Bug 87089 [Viewers] LabelProvider.getImage is not invoked after the TreeViewer changes introduced on 24/01/2005
If you compare the versions 1.26 and 1.25 of the method doUpdateItem(Item item, Object element) in org.eclipse.jface.viewers.TreeViewer, you will notice a change in the way the image of the element is calculated. In 1.25, the image of the Element is set in the "buildLabel" method which doesn't have a special treatment for ITableLabelProvider. In 1.26, if the label provider is a ITableLabelProvider, instead of calling ILabelProvider.getImage(Object), the code always invokes ITableLabelProvider.getColunmImage(Object). This change has broken the icons on one of the EMF generated editors (the mapping editor) as the images I will attach here demostrate.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
getTree().showSelection();
			}
			void setLayoutData(CellEditor.LayoutData layoutData) {
				treeEditor.grabHorizontal = layoutData.grabHorizontal;
				treeEditor.horizontalAlignment = layoutData.horizontalAlignment;
				treeEditor.minimumWidth = layoutData.minimumWidth;
			}
			void handleDoubleClickEvent() {
				Viewer viewer = getViewer();
				fireDoubleClick(new DoubleClickEvent(viewer, viewer
						.getSelection()));
				fireOpen(new OpenEvent(viewer, viewer.getSelection()));
			}
		};
	}
	
	/**
	 * Returns whether there is an active cell editor.
	 * 
	 * @return <code>true</code> if there is an active cell editor, and
	 *         <code>false</code> otherwise
	 * @since 3.1
	 */
	public boolean isCellEditorActive() {
		return treeViewerImpl.isCellEditorActive();
	}
	
    /* (non-Javadoc)
     * Method declared in AbstractTreeViewer.
     */