/*
 * Copyright (c) 2012, the Dart project authors.
 * 
 * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 * 
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package com.google.dart.tools.designer.editor;

import org.eclipse.jface.action.IAction;
import org.eclipse.ui.IActionBars;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.ide.IDEActionFactory;
import org.eclipse.ui.part.MultiPageEditorActionBarContributor;
import org.eclipse.ui.part.MultiPageEditorPart;
import org.eclipse.ui.texteditor.ITextEditor;
import org.eclipse.ui.texteditor.ITextEditorActionConstants;

/**
 * Manages the installation/deinstallation of global actions for multi-page editors. Responsible for
 * the redirection of global actions to the active editor. Multi-page contributor replaces the
 * contributors for the individual editors in the multi-page editor.
 * 
 * @author scheglov_ke
 * @coverage XML.editor
 */
public class AbstractXmlEditorContributor extends MultiPageEditorActionBarContributor {
  private IEditorPart m_activeEditor;
  private AbstractXmlEditor m_designerEditor;

  ////////////////////////////////////////////////////////////////////////////
  //
  // MultiPageEditorActionBarContributor
  //
  ////////////////////////////////////////////////////////////////////////////
  @Override
  public void setActiveEditor(IEditorPart part) {
    if (part instanceof MultiPageEditorPart) {
      m_designerEditor = (AbstractXmlEditor) part;
    }
    super.setActiveEditor(part);
  }

  @Override
  public void setActivePage(IEditorPart part) {
    if (m_activeEditor == part) {
      return;
    }
    m_activeEditor = part;
    // update IActionBars
    IActionBars actionBars = getActionBars();
    if (actionBars != null) {
      redirectTextActions(actionBars);
    }
  }

  /**
   * Configures {@link IActionBars} to use global action handlers from {@link ITextEditor}.
   */
  private void redirectTextActions(IActionBars actionBars) {
    ITextEditor editor = m_activeEditor instanceof ITextEditor ? (ITextEditor) m_activeEditor
        : null;
    redirectTextAction(actionBars, editor, ITextEditorActionConstants.DELETE);
    redirectTextAction(actionBars, editor, ITextEditorActionConstants.CUT);
    redirectTextAction(actionBars, editor, ITextEditorActionConstants.COPY);
    redirectTextAction(actionBars, editor, ITextEditorActionConstants.PASTE);
    redirectTextAction(actionBars, editor, ITextEditorActionConstants.SELECT_ALL);
    redirectTextAction(actionBars, editor, ITextEditorActionConstants.FIND);
    redirectTextAction(actionBars, editor, ITextEditorActionConstants.DELETE_LINE);
    //redirectTextAction(actionBars, editor, ITextEditorActionConstants.DELETE_LINE_TO_BEGINNING);
    //redirectTextAction(actionBars, editor, ITextEditorActionConstants.DELETE_LINE_TO_END);
    redirectTextAction(actionBars, editor, IDEActionFactory.BOOKMARK.getId());
    // UNDO and REDO should be handled by XML editor
    if (m_activeEditor == null && m_designerEditor != null) {
      ITextEditor xmlEditor = m_designerEditor.getSourcePage().getXmlEditor();
      redirectTextAction(actionBars, xmlEditor, ITextEditorActionConstants.UNDO);
      redirectTextAction(actionBars, xmlEditor, ITextEditorActionConstants.REDO);
    }
    // update
    actionBars.updateActionBars();
  }

  /**
   * Configures {@link IActionBars} to use global action handler from {@link ITextEditor}.
   */
  private static void redirectTextAction(IActionBars actionBars, ITextEditor editor, String id) {
    actionBars.setGlobalActionHandler(id, getTextAction(editor, id));
  }

  /**
   * @return the {@link IAction} registered with the given text {@link ITextEditor}, may be
   *         <code>null</code>.
   */
  private static IAction getTextAction(ITextEditor editor, String actionID) {
    return editor == null ? null : editor.getAction(actionID);
  }
}