Using JFace with PFGrid.SWT

In this tutorial is shown how to use a JFace-TreeListViewer of PFGrid to display hierarchical content in an RCP-Application.

First of all we are using the Eclipse-wizard to create an RCP-Application with UI. The wizard creates a plugin with a class derived from ViewPart. Remove all code in this class so that an empty composite will remain.

Add Content- and LabelProvider

When displaying hierarchical content you have to define a ContentProvider that implements ITreeContentProvider. In our sample we will display objects of the class Group, each Group can contain a list of User-objects (your business classes). Here are the Content- and LabelProvider-classes:

/** The contentprovider for treelist */
class GroupUserContentProvider implements ITreeContentProvider {

	public Object[] getChildren(Object parentElement) {
		Group g = (Group) parentElement;
		return g.getUsers().toArray();
	}

	public boolean hasChildren(Object element) {
		if (!(element instanceof Group))
			return false;

		Group g = (Group) element;
		return (g.getUsers().size() > 0);

	}

	public Object[] getElements(Object inputElement) {
		return ((ArrayList) inputElement).toArray();
	}
} 

/** the labelprovider for treelist */
class GroupUserLabelProvider implements ITableLabelProvider {

	@Override
	public Image getColumnImage(Object element, int columnIndex) {

		if (columnIndex == 0) {
			IGrantee grantee = (IGrantee) element;
			return grantee.getImage();
		}

		return null;
	}

	@Override
	public String getColumnText(Object element, int columnIndex) {
		IGrantee grantee = (IGrantee) element;
		switch (columnIndex) {
		case 0:
			return grantee.getName();
		case 1:
			return grantee.getShortName();
		case 2:
			return (grantee.isActive()) ? "true" : "false";
		}
		return null;
	}

	@Override
	public boolean isLabelProperty(Object element, String property) {
		return false;
	}

	@Override
	public void removeListener(ILabelProviderListener listener) {

	}
} 
        

Defining the UI

The UI is created in the method createTreeViewer which is defined in the ViewPart of the RCP-Application:

private void createTreeViewer(Composite parent, ArrayList groups) {

	viewer = new TreeListViewer(parent, SWT.NONE);

	// Initialize the underlying widget
	final TreeListView treeList = viewer.getTreeListView();
	treeList.addTreeListEditorListener(new GranteeEditorListener());

	treeList.setSelectionType(SelectionType.Cell);

	// Create columns
	TreeListViewerColumn viewerColumnName = new TreeListViewerColumn(viewer);
	TreeListColumn colName = viewerColumnName.getColumn();
	colName.setText("Name");
	colName.setWidth(350);

	TreeListViewerColumn viewerColumnShortName = new TreeListViewerColumn(
			viewer);
	TreeListColumn colShortName = viewerColumnShortName.getColumn();
	colShortName.setText("Shortname");
	colShortName.setWidth(100);
		
	TreeListViewerColumn viewerColumnActive = new TreeListViewerColumn(
			viewer, new CheckBoxColumn(treeList));
	TreeListColumn colActive = viewerColumnActive.getColumn();
	colActive.setText("Active");
	colActive.setWidth(50);


	// Set Content- and LabelProvider
	viewer.setContentProvider(new GroupUserContentProvider());
	viewer.setLabelProvider(new GroupUserLabelProvider());
	viewer.setInput(groups);

	// Initially expand the root nodes
	viewer.setExpandedState(groups.get(0), true);
	viewer.setExpandedState(groups.get(1), true);
		
	viewer.addDoubleClickListener(this);
}
    

In this method the TreeListViewer and the TreeListViewerColumns are defined (the JFace-representation of the UI) and the content- and labelprovider are assigned. The root-nodes of the content are expanded.

Add the content

The last thing to do is adding the input-data to the viewer. The method createInputData delivers a list of Group-objects which are assigend to the viewer in the method createTreeViewer:

private ArrayList createInputData(Image imgGroup, Image imgUser) {
	ArrayList groups = new ArrayList();

	// Group of developers
	Group developers = new Group(imgGroup, "Developers", "Grp. 1");
	developers.getUsers().add(new User(imgUser, "Matthias P.", "mp"));
	developers.getUsers().add(new User(imgUser, "Georg S.", "gs"));

	// Group of teamleaders
	Group teamleaders = new Group(imgGroup, "Team leaders", "Grp. 2");
	teamleaders.getUsers().add(new User(imgUser, "Günther F.", "gf"));
	teamleaders.getUsers().add(new User(imgUser, "Herbert E.", "he"));

	groups.add(developers);
	groups.add(teamleaders);
	return groups;
}

    

The column Active represents a boolean-value which is displayed as CheckBox. This is achieved by the following code:

	TreeListViewerColumn viewerColumnActive = new TreeListViewerColumn(
			viewer, new CheckBoxColumn(treeList));
    

That's all - please refer to the sample in the Download-section.