HOWTO: Implement Explore and Open in a Namespace ExtensionLast reviewed: March 10, 1998Article ID: Q179911 |
The information in this article applies to:
SUMMARYWhen you are creating a namespace extension that has multiple levels of folders, you may have to implement the Explore and Open commands from the context menu. This article discusses how to implement Explore and Open commands from a context menu in the Windows Explorer tree. This article assumes you are already familiar with development of namespace extensions. For additional information on writing namespace extensions, see David Campbell's article "Extending the Windows Explorer with Name Space Extensions" in the July, 1996 issue of the Microsoft Systems Journal. In addition, please see the following article in the Microsoft Knowledge Base:
ARTICLE-ID: Q178665 TITLE : Sample: RegView.exe: Shell Namespace Extension Example MORE INFORMATIONWhen you want to implement Explore and Open commands from your shell view, normally you will call IShellBrowser::BrowseObject, specifying the proper options for the desired commands. But you cannot do this for your folder items in the Windows Explorer tree because the IShellBrowser interface is not always available to use. Fortunately, you can implement these commands using ShellExecuteEx and these commands can be used by both the shell folder and shell view implementations. If you want to implement Explore and Open commands in the context menus for your items in the Windows Explorer tree, you must first add these items to the menu in your IContextMenu::QueryContextMenu. Because you will be handling the execution of the commands, you can supply any command ID for the menu items that you want. Remember that the Explore and Open menu strings should be localized for use with other languages. The first challenge is how to determine which item should be the default item. Normally, if the item is displayed in Explore mode (a window that contains a tree), the Explore command is the default. If the item is displayed in Open mode (no tree present), then Open is the default item in the context menu. If the context menu is being generated by the shell from a Explore mode window, it will set the CMF_EXPLORE flag when it calls your IContextMenu::QueryContextMenu. If this flag is set, you should make Explore the first and default item in the menu. If this flag is not set, then you should make Open the first and default item.
Sample CodeFollowing is an example of how you may accomplish this:
#define IDM_EXPLORE 0
#define IDM_OPEN 1
#define IDM_LAST IDM_OPEN
STDMETHODIMP CContextMenu::QueryContextMenu( HMENU hMenu,
UINT indexMenu,
UINT idCmdFirst,
UINT idCmdLast,
UINT uFlags)
{
if(!(CMF_DEFAULTONLY & uFlags))
{
MENUITEMINFO mii;
if(uFlags & CMF_EXPLORE)
{
//add the Explore command first and make it the default item
ZeroMemory(&mii, sizeof(mii));
mii.cbSize = sizeof(mii);
mii.fMask = MIIM_ID | MIIM_TYPE | MIIM_STATE;
mii.wID = idCmdFirst + IDM_EXPLORE;
mii.fType = MFT_STRING;
mii.dwTypeData = TEXT("&Explore");
mii.fState = MFS_ENABLED | MFS_DEFAULT;
InsertMenuItem( hMenu,
indexMenu++,
TRUE,
&mii);
ZeroMemory(&mii, sizeof(mii));
mii.cbSize = sizeof(mii);
mii.fMask = MIIM_ID | MIIM_TYPE | MIIM_STATE;
mii.wID = idCmdFirst + IDM_OPEN;
mii.fType = MFT_STRING;
mii.dwTypeData = TEXT("&Open");
mii.fState = MFS_ENABLED;
InsertMenuItem( hMenu,
indexMenu++,
TRUE,
&mii);
}
else
{
//add the Open command first and make it the default item
ZeroMemory(&mii, sizeof(mii));
mii.cbSize = sizeof(mii);
mii.fMask = MIIM_ID | MIIM_TYPE | MIIM_STATE;
mii.wID = idCmdFirst + IDM_OPEN;
mii.fType = MFT_STRING;
mii.dwTypeData = TEXT("&Open");
mii.fState = MFS_ENABLED | MFS_DEFAULT;
InsertMenuItem( hMenu,
indexMenu++,
TRUE,
&mii);
ZeroMemory(&mii, sizeof(mii));
mii.cbSize = sizeof(mii);
mii.fMask = MIIM_ID | MIIM_TYPE | MIIM_STATE;
mii.wID = idCmdFirst + IDM_EXPLORE;
mii.fType = MFT_STRING;
mii.dwTypeData = TEXT("&Explore");
mii.fState = MFS_ENABLED;
InsertMenuItem( hMenu,
indexMenu++,
TRUE,
&mii);
}
return MAKE_HRESULT(SEVERITY_SUCCESS, 0, USHORT(IDM_LAST + 1));
}
return MAKE_HRESULT(SEVERITY_SUCCESS, 0, USHORT(0));
}
To determine if your shell view is being displayed in Open or Explore mode,
use the IShellBrowser::GetControlWindow method passing FCW_TREE. If this
method returns NULL, then the view is in Open mode. If this method returns
a non-NULL value, then the view is in Explore mode. When the view needs to
display a context menu for an item, it can then obtain the IContextMenu
object using its parent's IShellFolder::GetUIObjectOf and then call the
IContextMenu object's QueryContextMenu method. If the tree is present, the
view should add the CMF_EXPLORE flag in the QueryContextMenu call.
Sample CodeFollowing is an example that obtains the context menu for the specified items in a view. The view object maintains the IShellFolder interface of the folder that created it in m_pSFParent.
#define MENU_OFFSET 1
#define MENU_MAX 100
HMENU CShellView::GetContextMenuForItems( UINT uItems,
LPITEMIDLIST *aItems)
{
HMENU hMenu;
if(aItems)
{
LPCONTEXTMENU pContextMenu = NULL;
m_pSFParent->GetUIObjectOf( m_hwndParent,
uItems,
(LPCITEMIDLIST*)aItems,
IID_IContextMenu,
NULL,
(LPVOID*)&pContextMenu);
if(pContextMenu)
{
HMENU hMenu = CreatePopupMenu();
/*
See if we are in Explore or Open mode. If the browser's tree is
present, then we are in Explore mode.
*/
BOOL fExplore = FALSE;
HWND hwndTree = NULL;
if(SUCCEEDED(m_pShellBrowser->GetControlWindow(FCW_TREE,
&hwndTree)) && hwndTree)
{
fExplore = TRUE;
}
if(hMenu && SUCCEEDED(pContextMenu->QueryContextMenu( hMenu,
0,
MENU_OFFSET,
MENU_MAX,
CMF_NORMAL | (fExplore ? CMF_EXPLORE : 0))))
{
}
else
{
DestroyMenu(hMenu);
hMenu = NULL;
}
}
}
return hMenu;
}
When the user selects an item in the menu, your IContextMenu::InvokeCommand
will be called. If the command identifier is your Explore or Open command,
then you should use ShellExecuteEx to Open or Explore the folder. To use
ShellexecuteEx to Open or Explore the folder, you need to do the following:
Sample CodeFollowing is an example of how this is performed:
STDMETHODIMP CContextMenu::InvokeCommand(LPCMINVOKECOMMANDINFO lpcmi)
{
if(HIWORD(lpcmi->lpVerb))
{
//the command is being sent via a verb
return NOERROR;
}
if(LOWORD(lpcmi->lpVerb) > IDM_LAST)
return E_INVALIDARG;
switch(LOWORD(lpcmi->lpVerb))
{
case IDM_EXPLORE:
case IDM_OPEN:
{
LPITEMIDLIST pidlFQ;
SHELLEXECUTEINFO sei;
/*
Only one PIDL can be passed to ShellExecuteEx, so default to the
first one in the list.
*/
pidlFQ = CreateFullyQualifiedPidl(m_aPidls[0]);
ZeroMemory(&sei, sizeof(sei));
sei.cbSize = sizeof(sei);
sei.fMask = SEE_MASK_IDLIST | SEE_MASK_CLASSNAME;
sei.lpIDList = pidlFQ;
sei.lpClass = TEXT("folder");
sei.hwnd = lpcmi->hwnd;
sei.nShow = SW_SHOWNORMAL;
if(LOWORD(lpcmi->lpVerb) == IDM_EXPLORE)
sei.lpVerb = TEXT("explore");
else
sei.lpVerb = TEXT("open");
ShellExecuteEx(&sei);
DeletePidl(pidlFQ);
}
break;
}
return NOERROR;
}
These steps allow your namespace extension to properly implement the
Explore and Open commands from a context menu.
REFERENCESMicrosoft Systems Journal, July 1996, "Extending the Windows Explorer with Name Space Extensions," page 41, David Campbell For additional information, please see the following article in the Microsoft Knowledge Base:
ARTICLE-ID: Q178665 TITLE : SAMPLE: RegView.exe: Shell Namespace Extension Example \* Keywords : UsrShell kbcode Version : WINDOWS:95; WINNT:4.0 Platform : WINDOWS winnt Issue type : kbhowto |
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