Oo_Installapphook - Texas Instruments TI-89 Developer's Manual

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OO_InstallAppHook

Declaration: BOOL OO_InstallAppHook (AppID appid , pFrame hookFrame ,
pFrame * retFrame )
Category(ies): Apps
Description: This routine refines an application, overriding or adding attributes, by
hooking a new frame at the head of the application's object frame parent
hierarchy.
Many application attributes are hard-coded in Flash memory and cannot be
changed — the app's table of strings, for example. A language localizer
gains the effect of changing the app's string table by hooking a new frame
containing the equivalent strings of a different language ahead of the app's
object frame.
Multiple hooks can be installed in an app, the latest-installed having highest
precedence during attribute look-up. Attribute search begins with the
latest-installed hook frame and proceeds through each hook all the way
back to the app's object frame until the attribute is found.
Hooks can be uninstalled in any order. See OO_UninstallAppHook or
OO_UninstallAppHookByName to learn how to uninstall hooks.
Inputs: appid
hookFrame — Pointer to hook frame.
retFrame
Returns TRUE if hook was installed. Returns FALSE if memory for RAM
Outputs:
link frame could not be allocated.
Assumptions: None
Side Effects: May cause heap compression.
Availability: On AMS 2.00 and higher.
TI-89 / TI-92 Plus
Differences: None
See Also: OO_InstallAppHookByName, OO_UninstallAppHook,
OO_UninstallAppHookByName
TI-89 / TI-92 Plus Developer Guide
Appendix A: System Routines — Apps
— ID of application into which a new frame is to be hooked.
— Returned pointer to RAM link frame. Keep this value
around and pass it to OO_UninstallAppHook when you
want to unhook the frame.
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Not for Distribution Beta Version January 26, 2001