How to detect onSelectionChanged?

[Jeffrey Tucker]

I'm building a clinical report writer (emits docx format document) that has a set of special tokens that begin with "[!" and end with "!]".  When the user changes the selection I need to get notification of the event.  If the selection is inside one of these tokens, show a special editor (modeless) to customize runtime text substitutions.  How can I setup to get that notification?  I already tried Left mouse down and it does not even get called..

 private void radRichTextBox1_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
    if (radRichTextBox1.Document != null && radRichTextBox1.Document.Selection != null)
    {
         DocumentSelection selection = radRichTextBox1.Document.Selection;
         string selectedText = selection.GetSelectedText();
    }
}

[Boby]

Hi Jeffrey,
You can use DocumentSelection.SelectionChanged event. Note that  if RadRichTextBox's document is changed you have to unsubscribe from the event hander for the old document's selection and subscribe for the new one:

public MainPage()
{
    InitializeComponent();

    this.radRichTextBox1.DocumentChanging += (s, e) =>
    {
        if (this.radRichTextBox1.Document != null)
        {
            this.radRichTextBox1.Document.Selection.SelectionChanged -= Selection_SelectionChanged;
        }
    };

    this.radRichTextBox1.DocumentChanged += (s, e) =>
    {
        if (this.radRichTextBox1.Document != null)
        {
            this.radRichTextBox1.Document.Selection.SelectionChanged += Selection_SelectionChanged;
        }
    };

    this.radRichTextBox1.Document.Selection.SelectionChanged += Selection_SelectionChanged;
}

private void Selection_SelectionChanged(object sender, EventArgs e)
{
    if (this.radRichTextBox1.Document.Selection.GetSelectedText() == "test")
    {
        MessageBox.Show("test");
    }
}

private void Button_Click(object sender, RoutedEventArgs e)
{
    // if the document is changed, you have to subscribe for the event of the new selection
    this.radRichTextBox1.Document = new Telerik.Windows.Documents.Model.RadDocument();
}

We will consider exposing such event directly on RadRichTextBox to simplify scenarios like yours.
Don't hesitate to contact us if you have other questions.

Best wishes,
Boby
the Telerik team