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
*/
	protected void updateSelection(ISelection selection) {
		SelectionChangedEvent event = new SelectionChangedEvent(this, selection);
		fireSelectionChanged(event);
	}
	/**
	 * Returns whether this structured viewer is configured to use an internal
	 * map to speed up the mapping between elements and SWT items.
	 * <p>
	 * The default implementation of this framework method checks whether the
	 * internal map has been initialized.
	 * </p>
	 * 
	 * @return <code>true</code> if the element map is enabled, and
	 *         <code>false</code> if disabled
	 */
	protected boolean usingElementMap() {
		return elementMap != null;
	}
	/* (non-Javadoc)
	 * @see org.eclipse.jface.viewers.ContentViewer#setLabelProvider(org.eclipse.jface.viewers.IBaseLabelProvider)
	 */
	public void setLabelProvider(IBaseLabelProvider labelProvider) {
		colorAndFontCollector = new ColorAndFontCollector(labelProvider);
		super.setLabelProvider(labelProvider);
		
	}
	
	/**
	 * Build a label up for the element using the supplied label provider.