Bug 82240 [Viewers] Need a content provider for tables that gets elements lazily
Currently all of our viewers assume that all of the elements are avialble. In the case of a virtual table we also want to be able to load elements as they become visible rather than all at once (common issue for databases). Here are some of the issues 1) Need to setItemCount on the table from the content provider 2) Need a getElements(start,finish) method on the content provider 3) Need to decide how to handle staleness. If there are a million items and the viewer just sits there scrolled to the bottom that is a million TableItems and a million Objects represented. How do we manage memory for this?
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
}
	/**
	 * Handles an open event from the OpenStrategy.
	 * <p>
	 * This method is internal to the framework; subclassers should not call
	 * this method.
	 * </p>
	 * 
	 * @param event
	 *            the SWT selection event
	 */
	protected void handleOpen(SelectionEvent event) {
		Control control = getControl();
		if (control != null && !control.isDisposed()) {
			ISelection selection = getSelection();
			fireOpen(new OpenEvent(this, selection));
		}
	}
	/**
	 * Handles an invalid selection.
	 * <p>
	 * This framework method is called if a model change picked up by a viewer
	 * results in an invalid selection. For instance if an element contained in
	 * the selection has been removed from the viewer, the viewer is free to
	 * either remove the element from the selection or to pick another element
	 * as its new selection. The default implementation of this method calls
	 * <code>updateSelection</code>. Subclasses may override it to implement
	 * a different strategy for picking a new selection when the old selection
	 * becomes invalid.
	 * </p>