JFace TableViewer with java.util.Map input

I am implementing a SWT dialog to edit some configuration settings. The configuration has a java.util.Map<String, String> which contains additional parameters.

The parameters Map should be presented/edited by a JFace TableViewer:

• Column 1: Parameter name => map key
• Column 2: Parameter value => corresponding value

Editing can then be down "in table" by implementing EditingSupport or via a small popup dialog.

Screenshot: settings dialog with java.util.Map based JFace TableViewer

Unfortunately org.eclipse.jface.viewers.ArrayContentProvider cannot deal with java.util.Map. The table stayed empty.

I did a quick search for another ContentProvider that supports java.util.Map - but could not find anything.

Here comes my own implementation:

 /**  
  * IStructuredContentProvider for java.util.Map  
  *   
  * @author Peter Pinnau  
  *  
  */  
 class MapContentProvider implements IStructuredContentProvider {  
   
      @Override  
      public void dispose() { }  
   
      @Override  
      public void inputChanged(Viewer viewer, Object oldInput, Object newInput) { }  
   
      @SuppressWarnings("rawtypes")  
      @Override  
      public Object[] getElements(Object inputElement) {  
           if (inputElement == null) return null;  
             
           if (inputElement instanceof Map) {  
                return ((Map) inputElement).entrySet().toArray();  
           }  
        
           throw new RuntimeException("Invalid input für MapContentProvider: " + inputElement.getClass());  
      }  
 }  

The ContentProvider simply returns java.util.Map.entrySet().toArray().

The implementation for the TableViewer lable providers is straight forward:

 viewerParameter = new TableViewer(composite, SWT.FULL_SELECTION);                 
 viewerParameter.getTable().setHeaderVisible(true);  
   
 // Set the MapContentProvider  
 viewerParameter.setContentProvider( new MapContentProvider() );  
             
 // Column for map-key  
 TableViewerColumn column = new TableViewerColumn(viewerParameter, SWT.NONE);  
 column.getColumn().setText("Parameter");  
 column.getColumn().setWidth(150);  
 column.setLabelProvider( new CellLabelProvider() {                 
      @Override  
      public void update(ViewerCell cell) {       
           @SuppressWarnings("rawtypes")  
           Object value = ((Entry) cell.getElement()).getKey();  
             
           if (value != null)                      
                cell.setText(value.toString());  
           else  
                cell.setText("");  
      }  
 });  
   
 // Column for map-value  
 column = new TableViewerColumn(viewerParameter, SWT.NONE);  
 column.getColumn().setText("Wert");  
 column.getColumn().setWidth(250);  
 column.setLabelProvider( new CellLabelProvider() {                 
      @Override  
      public void update(ViewerCell cell) {       
           @SuppressWarnings("rawtypes")  
           Object value = ((Entry) cell.getElement()).getValue();  
             
           if (value != null)                      
                cell.setText(value.toString());  
           else  
                cell.setText("");  
      }  
 });  
   
 // Pass a java.util.Map as input  
 viewerParameter.setInput( mapObject );