feat: add basic canvas widget support

examples/canvas.lua

@@ -0,0 +1,38 @@
+local root = lvgl.Object(nil, {
+    w = 120,
+    h = 120,
+    border_width = 1,
+    border_color = "#000",
+    radius = 10,
+    align = lvgl.ALIGN.CENTER,
+})
+
+local canvas = lvgl.Canvas(root, {
+    border_width = 1,
+    border_color = "#F00",
+    align = lvgl.ALIGN.CENTER,
+})
+
+canvas:set {
+    buffer = {
+        w = 100,
+        h = 100,
+        cf = 5,
+    },
+}
+
+canvas:set {
+    img_recolor = 0xff0000ff,
+}
+
+canvas:fill_bg("#000", lvgl.OPA(100))
+
+canvas:blur_ver(
+    {
+        x1 = 10,
+        y1 = 10,
+        x2 = 90,
+        y2 = 90,
+    },
+    80
+)

examples/examples.lua

@@ -38,6 +38,7 @@ end
 
 createBtn(container, "keyboard")
 createBtn(container, "animation")
+createBtn(container, "canvas")
 createBtn(container, "pointer")
 createBtn(container, "analogTime")
 createBtn(container, "flappyBird/flappyBird")

src/private.h

@@ -9,8 +9,7 @@
 #include <stdlib.h>
 
 /* clang-format off */
-#define debug(format, ...)
-// fprintf(stderr, "[luavgl] %s: " format, __FUNCTION__, ##__VA_ARGS__)
+#define debug(format, ...) fprintf(stderr, "[luavgl] %s: " format, __FUNCTION__, ##__VA_ARGS__)
 // syslog(LOG_DEBUG, "[luavgl] %s: " format, __FUNCTION__, ##__VA_ARGS__)
 /* clang-format on */
 

src/style.c

@@ -574,8 +574,8 @@ static int luavgl_style_gc(lua_State *L)
 {
   luavgl_style_t *s = luavgl_check_style(L, 1);
   lv_style_reset(&s->style);
-  free(s);
   debug("gc style:%p\n", s);
+  free(s);
   return 0;
 }
 

src/widgets/canvas.c

@@ -0,0 +1,242 @@
+#include "luavgl.h"
+#include "private.h"
+
+static int luavgl_canvas_create(lua_State *L)
+{
+  return luavgl_obj_create_helper(L, lv_canvas_create);
+}
+
+static void _lv_canvas_set_buffer(void *obj, lua_State *L)
+{
+  luaL_argcheck(L, lua_istable(L, -1), -1, "expect a table.");
+
+  lua_getfield(L, -1, "w");
+  int w = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+
+  lua_getfield(L, -1, "h");
+  int h = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+
+  lua_getfield(L, -1, "cf");
+  lv_img_cf_t cf = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+
+  lv_img_dsc_t *dsc = (lv_img_dsc_t *)lv_img_get_src(obj);
+  if (dsc->data != NULL) {
+    luaL_error(L, "canvas buffer already set.");
+  }
+
+  void *buf = lv_mem_alloc(lv_img_buf_get_img_size(w, h, cf));
+  if (buf == NULL) {
+    luaL_error(L, "No memory.");
+  }
+
+  lv_canvas_set_buffer(obj, buf, w, h, cf);
+}
+
+static void _lv_canvas_set_px(void *obj, lua_State *L)
+{
+  luaL_argcheck(L, lua_istable(L, -1), -1, "expect a table.");
+
+  lua_getfield(L, -1, "x");
+  int x = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+
+  lua_getfield(L, -1, "y");
+  int y = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+
+  lua_getfield(L, -1, "color");
+  lv_color_t color = luavgl_tocolor(L, -1);
+  lua_pop(L, 1);
+
+  lv_canvas_set_px(obj, x, y, color);
+}
+
+static void _lv_canvas_set_px_opa(void *obj, lua_State *L)
+{
+  luaL_argcheck(L, lua_istable(L, -1), -1, "expect a table.");
+
+  lua_getfield(L, -1, "x");
+  int x = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+
+  lua_getfield(L, -1, "y");
+  int y = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+
+  lua_getfield(L, -1, "opa");
+  lv_opa_t opa = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+
+  lv_canvas_set_px_opa(obj, x, y, opa);
+}
+
+static void _lv_canvas_set_palette(void *obj, lua_State *L)
+{
+  luaL_argcheck(L, lua_istable(L, 2), 2, "expect a table.");
+
+  lua_getfield(L, 2, "id");
+  int id = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+
+  lua_getfield(L, 2, "color");
+  lv_color_t color = luavgl_tocolor(L, -1);
+  lua_pop(L, 1);
+
+  lv_canvas_set_palette(obj, id, color);
+}
+
+static const luavgl_value_setter_t canvas_property_table[] = {
+    {"buffer",  SETTER_TYPE_STACK, {.setter_stack = _lv_canvas_set_buffer} },
+    {"px",      SETTER_TYPE_STACK, {.setter_stack = _lv_canvas_set_px}     },
+    {"px_opa",  SETTER_TYPE_STACK, {.setter_stack = _lv_canvas_set_px_opa} },
+    {"palette", SETTER_TYPE_STACK, {.setter_stack = _lv_canvas_set_palette}},
+};
+
+LUALIB_API int luavgl_canvas_set_property_kv(lua_State *L, void *data)
+{
+  lv_obj_t *obj = data;
+  int ret = luavgl_set_property(L, obj, canvas_property_table);
+
+  if (ret == 0) {
+    return 0;
+  }
+
+  /* a base obj property? */
+  ret = luavgl_img_set_property_kv(L, obj);
+  if (ret != 0) {
+    debug("unkown property for canvas.\n");
+  }
+
+  return ret;
+}
+
+static int luavgl_canvas_set(lua_State *L)
+{
+  lv_obj_t *obj = luavgl_to_obj(L, 1);
+
+  if (!lua_istable(L, -1)) {
+    luaL_error(L, "expect a table on 2nd para.");
+    return 0;
+  }
+
+  luavgl_iterate(L, -1, luavgl_canvas_set_property_kv, obj);
+
+  return 0;
+}
+
+static int luavgl_canvas_get_px(lua_State *L)
+{
+  lv_obj_t *obj = luavgl_to_obj(L, 1);
+  int x = luaL_checkinteger(L, 2);
+  int y = luaL_checkinteger(L, 3);
+
+  lv_color_t c = lv_canvas_get_px(obj, x, y);
+  lua_newtable(L);
+  lua_pushinteger(L, c.ch.red);
+  lua_setfield(L, -2, "r");
+  lua_pushinteger(L, c.ch.green);
+  lua_setfield(L, -2, "g");
+  lua_pushinteger(L, c.ch.blue);
+  lua_setfield(L, -2, "b");
+
+  return 1;
+}
+
+static int luavgl_canvas_get_img(lua_State *L)
+{
+  lv_obj_t *obj = luavgl_to_obj(L, 1);
+  lv_img_dsc_t *img = lv_canvas_get_img(obj);
+  if (img == NULL) {
+    lua_pushnil(L);
+    return 1;
+  }
+
+  lua_pushlightuserdata(L, img);
+  return 1;
+}
+
+static int luavgl_canvas_blur_hor(lua_State *L)
+{
+  lv_obj_t *obj = luavgl_to_obj(L, 1);
+  lv_area_t area;
+
+  if (!lua_istable(L, 2)) {
+    luaL_error(L, "expect a table on 2nd para.");
+    return 0;
+  }
+
+  lua_getfield(L, 2, "x1");
+  area.x1 = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+  lua_getfield(L, 2, "y1");
+  area.y1 = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+  lua_getfield(L, 2, "x2");
+  area.x2 = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+  lua_getfield(L, 2, "y2");
+  area.y2 = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+
+  uint16_t r = luaL_checkinteger(L, 3);
+  lv_canvas_blur_hor(obj, &area, r);
+  return 0;
+}
+
+static int luavgl_canvas_blur_ver(lua_State *L)
+{
+  lv_obj_t *obj = luavgl_to_obj(L, 1);
+  lv_area_t area;
+
+  if (!lua_istable(L, 2)) {
+    luaL_error(L, "expect a table on 2nd para.");
+    return 0;
+  }
+
+  lua_getfield(L, 2, "x1");
+  area.x1 = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+  lua_getfield(L, 2, "y1");
+  area.y1 = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+  lua_getfield(L, 2, "x2");
+  area.x2 = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+  lua_getfield(L, 2, "y2");
+  area.y2 = lua_tointeger(L, -1);
+  lua_pop(L, 1);
+
+  uint16_t r = luaL_checkinteger(L, 3);
+  lv_canvas_blur_ver(obj, &area, r);
+  return 0;
+}
+
+static int luavgl_canvas_fill_bg(lua_State *L)
+{
+  lv_obj_t *obj = luavgl_to_obj(L, 1);
+  lv_color_t color = luavgl_tocolor(L, 2);
+  lv_opa_t opa = luaL_checkinteger(L, 3);
+  lv_canvas_fill_bg(obj, color, opa);
+  return 0;
+}
+
+static const luaL_Reg luavgl_canvas_methods[] = {
+    {"set",      luavgl_canvas_set     },
+    {"get_px",   luavgl_canvas_get_px  },
+    {"get_img",  luavgl_canvas_get_img },
+    {"blur_hor", luavgl_canvas_blur_hor},
+    {"blur_ver", luavgl_canvas_blur_ver},
+    {"fill_bg",  luavgl_canvas_fill_bg },
+
+    {NULL,       NULL                  },
+};
+
+static void luavgl_canvas_init(lua_State *L)
+{
+  luavgl_obj_newmetatable(L, &lv_canvas_class, "lv_canvas",
+                          luavgl_canvas_methods);
+  lua_pop(L, 1);
+}

src/widgets/img.c

@@ -48,7 +48,7 @@ LUALIB_API int luavgl_img_set_property_kv(lua_State *L, void *data)
   /* a base obj property? */
   ret = luavgl_obj_set_property_kv(L, obj);
   if (ret != 0) {
-    debug("unkown property for image.\n");
+    debug("unkown property for image: %s\n", lua_tostring(L, -2));
   }
 
   return ret;

src/widgets/widgets.c

@@ -5,6 +5,10 @@
 #include "calendar.c"
 #endif
 
+#if LV_USE_CANVAS
+#include "canvas.c"
+#endif
+
 #if LV_USE_CHECKBOX
 #include "checkbox.c"
 #endif
@@ -50,6 +54,10 @@ static const luaL_Reg widget_create_methods[] = {
     {"Calendar", luavgl_calendar_create},
 #endif
 
+#if LV_USE_CANVAS
+    {"Canvas",   luavgl_canvas_create},
+#endif
+
 #if LV_USE_CHECKBOX
     {"Checkbox", luavgl_checkbox_create},
 #endif
@@ -130,4 +138,7 @@ static void luavgl_widgets_init(lua_State *L)
   luavgl_dropdown_init(L);
 #endif
 
+#if LV_USE_CALENDAR
+  luavgl_canvas_init(L);
+#endif
 }