EditEventWindow.on_entry_angle_changed C# (CSharp) Method

    private void on_entry_angle_changed(object o, EventArgs args)
    {
        string angleString = entry_angle_value.Text.ToString();
        if(Util.IsNumber(angleString, true)) {
            entryAngle = angleString;
            button_accept.Sensitive = true;
        } else if(angleString == "-") {
            entryAngle = "-1,0";
            button_accept.Sensitive = true;
        } else
            button_accept.Sensitive = false;
    }