/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.hadoop.eclipse.dfs;
import java.util.HashMap;
import java.util.Map;
import org.apache.hadoop.eclipse.ImageLibrary;
import org.apache.hadoop.eclipse.server.HadoopServer;
import org.apache.hadoop.eclipse.servers.ServerRegistry;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.ILabelProviderListener;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.StructuredViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Display;
/**
* Handles viewing of DFS locations
* <p>
*
* The content handled by this provider is a tree:
*
* <tt>
* <br>DFSLocationsRoot
* <br>\_HadoopServer
* <br>| \_DfsFolder
* <br>| | \_DfsFile
* <br>| \_DfsFolder
* <br>| ...
* <br>\_HadoopServer...
* </tt>
*
* The code should not block here: blocking operations need to be done
* asynchronously so as not to freeze the UI!
*/
public class DFSContentProvider implements ITreeContentProvider,
ILabelProvider {
/**
* The viewer that displays this Tree content
*/
private Viewer viewer;
private StructuredViewer sviewer;
private Map<HadoopServer, DFSContent> rootFolders =
new HashMap<HadoopServer, DFSContent>();
/**
* Constructor: load resources (icons).
*/
public DFSContentProvider() {
}
private final DFSLocationsRoot locationsRoot = new DFSLocationsRoot(this);
/*
* ITreeContentProvider implementation
*/
/* @inheritDoc */
public Object[] getChildren(Object parent) {
if (!(parent instanceof DFSContent))
return null;
DFSContent content = (DFSContent) parent;
return content.getChildren();
}
public Object[] test(Object parentElement) {
if (parentElement instanceof DFSLocationsRoot) {
return ServerRegistry.getInstance().getServers().toArray();
} else if (parentElement instanceof HadoopServer) {
final HadoopServer location = (HadoopServer) parentElement;
Object root = rootFolders.get(location);
if (root != null)
return new Object[] { root };
return new Object[] { "Connecting to DFS..." };
} else if (parentElement instanceof DFSFolder) {
DFSFolder folder = (DFSFolder) parentElement;
return folder.getChildren();
}
return new Object[] { "<Unknown DFSContent>" };
}
/* @inheritDoc */
public Object getParent(Object element) {
if (element instanceof DFSPath) {
return ((DFSPath) element).getParent();
} else if (element instanceof HadoopServer) {
return locationsRoot;
}
return null;
}
/* @inheritDoc */
public boolean hasChildren(Object element) {
if (element instanceof DFSContent) {
DFSContent content = (DFSContent) element;
return content.hasChildren();
}
return false;
}
/*
* IStructureContentProvider implementation
*/
/* @inheritDoc */
public Object[] getElements(final Object inputElement) {
return new Object[] { locationsRoot };
// return ServerRegistry.getInstance().getServers().toArray();
}
/*
* ILabelProvider implementation
*/
/* @inheritDoc */
public Image getImage(Object element) {
if (element instanceof DFSLocationsRoot)
return ImageLibrary.getImage("dfs.browser.root.entry");
else if (element instanceof DFSLocation)
return ImageLibrary.getImage("dfs.browser.location.entry");
else if (element instanceof DFSFolder)
return ImageLibrary.getImage("dfs.browser.folder.entry");
else if (element instanceof DFSFile)
return ImageLibrary.getImage("dfs.browser.file.entry");
return null;
}
/* @inheritDoc */
public String getText(Object element) {
if (element instanceof DFSFile)
return ((DFSFile) element).toDetailedString();
return element.toString();
}
/*
* IBaseLabelProvider implementation
*/
/* @inheritDoc */
public void addListener(ILabelProviderListener listener) {
}
/* @inheritDoc */
public void removeListener(ILabelProviderListener listener) {
}
/* @inheritDoc */
public boolean isLabelProperty(Object element, String property) {
return false;
}
/*
* IContentProvider implementation
*/
/* @inheritDoc */
public void dispose() {
}
/* @inheritDoc */
public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
this.viewer = viewer;
if ((viewer != null) && (viewer instanceof StructuredViewer))
this.sviewer = (StructuredViewer) viewer;
else
this.sviewer = null;
}
/*
* Miscellaneous
*/
/**
* Ask the viewer for this content to refresh
*/
void refresh() {
// no display, nothing to update
if (this.viewer == null)
return;
Display.getDefault().asyncExec(new Runnable() {
public void run() {
DFSContentProvider.this.viewer.refresh();
}
});
}
/**
* Ask the viewer to refresh a single element
*
* @param content what to refresh
*/
void refresh(final DFSContent content) {
if (this.sviewer != null) {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
DFSContentProvider.this.sviewer.refresh(content);
}
});
} else {
refresh();
}
}
Viewer getViewer() {
return this.viewer;
}
}