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
*            the parent widget
	 * @param style
	 *            SWT style bits
	 * @param index
	 *            if non-negative, indicates the position to insert the item
	 *            into its parent
	 * @return the newly-created item
	 */
	protected abstract Item newItem(Widget parent, int style, int index);
	/**
	 * Removes the given elements from this viewer. The selection is updated if
	 * required.
	 * <p>
	 * This method should be called (by the content provider) when elements have
	 * been removed from the model, in order to cause the viewer to accurately
	 * reflect the model. This method only affects the viewer, not the model.
	 * </p>
	 *
	 * @param elementsOrTreePaths
	 *            the elements to remove
	 */
	public void remove(final Object[] elementsOrTreePaths) {
		assertElementsNotNull(elementsOrTreePaths);
		if (elementsOrTreePaths.length == 0) {
			return;
		}
		if (checkBusy())
			return;
		preservingSelection(new Runnable() {
			public void run() {