DbRootNodeReader.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;

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

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.Platform;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.ui.PartInitException;

import com.motorola.studio.android.common.log.StudioLogger;
import com.motorolamobility.studio.android.db.core.ui.AbstractTreeNode;

public abstract class DbRootNodeReader
{
    public static final String DB_ROOT_NODE_EXTENSION_POINT_ID =
            "com.motorolamobility.studio.android.db.core.dbRootNode"; //$NON-NLS-1$

    public static final String DB_ROOT_NODE_EXTENSION_POINT_ATTRIBUTE_ID = "id"; //$NON-NLS-1$

    public static final String DB_ROOT_NODE_EXTENSION_POINT_ATTRIBUTE_NAME = "name"; //$NON-NLS-1$

    public static final String DB_ROOT_NODE_EXTENSION_POINT_ATTRIBUTE_ICON = "icon"; //$NON-NLS-1$

    public static final String DB_ROOT_NODE_EXTENSION_POINT_ATTRIBUTE_CLASS = "class"; //$NON-NLS-1$

    /**
     * Load existing root nodes, mapped by extension id      
     * 
     * @param treeNodeList The map of root nodes to be populated 
     * 
     */
    public static void loadRootNode(HashMap<String, AbstractTreeNode> treeNodeList)
            throws PartInitException

    {
        List<String> failedNodeNames = new ArrayList<String>();
        treeNodeList.clear();

        IExtensionRegistry extReg = Platform.getExtensionRegistry();
        IExtensionPoint extPoint = extReg.getExtensionPoint(DB_ROOT_NODE_EXTENSION_POINT_ID);

        String id = null;
        String name = null;
        if (extPoint != null)
        {

            IExtension[] extensions = extPoint.getExtensions();

            for (IExtension aExtension : extensions)
            {
                IConfigurationElement[] configElements = aExtension.getConfigurationElements();
                for (IConfigurationElement aConfig : configElements)
                {

                    id = aConfig.getAttribute(DB_ROOT_NODE_EXTENSION_POINT_ATTRIBUTE_ID);
                    name = aConfig.getAttribute(DB_ROOT_NODE_EXTENSION_POINT_ATTRIBUTE_NAME);

                    String nodeClassName =
                            aConfig.getAttribute(DB_ROOT_NODE_EXTENSION_POINT_ATTRIBUTE_CLASS);

                    AbstractTreeNode treeNode = null;
                    if (nodeClassName != null)
                    {

                        try
                        {
                            treeNode =
                                    (AbstractTreeNode) aConfig
                                            .createExecutableExtension(DB_ROOT_NODE_EXTENSION_POINT_ATTRIBUTE_CLASS);
                            treeNode.setId(id);
                            treeNode.setName(name);
                            if (aConfig.getAttribute(DB_ROOT_NODE_EXTENSION_POINT_ATTRIBUTE_ICON) != null)
                            {
                                ImageDescriptor icon =
                                        DbCoreActivator
                                                .imageDescriptorFromPlugin(
                                                        DbCoreActivator.PLUGIN_ID,
                                                        aConfig.getAttribute(DB_ROOT_NODE_EXTENSION_POINT_ATTRIBUTE_ICON));
                                treeNode.setIcon(icon);
                            }

                            treeNodeList.put(id, treeNode);
                        }
                        catch (CoreException e)
                        {
                            StudioLogger
                                    .error(DbRootNodeReader.class,
                                            "Unexpected error with the root node extension point. Name:" + name + " ID:" + id, e); //$NON-NLS-1$ //$NON-NLS-2$
                            failedNodeNames.add(name);
                        }
                    }
                }
            }

            if (!failedNodeNames.isEmpty())
            {
                throw new PartInitException("The following nodes could not be loaded : " //$NON-NLS-1$
                        + failedNodeNames);
            }
        }
    }
}