' Copyright 2006 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
Imports System.Data
Imports System.Runtime.InteropServices

Imports ESRI.ArcGIS.Carto
Imports ESRI.ArcGIS.Geodatabase
Imports ESRI.ArcGIS.esriSystem
Imports ESRI.ArcGIS.Geometry
Imports ESRI.ArcGIS.Display



  ''' <summary>
  ''' Summary description for clsCustomLayer.
  ''' </summary>
  Public MustInherit Class CustomLayerBase : Implements ILayer, IGeoDataset, IPersistVariant, ILayerGeneralProperties, IEnumerable, IDisposable
#Region "Class members"
    ''' <summary>
    ''' Keep the layer's extent. Returned by the ILayer::Extent property
    ''' </summary>
    ''' <remarks>The extent should be spatial-referenced to the DateFrame's spatial reference.
    ''' </remarks>
    Protected m_extent As IEnvelope = Nothing

    ''' <summary>
    ''' Store the layer's underlying data spatial reference. Returned by IGeoDataset::SpatialReference.
    ''' </summary>
    ''' <remarks>This spatial reference should not be reprojected. In your inheriting 
    ''' class you will need to have another parameter that will keep the DataFrame's spatial reference
    ''' that would use to reproject the geometries and the extent of the layer.</remarks>
    Protected m_spatialRef As ISpatialReference = Nothing

    ''' <summary>
    ''' Layer's name. Returned by ILayer::Name property
    ''' </summary>
    Protected m_sName As String

    ''' <summary>
    ''' Flag which determines whether the layers is visible. Returned by ILayer::Visible
    ''' </summary>
    ''' <remarks>You should use this member in your inherited class in the Draw method.</remarks>
    Protected m_visible As Boolean

    ''' <summary>
    ''' determines whether the layers is cached
    ''' </summary>
    Protected m_IsCached As Boolean

    ''' <summary>
    ''' Flag thich determine whether the layer is valid (connected to its data source, has valid information etc.).
    ''' Returned by ILAyer::Valid.
    ''' </summary>
    ''' <remarks>You can use this flag to determine for example whether the layer can be available or not.</remarks>
    Protected m_bValid As Boolean = True

    ''' <summary>
    ''' Keep the maximum scale value at which the layer will display
    ''' </summary>
    Protected m_MaximumScale As Double

    ''' <summary>
    ''' Keep the minimum scale value at which the layer will display
    ''' </summary>
    Protected m_MinimumScale As Double

    ''' <summary>
    ''' determines whether the layers is supposed to show its MapTips
    ''' </summary>
    Protected m_ShowTips As Boolean

    ''' <summary>
    ''' The data structure for the custom layer
    ''' </summary>
    ''' <remarks>By default, the DataTable gets initialized in the BaseClass Ctor with an ID column
    ''' which is AutoIncremented. The BaseClass also support enumerator which is actually en enumerator of
    ''' the table as well as a direct indexer.</remarks>
    Protected m_table As DataTable
#End Region

#Region "CTor"

    ''' <summary>
    ''' Default Ctor
    ''' </summary>
    Public Sub New()
      m_sName = String.Empty
      m_visible = True
      m_IsCached = False
      m_MaximumScale = 0
      m_MinimumScale = 0
      m_table = New DataTable("RECORDS")

      m_table.Columns.Add("ID", GetType(Long))
    End Sub
#End Region

#Region "IGeoDataset Members"

    ''' <summary>
    '''The layers geodataset extent which is a union of the extents of all
    ''' the items of the layer
    ''' </summary>
    ''' <remarks>In your inheriting class, consider the following code to calculate the layer's extent:
    ''' <code>
    ''' public override IEnvelope Extent
    '''{
    '''  get
    '''  {
    '''    m_extent  = GetLayerExtent();
    '''    if (null == m_extent )
    '''      return null;
    '''
    '''    IEnvelope env = ((IClone)m_extent ).Clone() as IEnvelope;
    '''    if(null != m_layerSpatialRef)
    '''       env.Project(m_layerSpatialRef);
    ''' 
    '''    return env;
    '''  }
    '''}
    '''    private IEnvelope GetLayerExtent()
    '''{
    '''  if (null == base.m_spRef)
    '''  {
    '''    base.m_spRef = CreateGeographicSpatialReference();
    '''  }
    '''
    '''  IEnvelope env = new EnvelopeClass();
    '''  env.SpatialReference = base.m_spRef;
    '''  IPoint point = new PointClass();
    '''  point.SpatialReference = m_spRef;
    '''  foreach (DataRow r in m_table.Rows)
    '''  {
    '''    point.Y = Convert.ToDouble(r["Y"]);
    '''    point.X = Convert.ToDouble(r["X"]);
    '''
    '''    env.Union(point.Envelope);
    '''  }
    ''' 
    '''  return env;
    '''} 
    ''' </code>
    ''' </remarks>    
    Public Overridable ReadOnly Property Extent() As IEnvelope Implements IGeoDataset.Extent
      Get
        Return m_extent
      End Get
    End Property

    ''' <summary>
    ''' The spatial reference of the underlying data.
    ''' </summary>
    ''' <remarks>The property must return the underlying data spatial reference and
    ''' must not reporoject it into the layer's spatial reference </remarks>

    Public Overridable ReadOnly Property SpatialReference1() As ISpatialReference Implements IGeoDataset.SpatialReference ''ILayer.SpatialReference,
      Get
        Return m_spatialRef
      End Get
    End Property

#End Region

#Region "IPersistVariant Members"

    ''' <summary>
    ''' The ID of the object.
    ''' </summary>
    Public Overridable ReadOnly Property ID() As UID Implements IPersistVariant.ID
      Get
        ' TODO:  Add clsCustomLayer.ID getter implementation
        Return Nothing
      End Get
    End Property

    ''' <summary>
    ''' Loads the object properties from the stream.
    ''' </summary>
    ''' <param name="Stream"></param>
    ''' <remarks>The Load method must read the data from the stream in the same order the data was 
    ''' written to the stream in the Save method. 
    ''' Streams are sequential; you mut ensure that your data is saved and loaded in the correct order, 
    ''' so that the correct data is written to the correct member.
    ''' </remarks>
    Public Overridable Sub Load(ByVal Stream As IVariantStream) Implements IPersistVariant.Load
      ' TODO:  Add clsCustomLayer.Load implementation
    End Sub

    ''' <summary>
    ''' Saves the object properties to the stream.
    ''' </summary>
    ''' <param name="Stream"></param>
    Public Overridable Sub Save(ByVal Stream As IVariantStream) Implements IPersistVariant.Save
      ' TODO:  Add clsCustomLayer.Save implementation
    End Sub

#End Region

#Region "ILayer Members"

#Region "Properties"

    ''' <summary>
    ''' Indicates if the layer shows map tips.
    ''' </summary>
    ''' <remarks>Indicates whether or not map tips are shown for the layer. 
    ''' If set to True, then map tips will be shown for the layer. 
    ''' You can determine the text that will be shown via TipText. 
    '''</remarks>
    Public Overridable Property ShowTips() As Boolean Implements ILayer.ShowTips
      Get
        Return m_ShowTips
      End Get
      Set(ByVal value As Boolean)
        m_ShowTips = Value
      End Set
    End Property

    ''' <summary>
    ''' The default area of interest for the layer. Returns the spatial-referenced extent of the layer.
    ''' </summary>
    Public Overridable ReadOnly Property AreaOfInterest() As IEnvelope Implements ILayer.AreaOfInterest
      Get
        Return m_extent
      End Get
    End Property

    ''' <summary>
    ''' Indicates if the layer is currently visible.
    ''' </summary>
    Public Overridable Property Visible() As Boolean Implements ILayer.Visible
      Get
        Return m_visible
      End Get
      Set(ByVal value As Boolean)
        m_visible = Value
      End Set
    End Property


    ''' <summary>
    ''' Indicates if the layer needs its own display cache.
    ''' </summary>
    ''' <remarks>This property indicates whether or not the layer requires its own display cache. 
    ''' If this property is True, then the Map will use a separate display cache for the layer so 
    ''' that it can be refreshed indpendently of other layers.</remarks>
    Public Overridable Property Cached() As Boolean Implements ILayer.Cached
      Get
        Return m_IsCached
      End Get
      Set(ByVal value As Boolean)
        m_IsCached = Value
      End Set
    End Property

    ''' <summary>
    ''' Minimum scale (representative fraction) at which the layer will display.
    ''' </summary>
    ''' <remarks>Specifies the minimum scale at which the layer will be displayed. 
    ''' This means that if you zoom out beyond this scale, the layer will not display. 
    ''' For example, specify 1000 to have the layer not display when zoomed out beyond 1:1000.</remarks>
    Public Overridable Property MinimumScale() As Double Implements ILayer.MinimumScale
      Get
        Return m_MinimumScale
      End Get
      Set(ByVal value As Double)
        m_MinimumScale = Value
      End Set
    End Property

    ''' <summary>
    ''' Indicates if the layer is currently valid.
    ''' </summary>
    ''' <remarks>The valid property indicates if the layer is currently valid.
    ''' Layers that reference feature classes are valid when they hold a reference to a valid feature class.
    ''' The property does not however validate the integrity of the feature classes reference to the database.
    ''' Therefore, in rare situations if a datasource is removed after a layer is initialized, 
    ''' the layer will report itself as valid but query attempts to the data source will error due to the lack 
    ''' of underlying data.</remarks>
    Public Overridable ReadOnly Property Valid() As Boolean Implements ILayer.Valid
      Get
        Return m_bValid
      End Get
    End Property

    ''' <summary>
    ''' The Layer name.
    ''' </summary>
    Public Overridable Property Name() As String Implements ILayer.Name
      Get
        Return m_sName
      End Get
      Set(ByVal value As String)
        m_sName = Value
      End Set
    End Property

    ''' <summary>
    ''' Maximum scale (representative fraction) at which the layer will display.
    ''' </summary>
    ''' <remarks>Specifies the maximum scale at which the layer will be displayed. 
    ''' This means that if you zoom in beyond this scale, the layer will not display. 
    ''' For example, specify 500 to have the layer not display when zoomed in beyond 1:500.</remarks>
    Public Overridable Property MaximumScale() As Double Implements ILayer.MaximumScale
      Get
        Return m_MaximumScale
      End Get
      Set(ByVal value As Double)
        m_MaximumScale = Value
      End Set
    End Property

    ''' <summary>
    ''' Supported draw phases.
    ''' </summary>
    ''' <remarks>Indicates the draw phases supported by the layer (esriDPGeography, esriDPAnnotation, 
    ''' esriDPSelection, or any combination of the three). 
    ''' The supported draw phases are defined by esriDrawPhase. 
    ''' When multiple draw phases are supported, the sum of the constants is used. 
    ''' For example, if SupportedDrawPhases = 3 then the layer supports drawing in the geography and annotation phases.</remarks>
    Public ReadOnly Property SupportedDrawPhases() As Integer Implements ILayer.SupportedDrawPhases
      Get
        Return CInt(esriDrawPhase.esriDPGeography)
      End Get
    End Property

    ''' <summary>
    ''' Spatial reference for the layer.
    ''' </summary>
    '''<remarks>This property is only used for map display, setting this property does not 
    '''change the spatial reference of the layer's underlying data. 
    '''The ArcGIS framework uses this property to pass the spatial reference from the map 
    '''to the layer in order to support on-the-fly projection.</remarks> 
    Private WriteOnly Property SpatialReference() As ISpatialReference Implements ESRI.ArcGIS.Carto.ILayer.SpatialReference
      Set(ByVal value As ISpatialReference)
        m_spatialRef = Value
      End Set
    End Property

    ''' <summary>
    ''' Map tip text at the specified location. 
    ''' </summary>
    ''' <param name="X"></param>
    ''' <param name="Y"></param>
    ''' <param name="Tolerance"></param>
    ''' <returns>The text string that gets displayed as a map tip if ShowTips = true.</returns>
    Public Overridable ReadOnly Property TipText(ByVal X As Double, ByVal Y As Double, ByVal Tolerance As Double) As String Implements ILayer.TipText
      Get
        Return Nothing
      End Get
    End Property

#End Region

#Region "Methods"
    ''' <summary>
    ''' Draws the layer to the specified display for the given draw phase.
    ''' </summary>
    ''' <param name="drawPhase"></param>
    ''' <param name="Display"></param>
    ''' <param name="trackCancel"></param>
    ''' <remarks>This method draws the layer to the Display for the specified DrawPhase. 
    ''' Use the TrackCancel object to allow the drawing of the layer to be interrupted by the user.
    ''' In order to implement you inheriting class, you must override this method</remarks>
    Public MustOverride Sub Draw(ByVal drawPhase As esriDrawPhase, ByVal Display As IDisplay, ByVal trackCancel As ITrackCancel) Implements ILayer.Draw
#End Region
#End Region

#Region "ILayerGeneralProperties Members"

    ''' <summary>
    ''' Last maximum scale setting used by layer.
    ''' </summary>
    Public Overridable ReadOnly Property LastMaximumScale() As Double Implements ILayerGeneralProperties.LastMaximumScale
      Get
        Return 0
      End Get
    End Property

    ''' <summary>
    ''' Last minimum scale setting used by layer.
    ''' </summary>
    Public Overridable ReadOnly Property LastMinimumScale() As Double Implements ILayerGeneralProperties.LastMinimumScale
      Get
        Return 0
      End Get
    End Property

    ''' <summary>
    ''' Description for the layer.
    ''' </summary>
    Public Overridable Property LayerDescription() As String Implements ILayerGeneralProperties.LayerDescription
      Get
        Return Nothing
      End Get
      Set(ByVal value As String)

      End Set
    End Property
#End Region

#Region "Data Structure basic functionality"
    ''' <summary>
    ''' Create a new item (does not add it to the layer)
    ''' </summary>
    ''' <returns></returns>
    Public Overridable Function NewItem() As DataRow
      Return m_table.NewRow()
    End Function

    ''' <summary>
    ''' Add an item to the layer
    ''' </summary>
    ''' <param name="row"></param>
    Public Overridable Sub AddItem(ByVal row As DataRow)
      m_table.Rows.Add(row)
    End Sub

    ''' <summary>
    ''' Add an item to the Layer
    ''' </summary>
    ''' <param name="values"></param>
    Public Overridable Sub AddItem(ByVal values As Object())
      m_table.Rows.Add(values)
    End Sub

    ''' <summary>
    ''' Query for items in the layer
    ''' </summary>
    ''' <param name="queryFilter">WHERE clause</param>
    ''' <returns></returns>
    Public Overridable Function [Select](ByVal queryFilter As String) As DataRow()
      Return m_table.Select(queryFilter)
    End Function

    ''' <summary>
    ''' Remove all items in the layer
    ''' </summary>
    Public Overridable Sub Clear()
      m_table.Rows.Clear()
    End Sub

    ''' <summary>
    ''' Remove the item from the layer
    ''' </summary>
    ''' <param name="row">The row to remove</param>
    Public Overridable Sub RemoveItem(ByVal row As DataRow)
      m_table.Rows.Remove(row)
    End Sub

    'indexer. Pass an index and return a record
    Default Public ReadOnly Property Item(ByVal index As Integer) As DataRow
      Get
        Return m_table.Rows(index)
      End Get
    End Property

    ''' <summary>
    ''' return the number of geometries in the layer
    ''' </summary>
    Public ReadOnly Property NumOfRecords() As Integer
      Get
        Return m_table.Rows.Count
      End Get
    End Property
#End Region

#Region "IEnumerable Members"

    ''' <summary>
    ''' Allow users to directly enumerate through the layer's records
    ''' </summary>
    ''' <returns></returns>
    Public Function GetEnumerator() As IEnumerator Implements IEnumerable.GetEnumerator
      Return m_table.Rows.GetEnumerator()
    End Function

#End Region

#Region "IDisposable Members"

    ''' <summary>
    ''' Dispose the layer
    ''' </summary>
    Public Sub Dispose() Implements IDisposable.Dispose
      m_extent = Nothing
      m_spatialRef = Nothing
    End Sub

#End Region
  End Class