Is there a "correct" way to add/remove a PieChart?

Question

I have an MVP GWT 2.5.1 app using version 1.1.1 of gwt-visualization. My view has two Buttons and a VerticalPanel (accessed by the presenter as display.getPanel()). One button adds a PieChart to the VerticalPanel, the the other removes it. The presenter holds the PieChart reference as a Widget so that it knows when it has been added/removed. It is initialized to null.

I checked chrome's dev tools to ensure that the add/remove code wasn't creating a DOM leak. But after the PieChart was removed, its elements were left behind in a detached DOM tree, all color coded red. When I tried the same add/remove code with a Label instead of a PieChart, no detached DOM tree remained after removal.

My questions is: am I doing something wrong when either adding or removing the PieChart? Perhaps gwt-visualization has some other method of handling this that I am not aware of, but my google-fu is unable to produce an answer.

The presenter add/remove code is below:

display.getAddChartButton().addClickHandler(new ClickHandler() {
    public void onClick(ClickEvent event) {
        if (widget == null) {
            Runnable onLoadCallback = new Runnable() {
                public void run() {
                    PieChart content = new PieChart(createTable(), createOptions());
                    // Label content = new Label("Content");
                    display.getPanel().add(content);
                    widget = content;
                }
            };
            VisualizationUtils.loadVisualizationApi(onLoadCallback, PieChart.PACKAGE);
        }
    }
});
display.getRemoveChartButton().addClickHandler(new ClickHandler() {
    public void onClick(ClickEvent event) {
        if (widget != null) {
            display.getPanel().remove(widget);
            widget = null;
        }
    }
});

private AbstractDataTable createTable() {
    DataTable data = DataTable.create();
    data.addColumn(ColumnType.STRING, "Task");
    data.addColumn(ColumnType.NUMBER, "Hours per Day");
    data.addRows(2);
    data.setValue(0, 0, "Work");
    data.setValue(0, 1, 14);
    data.setValue(1, 0, "Sleep");
    data.setValue(1, 1, 10);
    return data;
}

private Options createOptions() {
    Options options = Options.create();
    options.setWidth(400);
    options.setHeight(240);
    options.setTitle("My Daily Activities");
    return options;
}

Answer 1

I've traced the memory leak to the Google Chart API itself. The team is aware of memory leak issues.