Wrong usage/parameters at WaitEvent on AmigaOS - window opens correctly, crash before user interaction

[Adam Mierzwa]

Hi,

I'm developing a RapaGUI 2.2 application (Fotografista, a photo editor) compiled with Hollywood 11, targeting Windows, macOS ARM, and AmigaOS. I'm experiencing a crash on AmigaOS that I cannot reproduce on Windows or macOS.

Error message:
"Wrong usage/parameters for this command! Read the documentation!"
File: fotografista.hws (current line: 83 - In function: WaitEvent)

Observations:
- The main window opens correctly (title bar, scrollcanvas with border scroller, statusbar all visible)
- The crash occurs immediately after the window opens, before any user interaction
- The same error message appears on Windows when InstallEventHandler is missing — suggesting WaitEvent receives an event it cannot handle
- The application works correctly on Windows and macOS
- Reproduced on both AmiKit (emulated AmigaOS 3.x) and native AmigaOS 4.1 on X5000 hardware

Main loop (fotografista.hws):

Code: Select all

p_InitLanguage()       ; calls moai.CreateApp(), InstallEventHandler(), moai.Notify()
LoadBrush(10, "icons/icon128.png")
p_PrefsLoad()
p_SetMenusEnabled(False)
Repeat
  WaitEvent
Forever

p_InitLanguage() (i18n.hws):

Code: Select all

Function p_InitLanguage()
  If IsNil(g_prefs.lang$) Then g_prefs.lang$ = "polish"
  If g_prefs.lang$ <> "polish"
    p_WriteCatalogFile(g_prefs.lang$)
    OpenCatalog("Fotografista.catalog")
  EndIf
  g_current_lang$ = g_prefs.lang$
  moai.CreateApp(g_gui_xml$)
  moai.Set("sb", "fontsize", g_prefs.ui_font_size)
  InstallEventHandler({
    RapaGUI = p_EventFunc,
    OnRawKeyDown = Function(msg)
      If msg.Key = "LSHIFT" Or msg.Key = "RSHIFT" Then g_shift_down = True
    EndFunction,
    OnRawKeyUp = Function(msg)
      If msg.Key = "LSHIFT" Or msg.Key = "RSHIFT" Then g_shift_down = False
    EndFunction
  })
  moai.Notify("canvas", "MouseLeft", True)
  moai.Notify("canvas", "MouseMove", True)
  moai.Notify("canvas", "MouseRight", True)
EndFunction

Window XML (relevant fragment):

Code: Select all

xml
<window id="mainwin" title="Fotografista@i18n:187" sizegadget="true"
    width="900" height="650" remember="true"
    menubar="mainmenu"
    notify="closerequest; sizechange"
    usebottomborderscroller="true"
    userightborderscroller="true">
  <vgroup>
    <scrollcanvas id="canvas" autoscale="false"
      virtwidth="1" virtheight="1"
      weight="100"
      usewinborder="true"
      notify="paint"/>
    <statusbar id="sb" fontsize="14" height="32">
      <item id="sb_filename" i18n="188">Brak obrazu</item>
      <item id="sb_size"/>
      <item id="sb_format"/>
      <item id="sb_zoom"/>
      <item id="sb_undo"/>
      <item id="sb_sel"/>
    </statusbar>
  </vgroup>
</window>

Hypotheses already tested and excluded:
- InstallEventHandler position and parameters
- OnRawKeyDown / OnRawKeyUp availability on AmigaOS
- moai.Set() inside Paint callback (moved to RunCallback)
- help= attribute on menu items (removed, no change)
- Nested submenus (3 levels deep under Eksperymentalne)
- Incorrect XML (quotes in item text)
- fontsize/height attributes on statusbar
- Missing Catalogs directory at runtime
- @FILE / OpenCatalog logic
- p_SetMenusEnabled iterating menu IDs
- All menu IDs verified present in XML

Question:
What could cause "Wrong usage/parameters for this command" at WaitEvent on AmigaOS, when the window opens correctly and InstallEventHandler is called with a valid RapaGUI handler, but the crash occurs immediately on the first WaitEvent call?

Is there anything specific to AmigaOS/MUI that could trigger this — perhaps a Paint event fired before WaitEvent that causes a re-entrant call, or a specific GUI attribute that MUI handles differently?

Thank you.

[Adam Mierzwa]

SOLVED

After bisecting the git history, the root cause was identified: `InstallEventHandler` must be called before `moai.CreateApp()` on AmigaOS. On Windows and macOS the order doesn't matter, but on AmigaOS MUI fires events immediately during GUI creation — if the handler isn't registered yet, WaitEvent receives an unhandled event and crashes.

I had listed "InstallEventHandler position and parameters" as an excluded hypothesis - that was incorrect. The position relative to `moai.CreateApp()` was the key, not the position relative to `WaitEvent`.

Thanks to anyone who read the post.

[airsoftsoftwair]

After bisecting the git history, the root cause was identified: `InstallEventHandler` must be called before `moai.CreateApp()` on AmigaOS.

Since all the RapaGUI examples call InstallEventHandler() after moai.CreateApp(), what you experience is probably a bug. Can you post an MCVE that reproduces the issue? It looks like the code you posted is just a fragment but we need something that is self-contained that reproduces the issue in order to fix it. Thanks!

[Adam Mierzwa]

Thanks for your reply.

To be honest, I'm no longer certain that the issue was caused solely by the order of InstallEventHandler() and moai.CreateApp().

The problem appeared during a period when I was making larger changes to the application, including adding multilingual support and moving some initialization code between modules. The error message only pointed to WaitEvent(), which made debugging difficult because the actual cause could have been almost anywhere in the startup sequence.

Moving InstallEventHandler() before moai.CreateApp() made the problem disappear, but I cannot say with certainty that this was the real root cause rather than just a workaround.

Since then the code has evolved significantly and I no longer have a reproducible test case. Unfortunately I don't have the time to go back through old revisions and isolate the issue into a minimal example.

If I encounter the same problem again in a form that can be reproduced reliably, I'll be happy to report it.