diff --git a/src/themes/default/lv_theme_default.c b/src/themes/default/lv_theme_default.c
index 66494ba92c..cb42c6f154 100644
--- a/src/themes/default/lv_theme_default.c
+++ b/src/themes/default/lv_theme_default.c
@@ -727,8 +727,9 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
     LV_UNUSED(th);
 
     my_theme_t * theme = theme_def;
+    lv_obj_t * parent = lv_obj_get_parent(obj);
 
-    if(lv_obj_get_parent(obj) == NULL) {
+    if(parent == NULL) {
         lv_obj_add_style(obj, &theme->styles.scr, 0);
         lv_obj_add_style(obj, &theme->styles.scrollbar, LV_PART_SCROLLBAR);
         lv_obj_add_style(obj, &theme->styles.scrollbar_scrolled, LV_PART_SCROLLBAR | LV_STATE_SCROLLED);
@@ -737,20 +738,19 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
 
     if(lv_obj_check_type(obj, &lv_obj_class)) {
 #if LV_USE_TABVIEW
-        lv_obj_t * parent = lv_obj_get_parent(obj);
         /*Tabview content area*/
-        if(parent && lv_obj_check_type(parent, &lv_tabview_class) && lv_obj_get_index(obj) == 1) {
+        if(lv_obj_check_type(parent, &lv_tabview_class) && lv_obj_get_child(parent, 1) == obj) {
             return;
         }
         /*Tabview button container*/
-        else if(lv_obj_check_type(parent, &lv_tabview_class) && lv_obj_get_index(obj) == 0) {
+        else if(lv_obj_check_type(parent, &lv_tabview_class) && lv_obj_get_child(parent, 0) == obj) {
             lv_obj_add_style(obj, &theme->styles.bg_color_white, 0);
             lv_obj_add_style(obj, &theme->styles.outline_primary, LV_STATE_FOCUS_KEY);
             lv_obj_add_style(obj, &theme->styles.tab_bg_focus, LV_STATE_FOCUS_KEY);
             return;
         }
         /*Tabview pages*/
-        else if(parent && lv_obj_check_type(lv_obj_get_parent(parent), &lv_tabview_class)) {
+        else if(lv_obj_check_type(lv_obj_get_parent(parent), &lv_tabview_class)) {
             lv_obj_add_style(obj, &theme->styles.pad_normal, 0);
             lv_obj_add_style(obj, &theme->styles.rotary_scroll, 0);
             lv_obj_add_style(obj, &theme->styles.scrollbar, LV_PART_SCROLLBAR);
@@ -761,13 +761,13 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
 
 #if LV_USE_WIN
         /*Header*/
-        if(lv_obj_get_index(obj) == 0 && lv_obj_check_type(lv_obj_get_parent(obj), &lv_win_class)) {
+        if(lv_obj_check_type(parent, &lv_win_class) && lv_obj_get_child(parent, 0) == obj) {
             lv_obj_add_style(obj, &theme->styles.bg_color_grey, 0);
             lv_obj_add_style(obj, &theme->styles.pad_tiny, 0);
             return;
         }
         /*Content*/
-        else if(lv_obj_get_index(obj) == 1 && lv_obj_check_type(lv_obj_get_parent(obj), &lv_win_class)) {
+        else if(lv_obj_check_type(parent, &lv_win_class) && lv_obj_get_child(parent, 1) == obj) {
             lv_obj_add_style(obj, &theme->styles.scr, 0);
             lv_obj_add_style(obj, &theme->styles.pad_normal, 0);
             lv_obj_add_style(obj, &theme->styles.scrollbar, LV_PART_SCROLLBAR);
@@ -777,7 +777,7 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
 #endif
 
 #if LV_USE_CALENDAR
-        if(lv_obj_check_type(lv_obj_get_parent(obj), &lv_calendar_class)) {
+        if(lv_obj_check_type(parent, &lv_calendar_class)) {
             /*No style*/
             return;
         }
@@ -791,9 +791,9 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
     else if(lv_obj_check_type(obj, &lv_button_class)) {
 
 #if LV_USE_TABVIEW
-        lv_obj_t * parent = lv_obj_get_parent(obj);
-        if(parent && lv_obj_get_index(parent) == 0) { /*Tabview header*/
-            if(lv_obj_check_type(lv_obj_get_parent(parent), &lv_tabview_class)) {
+        lv_obj_t * tv = lv_obj_get_parent(parent); /*parent is the tabview header*/
+        if(tv && lv_obj_get_child(tv, 0) == parent) { /*The button is on the tab view header*/
+            if(lv_obj_check_type(tv, &lv_tabview_class)) {
                 lv_obj_add_style(obj, &theme->styles.pressed, LV_STATE_PRESSED);
                 lv_obj_add_style(obj, &theme->styles.bg_color_primary_muted, LV_STATE_CHECKED);
                 lv_obj_add_style(obj, &theme->styles.tab_btn, LV_STATE_CHECKED);
@@ -818,8 +818,8 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
         lv_obj_add_style(obj, &theme->styles.disabled, LV_STATE_DISABLED);
 
 #if LV_USE_MENU
-        if(lv_obj_check_type(lv_obj_get_parent(obj), &lv_menu_sidebar_header_cont_class) ||
-           lv_obj_check_type(lv_obj_get_parent(obj), &lv_menu_main_header_cont_class)) {
+        if(lv_obj_check_type(parent, &lv_menu_sidebar_header_cont_class) ||
+           lv_obj_check_type(parent, &lv_menu_main_header_cont_class)) {
             lv_obj_add_style(obj, &theme->styles.menu_header_btn, 0);
             lv_obj_add_style(obj, &theme->styles.menu_pressed, LV_STATE_PRESSED);
         }
@@ -837,7 +837,7 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
     else if(lv_obj_check_type(obj, &lv_buttonmatrix_class)) {
 
 #if LV_USE_CALENDAR
-        if(lv_obj_check_type(lv_obj_get_parent(obj), &lv_calendar_class)) {
+        if(lv_obj_check_type(parent, &lv_calendar_class)) {
             lv_obj_add_style(obj, &theme->styles.calendar_btnm_bg, 0);
             lv_obj_add_style(obj, &theme->styles.outline_primary, LV_STATE_FOCUS_KEY);
             lv_obj_add_style(obj, &theme->styles.outline_secondary, LV_STATE_EDITED);
@@ -1152,7 +1152,7 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
         return;
     }
 
-    if(lv_obj_check_type(lv_obj_get_parent(obj), &lv_msgbox_class)) {
+    if(lv_obj_check_type(parent, &lv_msgbox_class)) {
         lv_obj_add_style(obj, &theme->styles.pad_tiny, 0);
         return;
     }
diff --git a/src/themes/mono/lv_theme_mono.c b/src/themes/mono/lv_theme_mono.c
index fdcf11dcb1..5251e0b137 100644
--- a/src/themes/mono/lv_theme_mono.c
+++ b/src/themes/mono/lv_theme_mono.c
@@ -233,8 +233,9 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
     LV_UNUSED(th);
 
     my_theme_t * theme = theme_def;
+    lv_obj_t * parent = lv_obj_get_parent(obj);
 
-    if(lv_obj_get_parent(obj) == NULL) {
+    if(parent == NULL) {
         lv_obj_add_style(obj, &theme->styles.scr, 0);
         lv_obj_add_style(obj, &theme->styles.scrollbar, LV_PART_SCROLLBAR);
         return;
@@ -242,7 +243,6 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
 
     if(lv_obj_check_type(obj, &lv_obj_class)) {
 #if LV_USE_TABVIEW
-        lv_obj_t * parent = lv_obj_get_parent(obj);
         /*Tabview content area*/
         if(lv_obj_check_type(parent, &lv_tabview_class)) {
             return;
@@ -258,13 +258,13 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
 
 #if LV_USE_WIN
         /*Header*/
-        if(lv_obj_get_index(obj) == 0 && lv_obj_check_type(lv_obj_get_parent(obj), &lv_win_class)) {
+        if(lv_obj_check_type(parent, &lv_win_class) && lv_obj_get_child(parent, 0) == 0) {
             lv_obj_add_style(obj, &theme->styles.card, 0);
             lv_obj_add_style(obj, &theme->styles.no_radius, 0);
             return;
         }
         /*Content*/
-        else if(lv_obj_get_index(obj) == 1 && lv_obj_check_type(lv_obj_get_parent(obj), &lv_win_class)) {
+        else if(lv_obj_check_type(parent, &lv_win_class) && lv_obj_get_child(parent, 1) == obj) {
             lv_obj_add_style(obj, &theme->styles.card, 0);
             lv_obj_add_style(obj, &theme->styles.no_radius, 0);
             lv_obj_add_style(obj, &theme->styles.scrollbar, LV_PART_SCROLLBAR);
@@ -288,7 +288,7 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
 #if LV_USE_BUTTONMATRIX
     else if(lv_obj_check_type(obj, &lv_buttonmatrix_class)) {
 #if LV_USE_MSGBOX
-        if(lv_obj_check_type(lv_obj_get_parent(obj), &lv_msgbox_class)) {
+        if(lv_obj_check_type(parent, &lv_msgbox_class)) {
             lv_obj_add_style(obj, &theme->styles.pad_gap, 0);
             lv_obj_add_style(obj, &theme->styles.card, LV_PART_ITEMS);
             lv_obj_add_style(obj, &theme->styles.pr, LV_PART_ITEMS | LV_STATE_PRESSED);
@@ -299,7 +299,7 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
         }
 #endif
 #if LV_USE_TABVIEW
-        if(lv_obj_check_type(lv_obj_get_parent(obj), &lv_tabview_class)) {
+        if(lv_obj_check_type(parent, &lv_tabview_class)) {
             lv_obj_add_style(obj, &theme->styles.pad_gap, 0);
             lv_obj_add_style(obj, &theme->styles.card, LV_PART_ITEMS);
             lv_obj_add_style(obj, &theme->styles.pr, LV_PART_ITEMS | LV_STATE_PRESSED);
diff --git a/src/themes/simple/lv_theme_simple.c b/src/themes/simple/lv_theme_simple.c
index 6eb2b2c9c7..0b2f4484a4 100644
--- a/src/themes/simple/lv_theme_simple.c
+++ b/src/themes/simple/lv_theme_simple.c
@@ -206,8 +206,9 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
     LV_UNUSED(th);
 
     my_theme_t * theme = theme_def;
+    lv_obj_t * parent = lv_obj_get_parent(obj);
 
-    if(lv_obj_get_parent(obj) == NULL) {
+    if(parent == NULL) {
         lv_obj_add_style(obj, &theme->styles.scr, 0);
         lv_obj_add_style(obj, &theme->styles.scrollbar, LV_PART_SCROLLBAR);
         return;
@@ -215,7 +216,6 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
 
     if(lv_obj_check_type(obj, &lv_obj_class)) {
 #if LV_USE_TABVIEW
-        lv_obj_t * parent = lv_obj_get_parent(obj);
         /*Tabview content area*/
         if(lv_obj_check_type(parent, &lv_tabview_class)) {
             lv_obj_add_style(obj, &theme->styles.scr, 0);
@@ -231,12 +231,12 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
 
 #if LV_USE_WIN
         /*Header*/
-        if(lv_obj_get_index(obj) == 0 && lv_obj_check_type(lv_obj_get_parent(obj), &lv_win_class)) {
+        if(lv_obj_check_type(parent, &lv_win_class) && lv_obj_get_child(parent, 0) == obj) {
             lv_obj_add_style(obj, &theme->styles.light, 0);
             return;
         }
         /*Content*/
-        else if(lv_obj_get_index(obj) == 1 && lv_obj_check_type(lv_obj_get_parent(obj), &lv_win_class)) {
+        else if(lv_obj_check_type(parent, &lv_win_class) && lv_obj_get_child(parent, 1) == obj) {
             lv_obj_add_style(obj, &theme->styles.light, 0);
             lv_obj_add_style(obj, &theme->styles.scrollbar, LV_PART_SCROLLBAR);
             return;
@@ -254,13 +254,13 @@ static void theme_apply(lv_theme_t * th, lv_obj_t * obj)
 #if LV_USE_BUTTONMATRIX
     else if(lv_obj_check_type(obj, &lv_buttonmatrix_class)) {
 #if LV_USE_MSGBOX
-        if(lv_obj_check_type(lv_obj_get_parent(obj), &lv_msgbox_class)) {
+        if(lv_obj_check_type(parent, &lv_msgbox_class)) {
             lv_obj_add_style(obj, &theme->styles.light, LV_PART_ITEMS);
             return;
         }
 #endif
 #if LV_USE_TABVIEW
-        if(lv_obj_check_type(lv_obj_get_parent(obj), &lv_tabview_class)) {
+        if(lv_obj_check_type(parent, &lv_tabview_class)) {
             lv_obj_add_style(obj, &theme->styles.light, LV_PART_ITEMS);
             return;
         }