BrowseTableContentsHandler.java

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 * 
 * 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.motorolamobility.studio.android.db.core.command;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.commands.IHandler;

import com.motorolamobility.studio.android.db.core.DbCoreActivator;
import com.motorolamobility.studio.android.db.core.ui.ITableNode;
import com.motorolamobility.studio.android.db.core.ui.ITreeNode;
import com.motorolamobility.studio.android.db.core.ui.TableNode;

/**
 * This class implements the command to browse a table content using an instance of {@link TableNode} object.
 */
public class BrowseTableContentsHandler extends AbstractHandler implements IHandler
{

    private ITableNode tableNode = null;

    public BrowseTableContentsHandler()
    {
    }

    public BrowseTableContentsHandler(ITableNode tableNode)
    {
        this.tableNode = tableNode;
    }

    /* (non-Javadoc)
     * @see org.eclipse.core.commands.IHandler#execute(org.eclipse.core.commands.ExecutionEvent)
     */
    public Object execute(ExecutionEvent event) throws ExecutionException
    {

        if (tableNode == null)
        {
            tableNode = getSelectedItem();
        }

        if (tableNode != null)
        {
            tableNode.browseTableContents();
            tableNode = null; //clear selected node to force getSelectedItem to be called when calling via toolbar
        }

        return null;
    }

    private ITableNode getSelectedItem()
    {
        ITableNode selectedNode = null;
        ITreeNode selectedItem =
                DbCoreActivator.getMOTODEVDatabaseExplorerView().getSelectedItemOnTree();

        if (selectedItem instanceof ITableNode)
        {
            selectedNode = (ITableNode) selectedItem;
        }

        return selectedNode;
    }

}