ShellCtrls2 v1.03

One of the many GUI classes I have developed and published on my web site is CFileTreeCtrl. This is a implementation from first principles of a tree control similar to the left hand side of Windows Explorer. Because it was implemented with custom code, it has diverged from the tree control shown in Windows Explorer in recent versions of Windows. In addition, some features in CFileTreeCtrl such as network enumeration no longer work in recent versions of Windows. In addition It would be nice to have a list control implementation similar to the right hand side of Windows Explorer. As of Visual Studio 2008 Service Pack 1, two classes became available which implemented this functionality using MFC. They are called CMFCShellTreeCtrl and CMFCShellListCtrl. I've recently taken a look at these two classes, but I wanted to bring forward all the functionality of CFileTreeCtrl in an implementation which provides better integration with the shell. I also took inspiration and ideas from the following codeproject articles: https://www.codeproject.com/Articles/1073213/Extending-MFC-shell-controls-functionality and https://www.codeproject.com/Articles/2271/ShellFolderTree. The result of all this work is ShellCtrls2.

The classes provided are:

CPIDL which provides a RAII class wrapper for a LPITEMIDLIST aka PIDLs. PIDLs are identifiers which the Windows shell uses to identify all objects which make up the Shell namespace. This class is based on the PIDL class provided by Oz Solomon with WndTabs extension for Visual C++ 6.0 but reimplemented using modern C++ 11 idioms.
CShellItemInfo2 This class is what is stored in the item data for each item in the tree control or list control
CShellTreeCtrl2 This class is an improved version of the built-in MFC class CMFCShellTreeCtrl
CShellListCtrl2 This class is an improved version of the built-in MFC class CMFCShellListCtrl

The demo application included in the download exercises all the functionality of each of the classes. A screen capture of the sample app running is as follows:

Features

• CShellTreeCtrl2 by default derives from CTreeCtrl and can be created using the same mechanisms.
• CShellListCtrl2 by default derives from CMFCListCtrl and uses that class to provide sorting functionality and custom header functionality when the control is in details mode.
• Both CShellTreeCtrl2 and CShellListCtrl2 uses the system image list for the icons for folders and files.
• Can have multiple instances of each control active at one time.
• CShellTreeCtrl2 can optionally allows files to be displayed as well as folders.
• CShellListCtrl2 by default allows files to be displayed but can be changed at runtime to only display folders.
• Integrates with the shell to allow any item's default shell verb or properties page to be displayed.
• The tree control preserves selection state of items across refreshes and optionally allows files to be displayed.
• The tree control can optionally show the root item or not. In the screen capture above, this would correspond to showing or hiding the "Desktop" node in the tree control.
• The tree control can optionally show only items below a specific root folder.
• The tree control maintains a back forward item stack which client code can take advantage of.
• Both the tree and list controls can show different icons for shared folders and linked items, different colors for encrypted and compressed items, can customize the drives, folders and file types to be displayed and supports multiple filename masks.
• Both the tree and list controls support the shell context menu for items and the list control supports opening a folder in the control itself.
• Similar to the "Extending MFC shell controls functionality" CodeProject article, both controls support storing item data and the tree control supports keeping items on node collapse and expansion and contraction of all nodes.
• Provides a full set of keyboard accelerators similar to Windows Explorer.
• Almost all of the functionality of both controls are implemented in virtual functions making it easy to customize the behavior at runtime. In particular the shell enumeration logic implemented by both controls has been carefully arranged into easy to replace virtual functions.
• Similar to the built-in MFC classes, both controls can be tied together so that changing folder in one will auto update in the other. The sample program include in the download implements this concept using a simple MFC splitter window.
• Unlike the MFC classes, ShellCtrls2 uses built in MFC, ATL and custom RAII classes such as CPIDL, CMenu and CComPtr to avoid resource and memory leaks. In fact the author detected a number of code paths in the built in MFC classes which could cause resource and memory leaks.
• Both the tree and list controls support an "Auto Refresh" feature where any file system changes are detected for the current folder and automatically refreshed.
• Unicode enabled and all code compiles cleanly at warning level 4.
• The code is /analyze clean and has been compiled using Clang-Tidy.

Usage

• To use CShellTreeCtrl2, include "ShellTreeCtrl2.cpp / h" in your project and #include "ShellTreeCtrl2.h" in the module you want to instantiate it in. You can use the usual MFC ways of hooking up the class. You can also create the control dynamically by calling its parent classes CTreeCtrl::Create method.
• To use CShellListCtrl2, include "ShellListCtrl2.cpp / h" in your project and #include "ShellListCtrl2.h" in the module you want to instantiate it in. You can use the usual MFC ways of hooking up the class. You can also create the control dynamically by calling its parent classes CMFCListCtrl::Create method.
• You will also need to copy the IDR_SHELLCTRLS2_POPUP_NOTHING_SELECTED menu resource, associated ID_SHELLCTRLS2_* identifiers and IDS_SHELLCTRLS2* string resources from the sample app's rc file into your applications rc file.
• Note that the code has been developed using Visual Studio 2019 and probably will not compile on earlier versions of Visual Studio.

Copyright

• You are allowed to include the source code in any product (commercial, shareware, freeware or otherwise) when your product is released in binary form.
• You are allowed to modify the source code in any way you want except you cannot modify the copyright details at the top of each module.
• If you want to distribute source code with your application, then you are only allowed to distribute versions released by the author. This is to maintain a single distribution point for the source code.

History

v1.03 (4 June 2023)

• Updated copyright details.
• Reworked CShellListCtrl2::OnGetItemText to use IShellItem2.
• Reworked CShellListCtrl2::OnCompareItems to use IShellItem2.
• Reworked the logic in CShellListCtrl2::OnCompareItems to behave more similar to how Windows Explorer behaves.

v1.02 (23 April 2022)

• Updated copyright details
• Updated the code to use C++ uniform initialization for all variable declarations.

v1.01 (17 December 2021)

• Updated copyright details
• Fixed more static code analysis warnings in the code.

v1.0 (25 July 2020)

• Initial public release.

Contacting the Author

PJ Naughter
Email: pjna@naughter.com
Web: http://www.naughter.com
4 June 2023