/// <summary>
/// Enables an external user-interface handler. This external UI handler is called before the
/// normal internal user-interface handler. The external UI handler has the option to suppress
/// the internal UI by returning a non-zero value to indicate that it has handled the messages.
/// </summary>
/// <param name="uiHandler">A callback delegate that handles the UI messages</param>
/// <param name="messageFilter">Specifies which messages to handle using the external message handler.
/// If the external handler returns a non-zero result, then that message will not be sent to the UI,
/// instead the message will be logged if logging has been enabled.</param>
/// <returns>The previously set external handler, or null if there was no previously set handler</returns>
/// <remarks><p>
/// To restore the previous UI handler, a second call is made to SetExternalUI using the
/// ExternalUIHandler returned by the first call to SetExternalUI and specifying
/// <see cref="InstallLogModes.None"/> as the message filter.
/// </p><p>
/// The external user interface handler does not have full control over the external user
/// interface unless <see cref="SetInternalUI(InstallUIOptions)"/> is called with the uiLevel parameter set to
/// <see cref="InstallUIOptions.Silent"/>. If SetInternalUI is not called, the internal user
/// interface level defaults to <see cref="InstallUIOptions.Basic"/>. As a result, any message not
/// handled by the external user interface handler is handled by Windows Installer. The initial
/// "Preparing to install..." dialog always appears even if the external user interface
/// handler handles all messages.
/// </p><p>
/// SetExternalUI should only be called from a bootstrapping application. You cannot call
/// it from a custom action
/// </p><p>
/// Win32 MSI API:
/// <a href="http://msdn.microsoft.com/library/en-us/msi/setup/msisetexternalui.asp">MsiSetExternalUI</a>
/// </p></remarks>
internal static ExternalUIHandler SetExternalUI(ExternalUIHandler uiHandler, InstallLogModes messageFilter)
{
NativeExternalUIHandler nativeHandler = null;
if (uiHandler != null)
{
nativeHandler = new ExternalUIProxy(uiHandler).ProxyHandler;
Installer.externalUIHandlers.Add(nativeHandler);
}
NativeExternalUIHandler oldNativeHandler = NativeMethods.MsiSetExternalUI(nativeHandler, (uint)messageFilter, IntPtr.Zero);
if (oldNativeHandler != null && oldNativeHandler.Target is ExternalUIProxy)
{
Installer.externalUIHandlers.Remove(oldNativeHandler);
return(((ExternalUIProxy)oldNativeHandler.Target).Handler);
}
else
{
return(null);
}
}
/// <summary>
/// Enables an external user-interface handler. This external UI handler is called before the
/// normal internal user-interface handler. The external UI handler has the option to suppress
/// the internal UI by returning a non-zero value to indicate that it has handled the messages.
/// </summary>
/// <param name="uiHandler">A callback delegate that handles the UI messages</param>
/// <param name="messageFilter">Specifies which messages to handle using the external message handler.
/// If the external handler returns a non-zero result, then that message will not be sent to the UI,
/// instead the message will be logged if logging has been enabled.</param>
/// <returns>The previously set external handler, or null if there was no previously set handler</returns>
/// <remarks><p>
/// To restore the previous UI handler, a second call is made to SetExternalUI using the
/// ExternalUIHandler returned by the first call to SetExternalUI and specifying
/// <see cref="InstallLogModes.None"/> as the message filter.
/// </p><p>
/// The external user interface handler does not have full control over the external user
/// interface unless <see cref="SetInternalUI(InstallUIOptions)"/> is called with the uiLevel parameter set to
/// <see cref="InstallUIOptions.Silent"/>. If SetInternalUI is not called, the internal user
/// interface level defaults to <see cref="InstallUIOptions.Basic"/>. As a result, any message not
/// handled by the external user interface handler is handled by Windows Installer. The initial
/// "Preparing to install..." dialog always appears even if the external user interface
/// handler handles all messages.
/// </p><p>
/// SetExternalUI should only be called from a bootstrapping application. You cannot call
/// it from a custom action
/// </p><p>
/// Win32 MSI API:
/// <a href="http://msdn.microsoft.com/library/en-us/msi/setup/msisetexternalui.asp">MsiSetExternalUI</a>
/// </p></remarks>
internal static ExternalUIHandler SetExternalUI(ExternalUIHandler uiHandler, InstallLogModes messageFilter)
{
NativeExternalUIHandler nativeHandler = null;
if (uiHandler != null)
{
nativeHandler = new ExternalUIProxy(uiHandler).ProxyHandler;
Installer.externalUIHandlers.Add(nativeHandler);
}
NativeExternalUIHandler oldNativeHandler = NativeMethods.MsiSetExternalUI(nativeHandler, (uint) messageFilter, IntPtr.Zero);
if (oldNativeHandler != null && oldNativeHandler.Target is ExternalUIProxy)
{
Installer.externalUIHandlers.Remove(oldNativeHandler);
return ((ExternalUIProxy) oldNativeHandler.Target).Handler;
}
else
{
return null;
}
}