fix(snapshot): need to set disp refreshing firstly (#4816)

Signed-off-by: Xuxingliang <xuxingliang@xiaomi.com>

src/core/lv_refr.c

@@ -318,6 +318,15 @@ lv_display_t * _lv_refr_get_disp_refreshing(void)
     return disp_refr;
 }
 
+/**
+ * Get the display which is being refreshed
+ * @return the display being refreshed
+ */
+void _lv_refr_set_disp_refreshing(lv_display_t * disp)
+{
+    disp_refr = disp;
+}
+
 /**
  * Called periodically to handle the refreshing
  * @param tmr pointer to the timer itself

src/core/lv_refr.h

@@ -81,6 +81,12 @@ void _lv_inv_area(lv_display_t * disp, const lv_area_t * area_p);
  */
 lv_display_t * _lv_refr_get_disp_refreshing(void);
 
+/**
+ * Set the display which is being refreshed
+ * @param disp the display being refreshed
+ */
+void _lv_refr_set_disp_refreshing(lv_display_t * disp);
+
 /**
  * Called periodically to handle the refreshing
  * @param timer pointer to the timer itself

src/others/snapshot/lv_snapshot.c

@@ -132,6 +132,12 @@ lv_result_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_color_format_t cf, lv_ima
     layer.color_format = cf;
     layer.clip_area = snapshot_area;
 
+    lv_display_t * disp_old = _lv_refr_get_disp_refreshing();
+    lv_display_t * disp_new = lv_obj_get_disp(obj);
+    lv_layer_t * layer_old = disp_new->layer_head;
+    disp_new->layer_head = &layer;
+
+    _lv_refr_set_disp_refreshing(disp_new);
     lv_obj_redraw(&layer, obj);
 
     while(layer.draw_task_head) {
@@ -139,6 +145,9 @@ lv_result_t lv_snapshot_take_to_buf(lv_obj_t * obj, lv_color_format_t cf, lv_ima
         lv_draw_dispatch_layer(NULL, &layer);
     }
 
+    disp_new->layer_head = layer_old;
+    _lv_refr_set_disp_refreshing(disp_old);
+
     return LV_RESULT_OK;
 }