package org.eclipse.wst.xsd.ui.internal.refactor.wizard;

import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.action.IMenuCreator;
import org.eclipse.jface.text.ITextSelection;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.swt.events.MenuAdapter;
import org.eclipse.swt.events.MenuEvent;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.ui.IEditorActionDelegate;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.IObjectActionDelegate;
import org.eclipse.ui.IWorkbenchPart;

public abstract class RefactorGroupActionDelegate implements IObjectActionDelegate, IEditorActionDelegate, IMenuCreator {

	protected ISelection fSelection;
	private IAction fDelegateAction;
	// whether to re-fill the menu (reset on selection change)
	private boolean fFillMenu = true;
	protected IWorkbenchPart workbenchPart; 
	protected ResourceSet resourceSet = new ResourceSetImpl();
	

	public RefactorGroupActionDelegate() {

	}
	
	/*
	 * @see org.eclipse.ui.IObjectActionDelegate#setActivePart(org.eclipse.jface.action.IAction, org.eclipse.ui.IWorkbenchPart)
	 */
	public void setActivePart(IAction action, IWorkbenchPart targetPart) {
		workbenchPart = targetPart;
	}
	/* (non-Javadoc)
	 * @see org.eclipse.jface.action.IMenuCreator#dispose()
	 */
	public void dispose() {
		// nothing to do
	}
	/* (non-Javadoc)
	 * @see org.eclipse.jface.action.IMenuCreator#getMenu(org.eclipse.swt.widgets.Control)
	 */
	public Menu getMenu(Control parent) {
		// never called
		return null;
	}
	/* (non-Javadoc)
	 * @see org.eclipse.jface.action.IMenuCreator#getMenu(org.eclipse.swt.widgets.Menu)
	 */
	public Menu getMenu(Menu parent) {
		//Create the new menu. The menu will get filled when it is about to be shown. see fillMenu(Menu).
		Menu menu = new Menu(parent);
		/**
		 * Add listener to repopulate the menu each time
		 * it is shown because MenuManager.update(boolean, boolean) 
		 * doesn't dispose pulldown ActionContribution items for each popup menu.
		 */
		menu.addMenuListener(new MenuAdapter() {
			public void menuShown(MenuEvent e) {
				if (fFillMenu) {
					Menu m = (Menu)e.widget;
					MenuItem[] items = m.getItems();
					for (int i=0; i < items.length; i++) {
						items[i].dispose();
					}
					fillMenu(m);
					fFillMenu = false;
				}
			}
		});
		return menu;
	}

	/*
	 * @see org.eclipse.ui.IActionDelegate#run(org.eclipse.jface.action.IAction)
	 */
	public void run(IAction action) {
		// Never called because we become a menu.
	}
	
	/*
	 * @see org.eclipse.ui.IActionDelegate#selectionChanged(org.eclipse.jface.action.IAction, org.eclipse.jface.viewers.ISelection)
	 */
	public void selectionChanged(IAction action, ISelection selection) {
		fDelegateAction = action;
		updateWith(selection);
		
	}

    public void setActiveEditor(IAction action, IEditorPart targetEditor) {
		workbenchPart = targetEditor;
		fDelegateAction = action;
		if (targetEditor != null && targetEditor.getEditorSite() != null && targetEditor.getEditorSite().getSelectionProvider() != null) {
			updateWith(targetEditor.getEditorSite().getSelectionProvider().getSelection());
		}
		
	}
    
	public void updateWith(ISelection selection) {
		fSelection = selection;
		if (fDelegateAction != null) {
			boolean enable = false;
			if (selection != null) {
				if (selection instanceof ITextSelection) {
					//if (((ITextSelection) selection).getLength() > 0) {
						enable = true;
					//}
				}
				else if(selection instanceof IStructuredSelection ){
					enable = !selection.isEmpty();
				}
			}
			// enable action
			fDelegateAction.setEnabled(enable);
			
			// fill submenu
			fFillMenu = true;
			fDelegateAction.setMenuCreator(this);
			
			
		}
		
	}
	
	
    protected abstract void fillMenu(Menu menu);
	
	
}