Bug 171415 [Viewers] Table viewer needs to clear label, image when items are reused
If an item is reused for a different element on a refresh, the table viewer needs to clear the label and image from the item being reused. This is necessary to communicate to the label provider that a new label is needed (i.e. the label provider may defer providing a label if decorators are not ready). This is what the tree viewer does. To see the problem, open the Java Browsing perspective and select a Java project. Then click between different packages. Notice that some of the labels in the Types list take a while to update. Opening one of these reveals that the label is showing the wrong text.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTableViewer.java
* Returns an array of {@link Item} that are currently selected in the
	 * receiver. The order of the items is unspecified. An empty array indicates
	 * that no items are selected.
	 * 
	 * @return an array representing the selection
	 * 
	 * @since 3.3
	 */
	protected abstract Item[] doGetSelection();
	/**
	 * Returns the zero-relative indices of the items which are currently
	 * selected in the receiver. The order of the indices is unspecified. The
	 * array is empty if no items are selected.
	 * 
	 * @return an array representing the selection
	 * 
	 * @since 3.3
	 */
	protected abstract int[] doGetSelectionIndices();
	/**
	 * Clears all the items in the receiver. The text, icon and other attributes
	 * of the items are set to their default values. If the table was created
	 * with the <code>SWT.VIRTUAL</code> style, these attributes are requested
	 * again as needed.
	 * 
	 * @since 3.3
	 */
	protected abstract void doClearAll();
	/**
	 * Removes the items from the receiver which are between the given