelProvider= treeLabelProvider;
		fListLabelProvider= listLabelProvider;
		createContents(parent, width, height, style);
	}
	/**
	 * This method must be called just before this window becomes visible.
	 */
	public void aboutToOpen() {
		determineWhiteCheckedDescendents(fRoot);
		checkNewTreeElements(getTreeChildren(fRoot));
		fCurrentTreeSelection= null;
		
		Object[] elements= getTreeChildren(fRoot);
		Object primary= elements.length > 0 ? elements[0] : null;
		if (primary != null) {
			fTreeViewer.setSelection(new StructuredSelection(primary));
		}
		fTreeViewer.getControl().setFocus();
	}