[Solved] toggle line visibility with scroll and zoom

[scott]

I create a bunch of lines in a chart and then set them all but the first to invisible like this:

// set invisible to start with
for (int i=1 ; i < Chart.DefaultView.ChartArea.DataSeries.Count() ; i++)
    Chart.DefaultView.ChartArea.DataSeries[i].Definition.Visibility = SeriesVisibility.Hidden;

Visibility of these lines is controlled via checkboxes in a databound listbox in a radexpander and the lines are shown and hidden like this and this works great.

private void CheckBox_Click(object sender, RoutedEventArgs e)
{
    CheckBox cb = sender as CheckBox;
    string t = cb.Content.ToString();
    for (int i = 1; i < Chart.DefaultView.ChartArea.DataSeries.Count(); i++)
        if (Chart.DefaultView.ChartArea.DataSeries[i].LegendLabel == t)
        {
            if (cb.IsChecked == false)
                Chart.DefaultView.ChartArea.DataSeries[i].Definition.Visibility = SeriesVisibility.Hidden;
            else
                Chart.DefaultView.ChartArea.DataSeries[i].Definition.Visibility = SeriesVisibility.Visible;
            break;
        }
}

Things go bad when scroll and zoom get involved ... Zooming or unzooming a section of the chart enables visibility of all the lines which throws all of the checkboxes out of sync...

Ideas ?

[Evgenia]

Hello scott,

The sample project attached demonstrates how the ZoomScroll feature can be used together with manipulating the Series Visibility. The sample project is based on the Simple Filtering demo.
You can modify it so that it fits your requirements.
Some notes about it - it uses the MVVM pattern and the Chart is bound using the Manual Series Mappings as a necessary condition for having ZoomScroll feature.

Kind regards,
Evgenia
the Telerik team

[scott]

Thank you Evgenia.  I'll look at it.   Its probably more elegant than my hooking the zoom/scroll event and forcing a resync.    Here's what I came up with. 

void ZoomScroll_Changed(object sender, PropertyChangedEventArgs e)
{
    if (e.PropertyName != "RangeStart" && e.PropertyName != "RangeEnd")
        return;
    RadExpander exp = Expander.ChildrenOfType<RadExpander>().First();
    Telerik.Windows.Controls.ListBox lb = exp.Content as Telerik.Windows.Controls.ListBox;
    var checkboxes = from boxes in lb.Items select boxes;
    if (checkboxes == null) return;
    foreach (SelectorObject SO in checkboxes)
    {
        for (int i = 1; i < TSPredictionChart.DefaultView.ChartArea.DataSeries.Count(); i++)
            if (TSPredictionChart.DefaultView.ChartArea.DataSeries[i].LegendLabel == SO.Description)
            {
                if (SO.IsChecked == false)
                    TSPredictionChart.DefaultView.ChartArea.DataSeries[i].Definition.Visibility = SeriesVisibility.Hidden;
                else
                    TSPredictionChart.DefaultView.ChartArea.DataSeries[i].Definition.Visibility = SeriesVisibility.Visible;
            }
    }
}

[Evgenia]

Hi scott,

Let me know how the solution works for you.
Do not hesitate to contact us if any more questions arise.

Kind regards,
Evgenia
the Telerik team