MenuBarManager.java

/*******************************************************************************
 * Copyright (c) 2008, 2015 EclipseSource 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:
 *    EclipseSource - initial API and implementation
 ******************************************************************************/
package org.eclipse.rap.internal.design.example.managers;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.jface.action.IContributionItem;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.action.Separator;
import org.eclipse.jface.action.SubContributionItem;
import org.eclipse.rap.rwt.RWT;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.ToolBar;
import org.eclipse.swt.widgets.ToolItem;


public class MenuBarManager extends MenuManager {

  private static final String MENU_BAR_VARIANT = "menuBar"; //$NON-NLS-1$
  private Composite menuParent;
  private final List<ToolItem> toolItemList = new ArrayList<ToolItem>();
  private ToolBar toolbar;

  @Override
  public void fill( final Composite parent ) {
    menuParent = parent;
    toolbar = new ToolBar( parent, SWT.WRAP | SWT.RIGHT );
    toolbar.setData( RWT.CUSTOM_VARIANT, MENU_BAR_VARIANT );
    update( false, false );
  }

  @Override
  protected void update( final boolean force, final boolean recursive ) {
    super.update( force, recursive );
    if( menuParent != null && ( force || isDirty() ) ) {
      disposeToolItems();
      IContributionItem[] items = getItems();
      if( items.length > 0 && menuParent != null ) {
        for( int i = 0; i < items.length; i++ ) {
          IContributionItem item = items[ i ];
          if( item.isVisible() ) {
            makeEntry( item );
          }
        }
      }
      menuParent.layout( true, true );
    }
  }

  private void disposeToolItems() {
    for( ToolItem item : toolItemList ) {
      if( !item.isDisposed() ) {
        Object data = item.getData();
        if( data != null && data instanceof Menu ) {
          Menu menu = ( Menu )data;
          if( !menu.isDisposed() ) {
            menu.dispose();
          }
        }
        item.dispose();
      }
    }
  }

  private void makeEntry( final IContributionItem item ) {
    IContributionItem tempItem = null;
    if( item instanceof SubContributionItem ) {
      SubContributionItem subItem = ( SubContributionItem ) item;
      tempItem = subItem.getInnerItem();
    } else if( item instanceof MenuManager ) {
      tempItem = item;
    }
    if( tempItem != null && tempItem instanceof MenuManager ) {
      final MenuManager manager = ( MenuManager ) tempItem;
      int style = extractStyle( manager );
      final ToolItem toolItem = new ToolItem( toolbar, style );
      toolItem.setText( manager.getMenuText() );
      toolItem.setData( RWT.CUSTOM_VARIANT, MENU_BAR_VARIANT );
      createMenu( manager, toolItem );
      // needed to clear all controls in case of an update
      toolItemList.add( toolItem );
    }
  }

  private int extractStyle( MenuManager manager ) {
    int style = SWT.NONE;
    if( manager.getItems() != null && manager.getItems().length > 0 ) {
      style = SWT.DROP_DOWN;
    }
    return style;
  }

  private void createMenu( final MenuManager manager, final ToolItem toolItem ) {
    final Menu menu = new Menu( menuParent );
    toolItem.setData( menu );
    menu.setData( RWT.CUSTOM_VARIANT, MENU_BAR_VARIANT );
    toolItem.addSelectionListener( new SelectionAdapter() {
      @Override
      public void widgetSelected( final SelectionEvent e ) {
        // cleanup the menu
        MenuItem[] menuItems = menu.getItems();
        for( int i = 0; i < menuItems.length; i++ ) {
          menuItems[ i ].dispose();
        }
        hookMenuToToolItem( manager, menu );
        // set the menu position
        Display display = toolItem.getDisplay();
        Rectangle bounds = toolItem.getBounds();
        int leftIndent = bounds.x;
        int topIndent = bounds.y + bounds.height;
        Point indent = new Point( leftIndent, topIndent );
        Point menuLocation = display.map( toolbar, toolbar.getShell(), indent );
        menu.setLocation( menuLocation );
        // style the menuitems and show the menu
        menu.setData( RWT.CUSTOM_VARIANT, MENU_BAR_VARIANT );
        styleMenuItems( menu );
        menu.setVisible( true );
      }

      private void hookMenuToToolItem( MenuManager manager, Menu menu ) {
        IContributionItem[] contribItems = manager.getItems();
        if( contribItems != null && contribItems.length > 0 ) {
          for( int i = 0; i < contribItems.length; i++ ) {
            if( contribItems[ i ].isVisible() ) {
              if( i > 0 || !( contribItems[ i ] instanceof Separator ) ) {
                contribItems[ i ].fill( menu, -1 );
              }
            }
          }
        }
      }

    } );
  }

  private void styleMenuItems( Menu menu ) {
    MenuItem[] items = menu.getItems();
    if( items != null && items.length > 0 ) {
      for( int i = 0; i < items.length; i++ ) {
        items[ i ].setData( RWT.CUSTOM_VARIANT, MENU_BAR_VARIANT );
        Menu subMenu = items[ i ].getMenu();
        if( subMenu != null ) {
          subMenu.setData( RWT.CUSTOM_VARIANT, MENU_BAR_VARIANT );
          styleMenuItems( subMenu );
        }
      }
    }
  }

  public ToolBar getMenuToolBar() {
    return toolbar;
  }

}