' Copyright 2010 ESRI
' 
' All rights reserved under the copyright laws of the United States
' and applicable international laws, treaties, and conventions.
' 
' You may freely redistribute and use this sample code, with or
' without modification, provided you include the original copyright
' notice and use restrictions.
' 
' See the use restrictions.
' 

Imports Microsoft.VisualBasic
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Drawing
Imports System.Timers

Imports ESRI.ArcGIS.ADF
Imports ESRI.ArcGIS.ADF.BaseClasses
Imports ESRI.ArcGIS.Geodatabase
Imports ESRI.ArcGIS.Geometry
Imports ESRI.ArcGIS.Carto
Imports ESRI.ArcGIS.Display

  Public NotInheritable Class MyDynamicLayer : Inherits BaseDynamicLayer
  Public m_bOnce As Boolean = True
  Private m_myGlyph As IDynamicGlyph = Nothing
  Private m_dynamicSymbolProps As IDynamicSymbolProperties2 = Nothing
  Private m_point As IPoint = Nothing
  Private m_stepX As Double = 0
  Private m_stepY As Double = 0
  Private m_updateTimer As Timer = Nothing

  Public Sub New()
    MyBase.New()
    MyBase.m_sName = "My Dynamic layer"
    m_updateTimer = New Timer(15)
    m_updateTimer.Enabled = False
    AddHandler m_updateTimer.Elapsed, AddressOf OnTimerElapsed
  End Sub

  Public Overrides Sub DrawDynamicLayer(ByVal DynamicDrawPhase As esriDynamicDrawPhase, ByVal Display As IDisplay, ByVal DynamicDisplay As IDynamicDisplay)
    If DynamicDrawPhase <> esriDynamicDrawPhase.esriDDPImmediate Then
      Return
    End If

    If (Not m_bValid) OrElse (Not m_visible) Then
      Return
    End If

    Dim visibleExtent As IEnvelope = Display.DisplayTransformation.FittedBounds

    If m_bOnce Then
      Dim dynamicGlyphFactory As IDynamicGlyphFactory = DynamicDisplay.DynamicGlyphFactory
      m_dynamicSymbolProps = TryCast(DynamicDisplay, IDynamicSymbolProperties2)

      Dim markerSymbol As ICharacterMarkerSymbol = New CharacterMarkerSymbolClass()
            markerSymbol.Font = ESRI.ArcGIS.ADF.Connection.Local.Converter.ToStdFont(New Font("ESRI Default Marker", 25.0F, FontStyle.Bold))
      markerSymbol.Size = 25.0
      ' set the symbol color to white
            markerSymbol.Color = CType(ESRI.ArcGIS.ADF.Connection.Local.Converter.ToRGBColor(Color.FromArgb(255, 255, 255)), IColor)
      markerSymbol.CharacterIndex = 92

      ' create the dynamic glyph
      m_myGlyph = dynamicGlyphFactory.CreateDynamicGlyph(CType(markerSymbol, ISymbol))

      Dim r As Random = New Random()
      Dim X As Double = visibleExtent.XMin + r.NextDouble() * visibleExtent.Width
      Dim Y As Double = visibleExtent.YMin + r.NextDouble() * visibleExtent.Height
      m_point = New PointClass()
      m_point.PutCoords(X, Y)

      m_stepX = visibleExtent.Width / 250
      m_stepY = visibleExtent.Height / 250

      ' start the update timer
      m_updateTimer.Enabled = True

      m_bOnce = False
    End If

    ' draw the marker
    m_dynamicSymbolProps.DynamicGlyph(esriDynamicSymbolType.esriDSymbolMarker)= m_myGlyph
    m_dynamicSymbolProps.SetColor(esriDynamicSymbolType.esriDSymbolMarker, 1.0f, 0.0f, 0.0f, 1.0f)
    m_dynamicSymbolProps.SetScale(esriDynamicSymbolType.esriDSymbolMarker, 1.0f, 1.0f)
    DynamicDisplay.DrawMarker(m_point)

    ' update the point location for the next draw cycle
    m_point.X += m_stepX
    m_point.Y += m_stepY

    ' make sure that the point fall within the visible extent
    If m_point.X > visibleExtent.XMax Then
      m_stepX = -Math.Abs(m_stepX)
    End If
    If m_point.X < visibleExtent.XMin Then
      m_stepX = Math.Abs(m_stepX)
    End If
    If m_point.Y > visibleExtent.YMax Then
      m_stepY = -Math.Abs(m_stepY)
    End If
    If m_point.Y < visibleExtent.YMin Then
      m_stepY = Math.Abs(m_stepY)
    End If

    ' set the dirty flag to false since drawing is done.
    MyBase.m_bIsImmediateDirty = False
  End Sub

  Private Sub OnTimerElapsed(ByVal sender As Object, ByVal e As ElapsedEventArgs)
    ' set the dirty flag to true in order to assure the next drawing cycle
    MyBase.m_bIsImmediateDirty = True
  End Sub
  End Class