Bug 210448 [Viewers] [JFace] AbstractTreeViewer inputChanged setRedraw should be in try/finally
The inputChanged method on the AbstractTreeViewer makes use of setRedraw, which is good, but it doesn't use a try/finally block as per recommendations. If an exception is thrown from within one of the methods called, redraw will remain false. Additionally, the commented out portion is fine, but the fact that we have conditionals in the code that always evaluate to true is less fine. When we're ready to actually determine when to use redraw we could put them back in. Current code: protected void inputChanged(Object input, Object oldInput) { preservingSelection(new Runnable() { public void run() { Control tree = getControl(); boolean useRedraw = true; // (size > REDRAW_THRESHOLD) || (table.getItemCount() > // REDRAW_THRESHOLD); if (useRedraw) { tree.setRedraw(false); } removeAll(tree); tree.setData(getRoot()); internalInitializeTree(tree); if (useRedraw) { tree.setRedraw(true); } } }); } Suggestion: protected void inputChanged(Object input, Object oldInput) { preservingSelection(new Runnable() { public void run() { Control tree = getControl(); try { tree.setRedraw(false); removeAll(tree); tree.setData(getRoot()); internalInitializeTree(tree); } finally { tree.setRedraw(true); } } }); }
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
/**
	 * Inserts the given element as a new child element of the given parent
	 * element at the given position. If this viewer has a sorter, the position
	 * is ignored and the element is inserted at the correct position in the
	 * sort order.
	 * <p>
	 * This method should be called (by the content provider) when elements have
	 * been added to the model, in order to cause the viewer to accurately
	 * reflect the model. This method only affects the viewer, not the model.
	 * </p>
	 *
	 * @param parentElementOrTreePath
	 *            the parent element, or the tree path to the parent
	 * @param element
	 *            the element
	 * @param position
	 *            a 0-based position relative to the model, or -1 to indicate
	 *            the last position
	 *
	 * @since 3.2
	 */
	public void insert(Object parentElementOrTreePath, Object element,
			int position) {
		Assert.isNotNull(parentElementOrTreePath);
		Assert.isNotNull(element);
		if (checkBusy())
			return;
		if (getComparator() != null || hasFilters()) {
			add(parentElementOrTreePath, new Object[] { element });
			return;