content: /*******************************************************************************
   * Copyright (c) 2000, 2008 IBM Corporation and others.
   * 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:
   *     IBM Corporation - initial API and implementation
   *******************************************************************************/
  package org.eclipse.wst.jsdt.ui.actions;
  
  import org.eclipse.core.resources.IFile;
  import org.eclipse.core.resources.IResource;
  import org.eclipse.core.runtime.IAdaptable;
  import org.eclipse.jface.action.IAction;
  import org.eclipse.jface.action.IMenuManager;
  import org.eclipse.jface.action.MenuManager;
  import org.eclipse.jface.viewers.ISelection;
  import org.eclipse.jface.viewers.ISelectionProvider;
  import org.eclipse.jface.viewers.IStructuredSelection;
  import org.eclipse.ui.IActionBars;
  import org.eclipse.ui.IViewPart;
  import org.eclipse.ui.IWorkbenchSite;
  import org.eclipse.ui.actions.ActionGroup;
  import org.eclipse.ui.actions.OpenWithMenu;
  import org.eclipse.wst.jsdt.internal.ui.actions.ActionMessages;
  import org.eclipse.wst.jsdt.internal.ui.javaeditor.JavaEditor;
  import org.eclipse.wst.jsdt.ui.IContextMenuConstants;
  
  /**
   * Action group that adds the actions opening a new editor to the 
   * context menu and the action bar's navigate menu.
   *
   * <p>
   * This class may be instantiated; it is not intended to be subclassed.
   * </p>
   * 
   *
   * Provisional API: This class/interface is part of an interim API that is still under development and expected to
   * change significantly before reaching stability. It is being made available at this early stage to solicit feedback
   * from pioneering adopters on the understanding that any code that uses this API will almost certainly be broken
   * (repeatedly) as the API evolves.
   */
  public class OpenEditorActionGroup extends ActionGroup {
  
  	private IWorkbenchSite fSite;
  	private boolean fIsEditorOwner;
  	private OpenAction fOpen;
  
  	/**
  	 * Creates a new <code>OpenActionGroup</code>. The group requires
  	 * that the selection provided by the part's selection provider is of type <code>
  	 * org.eclipse.jface.viewers.IStructuredSelection</code>.
  	 * 
  	 * @param part the view part that owns this action group
  	 */
  	public OpenEditorActionGroup(IViewPart part) {
  		fSite= part.getSite();
  		fOpen= new OpenAction(fSite);
  		fOpen.setActionDefinitionId(IJavaEditorActionDefinitionIds.OPEN_EDITOR);
  		initialize(fSite.getSelectionProvider());
  	}
  	
  	/**
  	 * Note: This constructor is for internal use only. Clients should not call this constructor.
  	 * @param editor the JavaScript editor
  	 */
  	public OpenEditorActionGroup(JavaEditor editor) {
  		fIsEditorOwner= true;
  		fOpen= new OpenAction(editor);
  		fOpen.setActionDefinitionId(IJavaEditorActionDefinitionIds.OPEN_EDITOR);
  		editor.setAction("OpenEditor", fOpen); //$NON-NLS-1$
  		fSite= editor.getEditorSite();
  		initialize(fSite.getSelectionProvider());
  	}
  
  	/**
  	 * Returns the open action managed by this action group. 
  	 * 
  	 * @return the open action. Returns <code>null</code> if the group
  	 * 	doesn't provide any open action
  	 */
  	public IAction getOpenAction() {
  		return fOpen;
  	}
  
  	private void initialize(ISelectionProvider provider) {
  		ISelection selection= provider.getSelection();
  		fOpen.update(selection);
  		if (!fIsEditorOwner) {
  			provider.addSelectionChangedListener(fOpen);
  		}
  	}
  
  	/* (non-Javadoc)
  	 * Method declared in ActionGroup
  	 */
  	public void fillActionBars(IActionBars actionBar) {
  		super.fillActionBars(actionBar);
  		setGlobalActionHandlers(actionBar);
  	}
  	
  	/* (non-Javadoc)
  	 * Method declared in ActionGroup
  	 */
  	public void fillContextMenu(IMenuManager menu) {
  		super.fillContextMenu(menu);
  		appendToGroup(menu, fOpen);
  		if (!fIsEditorOwner) {
  			addOpenWithMenu(menu);
  		}
  	}
  
  	/*
  	 * @see ActionGroup#dispose()
  	 */
  	public void dispose() {
  		ISelectionProvider provider= fSite.getSelectionProvider();
  		provider.removeSelectionChangedListener(fOpen);
  		super.dispose();
  	}
  	
  	private void setGlobalActionHandlers(IActionBars actionBars) {
  		actionBars.setGlobalActionHandler(JdtActionConstants.OPEN, fOpen);
  	}
  	
  	private void appendToGroup(IMenuManager menu, IAction action) {
  		if (action.isEnabled())
  			menu.appendToGroup(IContextMenuConstants.GROUP_OPEN, action);
  	}
  	
  	private void addOpenWithMenu(IMenuManager menu) {
  		ISelection selection= getContext().getSelection();
  		if (selection.isEmpty() || !(selection instanceof IStructuredSelection))
  			return;
  		IStructuredSelection ss= (IStructuredSelection)selection;
  		if (ss.size() != 1)
  			return;
  
  		Object o= ss.getFirstElement();
  		if (!(o instanceof IAdaptable))
  			return;
  
  		IAdaptable element= (IAdaptable)o;
  		Object resource= element.getAdapter(IResource.class);
  		if (!(resource instanceof IFile))
  			return; 
  
  		// Create a menu.
  		IMenuManager submenu= new MenuManager(ActionMessages.OpenWithMenu_label); 
  		submenu.add(new OpenWithMenu(fSite.getPage(), (IFile) resource));
  
  		// Add the submenu.
  		menu.appendToGroup(IContextMenuConstants.GROUP_OPEN, submenu);
  	}
  }
  