Open File Dialog

Ok, this is not a Dialog... It is an Implicit List. As we do not have File Dialogs on LCDUI I decided to share my version with you. It did work with Sony Ericson and Motorola iDEN handsets and I use it in my Books application.

import java.io.IOException;
import java.util.Enumeration;
import java.util.Stack;

import javax.microedition.io.Connector;
import javax.microedition.io.file.FileConnection;
import javax.microedition.io.file.FileSystemRegistry;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.List;
import javax.microedition.lcdui.Ticker;


public class OpenFileDialog extends List 
  implements CommandListener
{
  public static final String PREFIX = "file:///";
  private static final String UP = "[ .. ]";
  private static final String DIR = " + ";
  private Stack stack = new Stack();
  private OpenFileListener listener;
  private CommandListener commandListener;
  private String extension;

  public OpenFileDialog (OpenFileListener listener, 
     String title, String extension)
  {
    super(title, List.IMPLICIT);
    super.setCommandListener(this);
    this.listener = listener;
    this.extension = extension;
    addRoots();
  }

  public void setCommandListener(CommandListener l) {
    this.commandListener = l;
  }

  public void commandAction(Command c, Displayable d) {
    if (c == List.SELECT_COMMAND) {
      this.changeSelection();
    } else {
      if (this.commandListener != null) {
        this.commandListener.commandAction(c, d);
      }
    }
  }

  private String getSelectedText () {
    int index = getSelectedIndex();
    if (index < 0 || index >= this.size()) {
      return "";
    }
    return this.getString(index);
  }

  private void changeSelection () {
    String target = this.getSelectedText();
    String parent = null;
    boolean goingUp = false;

    if (UP.equals(target)) {
      goingUp = true;
      stack.pop();
      if (stack.isEmpty() == false) {
        target = (String) stack.peek();
      } else {
        super.deleteAll();
        addRoots();
        this.setTicker(null);
        return;
      }
    } else {
      if (stack.isEmpty() == false) {
        parent = stack.peek().toString();
      }
    }

    try {
      if (target.startsWith(DIR)) {
        target = target.substring(3);
      }
      if (parent != null) {
        target = parent + target;
      }
      this.setTicker(new Ticker(target));
      FileConnection fc = (FileConnection)
          Connector.open(PREFIX + target, Connector.READ);
      if (fc.isDirectory()) {
        super.deleteAll();
        if (goingUp == false) {
          stack.push(target);
        }
        super.append(UP, null);
        
        Enumeration entries = fc.list();
        
        while (entries.hasMoreElements()) {
          String entry = (String) entries.nextElement();
          FileConnection fc2 = (FileConnection) 
              Connector.open(PREFIX + target + entry,
              Connector.READ);
          if (fc2.isDirectory()) {
            super.append(DIR + entry, null);
          } else if (entry.toLowerCase().endsWith(extension)) {
            super.append(entry, null);
          }
          fc2.close();
        }
        fc.close();
      } else {
        this.listener.fileSelected(fc);
      }
    } catch (IOException e) {
      e.printStackTrace();
    }
    
  }

  private void addRoots() {
    Enumeration roots = FileSystemRegistry.listRoots();
    while (roots.hasMoreElements()) {
      super.append(DIR + roots.nextElement().toString(), null);
    }
  }

}

Related topics:

• Books: a new study case


• Use LCDUI