Windows Explorer wildcard selection shell extension

#ifndef CTXMENU_H
#define CTXMENU_H

#include <comdef.h>
#include <shlobj.h>

#include <string>
#include <list>

using namespace std;

/**
 * Our context menu Shell Extension.
 *
 * Based on code by Michael Dunn.
 */
class ATL_NO_VTABLE CtxMenu : 
	public CComObjectRootEx<CComSingleThreadModel>,
	public CComCoClass<CtxMenu, &CLSID_CtxMenu>,
	public IShellExtInit,
	public IContextMenu
{
public:

	/** Constructor. */
	CtxMenu(void);

	/** Destructor. */
	virtual ~CtxMenu(void);

DECLARE_REGISTRY_RESOURCEID(IDR_CTXMENU)
DECLARE_NOT_AGGREGATABLE(CtxMenu)
DECLARE_PROTECT_FINAL_CONSTRUCT()

BEGIN_COM_MAP(CtxMenu)
	COM_INTERFACE_ENTRY(IShellExtInit)
	COM_INTERFACE_ENTRY(IContextMenu)
END_COM_MAP()

public:

	// IShellExtInit
	STDMETHOD(Initialize)(LPCITEMIDLIST, LPDATAOBJECT, HKEY);

	// IContextMenu
	STDMETHOD(GetCommandString)(UINT, UINT, UINT*, LPSTR, UINT);
	STDMETHOD(InvokeCommand)(LPCMINVOKECOMMANDINFO);
	STDMETHOD(QueryContextMenu)(HMENU, UINT, UINT, UINT, UINT);

	/**
	 * Finds the files and subfolders from the current folder 
	 * that match the specified wildcard pattern, and tells 
	 * Explorer's ListView to select them. 
	 */
	void SelectFiles(const char* pattern);

	/** 
	 * Selects the files and subfolders that were selected at 
	 * the time Wildcard Select was invoked.
	 */
	void RestoreOriginalSelection(void);

protected:

	/** Type for a list of file names. */
	typedef list<string> file_list_t;

	/** Iterator for a list of file names. */
	typedef file_list_t::iterator file_iter_t;

	/**
	 * Invoked when the user clicks the right mouse button 
	 * on the background of an Explorer window. In this case, 
	 * Wildcard Select will try to match all files.
	 */
	HRESULT ClickedOnBackground(LPCITEMIDLIST pidl);

	/**
	 * Invoked when the user clicks the right mouse button 
	 * on a file or subfolder name. In this case, we will 
	 * only try to match the files and subfolders that were 
	 * selected at the time Wildcard Select was invoked.
	 */
	HRESULT ClickedOnFileOrFolder(LPDATAOBJECT dataObj);

	/** Finds the ListView control inside an Explorer window. */
	bool FindListView(HWND explorerWnd);

	/** 
	 * Recursively searches "wnd" and all its child windows
	 * for a window with the specified window class name.
	 * Returns NULL if no such window could be found.
	 */
	HWND FindWindowWithClass(HWND wnd, const char* className);

	/**
	 * Selects the item with the specified filename in 
	 * Explorer's ListView.
	 */
	void SelectListViewItem(const char* filename);

	/**
	 * Returns the index of the specified filename in
	 * Explorer's ListView, or -1 if no such item exists.
	 */
	int GetListViewIndex(const char* filename);

	/** De-selects everthing in Explorer's ListView. */
	void ClearSelection(void);

	/** The folder the user is working in. */
	char folder[MAX_PATH + 1];

	/**
	 * Whether to look at all files and subfolders, or only at 
	 * the ones that were selected at the time Wildcard Select
	 * was invoked. In the latter case, "allFiles" is false and 
	 * "selected" keeps a list of these files.
	 */
	bool allFiles;

	/**
	 * The files and subfolders that were selected at the time 
	 * Wildcard Select was invoked. We restrict our search to 
	 * only these files. This collection is empty if "allFiles" 
	 * is true.
	 */
	file_list_t selected;

	/** Explorer's ListView control. */
	HWND listView;

	/** The icon we display in the context menu. */
	HBITMAP bitmap;
};

#endif // CTXMENU_H