Open Class Library (OCL) FAQ

By Stéphane Charette

General Information

History of the Open Class Library FAQ

The revision history is as follows:

Version	Comment	Author	Date
0.1	initial write-up in OS/2's IPF (.INF) format	SC	1997June20-21
0.1a	added table of files at Hobbes	SC	1997June24
0.1b	converted the FAQ to HTML format	SC	1997June28
0.1d	Added animation sample Added LNK2029 information Updated fixpak information Created "Errors in IBM's include files"	SC	1997Sept05
0.1e	Changed e-mail address Added POV_Launch to the Hobbes index Added custom-draw container information	SC	1997Nov02

How to obtain a copy of the FAQ

To obtain a HTML copy of the FAQ for local installation, download the file ftp://hobbes.nmsu.edu/pub/os2/dev/cplusplus/ocl_faq.zip.

Unzip this file in it's own directory (if using PKUNZIP, remember to use the /D option to create the subdirectories) and use your favorite web browser to access the files locally.

Where to obtain additional information

The on-line reference for OCL is located in your VisualAge folder, under the VisualAge C++ Information folder. The reference .INF file should be titled Open Class Library Reference (D:\IBMCPP\HELP\CLREF.INF) while a second .INF user's guide is called Open Class Library User's Guide (D:\IBMCPP\HELP\CPPCLSUG.INF).

The first book, Open Class Library Reference has all of the documented methods, objects, and necessary include files. The easiest way to find what you need is probably to click on Classes By Name, normally the second option from the top (may depend on the version of the documentation).

Note that one of the most useful .INF books which IBM ships with VisualAge can easily be overlooked; in the VisualAge C++ Information folder is a book called VisualAge C++ Frequently Asked Questions which deals with quite a few OCL topics.

Additional information on programming using OCL can be obtained from a variety of sources. There is an increase in books published (some of which by IBM) which deal with OCL, as well as numerous sources on the Internet.

For more information, consult:

• D:\IBMCPP\SAMPLES\IOC\*
• ftp://hobbes.nmsu.edu/pub/os2/dev/cplusplus/ocl*.zip ([hobbes_index.html index of samples])
• ftp://service.boulder.ibm.com/ps/products/visualagecpp/tools (IBM VB and OCL sample code)
• http://??? (Chinese version of the OCL-FAQ)
• http://www.davebsoft.com/Programming/tips (Dave Briccetti's OS/2 Warp Programming Tips and Samples)
• news://comp.os.os2.programmer.oop
• news://productnews.taligent.com/taligent.products.openclass (Taligent's OCL News Server)

Books which deal with OCL are:

OS/2 Class Library

Power GUI programming with C/Set++

Written by Leon, Law, Love Tsuji & Olson
Published by John Wiley & Sons
ISBN 0-471-13117-2
(Obsolete and replaced by the following book)

Power GUI Programming with VisualAge C++

Written by Law, Love, Olson & Tsuji
Published by John Wiley & Sons
ISBN 0-471-16482-8
(recommended by Mark Anderson, os2team@romeop03.fishkill.ibm.com)

Index of samples on Hobbes

tarting mid-June, 1997, I have begun to upload to ftp://hobbes.nmsu.edu/pub/os2/dev/cplusplus a series of Open Class Library samples that I have written. The following table is the index of these samples.

Filename	Description	Classes Used
OCL_ANI1.ZIP	animation sample	IApplication, IColor, IDrawingCanvas, IEvent, IFrameWindow, IGBitmap, IGList, IRectangle, ITimer
OCL_CON1.ZIP	details view container sample	IApplication, IContainerColumn, IContainerControl, IContainerObject, IFrameWindow, IString
OCL_THR1.ZIP	thread and timer sample (minimized icon fix explained)	IApplication, ICommandEvent, ICommandHandler, IFrameWindow, IListBox, IPushButton, IString, ISystemMenu, IThread, IThreadFn, ITimer
OCL_ANI2.ZIP	animation sample #2	IApplication, ICommandEvent, ICommandHandler, IColor, IControlEvent, IDrawingCanvas, IFrameWindow, IFrameEvent, IFrameHandler, IGBitmap, IGList, IGraphicContext, IMouseClickEvent, IMouseHandler, IPopUpMenu, ITimerMemberFn0
OCL_CON2.ZIP	custom drawing in a details-view container	IApplication, ICnrDrawHandler, IContainerColumn, IContainerControl, IContainerObject, IFrameWindow
PLNCH01G.ZIP	POV front-end	Some of almost all classes available, including threads, canvases, icons, bitmaps, standard controls, profiles and exceptions.

Note

See also #Where to Obtain Additional Information

OCL - Compiling

How to Compile

If you wish to correctly compile your OCL application, then the following should be used:

• if you are using the project templates and WorkFrame that come with Visual Age, then
  1. click on Tools
  2. make certain that View is set to Actions
  3. expand the Compile subtree
  4. right-mouse-click on C++ Compiler
  5. select File Options
  6. select the Object tab
  7. select the Multithread option for Library selection (this sets the /Gm+ flag)
  8. click on OK
  9. close the tools setup
  10. regenerate the makefile and recompile
• if you are compiling from the command-line, or using your own makefiles, then
  1. use the command icc.exe /Gm+ /C <other optional compiler flags> myfile.cpp

Note

See also #/Gm+, #How to Link, #Static Linking and #Dynamic Linking

Required compiler flag

There is one flag that absolutely must be specified when compiling source code which uses OCL calls. This flag is described as follows in the on-line help:

/Gm+
    Link with multithread runtime libraries. 

The default for ICC is to use /Gm- (no support for the multithreaded libraries) so the /Gm+ flag must be specified. Typical compiler behavior when this flag is not specified is:

D:\IBMCPP\INCLUDE\ibase.hpp(226:3) : error EDC3086: 
Error: Use of IBM Open Class Library requires the /Gm+ compiler option. 
D:\IBMCPP\INCLUDE\ibase.hpp(227:3) : error EDC3086: 
Check the makefile (or its profile) for a missing /Gm+ option.

Note: See also #How to Compile and #Error EDC3086

Errors in IBM's include files

If your source code has the extension .c and you are including some OCL #includes, then the compiler may generate many errors which seem to come from the IBMCPP include files. These errors are generated because the compiler assumes that .c files only contain C code, not C++, and the OCL include files require the compiler to be in the C++ mode.

To get around this problem, use the compiler flag /Tdp to tell the VAC++ to treat all files as C++ files.

Some of the errors you may be seeing include the following:

imsgtext.hpp(24:1) : error EDC0166: Definition of function class requires parentheses. 
imsgtext.hpp(24:7) : error EDC0275: Unexpected text IMessageText encountered. 
imsgtext.hpp(27:19) : error EDC0046: Syntax error. 
imsgtext.hpp(28:33) : error EDC0045: Undeclared identifier messageFileName. 
imsgtext.hpp(29:33) : error EDC0045: Undeclared identifier textInsert1.

Note: See also #How to Compile

Contributors

This document is (will be?!) the result of input from many sources. These include the following people who have been kind enough to submit hints, tips, examples, and other contributions:

• Stéphane Charette
• Charlie Choc, cchoc@mindspring.com
• Mark Anderson, os2team@romeop03.fishkill.ibm.com
• Dave Briccetti
• Bill Law, law@netscape.com
• Tsung-Hsun Yang, u7924811@cc.nctu.edu.tw