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
* <p>
	 * The value <code>ALL_LEVELS</code> means that all subtrees should be
	 * expanded.
	 * </p>
	 *
	 * @param level
	 *            non-negative level, or <code>ALL_LEVELS</code> to expand all
	 *            levels of the tree
	 */
	public void setAutoExpandLevel(int level) {
		expandToLevel = level;
	}
	/**
	 * The <code>AbstractTreeViewer</code> implementation of this method
	 * checks to ensure that the content provider is an
	 * <code>ITreeContentProvider</code>.
	 */
	public void setContentProvider(IContentProvider provider) {
		
		super.setContentProvider(provider);
	}
	protected void assertContentProviderType(IContentProvider provider) {
		Assert.isTrue(provider instanceof ITreeContentProvider
				|| provider instanceof ITreePathContentProvider);
	}
	/**
	 * Sets the expand state of the given item.
	 *
	 * @param item
	 *            the item