/**
 * Copyright (c) 2009-2010 Thales Corporate Services S.A.S.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 * Thales Corporate Services S.A.S - initial API and implementation
 */

package org.eclipse.egf.core.ui;

import org.eclipse.egf.common.ui.activator.EGFAbstractUIPlugin;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.IWorkbenchWindow;
import org.osgi.framework.BundleContext;

/**
 * The activator class controls the plug-in life cycle
 */
public class EGFCoreUIPlugin extends EGFAbstractUIPlugin {

  /**
   * The shared instance
   */
  private static EGFCoreUIPlugin __plugin;

  /**
   * 
   * Returns the currently active window for this workbench (if any). Returns
   * <code>null</code> if there is no active workbench window. Returns
   * <code>null</code> if called from a non-UI thread.
   * 
   * @return the active workbench window, or <code>null</code> if there is
   *         no active workbench window or if called from a non-UI thread
   */
  public static IWorkbenchWindow getActiveWorkbenchWindow() {
    return getDefault().getWorkbench().getActiveWorkbenchWindow();
  }

  /**
   * Returns the currently active shell for this workbench (if any).
   * 
   * @return the active workbench shell.
   */
  public static Shell getActiveWorkbenchShell() {
    IWorkbenchWindow window = getActiveWorkbenchWindow();
    if (window == null) {
      IWorkbenchWindow[] windows = getDefault().getWorkbench().getWorkbenchWindows();
      if (windows.length > 0) {
        return windows[0].getShell();
      }
    } else {
      return window.getShell();
    }
    return null;
  }

  /**
   * @see org.eclipse.ui.plugin.AbstractUIPlugin#start(org.osgi.framework.BundleContext)
   */
  @Override
  public void start(BundleContext context) throws Exception {
    super.start(context);
    __plugin = this;
  }

  /**
   * @see org.eclipse.ui.plugin.AbstractUIPlugin#stop(org.osgi.framework.BundleContext)
   */
  @Override
  public void stop(BundleContext context) throws Exception {
    __plugin = null;
    super.stop(context);
  }

  /**
   * Returns the shared instance
   * 
   * @return the shared instance
   */
  public static EGFCoreUIPlugin getDefault() {
    return __plugin;
  }

}