Bug 282875 [UI] Allow parts of models to be rendered
We need to change the rendering protocol to allow a 'createGui' to specify the container it should be created under (in SWT-land this would be a Composite). This is necessary to facilitate unit tests and to allow the ad-hoc rendering of chunks of a model within an arbitrary container (i.e. a Dialog or Wizard). In order to do this we'll have to make an API change to the PartFactory's 'createWidget' so that it will get the parent container as a parameter. In order to 'upgrade' an existing PartFactory you would simply replace the code you're currently using to find the correct container with the new parameter's value.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/workbench/ui/renderers/PartFactory.java
IContributionFactory contributionFactory) {
		this.renderer = renderer;
		this.contributionFactory = contributionFactory;
		this.context = context;
	}
	public abstract Object createWidget(MPart<?> element);
	public abstract <P extends MPart<?>> void processContents(MPart<P> me);
	public void postProcess(MPart<?> childME) {
	}
	public abstract void bindWidget(MPart<?> me, Object widget);
	protected abstract Object getParentWidget(MPart<?> element);
	public abstract void disposeWidget(MPart<?> part);
	public abstract void hookControllerLogic(final MPart<?> me);
	public abstract void childAdded(MPart<?> parentElement, MPart<?> element);
	public void childRemoved(MPart<?> parentElement, MPart<?> child) {
	}
	protected abstract Object getImage(MApplicationElement element);
	public Object createMenu(MPart<?> part, Object widgetObject, MMenu menu) {
		return null;
	}
	public Object createToolBar(MPart<?> part, Object widgetObject, MToolBar toolBar) {
		return null;
	}
	/**
	 * Return a parent context for this part.
	 * 
	 * @param part
	 *            the part to start searching from
	 * @return the parent's closest context, or global context if none in the hierarchy
	 */