ListBox - relu91/nifty-gui GitHub Wiki

// Using the builder pattern
control(new ListBoxBuilder("myListBox") {{
  displayItems(4);
  selectionModeMutliple();
  optionalHorizontalScrollbar();
  optionalVerticalScrollbar();
  width("*"); // standard nifty width attribute
}});

public class ListBoxTestScreenController implements ScreenController {
  ...

  /**
   * Fill the listbox with items. In this case with Strings.
   */
  public void fillMyListBox() {
    ListBox listBox = screen.findNiftyControl("myListBox", ListBox.class);
    listBox.addItem("a");
    listBox.addItem("b");
    listBox.addItem("c");
  }

  /**
   * When the selection of the ListBox changes this method is called.
   */
  @NiftyEventSubscriber(id="myListBox")
  public void onMyListBoxSelectionChanged(final String id, final ListBoxSelectionChangedEvent<String> event) {
    List<String> selection = event.getSelection();
    for (String selectedItem : selection) {
      System.out.println("listbox selection [" + selectedItem + "]");
    }
  }
}

/**
 * This is just an example. This should really be your own model. The ListBox does call toString() on this
 * to get the label it should display. But you can use your own ListBoxViewConverter if you want to use more
 * sophisticated mechanism.
 * @author void
 */
public class JustAnExampleModelClass {
  private String label;

  public JustAnExampleModelClass(final String label) {
    this.label = label;
  }

  public String toString() {
    return label; // we could really use anything in here, the name of the sword or something ;-)
  }
}
...
  /**
   * Fill the listbox with items. In this case with JustAnExampleModelClass.
   */
  public void fillMyListBox() {
    ListBox<JustAnExampleModelClass> listBox = (ListBox<JustAnExampleModelClass>) screen.findNiftyControl("myListBox", ListBox.class);
    listBox.addItem(new JustAnExampleModelClass("You can add more lines to this ListBox."));
    listBox.addItem(new JustAnExampleModelClass("Use the append button to do this."));
  }
...
  @NiftyEventSubscriber(id="myListBox")
  public void onListBoxSelectionChanged(final String id, final ListBoxSelectionChangedEvent<JustAnExampleModelClass> event) {
    List<JustAnExampleModelClass> selection = event.getSelection();
    // do something with the selection
  }

<!-- this defines the control for a single line of text in the chat and player window -->
<controlDefinition name="nifty-chat-line">
  <panel childLayout="horizontal" width="100%" align="center">
    <image id="#chat-line-icon" width="23px" height="23px" />
    <control id="#chat-line-text" name="label" align="left" textHAlign="left" height="23px" width="*" wrap="true" />
  </panel>
</controlDefinition>

<control id="myCustomListBox" name="listBox" vertical="optional" horizontal="off" selection="Disabled" displayItems="15" 
       viewConverterClass="de.lessvoid.nifty.controls.chatcontrol.ChatBoxViewConverter">
  <control name="nifty-chat-line" controller="de.lessvoid.nifty.controls.listbox.ListBoxItemController" /> <!-- here we tell Nifty what element to display in each line and the controller is necessary if you want to support selections -->
</control>

/**
 * Handles a line in the chat controller. This can be either a chat line or an
 * entry in the list of players.
 * 
 * @author Mark
 * @version 0.1
 */
public final class ChatEntryModelClass {
    private String label;
    private NiftyImage icon;

    /**
     * Constructor excepting the line and the icon.
     * @param labelParam The label to put in the entry. This can be either a chat line or a player name.
     * @param iconParam The icon to display in the entry, this one is optional.
     */
    public ChatEntryModelClass(final String labelParam, final NiftyImage iconParam) {
        this.label = labelParam;
        this.icon = iconParam;
    }

    /**
     * Return the supplied label. This can be either a chat line or a player name.
     * @return The supplied label.
     */
    public String getLabel() {
        return label;
    }

    /**
     * Return the supplied icon.
     * @return The supplied icon.
     */
    public NiftyImage getIcon() {
        return icon;
    }
}

/**
 * Handles the displaying of the items in the ChatBox.
 * @author Mark
 * @version 0.1
 */
public class ChatBoxViewConverter implements ListBoxViewConverter<ChatEntryModelClass> {
    private static final String CHAT_LINE_ICON = "#chat-line-icon";
    private static final String CHAT_LINE_TEXT = "#chat-line-text";

    /**
     * Default constructor.
     */
    public ChatBoxViewConverter() {
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    public final void display(final Element listBoxItem, final ChatEntryModelClass item) {
        final Element text = listBoxItem.findElementByName(CHAT_LINE_TEXT);
        final TextRenderer textRenderer = text.getRenderer(TextRenderer.class);
        final Element icon = listBoxItem.findElementByName(CHAT_LINE_ICON);
        final ImageRenderer iconRenderer = icon.getRenderer(ImageRenderer.class);
        if (item != null) {
            textRenderer.setText(item.getLabel());
            iconRenderer.setImage(item.getIcon());
        } else {
            textRenderer.setText("");
            iconRenderer.setImage(null);
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public final int getWidth(final Element listBoxItem, final ChatEntryModelClass item) {
        final Element text = listBoxItem.findElementByName(CHAT_LINE_TEXT);
        final TextRenderer textRenderer = text.getRenderer(TextRenderer.class);
        final Element icon = listBoxItem.findElementByName(CHAT_LINE_ICON);
        final ImageRenderer iconRenderer = icon.getRenderer(ImageRenderer.class);
        return ((textRenderer.getFont() == null) ? 0 : textRenderer.getFont().getWidth(item.getLabel()))
                + ((item.getIcon() == null) ? 0 : item.getIcon().getWidth());
    }
}