/// <summary>
/// Carry out the command associated with a shortcut menu item.
/// </summary>
/// <param name="pici">A pointer to a CMINVOKECOMMANDINFO or CMINVOKECOMMANDINFOEX structure containing information about the command.</param>
public void InvokeCommand(IntPtr pici)
{
var isUnicode = false;
// Determine which structure is being passed in, CMINVOKECOMMANDINFO or
// CMINVOKECOMMANDINFOEX based on the cbSize member of lpcmi. Although
// the lpcmi parameter is declared in Shlobj.h as a CMINVOKECOMMANDINFO
// structure, in practice it often points to a CMINVOKECOMMANDINFOEX
// structure. This struct is an extended version of CMINVOKECOMMANDINFO
// and has additional members that allow Unicode strings to be passed.
var ici = (CMINVOKECOMMANDINFO)Marshal.PtrToStructure(pici, typeof(CMINVOKECOMMANDINFO));
var iciex = new CMINVOKECOMMANDINFOEX();
if (ici.cbSize == Marshal.SizeOf(typeof(CMINVOKECOMMANDINFOEX)))
{
if ((ici.fMask & CMIC.CMIC_MASK_UNICODE) != 0)
{
isUnicode = true;
iciex = (CMINVOKECOMMANDINFOEX)Marshal.PtrToStructure(pici, typeof(CMINVOKECOMMANDINFOEX));
}
}
// Determines whether the command is identified by its offset or verb.
// There are two ways to identify commands:
//
// 1) The command's verb string
// 2) The command's identifier offset
//
// If the high-order word of lpcmi->lpVerb (for the ANSI case) or
// lpcmi->lpVerbW (for the Unicode case) is nonzero, lpVerb or lpVerbW
// holds a verb string. If the high-order word is zero, the command
// offset is in the low-order word of lpcmi->lpVerb.
var activeCommand = default(ActiveCommand);
if (!isUnicode && NativeHelpers.GetHighWord(ici.verb.ToInt32()) != 0)
{
// For the ANSI case, if the high-order word is not zero, the command's
// verb string is in lpcmi->lpVerb.
// Is the verb supported by this context menu extension?
var verb = Marshal.PtrToStringAnsi(ici.verb);
activeCommand = GetActiveCommand(verb);
}
else if (isUnicode && NativeHelpers.GetHighWord(iciex.verbW.ToInt32()) != 0)
{
// For the Unicode case, if the high-order word is not zero, the
// command's verb string is in lpcmi->lpVerbW.
// Is the verb supported by this context menu extension?
var verb = Marshal.PtrToStringAnsi(iciex.verbW);
activeCommand = GetActiveCommand(verb);
}
else
{
// If the command cannot be identified through the verb string, then
// check the identifier offset.
// Is the command identifier offset supported by this context menu
// extension?
var offset = NativeHelpers.GetLowWord(ici.verb.ToInt32());
activeCommand = GetActiveCommand(offset);
}
if (activeCommand != null)
{
var context = new CommandContext(this.selectedShellItems, this.isExtendedContextMenu);
try
{
activeCommand.Command.Execute(context);
}
catch (Exception exc)
{
Logger.LogError($"Error invoking command \"{activeCommand.Command.Name}\": {exc.ToString()}");
}
}
else
{
// If the verb is not recognized by the context menu handler, it
// must return E_FAIL to allow it to be passed on to the other
// context menu handlers that might implement that verb.
Marshal.ThrowExceptionForHR(WinError.E_FAIL);
}
}
/// <summary>
/// Add commands to a shortcut menu.
/// </summary>
/// <param name="hMenu">A handle to the shortcut menu.</param>
/// <param name="iMenu">The zero-based position at which to insert the first new menu item.</param>
/// <param name="idCmdFirst">The minimum value that the handler can specify for a menu item ID.</param>
/// <param name="idCmdLast">The maximum value that the handler can specify for a menu item ID.</param>
/// <param name="uFlags">Optional flags that specify how the shortcut menu can be changed.</param>
/// <returns>
/// If successful, returns an HRESULT value that has its severity value set
/// to SEVERITY_SUCCESS and its code value set to the offset of the largest
/// command identifier that was assigned, plus one.
/// </returns>
public int QueryContextMenu(IntPtr hMenu, uint iMenu, uint idCmdFirst, uint idCmdLast, uint uFlags)
{
// If uFlags include CMF_DEFAULTONLY then we should not do anything.
if (((uint)CMF.CMF_DEFAULTONLY & uFlags) != 0)
{
return(NativeHelpers.MakeHResult(WinError.SEVERITY_SUCCESS, 0, 0));
}
// Check if the user wants to see the extended context menu (i.e. pressing Shift while opening the context menu).
this.isExtendedContextMenu = ((uint)CMF.CMF_EXTENDEDVERBS & uFlags) != 0;
this.activeCommands.Clear();
var maxItems = (idCmdLast - idCmdFirst) + 1 - 2 /* Subtract 2 for the separators */;
if (maxItems > 0)
{
var menuIndex = iMenu;
// Add a separator.
var beginSeparator = new MENUITEMINFO();
beginSeparator.cbSize = (uint)Marshal.SizeOf(beginSeparator);
beginSeparator.fMask = MIIM.MIIM_TYPE;
beginSeparator.fType = MFT.MFT_SEPARATOR;
if (!NativeMethods.InsertMenuItem(hMenu, menuIndex++, true, ref beginSeparator))
{
return(Marshal.GetHRForLastWin32Error());
}
// Add the commands.
var context = new CommandContext(this.selectedShellItems, this.isExtendedContextMenu);
var commandOffset = default(uint);
foreach (var command in CommandFactory.GetAvailableCommands())
{
try
{
var commandState = command.GetState(context);
if (commandState != null && commandState.IsVisible)
{
var verb = Guid.NewGuid().ToString(); // Create a unique verb to be able to retrieve the right command later on based on that verb.
var activeCommand = new ActiveCommand(command, verb, commandOffset++);
this.activeCommands.Add(activeCommand);
var mii = new MENUITEMINFO();
mii.cbSize = (uint)Marshal.SizeOf(mii);
mii.fMask = MIIM.MIIM_BITMAP | MIIM.MIIM_STRING | MIIM.MIIM_FTYPE | MIIM.MIIM_ID | MIIM.MIIM_STATE;
mii.wID = idCmdFirst + activeCommand.Offset;
mii.fType = MFT.MFT_STRING;
mii.dwTypeData = commandState.MenuText;
if (!commandState.IsEnabled)
{
mii.fState = MFS.MFS_DISABLED;
}
else if (commandState.IsChecked)
{
mii.fState = MFS.MFS_CHECKED;
}
else
{
mii.fState = MFS.MFS_ENABLED;
}
if (!NativeMethods.InsertMenuItem(hMenu, menuIndex++, true, ref mii))
{
return(Marshal.GetHRForLastWin32Error());
}
if (this.activeCommands.Count >= maxItems)
{
break;
}
}
}
catch (Exception exc)
{
Logger.LogError($"Error querying command \"{command.Name}\": {exc.ToString()}");
}
}
// Add a separator.
var endSeparator = new MENUITEMINFO();
endSeparator.cbSize = (uint)Marshal.SizeOf(endSeparator);
endSeparator.fMask = MIIM.MIIM_TYPE;
endSeparator.fType = MFT.MFT_SEPARATOR;
if (!NativeMethods.InsertMenuItem(hMenu, menuIndex++, true, ref endSeparator))
{
return(Marshal.GetHRForLastWin32Error());
}
}
// Return an HRESULT value with the severity set to SEVERITY_SUCCESS.
// Set the code value to the offset of the largest command identifier
// that was assigned, plus one (1).
return(NativeHelpers.MakeHResult(WinError.SEVERITY_SUCCESS, 0, (uint)this.activeCommands.Count));
}