Customize properties

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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);
     }
  }
  

• Change your XXXPropertySection in the package "sheet" as follows:

  /**
   * @generated NOT
   */
  public IPropertySource getPropertySource(Object object) {
     if (object instanceof IPropertySource) {
  	return (IPropertySource) object;
     }
     AdapterFactory af = getAdapterFactory(object);
     if (af != null) {
  	IItemPropertySource ips = (IItemPropertySource) af.adapt(object,
  				IItemPropertySource.class);
  	if (ips != null) {
  	   return new EMFCompositePropertySource(object, ips,
  					null) {
  		protected IPropertyDescriptor newPropertyDescriptor(
  			IItemPropertyDescriptor itemPropertyDescriptor) {
  			return new ExhibitionPropertyDescriptor(object,
  				itemPropertyDescriptor, getCategory());
  		}
  	   };
  	}
     }
     if (object instanceof IAdaptable) {
  	return (IPropertySource) ((IAdaptable) object)
  		.getAdapter(IPropertySource.class);
  	}
     return null;
  }