public void addSelectedFilesToTargetList() {
    ISelection selection = sourceFileViewer.getSelection();

    if (isValidSourceFileViewerSelection(selection)) {
      java.util.List list = null;
      if (selection instanceof IStructuredSelection) {
        list = ((IStructuredSelection) selection).toList();

        if (list != null) {
          list = ((IStructuredSelection) selection).toList();
          for (Iterator i = list.iterator(); i.hasNext(); ) {
            IResource resource = (IResource) i.next();
            if (resource instanceof IFile) {
              // Check if its in the list. Don't add it if it is.
              String resourceName = resource.getFullPath().toString();
              if (selectedListBox.indexOf(resourceName) == -1) selectedListBox.add(resourceName);
            }
          }
          setFiles(selectedListBox.getItems());
        }

        setAddButtonEnabled(false);

        if (selectedListBox.getItemCount() > 0) {
          removeAllButton.setEnabled(true);
          if (isFileMandatory) setPageComplete(true);
          if (selectedListBox.getSelectionCount() > 0) setRemoveButtonEnabled(true);
          else setRemoveButtonEnabled(false);
        }
      }
    }
  }
  private void createButtonPanel(Composite pageContent) {
    Composite buttonPanel = new Composite(pageContent, SWT.NONE);
    GridLayout layout = new GridLayout();
    layout.numColumns = 1;
    buttonPanel.setLayout(layout);

    GridData gridData = new GridData();
    gridData.grabExcessHorizontalSpace = false;
    gridData.grabExcessVerticalSpace = true;
    gridData.verticalAlignment = GridData.CENTER;
    gridData.horizontalAlignment = GridData.CENTER;
    buttonPanel.setLayoutData(gridData);

    addButton = new Button(buttonPanel, SWT.PUSH);
    addButton.setText(Messages._UI_ADD_BUTTON);
    gridData = new GridData();
    gridData.horizontalAlignment = GridData.FILL;
    gridData.verticalAlignment = GridData.CENTER;
    addButton.setLayoutData(gridData);
    addButton.addSelectionListener(new ButtonSelectListener());
    addButton.setToolTipText(Messages._UI_ADD_BUTTON_TOOL_TIP);
    addButton.setEnabled(false);

    removeButton = new Button(buttonPanel, SWT.PUSH);
    removeButton.setText(Messages._UI_REMOVE_BUTTON);
    gridData = new GridData();
    gridData.horizontalAlignment = GridData.FILL;
    gridData.verticalAlignment = GridData.CENTER;
    removeButton.setLayoutData(gridData);
    removeButton.addSelectionListener(new ButtonSelectListener());
    removeButton.setToolTipText(Messages._UI_REMOVE_BUTTON_TOOL_TIP);
    removeButton.setEnabled(false);

    removeAllButton = new Button(buttonPanel, SWT.PUSH);
    removeAllButton.setText(Messages._UI_REMOVE_ALL_BUTTON);
    gridData = new GridData();
    gridData.horizontalAlignment = GridData.FILL;
    gridData.verticalAlignment = GridData.CENTER;
    removeAllButton.setLayoutData(gridData);
    removeAllButton.addSelectionListener(new ButtonSelectListener());
    removeAllButton.setToolTipText(Messages._UI_REMOVE_ALL_BUTTON_TOOL_TIP);
    removeAllButton.setEnabled(false);
  }
 public void setRemoveButtonEnabled(boolean isEnabled) {
   removeButton.setEnabled(isEnabled);
 }
 public void setAddButtonEnabled(boolean isEnabled) {
   addButton.setEnabled(isEnabled);
 }