/// <summary>
/// Retrieves an OLE interface that can be used to carry out actions on the
/// specified file objects or folders. Return value: error code, if any
/// </summary>
/// <param name="hwndOwner">Handle to the owner window that the client should specify if it displays a dialog box or message box.</param>
/// <param name="cidl">Number of file objects or subfolders specified in the apidl parameter.</param>
/// <param name="apidl">Address of an array of pointers to ITEMIDLIST structures, each of which uniquely identifies a file object or subfolder relative to the parent folder.</param>
/// <param name="riid">Identifier of the COM interface object to return.</param>
/// <param name="rgfReserved">Reserved.</param>
/// <param name="ppv">Pointer to the requested interface.</param>
/// <returns>
/// If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.
/// </returns>
int IShellFolder.GetUIObjectOf(IntPtr hwndOwner, uint cidl, IntPtr apidl, ref Guid riid, uint rgfReserved, out IntPtr ppv)
{
// Get the ID lists from the array of PIDLs provided.
var idLists = PidlManager.APidlToIdListArray(apidl, (int)cidl);
if (riid == typeof(IContextMenu).GUID || riid == typeof(IContextMenu2).GUID || riid == typeof(IContextMenu3).GUID)
{
// If the folder implments the context menu provider, we can use that.
var contextMenuProvider = proxyFolder as IShellNamespaceFolderContextMenuProvider;
if (contextMenuProvider != null)
{
ppv = Marshal.GetComInterfaceForObject(contextMenuProvider.CreateContextMenu(idListAbsolute, idLists),
typeof(IContextMenu));
return(WinError.S_OK);
}
var dcm = new DEFCONTEXTMENU
{
hwnd = hwndOwner,
pcmcb = null,
pidlFolder = PidlManager.IdListToPidl(idListAbsolute),
psf = this,
cidl = cidl,
apidl = apidl,
punkAssociationInfo = IntPtr.Zero,
cKeys = 0,
aKeys = null
};
// Create the default context menu.
var result = Shell32.SHCreateDefaultContextMenu(dcm, riid, out ppv);
}
else if (riid == Shell32.IID_ExtractIconW)
{
// If we've been asked for an icon, it should only be for a single PIDL.
if (idLists.Length != 1)
{
Diagnostics.Logging.Error(string.Format("The Shell Folder Impl for folder {0} has been asked for icons for multiple files at once, this is not supportedd.",
proxyFolder.GetDisplayName(DisplayNameContext.Normal)));
ppv = IntPtr.Zero;
return(WinError.E_FAIL);
}
// Get the idlist and item.
var idList = idLists[0];
var item = GetChildItem(idList);
// Now get the icon. If we don't provide one we'll use the defaults.
var icon = item.GetIcon();
if (icon == null)
{
ProvideDefaultIExtractIcon(item is IShellNamespaceFolder, out ppv);
return(WinError.S_OK);
}
else
{
// Create an icon provider.
var provider = new Components.ExtractIconImpl()
{
DoNotCacheIcons = false, Icon = icon
};
ppv = Marshal.GetComInterfaceForObject(provider, typeof(IExtractIconW));
return(WinError.S_OK);
}
}
else if (riid == Shell32.IID_IDataObject)
{
// Create the data object.
Shell32.SHCreateDataObject(PidlManager.IdListToPidl(idListAbsolute), cidl, apidl, null, riid, out ppv);
}
else if (riid == Shell32.IID_IQueryAssociations)
{
// If we've been asked for a query associations, it should only be for a single PIDL.
if (idLists.Length != 1)
{
Diagnostics.Logging.Error(string.Format("The Shell Folder Impl for folder {0} has been asked for query associations for multiple files at once, this is not supportedd.",
proxyFolder.GetDisplayName(DisplayNameContext.Normal)));
ppv = IntPtr.Zero;
return(WinError.E_FAIL);
}
var item = GetChildItem(idLists[0]);
var isFolder = item is IShellNamespaceFolder;
if (isFolder)
{
// todo perhaps a good class name would simply be the
// name of the item type? or an attribute that uses the classname as a
// fallback.
var associations = new ASSOCIATIONELEMENT[]
{
new ASSOCIATIONELEMENT
{
ac = ASSOCCLASS.ASSOCCLASS_PROGID_STR,
hkClass = IntPtr.Zero,
pszClass = "FolderViewSampleType"
},
new ASSOCIATIONELEMENT
{
ac = ASSOCCLASS.ASSOCCLASS_FOLDER,
hkClass = IntPtr.Zero,
pszClass = "FolderViewSampleType"
}
};
Shell32.AssocCreateForClasses(associations, (uint)associations.Length, riid, out ppv);
}
else
{
var associations = new ASSOCIATIONELEMENT[]
{
new ASSOCIATIONELEMENT
{
ac = ASSOCCLASS.ASSOCCLASS_PROGID_STR,
hkClass = IntPtr.Zero,
pszClass = "FolderViewSampleType"
}
};
Shell32.AssocCreateForClasses(associations, (uint)associations.Length, riid, out ppv);
}
}
/* } */
// We have a set of child pidls (i.e. length one). We can now offer interfaces such as:
/*
* IContextMenu The cidl parameter can be greater than or equal to one.
* IContextMenu2 The cidl parameter can be greater than or equal to one.
* IDataObject The cidl parameter can be greater than or equal to one.
* IDropTarget The cidl parameter can only be one.
* IExtractIcon The cidl parameter can only be one.
* IQueryInfo The cidl parameter can only be one.
* */
// IID_IExtractIconW
// IID_IDataObject
// IID_IQueryAssociations
// Currently, we don't offer any extra child item UI objects.
ppv = IntPtr.Zero;
return(WinError.E_NOINTERFACE);
}