Bug 53582 Rebuild Project are not run in the background?
The "Build All" and "Rebuild All" actions are run in the background, but the "Build Project" and "Rebuild Project" actions aren't. This is not consistent and I was surprised to get a modal dialog when performing a "Rebuild Project".
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/WorkspaceAction.java
/**
 * The abstract superclass for actions whose only role in life is to invoke 
 * core commands on a set of selected resources.
 * When the action is run, all the work is done within a modal progress
 * dialog. It iterates over all selected resources; errors are collected and
 * displayed to the user via a problems dialog at the end of the operation.
 * User requests to cancel the operation are passed along to the core.
 * <p>
 * Subclasses must implement the following methods:
 * <ul>
 *   <li><code>invokeOperation</code> - to perform the operation on one of the 
 *      selected resources</li>
 *   <li><code>getOperationMessage</code> - to furnish a title for the progress
 *      dialog</li>
 * </ul>
 * </p>
 * <p>
 * Subclasses may override the following methods:
 * <ul>
 *   <li><code>shouldPerformResourcePruning</code> - reimplement to turn off</li>
 *   <li><code>updateSelection</code> - extend to refine enablement criteria</li>
 *   <li><code>getProblemsTitle</code> - reimplement to furnish a title for the
 *      problems dialog</li>
 *   <li><code>getProblemsMessage</code> - reimplement to furnish a message for 
 *      the problems dialog</li>
 *   <li><code>run</code> - extend to </li>
 * </ul>
 * </p>
 */
public abstract class WorkspaceAction extends SelectionListenerAction {