quickjs/examples/point.c
2020-09-06 18:53:08 +02:00

151 lines
4.7 KiB
C

/*
* QuickJS: Example of C module with a class
*
* Copyright (c) 2019 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "../quickjs.h"
#include <math.h>
#define countof(x) (sizeof(x) / sizeof((x)[0]))
/* Point Class */
typedef struct {
int x;
int y;
} JSPointData;
static JSClassID js_point_class_id;
static void js_point_finalizer(JSRuntime *rt, JSValue val)
{
JSPointData *s = JS_GetOpaque(val, js_point_class_id);
/* Note: 's' can be NULL in case JS_SetOpaque() was not called */
js_free_rt(rt, s);
}
static JSValue js_point_ctor(JSContext *ctx,
JSValueConst new_target,
int argc, JSValueConst *argv)
{
JSPointData *s;
JSValue obj = JS_UNDEFINED;
JSValue proto;
s = js_mallocz(ctx, sizeof(*s));
if (!s)
return JS_EXCEPTION;
if (JS_ToInt32(ctx, &s->x, argv[0]))
goto fail;
if (JS_ToInt32(ctx, &s->y, argv[1]))
goto fail;
/* using new_target to get the prototype is necessary when the
class is extended. */
proto = JS_GetPropertyStr(ctx, new_target, "prototype");
if (JS_IsException(proto))
goto fail;
obj = JS_NewObjectProtoClass(ctx, proto, js_point_class_id);
JS_FreeValue(ctx, proto);
if (JS_IsException(obj))
goto fail;
JS_SetOpaque(obj, s);
return obj;
fail:
js_free(ctx, s);
JS_FreeValue(ctx, obj);
return JS_EXCEPTION;
}
static JSValue js_point_get_xy(JSContext *ctx, JSValueConst this_val, int magic)
{
JSPointData *s = JS_GetOpaque2(ctx, this_val, js_point_class_id);
if (!s)
return JS_EXCEPTION;
if (magic == 0)
return JS_NewInt32(ctx, s->x);
else
return JS_NewInt32(ctx, s->y);
}
static JSValue js_point_set_xy(JSContext *ctx, JSValueConst this_val, JSValue val, int magic)
{
JSPointData *s = JS_GetOpaque2(ctx, this_val, js_point_class_id);
int v;
if (!s)
return JS_EXCEPTION;
if (JS_ToInt32(ctx, &v, val))
return JS_EXCEPTION;
if (magic == 0)
s->x = v;
else
s->y = v;
return JS_UNDEFINED;
}
static JSValue js_point_norm(JSContext *ctx, JSValueConst this_val,
int argc, JSValueConst *argv)
{
JSPointData *s = JS_GetOpaque2(ctx, this_val, js_point_class_id);
if (!s)
return JS_EXCEPTION;
return JS_NewFloat64(ctx, sqrt((double)s->x * s->x + (double)s->y * s->y));
}
static JSClassDef js_point_class = {
"Point",
.finalizer = js_point_finalizer,
};
static const JSCFunctionListEntry js_point_proto_funcs[] = {
JS_CGETSET_MAGIC_DEF("x", js_point_get_xy, js_point_set_xy, 0),
JS_CGETSET_MAGIC_DEF("y", js_point_get_xy, js_point_set_xy, 1),
JS_CFUNC_DEF("norm", 0, js_point_norm),
};
static int js_point_init(JSContext *ctx, JSModuleDef *m)
{
JSValue point_proto, point_class;
/* create the Point class */
JS_NewClassID(&js_point_class_id);
JS_NewClass(JS_GetRuntime(ctx), js_point_class_id, &js_point_class);
point_proto = JS_NewObject(ctx);
JS_SetPropertyFunctionList(ctx, point_proto, js_point_proto_funcs, countof(js_point_proto_funcs));
JS_SetClassProto(ctx, js_point_class_id, point_proto);
point_class = JS_NewCFunction2(ctx, js_point_ctor, "Point", 2, JS_CFUNC_constructor, 0);
/* set proto.constructor and ctor.prototype */
JS_SetConstructor(ctx, point_class, point_proto);
JS_SetModuleExport(ctx, m, "Point", point_class);
return 0;
}
JSModuleDef *js_init_module(JSContext *ctx, const char *module_name)
{
JSModuleDef *m;
m = JS_NewCModule(ctx, module_name, js_point_init);
if (!m)
return NULL;
JS_AddModuleExport(ctx, m, "Point");
return m;
}