Hi,

I am using the tooltip controller that triggers immediately when the mouse cursor passes over a line. The problem is that for a split second you can see there is a small tooltip box that has no content that appears before the real tooltip box appears. I was wondering if there was a way to make that empty tooltip box not appear. I am sending a project reproducing this situation.

Also I  wanted to know if there was a way customize the appearance of the tooltip controller. Specifically to make the border color of the tooltip match the color of the series that is displaying the tooltip.

Thanks in advance!

Hi Fabio,

The tooltip issue has been fixed in the latest SP (16.5.31.12) and you should receive a download link from support when it's uploaded. In this SP we have also extended the tooltip tool so that you can override what happens when a tooltip is shown / hidden. The following code shows how to implement a tooltip with dynamically changing border depending on the underlying line series stroke:

using Nevron;
using Nevron.Chart;
using Nevron.Chart.Windows;
using Nevron.Dom;
using Nevron.GraphicsCore;
using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Media;

namespace SmallNevronProject
{
  /// <summary>
  /// Interaction logic for Mainwindow.xaml
  /// </summary>
  public partial class MainWindow : Window
  {
   private NAxis _xAxis;
   private NAxis _yAxis;
   private NCartesianChart _chart;

   class MyTooltipTool : NTooltipTool
   {
    public MyTooltipTool(Nevron.Chart.Wpf.NChartControl chartControl)
    {
      m_ChartControl = chartControl;
    }
    protected override void SetTooltip(NPointF mousePosition, string tooltip)
    {
      if (tooltip == null || tooltip.Length == 0)
      {
       ClearTooltip();
       return;
      }

      NHitTestResult hitTestResult = m_ChartControl.HitTest((int)mousePosition.X, (int)mousePosition.Y);

      if (tooltip != m_Tooltip)
      {
       ClearTooltip();
       m_Tooltip = tooltip;
      }

      System.Windows.Controls.ToolTip tooltipControl = m_ChartControl.ToolTip as System.Windows.Controls.ToolTip;

      if (tooltipControl == null)
      {
       tooltipControl = new System.Windows.Controls.ToolTip();
       m_ChartControl.ToolTip = tooltipControl;
       tooltipControl.Placement = System.Windows.Controls.Primitives.PlacementMode.Mouse;
      }

      if (hitTestResult.ChartElement == ChartElement.DataPoint)
      {
       NLineSeries lineSeries = hitTestResult.Series as NLineSeries;

       if (lineSeries != null)
       {
        System.Drawing.Color color = lineSeries.BorderStyle.Color;
        tooltipControl.BorderBrush = new SolidColorBrush(Color.FromRgb(color.R, color.G, color.B));
        tooltipControl.BorderThickness = new Thickness(2);
       }
      }

      if (tooltipControl.Content != tooltip)
      {
       tooltipControl.Content = tooltip;
       tooltipControl.IsOpen = true;
      }
    }

    protected override void ClearTooltip()
    {
      System.Windows.Controls.ToolTip tooltipControl = m_ChartControl.ToolTip as System.Windows.Controls.ToolTip;

      if (tooltipControl != null)
      {
       tooltipControl.IsOpen = false;
      }
    }

    Nevron.Chart.Wpf.NChartControl m_ChartControl;
    string m_Tooltip;
   }
 

   public MainWindow()
   {
    InitializeComponent();
    _chart = new NCartesianChart();
    Plot.Charts.Clear();
    Plot.Charts.Add(_chart);
    Plot.BackgroundStyle.FrameStyle.Visible = false;

    _chart.RangeSelections.Add(new NRangeSelection());
    _chart.LabelLayout.EnableInitialPositioning = true;
    _chart.LabelLayout.EnableLabelAdjustment = true;
    _chart.BoundsMode = BoundsMode.Stretch;
    _chart.DockMode = PanelDockMode.Fill;

    _yAxis = _chart.Axis(StandardAxis.PrimaryY);
    _xAxis = _chart.Axis(StandardAxis.PrimaryX);

    var scale = new NLinearScaleConfigurator();
    scale.RoundToTickMax = false;
    scale.MinorGridStyle.SetShowAtWall(ChartWallType.Back, true);
    scale.MajorGridStyle.SetShowAtWall(ChartWallType.Back, true);
    scale.MinorTickCount = 4;
    _yAxis.ScaleConfigurator = scale;

    var timeLineScale = new NDateTimeScaleConfigurator();
    timeLineScale.RoundToTickMax = false;
    timeLineScale.RoundToTickMin = false;
    timeLineScale.MinorGridStyle.SetShowAtWall(ChartWallType.Back, false);
    timeLineScale.MajorGridStyle.SetShowAtWall(ChartWallType.Back, true);
    timeLineScale.MajorTickMode = MajorTickMode.AutoMaxCount;
    timeLineScale.LabelValueFormatter = new NDateTimeValueFormatter("mm/yyyy");
    timeLineScale.EnableUnitSensitiveFormatting = false;
    timeLineScale.MaxTickCount = 6;
    timeLineScale.MinorTickCount = 1;
    timeLineScale.AutoDateTimeUnits = new NDateTimeUnit[] { NDateTimeUnit.Day, NDateTimeUnit.Month, NDateTimeUnit.Year, };

    timeLineScale.MajorTickMode = MajorTickMode.AutoMaxCount;
    timeLineScale.MaxTickCount = 6;

    timeLineScale.DateTimeUnitFormatterPairs.MonthFormatter = new NDateTimeValueFormatter(DateTimeValueFormat.MonthShortName);
    timeLineScale.DateTimeUnitFormatterPairs.YearFormatter = new NDateTimeValueFormatter(DateTimeValueFormat.Year4Digit);

    _xAxis.ScaleConfigurator = timeLineScale;

    var selector = new NSelectorTool();
    selector.Focus = true; // make sure the control gets focus when mouse down occurs
    Plot.Controller.Tools.Add(selector);

    var dzt = new NDataZoomTool();
    dzt.WheelZoomAtMouse = true;
    dzt.BeginDragMouseCommand = new NMouseCommand(MouseAction.Wheel, Nevron.Chart.Windows.MouseButton.None, 0);

    var ttl = new NTooltipTool();
    ttl.InitialDelay = 0;
    ttl.AutoPopDelay = -1;
    Plot.Controller.Tools.Add(dzt);
    Plot.Controller.Tools.Add(new MyTooltipTool(Plot));
    Plot.Controller.Tools.Add(new NDataPanTool());

    NSeries newSeries;
    
    newSeries = new NLineSeries() { Name = "aa" };
    var timeList = new List<DateTime>
    {
      new DateTime(1999, 5, 2), new DateTime(2000, 5, 3), new DateTime(2001,6,4),
      new DateTime(2002, 2, 3), new DateTime(2003, 4, 3)
    };
    var valuesList = new List<float> {2, -1, 3, -4, 5};
    (newSeries as NLineSeries).XValues.AddRange(timeList);
    (newSeries as NLineSeries).XValues.ValueFormatter = new NDateTimeValueFormatter("mm/yyyy");
    (newSeries as NLineSeries).UseXValues = true;
    newSeries.Values.AddRange(valuesList);

    newSeries.Values.ValueFormatter = new NNumericValueFormatter("0.000");
    newSeries.InteractivityStyle.Tooltip.Text = "Y: <value>" + '\n' + "X: <xvalue>";
    
    newSeries.BorderStyle.LineJoin = System.Drawing.Drawing2D.LineJoin.MiterClipped;
    newSeries.BorderStyle.LineJoin = System.Drawing.Drawing2D.LineJoin.Round;
    newSeries.BorderStyle.Width = new NLength(3);

    newSeries.InflateMargins = true;
    newSeries.DataLabelStyle.Visible = false;

    _chart.Series.Add(newSeries);

    Plot.Refresh();
   }
  }
}

Hope this helps - let us know if you meet any problems or have any questions.

Best Regards,
Nevron Support Team