DEV-SAMPLES-C-PM-ControllingPMControls

Description

This sample demonstrates how to implement a custom PM control by superclassing an existing PM window class. The BAR control is built on top of WC_STATIC and renders a decorative horizontal or vertical separator bar — with optional text, raised/depressed appearance, mnemonic support, and auto-sizing.

The project was originally written by Alessandro Cantatore in 2002 for IBM VisualAge C++ on OS/2.

Article: http://www.edm2.com/index.php/Controlling_PM_Controls

What it demonstrates

• Superclassing: registering a new window class (WC_BAR) that intercepts messages before forwarding to the original WC_STATIC window procedure
• Custom control styles: BARS_VERTICAL, BARS_RAISED, BARS_THICK, BARS_AUTOSIZE, BARS_CENTER, BARS_RIGHT, BARS_MNEMONIC
• Presentation parameters: responding to font/color changes via WM_PRESPARAMCHANGED
• Window parameters protocol: implementing WM_SETWINDOWPARAMS / WM_QUERYWINDOWPARAMS for text and control-data queries
• Mnemonic support: WM_MATCHMNEMONIC handling and underline drawing
• 3D border rendering: Win3DBorderDraw() utility in ctrlutil.C
• Control text measurement: CtrlTextSet() / CtrlTextSize() / CtrlTextDraw() helpers

Files

src/
  ctrlutil.C      - PM control utility functions (text, color, border drawing)
  superclass.C    - Bar control registration, window proc, paint, and main()
  ctrlutil.h      - CTRLTXT, SIZES structures and ctrlutil function prototypes
  superclass.h    - WC_BAR class name, BARS_* style constants, BARM_* messages
  dllmain.h       - Common includes, memory allocation macros (BUILD_TEST_EXE)
  ApiExPM.h       - General PM macros (MRFALSE, MRTRUE, RectSet, WinStyle, ...)
  bar.rc          - Dialog resource with nine BAR control instances
  bar-gcc.def     - Module definition file for GCC/wlink build
  bar-ow.lnk      - Linker response file for OpenWatcom wlink

Build

GCC 9.2 / kLIBC (bitwiseworks)

compile-gcc.cmd

Output: bin-gcc\BAR.EXE

OpenWatcom 2.0

compile-ow.cmd

Output: bin-ow\BAR.EXE

Running

Execute BAR.EXE on OS/2 (ArcaOS 5.0.7 or later recommended). A dialog window appears showing nine bar controls demonstrating all style combinations.

History

• 2002-01-10 — Alessandro Cantatore — Original version 0.1, built with IBM VisualAge C++
• 2026-07-28 — Martin Iturbide — Moved sources to src/, added GCC and OpenWatcom build systems, fixed main() return type

License

BSD 3-Clause

Authors

• Alessandro Cantatore
• Martin Iturbide