GridRowExample.java

    public static class MyGridRow extends GridRow<String> {
        private Label label = new Label("");
        private TextBox innerBox = new TextBox();
        private ValidatingWidget<String> textBox = new ValidatingWidget<String>();
        private DeleteIconWidget<String> deleteIcon = new DeleteIconWidget<String>();

        public MyGridRow() {
            textBox.setWidget(innerBox);
            textBox.setValidator(new HasValidation<String>() {
                @Override
                public boolean isValid(String value) {
                    if (value.contains("ass")) {
                        textBox.setHelpText("Watch your language!");
                        return false;
                    }
                    return true;
                }
            });
            textBox.addValueChangeHandler(new ValueChangeHandler<String>() {
                @Override
                public void onValueChange(ValueChangeEvent<String> event) {
                    label.setText("" + event.getValue().length());
                    ValueChangeEvent.fire(MyGridRow.this, event.getValue());
                }
            });
            deleteIcon.setAttachedWidget(this);
        }
        
        public TextBox getTextBox() {
            return innerBox;
        }

        @Override
        public Widget[] getGridCells() {
            return new Widget[] { textBox, label, deleteIcon };
        }

        @Override
        public String getValue() {
            return textBox.getValue();
        }

        @Override
        public void setValue(String value) {
            setValue(value, false);
        }

        @Override
        public void setValue(String value, boolean fireEvents) {
            textBox.setValue(value);
            ValueChangeEvent.fire(this, value);
        }
        
        public static void addRowTo(final SortingGrid grid) {
            MyGridRow row = new MyGridRow();
            row.addValueChangeHandler(new ValueChangeHandler<String>() {
                @Override
                public void onValueChange(ValueChangeEvent<String> event) {
                    addRowTo(grid);
                }
            });
            grid.addRow(row);
            row.getTextBox().setFocus(true);
        }
    }
    
    private void someInitMethod() {
        // ...
        SortingGrid myGrid = new SortingGrid();
        myGrid.addHeader("Word").setSorting(true);
        myGrid.addHeader("Length").setGrouping(true).setSorting(true);
        myGrid.addHeader(""); // Empty header for the delete icon.
        MyGridRow.addRowTo(myGrid);
        panel.add(myGrid);
        // ...
    }