first step to simplify FS API

src/lv_draw/lv_img_decoder.c

@@ -277,13 +277,12 @@ lv_res_t lv_img_decoder_built_in_info(lv_img_decoder_t * decoder, const void * s
     }
 #if LV_USE_FILESYSTEM
     else if(src_type == LV_IMG_SRC_FILE) {
-        lv_fs_file_t file;
+        lv_fs_file_t * f;
-        lv_fs_res_t res;
         uint32_t rn;
-        res = lv_fs_open(&file, src, LV_FS_MODE_RD);
+        f = lv_fs_open(src, LV_FS_MODE_RD);
-        if(res == LV_FS_RES_OK) {
+        if(f) {
-            res = lv_fs_read(&file, header, sizeof(lv_img_header_t), &rn);
+            lv_fs_res_t res = lv_fs_read(f, header, sizeof(lv_img_header_t), &rn);
-            lv_fs_close(&file);
+            lv_fs_close(f);
             if(res != LV_FS_RES_OK || rn != sizeof(lv_img_header_t)) {
                 LV_LOG_WARN("Image get info get read file header");
                 return LV_RES_INV;
@@ -325,9 +324,8 @@ lv_res_t lv_img_decoder_built_in_open(lv_img_decoder_t * decoder, lv_img_decoder
         /*Support only "*.bin" files*/
         if(strcmp(lv_fs_get_ext(dsc->src), "bin")) return LV_RES_INV;
 
-        lv_fs_file_t f;
+        lv_fs_file_t * f = lv_fs_open(dsc->src, LV_FS_MODE_RD);
-        lv_fs_res_t res = lv_fs_open(&f, dsc->src, LV_FS_MODE_RD);
+        if(f == NULL) {
-        if(res != LV_FS_RES_OK) {
             LV_LOG_WARN("Built-in image decoder can't open the file");
             return LV_RES_INV;
         }
@@ -415,7 +413,7 @@ lv_res_t lv_img_decoder_built_in_open(lv_img_decoder_t * decoder, lv_img_decoder
         if(dsc->src_type == LV_IMG_SRC_FILE) {
             /*Read the palette from file*/
 #if LV_USE_FILESYSTEM
-            lv_fs_seek(user_data->f, 4); /*Skip the header*/
+            lv_fs_seek(user_data->f, 4, LV_FS_SEEK_SET); /*Skip the header*/
             lv_color32_t cur_color;
             uint32_t i;
             for(i = 0; i < palette_size; i++) {
@@ -552,7 +550,7 @@ static lv_res_t lv_img_decoder_built_in_line_true_color(lv_img_decoder_dsc_t * d
 
     uint32_t pos = ((y * dsc->header.w + x) * px_size) >> 3;
     pos += 4; /*Skip the header*/
-    res = lv_fs_seek(user_data->f, pos);
+    res = lv_fs_seek(user_data->f, pos, LV_FS_SEEK_SET);
     if(res != LV_FS_RES_OK) {
         LV_LOG_WARN("Built-in image decoder seek failed");
         return LV_RES_INV;
@@ -654,7 +652,7 @@ static lv_res_t lv_img_decoder_built_in_line_alpha(lv_img_decoder_dsc_t * dsc, l
     }
     else {
 #if LV_USE_FILESYSTEM
-        lv_fs_seek(user_data->f, ofs + 4); /*+4 to skip the header*/
+        lv_fs_seek(user_data->f, ofs + 4, LV_FS_SEEK_SET); /*+4 to skip the header*/
         lv_fs_read(user_data->f, fs_buf, w, NULL);
         data_tmp = fs_buf;
 #else
@@ -740,7 +738,7 @@ static lv_res_t lv_img_decoder_built_in_line_indexed(lv_img_decoder_dsc_t * dsc,
     }
     else {
 #if LV_USE_FILESYSTEM
-        lv_fs_seek(user_data->f, ofs + 4); /*+4 to skip the header*/
+        lv_fs_seek(user_data->f, ofs + 4, LV_FS_SEEK_SET); /*+4 to skip the header*/
         lv_fs_read(user_data->f, fs_buf, w, NULL);
         data_tmp = fs_buf;
 #else

src/lv_misc/lv_fs.c

@@ -83,51 +83,52 @@ bool lv_fs_is_ready(char letter)
  * @param mode read: FS_MODE_RD, write: FS_MODE_WR, both: FS_MODE_RD | FS_MODE_WR
  * @return LV_FS_RES_OK or any error from lv_fs_res_t enum
  */
-lv_fs_res_t lv_fs_open(lv_fs_file_t * file_p, const char * path, lv_fs_mode_t mode)
+void * lv_fs_open(const char * path, lv_fs_mode_t mode)
 {
-    file_p->drv    = NULL;
+    if(path == NULL) {
-    file_p->file_d = NULL;
+        LV_LOG_WARN("Can't open file: path is NULL");
-
+        return NULL;
-    if(path == NULL) return LV_FS_RES_INV_PARAM;
+    }
 
     char letter = path[0];
+    lv_fs_drv_t * drv = lv_fs_get_drv(letter);
 
-    file_p->drv = lv_fs_get_drv(letter);
 
-    if(file_p->drv == NULL) {
+    if(drv == NULL) {
+        LV_LOG_WARN("Can't open file (%s): unknown driver letter", path);
+        return NULL;
+    }
+
+    if(drv->ready_cb) {
+        if(drv->ready_cb(drv) == false) {
+            LV_LOG_WARN("Can't open file (%s): driver not ready", path);
+            return NULL;
+        }
+    }
+
+    if(drv->open_cb == NULL) {
+        LV_LOG_WARN("Can't open file (%s): open function not exists", path);
+        return NULL;
+    }
+
+    lv_fs_file_t * file_p = lv_mem_alloc(sizeof(lv_fs_file_t));
+    if(file_p == NULL) {
+        LV_LOG_WARN("Can't open file (%s): out of memory", path);
+        return NULL;
+    }
+
+    file_p->drv = drv;
     file_p->file_d = NULL;
-        return LV_FS_RES_NOT_EX;
-    }
-
-    if(file_p->drv->ready_cb != NULL) {
-        if(file_p->drv->ready_cb(file_p->drv) == false) {
-            file_p->drv    = NULL;
-            file_p->file_d = NULL;
-            return LV_FS_RES_HW_ERR;
-        }
-    }
-
-    file_p->file_d = lv_mem_alloc(file_p->drv->file_size);
-    LV_ASSERT_MEM(file_p->file_d);
-    if(file_p->file_d == NULL) {
-        file_p->drv = NULL;
-        return LV_FS_RES_OUT_OF_MEM; /* Out of memory */
-    }
-
-    if(file_p->drv->open_cb == NULL) {
-        return LV_FS_RES_NOT_IMP;
-    }
 
     const char * real_path = lv_fs_get_real_path(path);
-    lv_fs_res_t res        = file_p->drv->open_cb(file_p->drv, file_p->file_d, real_path, mode);
+    file_p->file_d = drv->open_cb(drv, real_path, mode);
 
-    if(res != LV_FS_RES_OK) {
+    if(file_p->file_d == NULL || file_p->file_d == (void*)(-1)) {
-        lv_mem_free(file_p->file_d);
+        lv_mem_free(file_p);
-        file_p->file_d = NULL;
+        return NULL;
-        file_p->drv    = NULL;
     }
 
-    return res;
+    return file_p;
 }
 
 /**
@@ -147,10 +148,7 @@ lv_fs_res_t lv_fs_close(lv_fs_file_t * file_p)
 
     lv_fs_res_t res = file_p->drv->close_cb(file_p->drv, file_p->file_d);
 
-    lv_mem_free(file_p->file_d); /*Clean up*/
+    lv_mem_free(file_p); /*Clean up*/
-    file_p->file_d = NULL;
-    file_p->drv    = NULL;
-    file_p->file_d = NULL;
 
     return res;
 }
@@ -234,7 +232,7 @@ lv_fs_res_t lv_fs_write(lv_fs_file_t * file_p, const void * buf, uint32_t btw, u
  * @param pos the new position expressed in bytes index (0: start of file)
  * @return LV_FS_RES_OK or any error from lv_fs_res_t enum
  */
-lv_fs_res_t lv_fs_seek(lv_fs_file_t * file_p, uint32_t pos)
+lv_fs_res_t lv_fs_seek(lv_fs_file_t * file_p, uint32_t pos, lv_fs_whence_t whence)
 {
     if(file_p->drv == NULL) {
         return LV_FS_RES_INV_PARAM;
@@ -244,7 +242,7 @@ lv_fs_res_t lv_fs_seek(lv_fs_file_t * file_p, uint32_t pos)
         return LV_FS_RES_NOT_IMP;
     }
 
-    lv_fs_res_t res = file_p->drv->seek_cb(file_p->drv, file_p->file_d, pos);
+    lv_fs_res_t res = file_p->drv->seek_cb(file_p->drv, file_p->file_d, pos, whence);
 
     return res;
 }

src/lv_misc/lv_fs.h

@@ -52,7 +52,7 @@ enum {
 typedef uint8_t lv_fs_res_t;
 
 /**
- * Filesystem mode.
+ * File open mode.
  */
 enum {
     LV_FS_MODE_WR = 0x01,
@@ -60,18 +60,28 @@ enum {
 };
 typedef uint8_t lv_fs_mode_t;
 
+
+/**
+ * Seek modes.
+ */
+enum {
+    LV_FS_SEEK_SET = 0x01,
+    LV_FS_SEEK_CUR = 0x02,
+    LV_FS_SEEK_END = 0x03,
+};
+typedef uint8_t lv_fs_whence_t;
+
 typedef struct _lv_fs_drv_t {
     char letter;
-    uint16_t file_size;
     uint16_t rddir_size;
     bool (*ready_cb)(struct _lv_fs_drv_t * drv);
 
-    lv_fs_res_t (*open_cb)(struct _lv_fs_drv_t * drv, void * file_p, const char * path, lv_fs_mode_t mode);
+    void * (*open_cb)(struct _lv_fs_drv_t * drv, const char * path, lv_fs_mode_t mode);
     lv_fs_res_t (*close_cb)(struct _lv_fs_drv_t * drv, void * file_p);
     lv_fs_res_t (*remove_cb)(struct _lv_fs_drv_t * drv, const char * fn);
     lv_fs_res_t (*read_cb)(struct _lv_fs_drv_t * drv, void * file_p, void * buf, uint32_t btr, uint32_t * br);
     lv_fs_res_t (*write_cb)(struct _lv_fs_drv_t * drv, void * file_p, const void * buf, uint32_t btw, uint32_t * bw);
-    lv_fs_res_t (*seek_cb)(struct _lv_fs_drv_t * drv, void * file_p, uint32_t pos);
+    lv_fs_res_t (*seek_cb)(struct _lv_fs_drv_t * drv, void * file_p, uint32_t pos, lv_fs_whence_t whence);
     lv_fs_res_t (*tell_cb)(struct _lv_fs_drv_t * drv, void * file_p, uint32_t * pos_p);
     lv_fs_res_t (*trunc_cb)(struct _lv_fs_drv_t * drv, void * file_p);
     lv_fs_res_t (*size_cb)(struct _lv_fs_drv_t * drv, void * file_p, uint32_t * size_p);
@@ -143,7 +153,7 @@ bool lv_fs_is_ready(char letter);
  * @param mode read: FS_MODE_RD, write: FS_MODE_WR, both: FS_MODE_RD | FS_MODE_WR
  * @return LV_FS_RES_OK or any error from lv_fs_res_t enum
  */
-lv_fs_res_t lv_fs_open(lv_fs_file_t * file_p, const char * path, lv_fs_mode_t mode);
+void * lv_fs_open(const char * path, lv_fs_mode_t mode);
 
 /**
  * Close an already opened file
@@ -185,7 +195,7 @@ lv_fs_res_t lv_fs_write(lv_fs_file_t * file_p, const void * buf, uint32_t btw, u
  * @param pos the new position expressed in bytes index (0: start of file)
  * @return LV_FS_RES_OK or any error from lv_fs_res_t enum
  */
-lv_fs_res_t lv_fs_seek(lv_fs_file_t * file_p, uint32_t pos);
+lv_fs_res_t lv_fs_seek(lv_fs_file_t * file_p, uint32_t pos, lv_fs_whence_t whence);
 
 /**
  * Give the position of the read write pointer