Texas Instruments TI89 Developer Guide - Page 362

320 Appendix A: System Routines - Apps OO_InstallSystemHook Declaration: BOOL OO_InstallSystemHook (pFrame hookFrame, pFrame * retFrame) Category(ies): Apps, Operating System Description: This routine refines the system object frame, overriding or adding attributes, by hooking a new frame at the head of the system object parent hierarchy. Many system attributes are hard-coded in Flash memory and cannot be changed - the built-in table of strings, for example. A language localizer gains the effect of changing the system string table by hooking a new frame containing the equivalent strings of a different language ahead of the system object frame. Multiple hooks can be installed over the system frame, the latest-installed having highest precedence during attribute look-up. Attribute search begins the with latest-installed hook frame and proceeds through each hook all the way back to the system object frame until the attribute is found. Hooks can be uninstalled in any order. See OO_UninstallSystemHook to learn how to uninstall system hooks. Inputs: hookFrame - Pointer to hook frame. retFrame - Returned pointer to RAM link frame. Keep this value around and pass it to OO_UninstallSystemHook when you want to unhook the frame. Outputs: Returns TRUE if hook was installed. Returns FALSE if memory for RAM 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_UninstallSystemHook (continued) TI-89 / TI-92 Plus Developer Guide Not for Distribution Beta Version January 26, 2001