Bug 158778 [Viewers] request for remove(parent, index) API on tree viewer
3.3 It would be helpful to have a 'remove(Object parent, int index)' method on the tree viewer to complement that 'replace(...)' and 'setChildCount(...)' APIs. The debug platform requires such a method to implement filtering in virtual tree views. Rather than performing a 'replace/remove' based on elements, the content provider can make one atomic call to remove an element at a specific index.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
return;
			}
		}
		if (childElements.length > 0) {
			
			Object[] filtered = filter(parentElementOrTreePath, childElements);
			ViewerComparator comparator = getComparator();
			if (comparator != null) {
				if (comparator instanceof TreePathViewerSorter) {
					TreePathViewerSorter tpvs = (TreePathViewerSorter) comparator;
					if (path == null) {
						path = internalGetSorterParentPath(widget, comparator);
					}
					tpvs.sort(this, path, filtered);
				} else {
					comparator.sort(this, filtered);
				}
			}
			createAddedElements(widget, filtered);
		}
	}
	/**
	 * Filter the children elements.
	 * 
	 * @param parentElementOrTreePath
	 *            the parent element or path
	 * @param elements
	 *            the child elements
	 * @return the filter list of children
	 */