How to: Expose Lists of Symbols Provided by the Library to the Object Manager

The symbol-browsing tools, Class View, Object Browser, Call Browser and Find Symbol Results, pass requests for new data to the Visual Studio object manager. The object manager finds the appropriate libraries and requests new lists of symbols. The libraries respond by providing requested data to the Visual Studio object manager through the IVsSimpleObjectList2 interface. The Visual Studio object manager calls the methods in IVsSimpleObjectList2 interface to obtain the data and uses it to populate or update the views of the symbol-browsing tools.

A library may get requests for data when the tool is invoked, the node is expanded, or the view is refreshed. When a symbol-browsing tool is invoked for the first time, the object manager requests the library to provide the top-level list. When the user expands a list node, the library provides a list of children under that node. Every object manager inquiry contains an index of the item of interest. To display a new list, the object manager must determine how many items are in the list, the type of the items, their names, accessibility, and other properties.

Nota

The following managed code examples demonstrate how to provide lists of symbols through implementing the IVsSimpleObjectList2 interface. The object manager calls the methods in this interface and uses the obtained data to populate or update the symbol-browsing tools.

For native code symbol provider implementation, use the IVsObjectList2 interface.

Providing Lists of Symbols to the Object Manager

To provide lists of symbols to the object manager

1. Get the number of items in the list of symbols by implementing the GetItemCount method. The following example demonstrates how the object manager obtains the information on the number of items in the list.

   Protected m_Methods As System.Collections.Generic.SortedList(Of String, Method) = New System.Collections.Generic.SortedList(Of String, Method)()
   
   Public Function GetItemCount(ByRef pCount As UInteger) As Integer
       pCount = CUInt(m_Methods.Count)
       Return Microsoft.VisualStudio.VSConstants.S_OK
   End Function
   

   protected System.Collections.Generic.SortedList<string, Method> m_Methods = new System.Collections.Generic.SortedList<string, Method>();
   
   public int GetItemCount(out uint pCount)
   {
       pCount = (uint)m_Methods.Count;
       return Microsoft.VisualStudio.VSConstants.S_OK;
   }
   

2. Get information about the categories and the attributes of a given list item by implementing the GetCategoryField2 method. The item categories are specified in the LIB_CATEGORY enumeration. The following example demonstrates how the object manager obtains attributes of items for a given category.

   Public Function GetCategoryField2(ByVal index As UInteger, ByVal Category As Integer, ByRef pfCatField As UInteger) As Integer
       pfCatField = 0
   
       Select Case CType(Category, LIB_CATEGORY)
           Case LIB_CATEGORY.LC_MEMBERTYPE
               pfCatField = CUInt(_LIBCAT_MEMBERTYPE.LCMT_METHOD)
   
           Case LIB_CATEGORY.LC_MEMBERACCESS
               Dim method As Method = m_Methods.Values(CInt(Fix(index)))
   
               If method.IsPublic Then
                   pfCatField = CUInt(_LIBCAT_MEMBERACCESS.LCMA_PUBLIC)
               ElseIf method.IsPrivate Then
                   pfCatField = CUInt(_LIBCAT_MEMBERACCESS.LCMA_PRIVATE)
               ElseIf method.IsFamily Then
                   pfCatField = CUInt(_LIBCAT_MEMBERACCESS.LCMA_PROTECTED)
               ElseIf method.IsFamilyOrAssembly Then
                   pfCatField = CUInt(_LIBCAT_MEMBERACCESS.LCMA_PROTECTED) Or CUInt(_LIBCAT_MEMBERACCESS.LCMA_PACKAGE)
               Else
                   ' Show everything else as internal.
                   pfCatField = CUInt(_LIBCAT_MEMBERACCESS.LCMA_PACKAGE)
               End If
   
           Case LIB_CATEGORY.LC_VISIBILITY
               pfCatField = CUInt(_LIBCAT_VISIBILITY.LCV_VISIBLE)
   
           Case LIB_CATEGORY.LC_LISTTYPE
               pfCatField = CUInt(_LIB_LISTTYPE.LLT_MEMBERS)
   
           Case Else
               Return Microsoft.VisualStudio.VSConstants.S_FALSE
       End Select
       Return Microsoft.VisualStudio.VSConstants.S_OK
   End Function
   

   public int GetCategoryField2(uint index, int Category, out uint pfCatField)
   {
       pfCatField = 0;
   
       switch ((LIB_CATEGORY)Category)
       {
           case LIB_CATEGORY.LC_MEMBERTYPE:
               pfCatField = (uint)_LIBCAT_MEMBERTYPE.LCMT_METHOD;
               break;
   
           case LIB_CATEGORY.LC_MEMBERACCESS:
               {
                   Method method = m_Methods.Values[(int)index];
   
                   if (method.IsPublic)
                   {
                       pfCatField = (uint)_LIBCAT_MEMBERACCESS.LCMA_PUBLIC;
                   }
                   else if (method.IsPrivate)
                   {
                       pfCatField = (uint)_LIBCAT_MEMBERACCESS.LCMA_PRIVATE;
                   }
                   else if (method.IsFamily)
                   {
                       pfCatField = (uint)_LIBCAT_MEMBERACCESS.LCMA_PROTECTED;
                   }
                   else if (method.IsFamilyOrAssembly)
                   {
                       pfCatField = (uint)_LIBCAT_MEMBERACCESS.LCMA_PROTECTED |
                                    (uint)_LIBCAT_MEMBERACCESS.LCMA_PACKAGE;
                   }
                   else
                   {
                       // Show everything else as internal.
                       pfCatField = (uint)_LIBCAT_MEMBERACCESS.LCMA_PACKAGE;
                   }
               }
               break;
   
           case LIB_CATEGORY.LC_VISIBILITY:
               pfCatField = (uint)_LIBCAT_VISIBILITY.LCV_VISIBLE;
               break;
   
           case LIB_CATEGORY.LC_LISTTYPE:
               pfCatField = (uint)_LIB_LISTTYPE.LLT_MEMBERS;
               break;
   
           default:
               return Microsoft.VisualStudio.VSConstants.S_FALSE;
       }
       return Microsoft.VisualStudio.VSConstants.S_OK;
   }
   

3. Get the text representation of a given list item by implementing the GetTextWithOwnership method. The following example demonstrates how to obtain a full name of a given item.

   Public Function GetTextWithOwnership(<System.Runtime.InteropServices.ComAliasNameAttribute("Microsoft.VisualStudio.OLE.Interop.ULONG")> ByVal index As UInteger, <System.Runtime.InteropServices.ComAliasNameAttribute("Microsoft.VisualStudio.Shell.Interop.VSTREETEXTOPTIONS")> ByVal tto As Microsoft.VisualStudio.Shell.Interop.VSTREETEXTOPTIONS, <System.Runtime.InteropServices.ComAliasNameAttribute("Microsoft.VisualStudio.OLE.Interop.WCHAR")> ByRef ppszText As String) As Integer
       ppszText = m_Methods.Values(CInt(Fix(index))).FullName
       Return Microsoft.VisualStudio.VSConstants.S_OK
   End Function
   

   public int GetTextWithOwnership([System.Runtime.InteropServices.ComAliasNameAttribute("Microsoft.VisualStudio.OLE.Interop.ULONG")] uint index, [System.Runtime.InteropServices.ComAliasNameAttribute("Microsoft.VisualStudio.Shell.Interop.VSTREETEXTOPTIONS")] Microsoft.VisualStudio.Shell.Interop.VSTREETEXTOPTIONS tto, [System.Runtime.InteropServices.ComAliasNameAttribute("Microsoft.VisualStudio.OLE.Interop.WCHAR")] out string ppszText)
   {
       ppszText = m_Methods.Values[(int)index].FullName;
       return Microsoft.VisualStudio.VSConstants.S_OK;
   }
   

4. Get the icon information for a given list item by implementing the GetDisplayData method. The icon represents the type (class, method, and so on), and accessibility (private, public, and so on) of a list item. The following example demonstrates how to obtain the icon information based on a given item attributes.

   Public Overridable Function GetDisplayData(ByVal index As UInteger, ByVal pData As Microsoft.VisualStudio.Shell.Interop.VSTREEDISPLAYDATA()) As Integer
       If pData Is Nothing Then
           Return Microsoft.VisualStudio.VSConstants.E_INVALIDARG
       End If
   
       Dim method As Method = m_Methods.Values(CInt(Fix(index)))
   
       Dim iImage As Integer = 12 * 6 ' See env\inc\OMGlyphs.h.
   
       Const OM_GLYPH_ACC_PUBLIC As Integer = 0
       Const OM_GLYPH_ACC_INTERNAL As Integer = 1
       Const OM_GLYPH_ACC_PROTECTED As Integer = 3
       Const OM_GLYPH_ACC_PRIVATE As Integer = 4
   
       If method.IsPublic Then
           iImage += OM_GLYPH_ACC_PUBLIC
       ElseIf method.IsPrivate Then
           iImage += OM_GLYPH_ACC_PRIVATE
       ElseIf method.IsFamily Then
           iImage += OM_GLYPH_ACC_PROTECTED
       ElseIf method.IsFamilyOrAssembly Then
           iImage += OM_GLYPH_ACC_PROTECTED
       Else
           iImage += OM_GLYPH_ACC_INTERNAL
       End If
   
       pData(0).Image = CUShort(iImage)
       pData(0).SelectedImage = CUShort(iImage)
   
       Return Microsoft.VisualStudio.VSConstants.S_OK
   End Function
   

   public virtual int GetDisplayData(uint index, Microsoft.VisualStudio.Shell.Interop.VSTREEDISPLAYDATA[] pData)
   {
       if (pData == null)
       {
           return Microsoft.VisualStudio.VSConstants.E_INVALIDARG;
       }
   
       Method method = m_Methods.Values[(int)index];
   
       int iImage = 12 * 6;    // See env\inc\OMGlyphs.h.
   
       const int OM_GLYPH_ACC_PUBLIC = 0;
       const int OM_GLYPH_ACC_INTERNAL = 1;
       const int OM_GLYPH_ACC_PROTECTED = 3;
       const int OM_GLYPH_ACC_PRIVATE = 4;
   
       if (method.IsPublic)
       {
           iImage += OM_GLYPH_ACC_PUBLIC;
       }
       else if (method.IsPrivate)
       {
           iImage += OM_GLYPH_ACC_PRIVATE;
       }
       else if (method.IsFamily)
       {
           iImage += OM_GLYPH_ACC_PROTECTED;
       }
       else if (method.IsFamilyOrAssembly)
       {
           iImage += OM_GLYPH_ACC_PROTECTED;
       }
       else
       {
           iImage += OM_GLYPH_ACC_INTERNAL;
       }
   
       pData[0].Image = (ushort)iImage;
       pData[0].SelectedImage = (ushort)iImage;
   
       return Microsoft.VisualStudio.VSConstants.S_OK;
   }
   

5. Get the information on whether a given list item is expandable by implementing the GetExpandable3 method. The following example demonstrates how to obtain the information on whether a given item can be expanded.

   Public Function GetExpandable(ByVal index As UInteger, ByRef pfExpandable As Integer) As Integer
       pfExpandable = Microsoft.VisualStudio.VSIP.Samples.CallBrowser.Constants.TRUE
       Return Microsoft.VisualStudio.VSConstants.S_OK
   End Function
   
   Public Function GetExpandable3(ByVal index As UInteger, ByVal ListTypeExcluded As UInteger, ByRef pfExpandable As Integer) As Integer
       Return GetExpandable(index, pfExpandable)
   End Function
   

   public int GetExpandable(uint index, out int pfExpandable)
   {
       pfExpandable = Microsoft.VisualStudio.VSIP.Samples.CallBrowser.Constants.TRUE;
       return Microsoft.VisualStudio.VSConstants.S_OK;
   }
   
   public int GetExpandable3(uint index, uint ListTypeExcluded, out int pfExpandable)
   {
       return GetExpandable(index, out pfExpandable);
   }
   

6. Get a child list of symbols of a given list item by implementing the GetList2 method. The following example demonstrates how to obtain a child list of symbols of a given item for Call or Callers graphs.

   ' Call graph list.
   Public Class CallsList
       Inherits ResultsList
       Implements Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2
       Public Sub New(ByVal library As Library)
           MyBase.New(library)
       End Sub
   
       Public Function GetList2(ByVal index As UInteger, ByVal ListType As UInteger, ByVal flags As UInteger, ByVal pobSrch As Microsoft.VisualStudio.Shell.Interop.VSOBSEARCHCRITERIA2(), ByRef ppList As Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2) As Integer
           Return MyBase.GetCallsList(index, ppList)
       End Function
   End Class
   
   ' Callers graph list.
   Public Class CallersList
       Inherits ResultsList
       Implements Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2
       Public Sub New(ByVal library As Library)
           MyBase.New(library)
       End Sub
   
       Public Function GetList2(ByVal index As UInteger, ByVal ListType As UInteger, ByVal flags As UInteger, ByVal pobSrch As Microsoft.VisualStudio.Shell.Interop.VSOBSEARCHCRITERIA2(), ByRef ppList As Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2) As Integer
           Return MyBase.GetCallersList(index, ppList)
       End Function
   End Class
   
   ' Call graph list.
   Public Function GetCallsList(ByVal index As UInteger, ByRef ppList As Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2) As Integer
       ppList = Nothing
       Dim callsList As ResultsList = New CallsList(m_Library)
   
       Dim method As Method = m_Methods.Values(CInt(Fix(index)))
       Dim strMethod As String = method.m_strPrototype
   
       Dim Calls As System.Collections.Generic.List(Of CallInstance) = m_Library.CallGraph.GetCallGraph(method)
   
       For i As Integer = 0 To Calls.Count - 1
           Dim caller As Method = Calls(i).m_Target
           callsList.AddMethod(caller)
       Next i
   
       ppList = CType(callsList, Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2)
       Return Microsoft.VisualStudio.VSConstants.S_OK
   End Function
   
   ' Callers graph list.
   Public Function GetCallersList(ByVal index As UInteger, ByRef ppList As Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2) As Integer
       ppList = Nothing
       Dim callersList As ResultsList = New CallersList(m_Library)
   
       Dim method As Method = m_Methods.Values(CInt(Fix(index)))
       Dim strMethod As String = method.m_strPrototype
   
       Dim Callers As System.Collections.Generic.List(Of CallInstance) = m_Library.CallGraph.GetCallersGraph(method)
   
       For i As Integer = 0 To Callers.Count - 1
           Dim caller As Method = Callers(i).m_Source
           callersList.AddMethod(caller)
       Next i
   
       ppList = CType(callersList, Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2)
       Return Microsoft.VisualStudio.VSConstants.S_OK
   End Function
   
   ' Get a child list of symbols for a given list item.
   Public Function GetList2(ByVal index As UInteger, ByVal ListType As UInteger, ByVal flags As UInteger, ByVal pobSrch As Microsoft.VisualStudio.Shell.Interop.VSOBSEARCHCRITERIA2(), ByRef ppList As Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2) As Integer
       ppList = Nothing
   
       Dim method As Method = m_Methods.Values(CInt(Fix(index)))
       Dim strMethod As String = method.m_strPrototype
   
       ' Determine if the list belongs to Call or Callers graphs.
       If CUInt(m_nFlags And CUInt(Microsoft.VisualStudio.Shell.Interop._VSOBSEARCHOPTIONS2.VSOBSO_CALLSFROM)) > 0 Then
           ' Build the list for the Call graph.
           Return MyBase.GetCallsList(index, ppList)
       ElseIf CUInt(m_nFlags And CUInt(Microsoft.VisualStudio.Shell.Interop._VSOBSEARCHOPTIONS2.VSOBSO_CALLSTO)) > 0 Then
           ' Build the list for the Callers graph.
           Return MyBase.GetCallersList(index, ppList)
       End If
   
       Return Microsoft.VisualStudio.VSConstants.E_FAIL
   End Function
   

   // Call graph list.
   public class CallsList :
       ResultsList,
       Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2
   {
       public CallsList(Library library) :
           base(library)
       {
       }
   
       public int GetList2(uint index, uint ListType, uint flags, Microsoft.VisualStudio.Shell.Interop.VSOBSEARCHCRITERIA2[] pobSrch, out Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2 ppList)
       {
           return base.GetCallsList(index, out ppList);
       }
   }
   
   // Callers graph list.
   public class CallersList :
       ResultsList,
       Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2
   {
       public CallersList(Library library) :
           base(library)
       {
       }
   
       public int GetList2(uint index, uint ListType, uint flags, Microsoft.VisualStudio.Shell.Interop.VSOBSEARCHCRITERIA2[] pobSrch, out Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2 ppList)
       {
           return base.GetCallersList(index, out ppList);
       }
   }
   
   // Call graph list.
   public int GetCallsList(uint index, out Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2 ppList)
   {
       ppList = null;
       ResultsList callsList = new CallsList(m_Library);
   
       Method method = m_Methods.Values[(int)index];
       string strMethod = method.m_strPrototype;
   
       System.Collections.Generic.List<CallInstance> Calls = m_Library.CallGraph.GetCallGraph(method);
   
       for (int i = 0; i < Calls.Count; i++)
       {
           Method caller = Calls[i].m_Target;
           callsList.AddMethod(caller);
       }
   
       ppList = (Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2)(callsList);
       return Microsoft.VisualStudio.VSConstants.S_OK;
   }
   
   // Callers graph list.
   public int GetCallersList(uint index, out Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2 ppList)
   {
       ppList = null;
       ResultsList callersList = new CallersList(m_Library);
   
       Method method = m_Methods.Values[(int)index];
       string strMethod = method.m_strPrototype;
   
       System.Collections.Generic.List<CallInstance> Callers = m_Library.CallGraph.GetCallersGraph(method);
   
       for (int i = 0; i < Callers.Count; i++)
       {
           Method caller = Callers[i].m_Source;
           callersList.AddMethod(caller);
       }
   
       ppList = (Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2)(callersList);
       return Microsoft.VisualStudio.VSConstants.S_OK;
   }
   
   // Get a child list of symbols for a given list item.
   public int GetList2(uint index, uint ListType, uint flags, Microsoft.VisualStudio.Shell.Interop.VSOBSEARCHCRITERIA2[] pobSrch, out Microsoft.VisualStudio.Shell.Interop.IVsSimpleObjectList2 ppList)
   {
       ppList = null;
   
       Method method = m_Methods.Values[(int)index];
       string strMethod = method.m_strPrototype;
   
       // Determine if the list belongs to Call or Callers graphs.
       if ((uint)(m_nFlags & (uint)Microsoft.VisualStudio.Shell.Interop._VSOBSEARCHOPTIONS2.VSOBSO_CALLSFROM) > 0)
       {
           // Build the list for the Call graph.
           return base.GetCallsList(index, out ppList);
       }
       else if ((uint)(m_nFlags & (uint)Microsoft.VisualStudio.Shell.Interop._VSOBSEARCHOPTIONS2.VSOBSO_CALLSTO) > 0)
       {
           // Build the list for the Callers graph.
           return base.GetCallersList(index, out ppList);
       }
   
       return Microsoft.VisualStudio.VSConstants.E_FAIL;
   }
   

See Also

Tasks

How to: Register a Library with the Object Manager

How to: Identify Symbols in a Library

Concepts

Supporting Symbol-Browsing Tools

Other Resources

Language Services