fix(snapshot): fix memleak in lv_snapshot (#6147)

Signed-off-by: rongyichang <rongyichang@xiaomi.com>

src/others/snapshot/lv_snapshot.c

@@ -121,7 +121,7 @@ lv_result_t lv_snapshot_take_to_draw_buf(lv_obj_t * obj, lv_color_format_t cf, l
 
     while(layer.draw_task_head) {
         lv_draw_dispatch_wait_for_request();
-        lv_draw_dispatch_layer(NULL, &layer);
+        lv_draw_dispatch();
     }
 
     disp_new->layer_head = layer_old;

tests/src/test_cases/test_snapshot.c

@@ -5,7 +5,7 @@
 
 #include "unity/unity.h"
 
-#define NUM_SNAPSHOTS 1
+#define NUM_SNAPSHOTS 10
 
 void test_snapshot_should_not_leak_memory(void)
 {
@@ -34,6 +34,39 @@ void test_snapshot_should_not_leak_memory(void)
     TEST_ASSERT_EQUAL(initial_available_memory, final_available_memory);
 }
 
+void test_snapshot_with_transform_should_not_leak_memory(void)
+{
+    uint32_t idx = 0;
+    size_t initial_available_memory = 0;
+    size_t final_available_memory = 0;
+    lv_mem_monitor_t monitor;
+
+    lv_draw_buf_t * snapshots[NUM_SNAPSHOTS] = {NULL};
+    lv_obj_t * label = lv_label_create(lv_screen_active());
+    lv_obj_center(label);
+    lv_obj_set_style_text_font(label, &lv_font_montserrat_28, 0);
+    lv_label_set_text(label, "Wubba lubba dub dub!");
+    lv_obj_set_style_transform_rotation(label, 450, 0);
+
+    lv_mem_monitor(&monitor);
+    initial_available_memory = monitor.free_size;
+
+    for(idx = 0; idx < NUM_SNAPSHOTS; idx++) {
+        snapshots[idx] = lv_snapshot_take(lv_screen_active(), LV_COLOR_FORMAT_NATIVE_WITH_ALPHA);
+        TEST_ASSERT_NOT_NULL(snapshots[idx]);
+    }
+
+    for(idx = 0; idx < NUM_SNAPSHOTS; idx++) {
+        lv_draw_buf_destroy(snapshots[idx]);
+    }
+
+    lv_mem_monitor(&monitor);
+    final_available_memory = monitor.free_size;
+    lv_obj_delete(label);
+
+    TEST_ASSERT_EQUAL(initial_available_memory, final_available_memory);
+}
+
 void test_snapshot_take_snapshot_immidiately_after_obj_create(void)
 {
     lv_obj_t * label = lv_label_create(lv_screen_active());
@@ -53,6 +86,29 @@ void test_snapshot_take_snapshot_immidiately_after_obj_create(void)
     lv_image_set_rotation(img_obj, 450);
 
     TEST_ASSERT_EQUAL_SCREENSHOT("snapshot_1.png");
+
+    lv_obj_delete(img_obj);
+    lv_draw_buf_destroy(draw_dsc);
+}
+
+void test_snapshot_take_snapshot_with_transform(void)
+{
+    lv_obj_t * label = lv_label_create(lv_screen_active());
+    lv_obj_set_style_text_font(label, &lv_font_montserrat_28, 0);
+    lv_label_set_text(label, "Wubba lubba dub dub!");
+    lv_obj_set_style_transform_rotation(label, 450, 0);
+
+    lv_draw_buf_t * draw_dsc = lv_snapshot_take(lv_screen_active(), LV_COLOR_FORMAT_ARGB8888);
+
+    lv_obj_delete(label);
+
+    lv_obj_t * img_obj = lv_image_create(lv_screen_active());
+    lv_image_set_src(img_obj, draw_dsc);
+
+    TEST_ASSERT_EQUAL_SCREENSHOT("snapshot_2.png");
+
+    lv_obj_delete(img_obj);
+    lv_draw_buf_destroy(draw_dsc);
 }
 
 #else /*LV_USE_SNAPSHOT*/
@@ -62,6 +118,21 @@ void test_snapshot_should_not_leak_memory(void)
 
 }
 
+void test_snapshot_with_transform_should_not_leak_memory(void)
+{
+
+}
+
+void test_snapshot_take_snapshot_immidiately_after_obj_create(void)
+{
+
+}
+
+void test_snapshot_take_snapshot_with_transform(void)
+{
+
+}
+
 #endif
 
 #endif