title: Creating a WPF Tooltip on a Rect object
body: <p>I'm working with an open source charting library that creates markers on a graph. (Dynamic Data Display) The markers that I'm creating are created with Rect objects. I noticed that all the Shapes in System.Windows.Shapes have a ToolTip property, but System.Windows.Rect does not. I want to have a tooltip pop up telling the user the price value of the marker when the mouse hovers over it.
  I was thinking about creating and popping up a tooltip when the mouse enters the area that the rect occupies, but I don't know how possible that is considering the rect will be zoomed/panned around by the chart. Any other suggestions? </p>
  
  <p>Here is my code for the marker I am creating (From Felice Pollano Blog)</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Windows.Shapes;
  using System.Windows.Controls;
  using System.Text;
  using System.Windows;
  using System.Windows.Media;
  
  namespace Microsoft.Research.DynamicDataDisplay.PointMarkers
  {
  public class CandleStickPointMarker:ShapePointMarker,ITransformAware
  {
      public double CandlestickWidth
      {
          get { return (double)GetValue(CandlestickWidthProperty); }
          set { SetValue(CandlestickWidthProperty, value); }
      }
      public static readonly DependencyProperty CandlestickWidthProperty =
          DependencyProperty.Register("CandlestickWidth", typeof(double), typeof(CandleStickPointMarker), new UIPropertyMetadata(4.0));
      public double CandlestickStrokeWidth
      {
          get { return (double)GetValue(CandlestickStrokeWidthProperty); }
          set { SetValue(CandlestickStrokeWidthProperty, value); }
      }
  
      public static readonly DependencyProperty CandlestickStrokeWidthProperty =
          DependencyProperty.Register("CandlestickStrokeWidth", typeof(double), typeof(CandleStickPointMarker), new UIPropertyMetadata(1.0));
      public Brush WhiteCandleFill
      {
          get { return (Brush)GetValue(WhiteCandleFillProperty); }
          set { SetValue(WhiteCandleFillProperty, value); }
      }
  
      public static readonly DependencyProperty WhiteCandleFillProperty =
          DependencyProperty.Register("WhiteCandleFill", typeof(Brush), typeof(CandleStickPointMarker), new UIPropertyMetadata(Brushes.White));
  
  
  
      public Brush WhiteCandleStroke
      {
          get { return (Brush)GetValue(WhiteCandleStrokeProperty); }
          set { SetValue(WhiteCandleStrokeProperty, value); }
      }
  
      public static readonly DependencyProperty WhiteCandleStrokeProperty =
          DependencyProperty.Register("WhiteCandleStroke", typeof(Brush), typeof(CandleStickPointMarker), new UIPropertyMetadata(Brushes.DarkGray));
  
  
  
      public Brush BlackCandleFill
      {
          get { return (Brush)GetValue(BlackCandleFillProperty); }
          set { SetValue(BlackCandleFillProperty, value); }
      }
      public static readonly DependencyProperty BlackCandleFillProperty =
          DependencyProperty.Register("BlackCandleFill", typeof(Brush), typeof(CandleStickPointMarker), new UIPropertyMetadata(Brushes.Black));
      public Brush BlackCandleStroke
      {
          get { return (Brush)GetValue(BlackCandleStrokeProperty); }
          set { SetValue(BlackCandleStrokeProperty, value); }
      }
  
      public static readonly DependencyProperty BlackCandleStrokeProperty =
          DependencyProperty.Register("BlackCandleStroke", typeof(Brush), typeof(CandleStickPointMarker), new UIPropertyMetadata(Brushes.Gray));
      public CoordinateTransform Transform { get; set; }
      public double High
      {
          get { return (double)GetValue(HighProperty); }
          set { SetValue(HighProperty, value); }
      }
  
      public static readonly DependencyProperty HighProperty =
          DependencyProperty.Register("High", typeof(double), typeof(CandleStickPointMarker), new UIPropertyMetadata(0.0));
  
      public double Low
      {
          get { return (double)GetValue(LowProperty); }
          set { SetValue(LowProperty, value); }
      }
  
      public static readonly DependencyProperty LowProperty =
          DependencyProperty.Register("Low", typeof(double), typeof(CandleStickPointMarker), new UIPropertyMetadata(0.0));
  
  
      public double Open
      {
          get { return (double)GetValue(OpenProperty); }
          set { SetValue(OpenProperty, value); }
      }
  
      public static readonly DependencyProperty OpenProperty =
          DependencyProperty.Register("Open", typeof(double), typeof(CandleStickPointMarker), new UIPropertyMetadata(0.0));
  
  
      public override void Render(System.Windows.Media.DrawingContext dc, Point screenPoint)
      {
          Point screenOpen = GetScreenPoint(Open,screenPoint.X);
          Point screenHigh = GetScreenPoint(High,screenPoint.X);
          Point screenLow = GetScreenPoint(Low, screenPoint.X);
          //screenPoint is the CLOSE by gentleman agreement.
          var close = screenPoint.ScreenToData(Transform).Y;
          Pen strokePen;
          if (Open &gt;= close) // black
          {
              strokePen = new Pen(BlackCandleStroke, CandlestickStrokeWidth);
              var h = -screenOpen.Y + screenPoint.Y;
              Rect blkRect = new Rect(screenPoint.X - CandlestickWidth / 2, screenOpen.Y, CandlestickWidth, h);                       
              dc.DrawRectangle(BlackCandleFill,strokePen, blkRect);
              dc.DrawLine(strokePen, screenLow, screenPoint);
              dc.DrawLine(strokePen, screenHigh, screenOpen);
          }
          else // white
          {
              strokePen=new Pen(WhiteCandleStroke, CandlestickStrokeWidth);
              var h = screenOpen.Y - screenPoint.Y;
              Rect whtRect = new Rect(screenPoint.X - CandlestickWidth / 2, screenPoint.Y, CandlestickWidth, h);
              dc.DrawRectangle(WhiteCandleFill, strokePen, whtRect);
              dc.DrawLine(strokePen, screenLow, screenOpen);
              dc.DrawLine(strokePen, screenHigh, screenPoint);
          }
      }
  
      private Point GetScreenPoint(double Open,double screenX)
      {
          Point screen = new Point(0, Open);
          return new Point(screenX,screen.DataToScreen(Transform).Y);
      }
  }
  </code></pre>
  
  <p>}</p>