CSE775 - Distributed Objects

Lecture #12 - ATL and Building ATL-based Projects

Web Resources:

Office Hours:Instructor & TAs

Content:

1. Syllabus
   Describes topics to be covered, reading material for you to digest before coming to class, and due dates for the assigned projects.
2. Uploading Project Submissions
   
3. All Distributed Objects Projects:

   Project #1, Project #2, Final Projects

4. Two useful references for this material:
   • ATL Internals, Second Edition, Working with ATL 8, Tavares, Fertitta, Rector, Sells, Addison-Wesley, 2007
     A quite detailed look at how ATL works - highly recommended.
   • Essential IDL, Interface Design for COM, Martin Gudgin, Addison-Wesley, 2001
     Covers almost everything you might want to know about IDL - again, highly recommended.
5. Starting Active Template Library (ATL):
   
   Project simulating ATL Structure
   MSDN ATL Class Overview
   ATL Presentation
   Discusses the relationship between ATL modules and a component developed with ATL.

   ATL Interactive Demo We will walk through using ATL Wizard to build an in-process component and C# client.

   FirstATLsu10 Demo Project
   Demonstrates how to implement a simple in-proc ATL commponent.

   FirstATLsu10 step by step

6. ATL Code Examples:
   
   ATL_Inproc_Ex1
   Our second ATL demonstration duplicates the raw C++ Inproc_Ex1 functionality. Here you will see CComBSTR and CComQIPtr in action.
   Building ATL_Inproc_Ex1
   

   FileHandler Component using SafeArray
   Uses SafeArray to marshal array of file names. Compare C++ client to C# client.

   Component Calls Component
   This document discusses briefly building a workspace with a client that calls a component that, in turn, calls another component.
   ComponentCallsComponent Project
   This Project shows you how to return an interface pointer from a COM interface.

   This project provides all the code used to generate screen shots for the presentation in the previous item. The code provides brief, but useful, examples of the CComQIPtr and CComBSTR classes. I believe this is the best way to build a client for components built with ATL.

   Marshaling Interface Pointers between Client Threads
   You can't pass interface pointers between apartments, without marshaling. To do so breaks the COM threading model. This project shows you how to do that.

7. ATL Support for COM Clients:
   
   CComQIPtr
   A smart pointer the makes client code simpler and easier to maintain.
   CComBSTR
   BSTRs are rather ackward to manipulate, but wrapping a BSTR in a CComBSTR makes it almost as easy to use as a std::string object.
   CComSafeArray
   SafeArrays are the favored way of passing arrays through COM interfaces. If you want to pass an array from COM to a C# client you will have to use a SafeArray.
   CComVariant
   Variants are tagged unions that can hold most of the Windows types. They are similar to .Net Objects.
8. ATL Windows:
   
   Frame window based on CWindowImpl<T>
   Dialog window based on CAxDialogImpl<T>
   atlctrls.h
   Provides small wrappers for a lot of Windows controls, shows how to crack messages.
   analysis of classes in atlctrls.h
   Listing of classes in atlctrls.h.
9. ATL and WTL Tutorials:
   
   ATL and WTL Windows Tutorial series - Part#1, Part#2, Part#3, Part#4, Part#5
   WTL #1 from GameDev, WTL #2 from GameDev
   Another ATL Windows Tutorial
   
10. COM Interop:
    
    ATLDemo7 will be called by C# client with both early and late binding
    COM/.Net Interoperation
    calling COM component from .Net
    Calling .Net library from COM Client
    Calling .Net Component from C++ ScreenShots
    
11. Out of Process COM Components:
    
    OutProc Components
    OutProc Single-Threaded
    OutProc Multi-Threaded
    ATL_OutProcST
    Building ATL_OutProcST
    ATL_OutProcMT