Java 类com.google.gwt.user.client.ui.SuggestBox.DefaultSuggestionDisplay 实例源码

private void onKey(int key) {
  if (key == KeyCodes.KEY_ESCAPE) {
    setText(prevText);

    Widget p = getParent();
    if (p instanceof SuggestBox) {
      // Since the text was changed, ensure that the SuggestBox is
      // aware of this change so that it will refresh properly on
      // the next keystroke.  Without this, if the first keystroke
      // recreates the same string as before ESC was pressed, the
      // SuggestBox will think that the string has not changed, and
      // it will not yet provide any Suggestions.
      ((SuggestBox) p).showSuggestionList();

      // The suggestion list lingers if we don't hide it.
      ((DefaultSuggestionDisplay) ((SuggestBox) p).getSuggestionDisplay()).hideSuggestions();
    }

    setFocus(false);
  }
}

@UiHandler("searchBox")
void searchBoxEnter(KeyDownEvent event) {
  if (event.getNativeKeyCode() == KeyCodes.KEY_ENTER) {
    SuggestionDisplay suggestionDisplay = searchBox.getSuggestionDisplay();

    // This should always be true unless GWT changes the type of the suggestion generated by the
    // SuggestBox. It is too complicated and nasty to switch out the SuggestBox suggestion display
    // factory, so we're left with this type safety check and broken functionality if GWT changes.
    Preconditions.checkState(suggestionDisplay instanceof DefaultSuggestionDisplay);

    // At this point this should always be true.
    if (suggestionDisplay instanceof DefaultSuggestionDisplay) {
      DefaultSuggestionDisplay suggestions = (DefaultSuggestionDisplay) suggestionDisplay;
      if (!suggestions.isSuggestionListShowing()) {
        presenter.handleSearch(searchBox.getValue());
      }
    }
  }
}

public RemoteSuggestBox(SuggestOracle oracle) {
  remoteSuggestOracle = new RemoteSuggestOracle(oracle);
  remoteSuggestOracle.setServeSuggestions(true);
  display = new DefaultSuggestionDisplay();

  textBox = new HintTextBox();
  textBox.addKeyDownHandler(
      new KeyDownHandler() {
        @Override
        public void onKeyDown(KeyDownEvent e) {
          submitOnSelection = false;
          if (e.getNativeKeyCode() == KeyCodes.KEY_ESCAPE) {
            CloseEvent.fire(RemoteSuggestBox.this, RemoteSuggestBox.this);
          } else if (e.getNativeKeyCode() == KeyCodes.KEY_ENTER) {
            if (display.isSuggestionListShowing()) {
              if (textBox.getValue().equals(remoteSuggestOracle.getLast())) {
                submitOnSelection = true;
              } else {
                display.hideSuggestions();
              }
            } else {
              SelectionEvent.fire(RemoteSuggestBox.this, getText());
            }
          }
        }
      });

  suggestBox = new SuggestBox(remoteSuggestOracle, textBox, display);
  suggestBox.addSelectionHandler(
      new SelectionHandler<Suggestion>() {
        @Override
        public void onSelection(SelectionEvent<Suggestion> event) {
          if (submitOnSelection) {
            SelectionEvent.fire(RemoteSuggestBox.this, getText());
          }
          remoteSuggestOracle.cancelOutstandingRequest();
          display.hideSuggestions();
        }
      });
  initWidget(suggestBox);
}