= Customize properties =

[wiki:gmf:gmf <back]

This section is about customizing properties on the basis of an example.

What I want: My element A has a property of type B. B is something like a file so it has a property "path" of type String. I want a file chooser to choose the file. The path of the file should be stored in the path property of the property B of element A.

What to do:

  - Write a class like the following. This is the file choose itself.
{{{
public class FileChooserCellEditor extends DialogCellEditor {

   private Composite parent;
	
   public FileChooserCellEditor(Composite parent) {
	super(parent);
	this.parent = parent;
   }

   protected Object openDialogBox(Control cellEditorWindow) {
	FileDialog dialog = new FileDialog(parent.getShell(), SWT.OPEN);
	return dialog.open();
   }
}

}}}

  - Write a property descriptor for all your properties:
{{{
public class ExhibitionPropertyDescriptor extends
		EMFCompositeSourcePropertyDescriptor {

   IItemPropertyDescriptor itemPropertyDescriptor;
	
   public ExhibitionPropertyDescriptor(Object object,
		IItemPropertyDescriptor itemPropertyDescriptor, String category) {
	super(object, itemPropertyDescriptor, category);
	this.itemPropertyDescriptor = itemPropertyDescriptor;
   }

   /* here you can instanciate whatever you want to be 
      opened when the user clicks on the button in the property field
   */
   protected CellEditor doCreateEditor(Composite composite) {
	if (itemPropertyDescriptor instanceof ImagePropertyDescriptor) {
	   return new FileChooserCellEditor(composite);
	}
	return super.doCreateEditor(composite);
   }
}
}}}