Can we change GWT Bootstrap 3 ButtonCell Icon Dynamically?

Question

I have a GWT bootstrap 3 button as a ButtonCell created with IconType and ButtonType:

public abstract class ButtonColumn<T> extends Column<T, String> {
    public ButtonColumn(IconType iconType, ButtonType buttonType) {
        this(new ButtonCell(buttonType, iconType));
    }
}

So when I create the button, I do

new ButtonColumn<Object>(IconType.PLAY, ButtonType.SUCCESS) {
  @Override
  public void onClick(Object obj) {
    doStuff(obj);
  }
};

I want to change my button IconType onClick. Is it possible to achieve it? And can I create a custom IconType extending the GWT IconType Enum? I wanted to put an animated icon (like a loading icon).

Answer 1

Well, you can not change the button's icon in a row, especially when you create the whole column with an icon already specified. But you can redraw() a row and this could be a way to achieve what you want.

I use AbstractCell to render a button and onBrowserEvent:

• first create an AbstractCell with ClickEvent in consumedEvents parameter
• in the render() method render a button based on the clicked state
• in the onBrowserEvent() method change the clicked state and re-render the row

The clicked state is best to be kept in the table's underlying data type so it is available for each row.

Here is a complete working example code:

final CellTable<TableType> table = new CellTable<TableType>();

AbstractCell<TableType> buttonCell = new AbstractCell<ButtonCellTest.TableType>(ClickEvent.getType().getName()) {
    @Override
    public void render(Context context, TableType value, SafeHtmlBuilder sb) {
        Button button = new Button();
        button.setType(ButtonType.SUCCESS);
        button.setSize(ButtonSize.SMALL);
        button.add(new Icon(value.isClicked() ? IconType.CHECK : IconType.TIMES));
        sb.append(SafeHtmlUtils.fromTrustedString(button.toString()));
    }

    @Override
    public void onBrowserEvent(Context context, Element parent, TableType value, NativeEvent event, ValueUpdater<TableType> valueUpdater) {
        value.setClicked(!value.isClicked());
        // ... do stuff...
        table.redrawRow(context.getIndex());
    }
};
table.addColumn(new Column<TableType, TableType>(buttonCell) {
    @Override
    public TableType getValue(TableType object) {
        return object;
    }
});

ArrayList<TableType> rowData = new ArrayList<TableType>();
rowData.add(new TableType("row 1"));
rowData.add(new TableType("row 2"));
...
table.setRowData(rowData);

And example table's data type keeping the clicked state:

public class TableType {
    String text;
    boolean clicked = false;

    public TableType(String text) {
        this.text = text;
    }

    public String getText() {
        return text;
    }

    public boolean isClicked() {
        return clicked;
    }

    public void setClicked(boolean clicked) {
        this.clicked = clicked;
    }
}

---

As for extending the IconType enum - no, you can not extend an enum in Java. See this question for example: Can enums be subclassed to add new elements?.

You could try to add your own CSS class but this should be asked as another question to get precise answers.