Texas Instruments TI89 Developer Guide - Page 358

316 Appendix A: System Routines - Apps 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 - ID of application into which a new frame is to be hooked. hookFrame - Pointer to hook frame. retFrame - Returned pointer to RAM link frame. Keep this value around and pass it to OO_UninstallAppHook 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_InstallAppHookByName, OO_UninstallAppHook, OO_UninstallAppHookByName (continued) TI-89 / TI-92 Plus Developer Guide Not for Distribution Beta Version January 26, 2001