Implementing the MIDlet FileView class

To implement the FileView class:

1. Create the FileView.java class file.

2. Import required packages and classes.

   import java.io.IOException;
   
   import com.nokia.mid.ui.FileSelect;
   import com.nokia.mid.ui.FileSelectDetail;
   
   import javax.microedition.lcdui.Form;
   import javax.microedition.lcdui.StringItem;

3. Set FileView class to extend Form and implement FileItem.Listener. The FileView class uses FileItem.Listener interface to receive notifications when file item is selected.

   public class FileView
               extends Form
               implements FileItem.Listener
   {

4. Create the required variables and the constructor.

   private Listener listener;
   private FileItem selectedFileItem;
   
   public FileView(Listener listener) {
       super("Selected files");
       this.listener = listener;
   
   }

5. Implement the FileItem.Listener interface methods.

   public void onPressed(FileItem fileItem) {
       if (selectedFileItem != null) {
           selectedFileItem.setIsSelected(false);
       }
   
       if (fileItem != null) {
           selectedFileItem = fileItem;
           selectedFileItem.setIsSelected(true);
       }
   }
   
   
   public void onReleased(FileItem fileItem) {
   }
   
   public FileSelectDetail getSelectedFileDetails() {
       if (selectedFileItem != null) {
           return selectedFileItem.getFileDetails();
       }
   
       return null;
   }

6. Create the getSelectedFile method, which runs a new thread for launching the file selector. The selected files are added to this Form.

   public void getSelectedFiles(final String startUrl,
                                final int mediaType,
                                final boolean multipleSelection)
   {
       final FileView fileView = this;
   
       deleteAll();
       setTitle("No files selected");
   
       new Thread(new Runnable() {
           public void run() {
               FileSelectDetail selectedFiles[] = null;
   
               try {
                   selectedFiles =
                       FileSelect.launch(startUrl, mediaType, multipleSelection);
               }
               catch (IllegalArgumentException e) {
                   e.printStackTrace();
               }
               catch (IOException e) {
                   setTitle("Error");
                   String errorMessage =
                       new String("Failed to launch the file selector: " + e.toString());
                   StringItem errorMessageItem = new StringItem(null, errorMessage);
                   append(errorMessageItem);
   
                   if (listener != null) {
                       listener.onError(errorMessage);
                   }
               }
   
               int numberOfSelectedFiles = 0;
   
               if (selectedFiles != null) {
                   numberOfSelectedFiles = selectedFiles.length;
               }
   
               if (numberOfSelectedFiles != 0) {
                   if (numberOfSelectedFiles > 1) {
                       setTitle(numberOfSelectedFiles + " files selected");
   
                       if (listener != null) {
                           listener.onMultipleFilesSelected(numberOfSelectedFiles);
                       }
                   }
                   else {
                       setTitle("One file selected");
   
                       if (listener != null) {
                           listener.onFileSelected(selectedFiles[0]);
                       }
                   }
   
                   for (int i = 0; i < numberOfSelectedFiles; ++i) {
                       append(new FileItem(selectedFiles[i], fileView));
                   }
               }
               else {
                   System.out.println("FileView::getSelectedFiles(): No files selected.");
               }
           }
       }).start();
   }

7. Create the interface to listen to file selection events.

   public interface Listener {
       void onMultipleFilesSelected(int count);
       void onFileSelected(FileSelectDetail fileDetails);
       void onError(String errorMessage);
   }