Shell Extension - Folders and File Icons

Hi,

We have a shell extension written in SharpShell using C#. We are familiar with icon overlay and icon handlers. However, for our needs, we are now thinking we may wish to approach this from the folder level vs. file-by-file.

We took note of:

https://github.com/dwmkerr/sharpshell/blob/master/SharpShell/SharpShell/SharpNamespaceExtension/ShellFolderImpl.cs

https://github.com/dwmkerr/sharpshell/blob/master/SharpShell/SharpShell/Interop/IShellFolder2.cs

https://github.com/dwmkerr/sharpshell/blob/master/SharpShell/SharpShell/Interop/Shell32.cs

and articles by the SharpShell author:

https://dwmkerr.com/effective-shell-part-5-understanding-the-shell/

https://dwmkerr.com/effective-shell-4-moving-around/

What we want or are wondering is:

can a Shell implementation be made such that when a user switches a folder, we are given the folder. From the folder we can loop through the files searching for, as an example, MS Word documents tagged with a custom document property.

If the folder contains documents tagged this way, then update the icons for both standard and tagged MS Word documents?

Potentially, there is a secondary piece of functionality related to the display size of the icon. We have noted that the OS provides a box container that icons are displayed in. For example, in a folder containing nothing but .ico files or, similarly, graphics files like .png, the icons are sized within these box containers according to the size of the file (i.e. 16x16, 128x128, etc.). We are wondering if we swapped out the icons with larger size for tagged files and smaller size non-tagged files if it would alter the display?

We have pre-existing source that work against the icons and pre-existing source that works with custom document properties using NPOI library.

It is the folder functionality and icon display functionality that we desire.