From 312303cb447f899fd55ea452774a35942cd38414 Mon Sep 17 00:00:00 2001
From: sparkles43 <112950468+sparkles43@users.noreply.github.com>
Date: Thu, 20 Apr 2023 20:29:58 +0200
Subject: [PATCH] fix(obj_tree): update parents of children after swapping
 (#4150)

---
 src/core/lv_obj_tree.c               |  3 ++
 tests/src/test_cases/test_obj_tree.c | 44 ++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/src/core/lv_obj_tree.c b/src/core/lv_obj_tree.c
index 254dd40c9..5d72d76dc 100644
--- a/src/core/lv_obj_tree.c
+++ b/src/core/lv_obj_tree.c
@@ -245,7 +245,10 @@ void lv_obj_swap(lv_obj_t * obj1, lv_obj_t * obj2)
     lv_obj_send_event(parent, LV_EVENT_CHILD_DELETED, obj1);
 
     parent->spec_attr->children[index1] = obj2;
+    obj2->parent = parent;
+
     parent2->spec_attr->children[index2] = obj1;
+    obj1->parent = parent2;
 
     lv_obj_send_event(parent, LV_EVENT_CHILD_CHANGED, obj2);
     lv_obj_send_event(parent, LV_EVENT_CHILD_CREATED, obj2);
diff --git a/tests/src/test_cases/test_obj_tree.c b/tests/src/test_cases/test_obj_tree.c
index 73bdb0f13..1b0ac45bc 100644
--- a/tests/src/test_cases/test_obj_tree.c
+++ b/tests/src/test_cases/test_obj_tree.c
@@ -36,4 +36,48 @@ void test_obj_tree_2(void)
     //TEST_ASSERT_EQUAL_SCREENSHOT("scr1.png")
 }
 
+void test_obj_tree_3(void)
+{
+    /* tests lv_obj_swap */
+    lv_obj_t * parent1 = lv_obj_create(lv_scr_act());
+    lv_obj_t * parent2 = lv_obj_create(lv_scr_act());
+    lv_obj_t * child1 = lv_obj_create(parent1);
+    lv_obj_t * child2 = lv_obj_create(parent2);
+
+    /* were the parents set correctly for the children? */
+    lv_obj_t * child1_parent_before = lv_obj_get_parent(child1);
+    lv_obj_t * child2_parent_before = lv_obj_get_parent(child2);
+
+    TEST_ASSERT_EQUAL(child1_parent_before, parent1);
+    TEST_ASSERT_EQUAL(child2_parent_before, parent2);
+
+    /* were the children set correctly for the parents? */
+    TEST_ASSERT_EQUAL(lv_obj_get_child_cnt(parent1), 1);
+    TEST_ASSERT_EQUAL(lv_obj_get_index(child1), 0);
+    TEST_ASSERT_EQUAL(lv_obj_get_child(parent1, 0), child1);
+
+    TEST_ASSERT_EQUAL(lv_obj_get_child_cnt(parent2), 1);
+    TEST_ASSERT_EQUAL(lv_obj_get_index(child2), 0);
+    TEST_ASSERT_EQUAL(lv_obj_get_child(parent2, 0), child2);
+
+    /* swap the children */
+    lv_obj_swap(child1, child2);
+
+    /* test for properly swapped parents */
+    lv_obj_t * child1_parent_after = lv_obj_get_parent(child1);
+    lv_obj_t * child2_parent_after = lv_obj_get_parent(child2);
+
+    TEST_ASSERT_EQUAL(child1_parent_after, parent2);
+    TEST_ASSERT_EQUAL(child2_parent_after, parent1);
+
+    /* test for correctly set children */
+    TEST_ASSERT_EQUAL(lv_obj_get_child_cnt(parent1), 1);
+    TEST_ASSERT_EQUAL(lv_obj_get_index(child2), 0);
+    TEST_ASSERT_EQUAL(lv_obj_get_child(parent1, 0), child2);
+
+    TEST_ASSERT_EQUAL(lv_obj_get_child_cnt(parent2), 1);
+    TEST_ASSERT_EQUAL(lv_obj_get_index(child1), 0);
+    TEST_ASSERT_EQUAL(lv_obj_get_child(parent2, 0), child1);
+}
+
 #endif