2022-06-03 22:57:05 +02:00

280 lines
8.7 KiB
C

/********************************************************************
* Callback module
*
* To use: `import cb`
*
*******************************************************************/
#include "be_constobj.h"
#include "be_mapping.h"
#include "be_gc.h"
#include "be_exec.h"
#include "be_vm.h"
#include "be_mem.h"
/*********************************************************************************************\
* Callback structures
*
* We allow 4 parameters, or 3 if method (first arg is `self`)
* This could be extended if needed
\*********************************************************************************************/
typedef int32_t (*berry_callback_t)(int32_t v0, int32_t v1, int32_t v2, int32_t v3);
static int32_t call_berry_cb(int32_t num, int32_t v0, int32_t v1, int32_t v2, int32_t v3);
#define BERRY_CB(n) int32_t berry_cb_##n(int32_t v0, int32_t v1, int32_t v2, int32_t v3) { return call_berry_cb(n, v0, v1, v2, v3); }
// list the callbacks
BERRY_CB(0);
BERRY_CB(1);
BERRY_CB(2);
BERRY_CB(3);
BERRY_CB(4);
BERRY_CB(5);
BERRY_CB(6);
BERRY_CB(7);
BERRY_CB(8);
BERRY_CB(9);
BERRY_CB(10);
BERRY_CB(11);
BERRY_CB(12);
BERRY_CB(13);
BERRY_CB(14);
BERRY_CB(15);
BERRY_CB(16);
BERRY_CB(17);
BERRY_CB(18);
BERRY_CB(19);
// array of callbacks
static const berry_callback_t berry_callback_array[BE_MAX_CB] = {
berry_cb_0,
berry_cb_1,
berry_cb_2,
berry_cb_3,
berry_cb_4,
berry_cb_5,
berry_cb_6,
berry_cb_7,
berry_cb_8,
berry_cb_9,
berry_cb_10,
berry_cb_11,
berry_cb_12,
berry_cb_13,
berry_cb_14,
berry_cb_15,
berry_cb_16,
berry_cb_17,
berry_cb_18,
berry_cb_19,
};
typedef struct be_callback_hook {
bvm *vm;
bvalue f;
} be_callback_hook;
typedef struct be_callback_handler_list_t {
bvm *vm;
bvalue f;
struct be_callback_handler_list_t *next;
} be_callback_handler_list_t;
static be_callback_hook be_cb_hooks[BE_MAX_CB] = {0};
static int32_t be_cb_gen_cb(bvm *vm);
static be_callback_handler_list_t be_callback_default_gen_cb = {
NULL,
be_const_func(&be_cb_gen_cb),
NULL
};
static be_callback_handler_list_t *be_callback_handler_list_head = &be_callback_default_gen_cb; /* linked list of handlers */
/*********************************************************************************************\
* `add_handler`: Add an external handler to `make_cb()`
*
* This is typically used by LVGL mapping to handle widget callbacks, the handler
* needs to record additional infomation to disambiguate the call
*
* arg1: function (or closure)
\*********************************************************************************************/
static int32_t be_cb_add_handler(bvm *vm) {
int32_t top = be_top(vm);
if (top >= 1 && be_isfunction(vm, 1)) {
bvalue *v = be_indexof(vm, 1);
be_callback_handler_list_t *elt = be_os_malloc(sizeof(be_callback_handler_list_t));
if (!elt) { be_throw(vm, BE_MALLOC_FAIL); }
if (be_isgcobj(v)) {
be_gc_fix_set(vm, v->v.gc, btrue); // mark the function as non-gc
}
elt->vm = vm;
elt->f = *v;
elt->next = be_callback_handler_list_head; /* insert as new head */
be_callback_handler_list_head = elt;
be_return_nil(vm);
}
be_raise(vm, "value_error", "arg must be a function");
}
/*********************************************************************************************\
* `list_handlers`: List all cb handlers registered for this VM
*
* Used for debugging only
*
* No args
\*********************************************************************************************/
static int32_t be_cb_list_handlers(bvm *vm) {
be_newobject(vm, "list");
for (be_callback_handler_list_t *elt = be_callback_handler_list_head; elt != NULL; elt = elt->next) {
if (elt->vm == vm) { /* on purpose don't show the default handler, just pretend it's not there since it's default */
bvalue *top = be_incrtop(vm);
*top = elt->f;
be_data_push(vm, -2);
be_pop(vm, 1);
}
}
be_pop(vm, 1);
be_return(vm);
}
/*********************************************************************************************\
* `make_cb`: high-level call for creating a callback.
*
* This function is called by `be_mapping` when generating a callback with a type name.
* LVGL typically needs to register typed callbacks
*
* arg1: function (or closure)
* arg2: type name for callback (optional)
* argN: any other callback specific arguments (unlimited number, passed as-is)
\*********************************************************************************************/
static int32_t be_cb_make_cb(bvm *vm) {
int32_t argc = be_top(vm);
if (argc >= 1 && be_isfunction(vm, 1)) {
for (be_callback_handler_list_t *elt = be_callback_handler_list_head; elt != NULL; elt = elt->next) {
if (elt->vm == vm || elt->vm == NULL) { // if elt->vm is NULL then we accept any VM
// call the handler and check result
bvalue *top = be_incrtop(vm);
*top = elt->f;
// var_setobj(top, elt->f->type, elt->f); // push function - arg0
for (int i=1; i<=argc; i++) { // push all arguments including function
be_pushvalue(vm, i);
}
be_call(vm, argc); // call handler
be_pop(vm, argc); // remove arguments, top of stack has the result
// if top of stack is `comptr` then it is successful
if (be_iscomptr(vm, -1)) {
be_return(vm);
} else {
be_pop(vm, 1); // remove top, rinse and repeat
}
}
}
// if we are here, it means that no handler has handled the request
}
be_raise(vm, "value_error", "arg must be a function");
}
/*********************************************************************************************\
* `gen_cb`: Generate a new callback
*
* arg1: function (or closure)
\*********************************************************************************************/
static int32_t be_cb_gen_cb(bvm *vm) {
int32_t top = be_top(vm);
if (top >= 1 && be_isfunction(vm, 1)) {
// find first available slot
int32_t slot;
for (slot = 0; slot < BE_MAX_CB; slot++) {
if (be_cb_hooks[slot].f.type == BE_NIL) break;
}
bvalue *v = be_indexof(vm, 1);
if (slot < BE_MAX_CB) {
if (be_isgcobj(v)) {
be_gc_fix_set(vm, v->v.gc, btrue); // mark the function as non-gc
}
// record pointers
be_cb_hooks[slot].vm = vm;
be_cb_hooks[slot].f = *v;
be_pushcomptr(vm, (void*) berry_callback_array[slot]);
be_return(vm);
} else {
be_raise(vm, "internal_error", "no more callbacks available, increase BE_MAX_CB");
}
}
be_raise(vm, "value_error", "arg must be a function");
}
/*********************************************************************************************\
* `get_cb_list`: Return the list of callbacks for this vm
*
\*********************************************************************************************/
static int32_t be_cb_get_cb_list(bvm *vm) {
be_newobject(vm, "list");
for (uint32_t i=0; i < BE_MAX_CB; i++) {
if (be_cb_hooks[i].vm) {
if (vm == be_cb_hooks[i].vm) { // make sure it corresponds to this vm
bvalue *top = be_incrtop(vm);
*top = be_cb_hooks[i].f;
// be_pushcomptr(vm, be_cb_hooks[i].f);
be_data_push(vm, -2);
be_pop(vm, 1);
}
} else {
break;
}
}
be_pop(vm, 1);
be_return(vm);
}
/*********************************************************************************************\
* Callback structures
*
* We allow 4 parameters, or 3 if method (first arg is `self`)
* This could be extended if needed
\*********************************************************************************************/
static int32_t call_berry_cb(int32_t num, int32_t v0, int32_t v1, int32_t v2, int32_t v3) {
// call berry cb dispatcher
int32_t ret = 0;
// retrieve vm and function
if (num < 0 || num >= BE_MAX_CB || be_cb_hooks[num].vm == NULL) return 0; // invalid call, avoid a crash
bvm * vm = be_cb_hooks[num].vm;
bvalue *f = &be_cb_hooks[num].f;
// push function (don't check type)
bvalue *top = be_incrtop(vm);
*top = *f;
// push args
be_pushint(vm, v0);
be_pushint(vm, v1);
be_pushint(vm, v2);
be_pushint(vm, v3);
ret = be_pcall(vm, 4); // 4 arguments
if (ret != 0) {
if (vm->obshook != NULL) (*vm->obshook)(vm, BE_OBS_PCALL_ERROR);
be_pop(vm, be_top(vm)); // clear Berry stack
return 0;
}
ret = be_toint(vm, -5);
be_pop(vm, 5); // remove result
return ret;
}
/* @const_object_info_begin
module cb (scope: global) {
gen_cb, func(be_cb_gen_cb)
get_cb_list, func(be_cb_get_cb_list)
add_handler, func(be_cb_add_handler)
list_handlers, func(be_cb_list_handlers)
make_cb, func(be_cb_make_cb)
}
@const_object_info_end */
#include "../../berry/generate/be_fixed_cb.h"