/*******************************************************************************
 * All Right Reserved. Copyright (c) 1998, 2004 Jackwind Li Guojie
 * 
 * Created on Mar 9, 2004 7:07:16 PM by JACK $Id$
 *  
 ******************************************************************************/

package testapp;

import java.io.File;

import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.ToolBarManager;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.TreeEditor;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.events.TreeEvent;
import org.eclipse.swt.events.TreeListener;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.program.Program;
import org.eclipse.swt.widgets.DirectoryDialog;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
import org.eclipse.swt.widgets.ToolBar;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;

public class FileBrowserSample {
  Display display = new Display();
  Shell shell = new Shell(display);

  Tree tree;

  File rootDir;

  public FileBrowserSample() {
    Action actionSetRootDir = new Action("Set Root Dir") {
      public void run() {
        DirectoryDialog dialog = new DirectoryDialog(shell);
        String path = dialog.open();
        if (path != null) {
          setRootDir(new File(path));
        }
      }
    };


    ToolBar toolBar = new ToolBar(shell, SWT.FLAT);
    ToolBarManager manager = new ToolBarManager(toolBar);
    manager.add(actionSetRootDir);

    manager.update(true);

    shell.setLayout(new GridLayout());

    tree = new Tree(shell, SWT.BORDER);
    tree.setLayoutData(new GridData(GridData.FILL_BOTH));

    setRootDir(new File("C:/"));

    tree.addTreeListener(new TreeListener() {
      public void treeCollapsed(TreeEvent e) {
      }

      public void treeExpanded(TreeEvent e) {
        TreeItem item = (TreeItem) e.item;
        TreeItem[] children = item.getItems();

        for (int i = 0; i < children.length; i++)
          if (children[i].getData() == null)
            children[i].dispose();
          else // Child files already added to the tree.
            return;

        File[] files = ((File) item.getData()).listFiles();
        for (int i = 0; files != null && i < files.length; i++)
          addFileToTree(item, files[i]);
      }
    });

    tree.addSelectionListener(new SelectionListener() {
      public void widgetSelected(SelectionEvent e) {
      }
      // Gets called when a tree item is double-clicked.
      public void widgetDefaultSelected(SelectionEvent e) {
        TreeItem item = (TreeItem) e.item;
        File file = (File) item.getData();
        if (Program.launch(file.getAbsolutePath())) {
          System.out.println("File has been launched: " + file);
        } else {
          System.out.println("Unable to launch file: " + file);
        }
      }
    });

    shell.setSize(400, 260);
    shell.open();
    //textUser.forceFocus();

    // Set up the event loop.
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch()) {
        // If no more entries in event queue
        display.sleep();
      }
    }

    display.dispose();
  }

  /**
   * Sets the root directory to browse from.
   * 
   * @param root
   */
  private void setRootDir(File root) {
    // validates the root first. 
    if( (!root.isDirectory()) || (!root.exists()))
      throw new IllegalArgumentException("Invalid root: " + root);
    
    this.rootDir = root;
    shell.setText("Now browsing: " + root.getAbsolutePath());

    // Remove all the items in the tree.
    if (tree.getItemCount() > 0) {
      TreeItem[] items = tree.getItems();
      for (int i = 0; i < items.length; i++) {
        items[i].dispose();
        // Dispose itself and all of its descendants.
      }
    }

    // Adds files under the root to the tree. 
    File[] files = root.listFiles();
    for(int i=0; files != null && i < files.length; i++)
      addFileToTree(tree, files[i]);
  }

  /**
   * Adds the given file to the tree.
   * 
   * @param parent
   * @param file
   */
  private void addFileToTree(Object parent, File file) {
    TreeItem item = null;

    if (parent instanceof Tree)
      item = new TreeItem((Tree) parent, SWT.NULL);
    else if (parent instanceof TreeItem)
      item = new TreeItem((TreeItem) parent, SWT.NULL);
    else
      throw new IllegalArgumentException(
        "parent should be a tree or a tree item: " + parent);

    item.setText(file.getName());
    item.setImage(getIcon(file));

    item.setData(file);

    if (file.isDirectory()) {
      //      // recursively adds all the children of this file.
      //      File[] files = file.listFiles();
      //      for(int i=0; i<files.length; i++)
      //        buildTree(item, files[i]);
      if (file.list() != null && file.list().length > 0)
        new TreeItem(item, SWT.NULL);
    }
  }

  private ImageRegistry imageRegistry;
  Image iconFolder = new Image(shell.getDisplay(), "icons/java2s.gif");
  Image iconFile = new Image(shell.getDisplay(), "icons/java2s.gif");

  /**
   * Returns an icon representing the specified file.
   * 
   * @param file
   * @return
   */
  private Image getIcon(File file) {
    if (file.isDirectory())
      return iconFolder;

    int lastDotPos = file.getName().indexOf('.');
    if (lastDotPos == -1)
      return iconFile;

    Image image = getIcon(file.getName().substring(lastDotPos + 1));
    return image == null ? iconFile : image;
  }

  /**
   * Returns the icon for the file type with the specified extension.
   * 
   * @param extension
   * @return
   */
  private Image getIcon(String extension) {
    if (imageRegistry == null)
      imageRegistry = new ImageRegistry();
    Image image = imageRegistry.get(extension);
    if (image != null)
      return image;

    Program program = Program.findProgram(extension);
    ImageData imageData = (program == null ? null : program.getImageData());
    if (imageData != null) {
      image = new Image(shell.getDisplay(), imageData);
      imageRegistry.put(extension, image);
    } else {
      image = iconFile;
    }

    return image;
  }

  public static void main(String[] args) {
    new FileBrowserSample();
  }
}