Eugenia: Nodes with images defined at run-time

This recipe addresses the case where the end-user needs to set an image for each node at runtime (based on Thomas Beyer's solution presented in the GMF newsgroup). For our example, we'll use the Component class.

Create an attribute to store the image path

First we need to create an imagePath attribute that will store the path of the image for each component.

Set the figure of Component to a custom ComponentFigure

The next step is to set the figure of Component in Eugenia to a custom figure. After those two steps, our definition of Component looks like this:

@gmf.node(label="name", figure="ccdl.diagram.figures.ComponentFigure", label.placement="external")
class Component {
  attr String name;
  attr String imagePath;
}

Once we generate the diagram code, we'll get an error because ComponentFigure has not been found. We need to create the ComponentFigure class and set its code to the following:

import java.io.File;
import java.util.HashMap;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.FileLocator;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Platform;
import org.eclipse.draw2d.ImageFigure;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.graphics.Image;

import ccdl.diagram.part.CcdlDiagramEditorPlugin;

public class ComponentFigure extends ImageFigure  {

  static Image unspecified = null;

  public ComponentFigure() {
      if (unspecified == null) {
      unspecified = ImageDescriptor.createFromURL(
               FileLocator.find(
                       Platform.getBundle(CcdlDiagramEditorPlugin.ID),
                       new Path("icons/ComponentDefault.png"), new HashMap()))
                                             .createImage();
      }
  }

  public static Image createImage(String imagePath) {
      try {
          IFile res=(IFile)ResourcesPlugin.getWorkspace().getRoot().
                               findMember(new Path(imagePath));
          File file = new File(res.getRawLocation().toOSString());
          return ImageDescriptor.createFromURL(file.toURI().toURL()).createImage();
      }
      catch (Exception ex) {
          return unspecified;
      }
  }

  public void setImagePath(String imagePath) {

      try {

          if (getImage()!=null && getImage() !=unspecified) {
              getImage().dispose();
          }

          this.setImage(createImage(imagePath));
      }
      catch (Exception ex) {
          ex.printStackTrace();
      }
  }

}

Create the image path property descriptor

The next step is to create the property descriptor for the image path so that we can eventually get a nice browse button in the properties view. To do this we need to create a new class named ComponentImagePathPropertyDescriptor.

import org.eclipse.emf.ecore.EAttribute;
import org.eclipse.emf.edit.provider.IItemPropertyDescriptor;
import org.eclipse.gmf.runtime.emf.ui.properties.descriptors.EMFCompositeSourcePropertyDescriptor;
import org.eclipse.jface.viewers.CellEditor;
import org.eclipse.swt.widgets.Composite;

public class ComponentImagePathPropertyDescriptor  extends
        EMFCompositeSourcePropertyDescriptor {

  public ComponentImagePathPropertyDescriptor(Object object,
          IItemPropertyDescriptor itemPropertyDescriptor, String category) {
      super(object, itemPropertyDescriptor, category);
  }

  protected CellEditor doCreateEditor(Composite composite) {
      try {
          if (((EAttribute) getFeature()).getName().equals("imagePath")) {
              return new ComponentImagePathCellEditor(composite);
          }
      }
      catch (Exception ex){}
      return super.doCreateEditor(composite);
  }
}

Create the image path property cell editor

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.jface.viewers.DialogCellEditor;
import org.eclipse.jface.window.Window;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.ui.dialogs.ResourceListSelectionDialog;

public class ComponentImagePathCellEditor extends DialogCellEditor  {

  public ComponentImagePathCellEditor(Composite parent) {
      super(parent);
  }

  protected Object openDialogBox(Control cellEditorWindow) {

      ResourceListSelectionDialog elementSelector = new ResourceListSelectionDialog(
                  cellEditorWindow.getShell(), ResourcesPlugin.getWorkspace().getRoot(),
                  IResource.DEPTH_INFINITE | IResource.FILE );
      elementSelector.setTitle("Image");
      elementSelector.setMessage("Please select an image");
      elementSelector.open();

      if (elementSelector.getReturnCode() == Window.OK){
          IFile f = (IFile) elementSelector.getResult()[0];
          return f.getFullPath().toString();
      }
      else {
          return null;
      }


  }

}

Update the XXXPropertySection under xxx.diagram.sheet

Update the getPropertySource method as follows:

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) {

      if (object instanceof Component) {
        return new PropertySource(object, ips) {
          protected IPropertyDescriptor createPropertyDescriptor(
              IItemPropertyDescriptor itemPropertyDescriptor) {

            EStructuralFeature feature = (EStructuralFeature) itemPropertyDescriptor.getFeature(object);

            if(feature.getName().equalsIgnoreCase("imagePath")) {

              return new ComponentImagePathPropertyDescriptor(
                  object, itemPropertyDescriptor, "Misc");


            }
            else {
              return new EMFCompositeSourcePropertyDescriptor(object, itemPropertyDescriptor, "Misc");
            }
          }
        };
      }

      //return new PropertySource(object, ips);
      return new EMFCompositePropertySource(object, ips, "Misc");
    }
  }
  if (object instanceof IAdaptable) {
    return (IPropertySource) ((IAdaptable) object)
        .getAdapter(IPropertySource.class);
  }
  return null;
  }

Modify the edit part

Modify the handleNotificationEvent method so that the figure is updated every time the value of imagePath changes

protected void handleNotificationEvent(Notification event) {
  if (event.getNotifier() == getModel()
      && EcorePackage.eINSTANCE.getEModelElement_EAnnotations()
          .equals(event.getFeature())) {
    handleMajorSemanticChange();
  } else {

    if (event.getFeature() instanceof EAttribute) {
      EAttribute eAttribute = (EAttribute) event.getFeature();

      if (eAttribute.getName().equalsIgnoreCase("imagePath")) {
        ComponentFigure figure = (ComponentFigure) this.getPrimaryShape();
        figure.setImagePath(event.getNewStringValue());
      }

    }


    super.handleNotificationEvent(event);
  }
}

Modify the createNodeShape method so that the figure is initialized from the existing imagePath the first time.

protected IFigure createNodeShape() {
  primaryShape = new ComponentFigure();
  Component component = (Component) ((Node)getNotationView()).getElement();
  ((ComponentFigure) primaryShape).setImagePath(component.getImagePath());
  return primaryShape;
}