Texas Instruments TI-89 - Interfacing with TI-BASIC

70
Chapter 8: Integrating a Flash Application
TI
-
89 / TI
-
92 Plus Developer Guide
Not for Distribution
Beta Version January 26, 2001
8.4. Interfacing with TI-BASIC
An app can directly call many of the TI
-
BASIC commands. These commands
begin with “cmd_” and are included in
Appendix A
. The C callable TI
-
BASIC
functions or operators usually begin with “push_”. Examples include clearing the
program I/O screen with the
cmd_clrio
routine and writing to the program I/O
screen using the
cmd_disp
routine. An example function is
push_getfold
which
is the TI
-
BASIC getFold function. TI
-
BASIC uses the expression stack (estack) to
pass and return parameters. See chapter
15. Expressions and the Expression
Stack
for a description of this stack and its contents. For a description of the data
types used by TI
-
BASIC see chapter
14. Data Types
.
An app can also embed entire TI
-
BASIC programs or data. In fact, an app can
consist of essentially nothing but TI
-
BASIC programs and data as shown in the
following example. This example loads a TI
-
BASIC program using its StoProg
function (which can store any TI
-
BASIC data item). The tokenized version of the
program is in the prog1Data array. This array came from the TI
-
GRAPH LINK™
file containing the program. The program is run by using RunProg. The example
program merely displays “Test” to the Program I/O screen. After the program
runs, it is deleted. The TIBASIC_run function handles all errors including the
´
key (to break the app). In this way, the user of the app does not even know a
TI
-
BASIC program is running.
/* BASIC -> APP Wrapper */
#include "product.h"
#include "tiams.h"
static void AP_app(pFrame self, PEvent e);
#define ProgEnd(Prog) (Prog+(sizeof(Prog) - 1))
FRAME(appObj, OO_SYSTEM_FRAME, 0, OO_APP_FLAGS, 3)
ATTR(OO_APP_FLAGS, APP_INTERACTIVE)
ATTR(OO_APP_NAME, "prog1" )
ATTR(OO_APP_PROCESS_EVENT, &AP_app)
ENDFRAME
pFrame pAppObj = (pFrame)&appObj;
runningBASIC = FALSE;
const BYTE prog1Data[]={0X00,0X1D,0XE9,0X12,0XE4,0X00,0XE8,0XE5,0X51,
0XE4,0X02,0XE8,0XE5,0X00,0X54,0X65,0X73,0X74,0X00,0X2D,0X7A,0XE4,
0X02,0XE8,0X19,0XE4,0XE5,0X00,0X00,0X00,0XDC};
/* Run a BASIC program */
HANDLE TIBASIC_run(HANDLE hProgram, SINT *errNo)
{
Access_AMS_Global_Variables;
EStackIndex savetop = top_estack;
USHORT errOffset;
HANDLE hTokenized = H_NULL;
HANDLE hResult = H_NULL;