fix(snapshot): set data_size on returned dsc (lvgl#4972)

OS-Q · Dec 11, 2023 · 9ba2992 · 9ba2992
1 parent 74d0a81
commit 9ba2992
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Showing 3 changed files with 20 additions and 19 deletions.
diff --git a/docs/others/snapshot.md b/docs/others/snapshot.md
@@ -37,7 +37,7 @@ void update_snapshot(lv_obj_t * obj, lv_obj_t * img_snapshot)
 ```
 
 ### Use Existing Buffer
-If the snapshot needs update now and then, or simply caller provides memory, use API `lv_res_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_img_cf_t cf, lv_img_dsc_t * dsc, void * buf, uint32_t buff_size);` for this case. It's caller's responsibility to alloc/free the memory.
+If the snapshot needs update now and then, or simply caller provides memory, use API `lv_res_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_img_cf_t cf, lv_img_dsc_t * dsc, void * buf, uint32_t buf_size);` for this case. It's caller's responsibility to alloc/free the memory.
 
 
 If snapshot is generated successfully, the image descriptor is updated and image data will be stored to provided `buf`.

diff --git a/src/extra/others/snapshot/lv_snapshot.c b/src/extra/others/snapshot/lv_snapshot.c
@@ -73,15 +73,15 @@ uint32_t lv_snapshot_buf_size_needed(lv_obj_t * obj, lv_img_cf_t cf)
 
 /** Take snapshot for object with its children, save image info to provided buffer.
  *
- * @param obj    The object to generate snapshot.
- * @param cf     color format for generated image.
- * @param dsc    image descriptor to store the image result.
- * @param buf    the buffer to store image data.
- * @param buff_size provided buffer size in bytes.
+ * @param obj      The object to generate snapshot.
+ * @param cf       color format for generated image.
+ * @param dsc      image descriptor to store the image result.
+ * @param buf      the buffer to store image data.
+ * @param buf_size provided buffer size in bytes.
  *
  * @return LV_RES_OK on success, LV_RES_INV on error.
  */
-lv_res_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_img_cf_t cf, lv_img_dsc_t * dsc, void * buf, uint32_t buff_size)
+lv_res_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_img_cf_t cf, lv_img_dsc_t * dsc, void * buf, uint32_t buf_size)
 {
     LV_ASSERT_NULL(obj);
     LV_ASSERT_NULL(dsc);
@@ -99,8 +99,8 @@ lv_res_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_img_cf_t cf, lv_img_dsc_t *
             return LV_RES_INV;
     }
 
-    if(lv_snapshot_buf_size_needed(obj, cf) > buff_size)
-        return LV_RES_INV;
+    uint32_t buf_size_needed = lv_snapshot_buf_size_needed(obj, cf);
+    if(buf_size_needed == 0 || buf_size < buf_size_needed) return LV_RES_INV;
 
     /*Width and height determine snapshot image size.*/
     lv_coord_t w = lv_obj_get_width(obj);
@@ -113,7 +113,7 @@ lv_res_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_img_cf_t cf, lv_img_dsc_t *
     lv_obj_get_coords(obj, &snapshot_area);
     lv_area_increase(&snapshot_area, ext_size, ext_size);
 
-    lv_memset(buf, 0x00, buff_size);
+    lv_memset(buf, 0x00, buf_size);
     lv_memset_00(dsc, sizeof(lv_img_dsc_t));
 
     lv_disp_t * obj_disp = lv_obj_get_disp(obj);
@@ -148,6 +148,7 @@ lv_res_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_img_cf_t cf, lv_img_dsc_t *
     lv_mem_free(draw_ctx);
 
     dsc->data = buf;
+    dsc->data_size = buf_size_needed;
     dsc->header.w = w;
     dsc->header.h = h;
     dsc->header.cf = cf;
@@ -164,9 +165,9 @@ lv_res_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_img_cf_t cf, lv_img_dsc_t *
 lv_img_dsc_t * lv_snapshot_take(lv_obj_t * obj, lv_img_cf_t cf)
 {
     LV_ASSERT_NULL(obj);
-    uint32_t buff_size = lv_snapshot_buf_size_needed(obj, cf);
+    uint32_t buf_size = lv_snapshot_buf_size_needed(obj, cf);
 
-    void * buf = lv_mem_alloc(buff_size);
+    void * buf = lv_mem_alloc(buf_size);
     LV_ASSERT_MALLOC(buf);
     if(buf == NULL) {
         return NULL;
@@ -179,7 +180,7 @@ lv_img_dsc_t * lv_snapshot_take(lv_obj_t * obj, lv_img_cf_t cf)
         return NULL;
     }
 
-    if(lv_snapshot_take_to_buf(obj, cf, dsc, buf, buff_size) == LV_RES_INV) {
+    if(lv_snapshot_take_to_buf(obj, cf, dsc, buf, buf_size) == LV_RES_INV) {
         lv_mem_free(buf);
         lv_mem_free(dsc);
         return NULL;

diff --git a/src/extra/others/snapshot/lv_snapshot.h b/src/extra/others/snapshot/lv_snapshot.h
@@ -61,15 +61,15 @@ uint32_t lv_snapshot_buf_size_needed(lv_obj_t * obj, lv_img_cf_t cf);
 
 /** Take snapshot for object with its children, save image info to provided buffer.
  *
- * @param obj    The object to generate snapshot.
- * @param cf     color format for generated image.
- * @param dsc    image descriptor to store the image result.
- * @param buff   the buffer to store image data.
- * @param buff_size provided buffer size in bytes.
+ * @param obj      The object to generate snapshot.
+ * @param cf       color format for generated image.
+ * @param dsc      image descriptor to store the image result.
+ * @param buf      the buffer to store image data.
+ * @param buf_size provided buffer size in bytes.
  *
  * @return LV_RES_OK on success, LV_RES_INV on error.
  */
-lv_res_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_img_cf_t cf, lv_img_dsc_t * dsc, void * buf, uint32_t buff_size);
+lv_res_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_img_cf_t cf, lv_img_dsc_t * dsc, void * buf, uint32_t buf_size);
 
 
 /**********************