' Copyright 2012 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.IO
Imports ESRI.ArcGIS.Framework
Imports ESRI.ArcGIS.esriSystem
Imports ESRI.ArcGIS.Carto
Imports ESRI.ArcGIS.Desktop.AddIns

Imports My

Namespace SelectionSample

  Public Class SelectionExtension
    Inherits ESRI.ArcGIS.Desktop.AddIns.Extension

    Private m_map As IMap
    Private m_hasSelectableLayer As Boolean
    Private Shared s_dockWindow As ESRI.ArcGIS.Framework.IDockableWindow
    Private Shared s_extension As SelectionExtension


    ' Overrides

    Protected Overrides Sub OnStartup()
      s_extension = Me

      ' Wire up events
      AddHandler ArcMap.Events.NewDocument, AddressOf ArcMap_NewOpenDocument
      AddHandler ArcMap.Events.OpenDocument, AddressOf ArcMap_NewOpenDocument

      Initialize()
    End Sub

    Protected Overloads Overrides Sub OnShutdown()
      Uninitialize()


      RemoveHandler ArcMap.Events.NewDocument, AddressOf ArcMap_NewOpenDocument
      RemoveHandler ArcMap.Events.OpenDocument, AddressOf ArcMap_NewOpenDocument

      m_map = Nothing
      s_dockWindow = Nothing
      s_extension = Nothing

      MyBase.OnShutdown()
    End Sub

    Protected Overrides Function OnSetState(ByVal state As ExtensionState) As Boolean
      ' Optionally check for a license here
      Me.State = state

      If state = ExtensionState.Enabled Then
        Initialize()
      Else
        Uninitialize()
      End If

      Return MyBase.OnSetState(state)
    End Function

    Protected Overrides Function OnGetState() As ExtensionState
      Return Me.State
    End Function

    ' Privates

    Private Sub Initialize()
      If s_extension Is Nothing Or Me.State <> ExtensionState.Enabled Then
        Return
      End If

      ' Reset event handlers
      Dim avEvent As IActiveViewEvents_Event = TryCast(ArcMap.Document.FocusMap, IActiveViewEvents_Event)
      AddHandler avEvent.ItemAdded, AddressOf AvEvent_ItemAdded
      AddHandler avEvent.ItemDeleted, AddressOf AvEvent_ItemAdded
      AddHandler avEvent.SelectionChanged, AddressOf UpdateSelCountDockWin
      AddHandler avEvent.ContentsChanged, AddressOf avEvent_ContentsChanged

      ' Update the UI
      m_map = ArcMap.Document.FocusMap
      FillComboBox()
      SelCountDockWin.SetEnabled(True)
      UpdateSelCountDockWin()
      m_hasSelectableLayer = CheckForSelectableLayer()
    End Sub

    Private Sub Uninitialize()
      If s_extension Is Nothing Then
        Return
      End If

      ' Detach event handlers
      Dim avEvent As IActiveViewEvents_Event = TryCast(m_map, IActiveViewEvents_Event)
      RemoveHandler avEvent.ItemAdded, AddressOf AvEvent_ItemAdded
      RemoveHandler avEvent.ItemDeleted, AddressOf AvEvent_ItemAdded
      RemoveHandler avEvent.SelectionChanged, AddressOf UpdateSelCountDockWin
      RemoveHandler avEvent.ContentsChanged, AddressOf avEvent_ContentsChanged
      avEvent = Nothing

      ' Update UI
      Dim selCombo As SelectionTargetComboBox = SelectionTargetComboBox.GetSelectionComboBox()
      If selCombo IsNot Nothing Then
        selCombo.ClearAll()
      End If

      SelCountDockWin.SetEnabled(False)
    End Sub

    Private Sub UpdateSelCountDockWin()
      ' If the dockview hasn't been created yet
      If (Not SelCountDockWin.Exists) Then
        Return
      End If

      ' Update the contents of the listView, when the selection changes in the map. 
      Dim featureLayer As IFeatureLayer
      Dim featSel As IFeatureSelection

      SelCountDockWin.Clear()

      ' Loop through the layers in the map and add the layer's name and
      ' selection count to the list box
      For i As Integer = 0 To m_map.LayerCount - 1
        If TypeOf m_map.Layer(i) Is IFeatureSelection Then
          featureLayer = TryCast(m_map.Layer(i), IFeatureLayer)
          If featureLayer Is Nothing Then
            Exit For
          End If

          featSel = TryCast(featureLayer, IFeatureSelection)

          Dim count As Integer = 0
          If featSel.SelectionSet IsNot Nothing Then
            count = featSel.SelectionSet.Count
          End If
          SelCountDockWin.AddItem(featureLayer.Name, count)
        End If
      Next i
    End Sub

    Private Sub FillComboBox()
      Dim selCombo As SelectionTargetComboBox = SelectionTargetComboBox.GetSelectionComboBox()
      If selCombo Is Nothing Then
        Return
      End If

      selCombo.ClearAll()

      Dim featureLayer As IFeatureLayer
      ' Loop through the layers in the map and add the layer's name to the combo box.
      For i As Integer = 0 To m_map.LayerCount - 1
        If TypeOf m_map.Layer(i) Is IFeatureSelection Then
          featureLayer = TryCast(m_map.Layer(i), IFeatureLayer)
          If featureLayer Is Nothing Then
            Exit For
          End If

          selCombo.AddItem(featureLayer.Name, featureLayer)
        End If
      Next i
    End Sub

    Private Function CheckForSelectableLayer() As Boolean
      Dim map As IMap = ArcMap.Document.FocusMap
      ' Bail if map has no layers
      If map.LayerCount = 0 Then
        Return False
      End If

      ' Fetch all the feature layers in the focus map
      ' and see if at least one is selectable
      Dim uid As New UIDClass()
      uid.Value = "{40A9E885-5533-11d0-98BE-00805F7CED21}"
      Dim enumLayers As IEnumLayer = map.Layers(uid, True)
      Dim featureLayer As IFeatureLayer = TryCast(enumLayers.Next(), IFeatureLayer)
      Do While featureLayer IsNot Nothing
        If featureLayer.Selectable = True Then
          Return True
        End If
        featureLayer = TryCast(enumLayers.Next(), IFeatureLayer)
      Loop
      Return False
    End Function

    ' Event handlers

    Private Sub ArcMap_NewOpenDocument()
      Dim pageLayoutEvent As IActiveViewEvents_Event = TryCast(ArcMap.Document.PageLayout, IActiveViewEvents_Event)
      AddHandler pageLayoutEvent.FocusMapChanged, AddressOf AVEvents_FocusMapChanged

      Initialize()
    End Sub

    Private Sub avEvent_ContentsChanged()
      m_hasSelectableLayer = CheckForSelectableLayer()
    End Sub

    Private Sub AvEvent_ItemAdded(ByVal Item As Object)
      m_map = ArcMap.Document.FocusMap
      FillComboBox()
      UpdateSelCountDockWin()
      m_hasSelectableLayer = CheckForSelectableLayer()
    End Sub

    Private Sub AVEvents_FocusMapChanged()
      Initialize()
    End Sub

    ' Statics

    Friend Shared Function GetSelectionCountWindow() As ESRI.ArcGIS.Framework.IDockableWindow
      If s_extension Is Nothing Then
        GetExtension()
      End If

      ' Only get/create the dockable window if they ask for it
      If s_dockWindow Is Nothing Then
        Dim dockWinID As UID = New UIDClass()
        dockWinID.Value = ThisAddIn.IDs.SelCountDockWin
        s_dockWindow = ArcMap.DockableWindowManager.GetDockableWindow(dockWinID)
        s_extension.UpdateSelCountDockWin()
      End If

      Return s_dockWindow
    End Function

    Friend Shared Function IsExtensionEnabled() As Boolean
      If s_extension Is Nothing Then
        GetExtension()
      End If

      If s_extension Is Nothing Then
        Return False
      End If

      Return s_extension.State = ExtensionState.Enabled
    End Function

    Friend Shared Function HasSelectableLayer() As Boolean
      If s_extension Is Nothing Then
        GetExtension()
      End If

      If s_extension Is Nothing Then
        Return False
      End If

      Return s_extension.m_hasSelectableLayer
    End Function

    Private Shared Function GetExtension() As SelectionExtension
      If s_extension Is Nothing Then
        Dim extID As UID = New UIDClass()
        extID.Value = ThisAddIn.IDs.SelectionExtension
        ' Call FindExtension to load this just-in-time extension.
        ArcMap.Application.FindExtensionByCLSID(extID)
      End If
      Return s_extension
    End Function
  End Class
End Namespace