Support pinning decoded images to RAM

lib/luavgl/src/imgdata.c

@@ -0,0 +1,38 @@
+#include "draw/lv_img_buf.h"
+#include "draw/lv_img_decoder.h"
+#include "lauxlib.h"
+#include "lua.h"
+#include "luavgl.h"
+#include "misc/lv_color.h"
+#include "misc/lv_mem.h"
+#include "misc/lv_types.h"
+#include "private.h"
+#include <stdint.h>
+#include <string.h>
+
+static int luavgl_imgdata_create(lua_State *L)
+{
+  if (!lua_isstring(L, 1)) {
+    return luaL_argerror(L, 1, "expect string");
+  }
+
+  lv_img_decoder_dsc_t descriptor;
+  lv_res_t res =
+      lv_img_decoder_open(&descriptor, lua_tostring(L, 1), lv_color_black(), 0);
+  if (res != LV_RES_OK) {
+    return luaL_error(L, "failed to decode image.");
+  }
+
+  lv_img_dsc_t *data = lv_mem_alloc(sizeof(lv_img_dsc_t));
+  data->header = descriptor.header;
+  data->data_size = data->header.w * data->header.h * sizeof(uint32_t); // ???
+
+  uint8_t *data_copy = lv_mem_alloc(data->data_size);
+  memcpy(data_copy, descriptor.img_data, data->data_size);
+  data->data = data_copy;
+
+  lv_img_decoder_close(&descriptor);
+
+  lua_pushlightuserdata(L, data);
+  return 1;
+}

lib/luavgl/src/luavgl.c

@@ -7,6 +7,7 @@
 #include "font.c"
 #include "fs.c"
 #include "group.c"
+#include "imgdata.c"
 #include "indev.c"
 #include "obj.c"
 #include "timer.c"
@@ -17,6 +18,7 @@ static const struct luaL_Reg luavgl_methods[] = {
     {"Font",  luavgl_font_create }, /* font.c */
     {"Style", luavgl_style_create}, /* style.c */
     {"Anim",  luavgl_anim_create }, /* anim.c */
+    {"ImgData",  luavgl_imgdata_create}, /* imgdata.c */
 
     {NULL,    NULL               },
 };

lua/playing.lua

@@ -7,16 +7,16 @@ local queue = require("queue")
 local screen = require("screen")
 
 local img = {
-  play = "//lua/img/play.png",
-  pause = "//lua/img/pause.png",
-  next = "//lua/img/next.png",
-  next_disabled = "//lua/img/next_disabled.png",
-  prev = "//lua/img/prev.png",
-  prev_disabled = "//lua/img/prev_disabled.png",
-  shuffle = "//lua/img/shuffle.png",
-  shuffle_disabled = "//lua/img/shuffle_disabled.png",
-  repeat_enabled = "//lua/img/repeat.png",
-  repeat_disabled = "//lua/img/repeat_disabled.png",
+  play = lvgl.ImgData("//lua/img/play.png"),
+  pause = lvgl.ImgData("//lua/img/pause.png"),
+  next = lvgl.ImgData("//lua/img/next.png"),
+  next_disabled = lvgl.ImgData("//lua/img/next_disabled.png"),
+  prev = lvgl.ImgData("//lua/img/prev.png"),
+  prev_disabled = lvgl.ImgData("//lua/img/prev_disabled.png"),
+  shuffle = lvgl.ImgData("//lua/img/shuffle.png"),
+  shuffle_disabled = lvgl.ImgData("//lua/img/shuffle_disabled.png"),
+  repeat_enabled = lvgl.ImgData("//lua/img/repeat.png"),
+  repeat_disabled = lvgl.ImgData("//lua/img/repeat_disabled.png"),
 }
 
 local is_now_playing_shown = false

lua/widgets.lua

@@ -6,6 +6,20 @@ local backstack = require("backstack")
 local theme = require("theme")
 local database = require("database")
 
+local img = {
+  db = lvgl.ImgData("//lua/img/db.png"),
+  chg = lvgl.ImgData("//lua/img/bat/chg.png"),
+  bat_100 = lvgl.ImgData("//lua/img/bat/100.png"),
+  bat_80 = lvgl.ImgData("//lua/img/bat/80.png"),
+  bat_60 = lvgl.ImgData("//lua/img/bat/60.png"),
+  bat_40 = lvgl.ImgData("//lua/img/bat/40.png"),
+  bat_20 = lvgl.ImgData("//lua/img/bat/20.png"),
+  bat_0 = lvgl.ImgData("//lua/img/bat/0.png"),
+  bat_0chg = lvgl.ImgData("//lua/img/bat/0chg.png"),
+  bt_conn = lvgl.ImgData("//lua/assets/bt_conn.png"),
+  bt = lvgl.ImgData("//lua/assets/bt.png")
+}
+
 local widgets = {}
 
 function widgets.MenuScreen(opts)
@@ -93,14 +107,10 @@ function widgets.StatusBar(parent, opts)
     status_bar.title:set { text = opts.title }
   end
 
-  status_bar.db_updating = status_bar.root:Image {
-    src = "//lua/img/db.png"
-  }
+  status_bar.db_updating = status_bar.root:Image { src = img.db }
   status_bar.bluetooth = status_bar.root:Image {}
   status_bar.battery = status_bar.root:Image {}
-  status_bar.chg = status_bar.battery:Image {
-    src = "//lua/img/bat/chg.png"
-  }
+  status_bar.chg = status_bar.battery:Image { src = img.chg }
   status_bar.chg:center()
 
   local is_charging = nil
@@ -110,20 +120,20 @@ function widgets.StatusBar(parent, opts)
     if is_charging == nil or percent == nil then return end
     local src
     if percent >= 95 then
-      src = "100.png"
+      src = img.bat_100
     elseif percent >= 75 then
-      src = "80.png"
+      src = img.bat_80
     elseif percent >= 55 then
-      src = "60.png"
+      src = img.bat_60
     elseif percent >= 35 then
-      src = "40.png"
+      src = img.bat_40
     elseif percent >= 15 then
-      src = "20.png"
+      src = img.bat_20
     else
       if is_charging then
-        src = "0chg.png"
+        src = img.bat_0chg
       else
-        src = "0.png"
+        src = img.bat_0
       end
     end
     if is_charging then
@@ -131,7 +141,7 @@ function widgets.StatusBar(parent, opts)
     else
       status_bar.chg:add_flag(lvgl.FLAG.HIDDEN)
     end
-    status_bar.battery:set_src("//lua/img/bat/" .. src)
+    status_bar.battery:set_src(src)
   end
 
   status_bar.bindings = {
@@ -159,9 +169,9 @@ function widgets.StatusBar(parent, opts)
     end),
     bluetooth.connected:bind(function(connected)
       if connected then
-        status_bar.bluetooth:set_src("//lua/assets/bt_conn.png")
+        status_bar.bluetooth:set_src(img.bt_conn)
       else
-        status_bar.bluetooth:set_src("//lua/assets/bt.png")
+        status_bar.bluetooth:set_src(img.bt)
       end
     end),
   }

luals-stubs/lvgl.lua

@@ -427,6 +427,13 @@ end
 function lvgl.Font(family, size, weight)
 end
 
+--- Decodes an image from the filesystem and pins it into RAM, returning a
+--- lightuserdata that can be passed to `img:set_src`.
+--- @param path? string path to the encoded image
+--- @return ImgData
+function lvgl.ImgData(path)
+end
+
 --- Create a new style that can be applied to objects via `obj:add_style`.
 --- @param p? StyleProp Style properties that will be applied by this style.
 --- @return Style
@@ -1248,6 +1255,12 @@ Font is a light userdata that can be uset to set style text_font.
 
 local font = {}
 
+
+--- Decoded image data that is pinned to memory.
+--- @class ImgData
+
+local ImgData = {}
+
 ---
 --- @class Style : lightuserdata
 ---