From 3951ea4b95c2f29c71bc70756b7d9dbef77129a2 Mon Sep 17 00:00:00 2001
From: Gabor Kiss-Vamosi <kisvegabor@gmail.com>
Date: Sat, 7 Jun 2025 18:23:01 +0200
Subject: [PATCH] feat(xml): add remove_style and remove_style_all support

---
 examples/others/xml/lv_example_xml_2.c        | 40 ++++++++-
 examples/others/xml/my_button.xml             |  7 +-
 examples/others/xml/view.xml                  | 47 +++++++++--
 src/others/xml/lv_xml.c                       |  5 ++
 src/others/xml/parsers/lv_xml_obj_parser.c    | 84 +++++++++++++++----
 src/others/xml/parsers/lv_xml_obj_parser.h    |  6 ++
 .../test_cases/xml/test_xml_screen_event.c    |  2 +-
 tests/src/test_cases/xml/test_xml_style.c     | 43 +++++++++-
 tests/unity/unity_support.h                   |  5 ++
 xmls/lv_obj.xml                               |  7 ++
 10 files changed, 211 insertions(+), 35 deletions(-)

diff --git a/examples/others/xml/lv_example_xml_2.c b/examples/others/xml/lv_example_xml_2.c
index b4fae5b899..f037a54ac3 100644
--- a/examples/others/xml/lv_example_xml_2.c
+++ b/examples/others/xml/lv_example_xml_2.c
@@ -3,10 +3,44 @@
 
 void lv_example_xml_2(void)
 {
-    lv_xml_component_register_from_file("A:lvgl/examples/others/xml/view.xml");
+    lv_result_t res;
+    res = lv_xml_component_register_from_file("A:lvgl/examples/others/xml/my_h3.xml");
+    if(res != LV_RESULT_OK) {
+        lv_obj_t * label = lv_label_create(lv_screen_active());
+        lv_label_set_text(label, "Couldn't open the XML files.");
+        lv_obj_center(label);
+        return;
+    }
+    lv_xml_component_register_from_file("A:lvgl/examples/others/xml/my_card.xml");
     lv_xml_component_register_from_file("A:lvgl/examples/others/xml/my_button.xml");
+    lv_xml_component_register_from_file("A:lvgl/examples/others/xml/view.xml");
 
-    lv_obj_t * obj = (lv_obj_t *) lv_xml_create(NULL, "view", NULL);
-    lv_screen_load(obj);
+    lv_xml_register_font(NULL, "lv_montserrat_18", &lv_font_montserrat_18);
+
+    lv_obj_t * obj = (lv_obj_t *) lv_xml_create(lv_screen_active(), "view", NULL);
+    lv_obj_set_pos(obj, 10, 10);
+
+    const char * my_button_attrs[] = {
+        "x", "10",
+        "y", "-10",
+        "align", "bottom_left",
+        "btn_text", "New button",
+        NULL, NULL,
+    };
+
+    lv_xml_component_unregister("my_button");
+
+    lv_xml_create(lv_screen_active(), "my_button", my_button_attrs);
+
+    const char * slider_attrs[] = {
+        "x", "200",
+        "y", "-15",
+        "align", "bottom_left",
+        "value", "30",
+        NULL, NULL,
+    };
+
+    lv_obj_t * slider = (lv_obj_t *) lv_xml_create(lv_screen_active(), "lv_slider", slider_attrs);
+    lv_obj_set_width(slider, 100);
 }
 #endif
diff --git a/examples/others/xml/my_button.xml b/examples/others/xml/my_button.xml
index cb4519a176..bcfb69a394 100644
--- a/examples/others/xml/my_button.xml
+++ b/examples/others/xml/my_button.xml
@@ -8,11 +8,8 @@
 		<prop name="btn_text" type="string"/>
 	</api>
 
-	<view width="#size">
-		<lv_button align="center">
-            <lv_label text="$btn_text" align="center" color="#orange"/>
-            <screen_load_event screen="main_screen"/>
-        </lv_button>
+	<view extends="lv_button" width="#size">
+		<my_h3 text="$btn_text" align="center" color="#orange"/>
 	</view>
 </component>
 
diff --git a/examples/others/xml/view.xml b/examples/others/xml/view.xml
index ee743705dd..6eea106786 100644
--- a/examples/others/xml/view.xml
+++ b/examples/others/xml/view.xml
@@ -1,8 +1,39 @@
-<screen>
-    <view style_bg_color="0xff7788" name="main_screen">
-        <lv_button>
-            <lv_label text="Load"/>
-            <screen_create_event screen="my_button" anim_type="over_right" duration="500" delay="1000"/>
-        </lv_button>
-    </view>
-</screen>
\ No newline at end of file
+<component>
+	<consts>
+		<color name="light_blue" value="0xbbbbff"/>
+		<color name="dark_blue" value="0x000080"/>
+	</consts>
+
+	<styles>
+		<style name="btn_style" bg_color="#dark_blue" bg_opa="150"/>
+		<style name="btn_pr_style" bg_opa="255"/>
+        <style name="red_border" border_width="2" border_side="full" border_color="0xff0000"></style>
+	</styles>
+
+    <subjects>
+        <int name="subject1" value="10"/>
+    </subjects>
+
+
+	<view extends="lv_obj" flex_flow="column" name="main" width="280" height="content" style_bg_color="#light_blue">
+		<lv_label bind_text="subject1" styles="btn_style:disabled red_border:checked">
+            <bind_flag_if_gt subject="subject1" flag="hidden" ref_value="60"/>
+            <bind_state_if_lt subject="subject1" state="checked" ref_value="40"/>
+            <bind_state_if_lt subject="subject1" state="disabled" ref_value="20"/>
+            <style name="btn_style" selector="disabled"/>
+            <style name="red_border" selector="knob checked"/>
+        </lv_label>
+		<lv_slider bind_value="subject1" />
+        <my_card title="Card 1" name="card1"
+				 y="100"
+                 styles="red_border"
+				 btn_rel_style="btn_style"
+				 btn_pr_style="btn_pr_style"/>
+
+		<my_card y="185"
+				 bg_color="0xffaaaa"
+				 action="Apply"
+				 btn_rel_style="btn_style"
+				 btn_pr_style="btn_pr_style"/>
+	</view>
+</component>
\ No newline at end of file
diff --git a/src/others/xml/lv_xml.c b/src/others/xml/lv_xml.c
index a2ea682d46..789f41f20b 100644
--- a/src/others/xml/lv_xml.c
+++ b/src/others/xml/lv_xml.c
@@ -110,6 +110,10 @@ void lv_xml_init(void)
                            lv_xml_calendar_header_dropdown_apply);
 
     lv_xml_widget_register("lv_obj-style", lv_obj_xml_style_create, lv_obj_xml_style_apply);
+    lv_xml_widget_register("lv_obj-remove_style", lv_obj_xml_remove_style_create, lv_obj_xml_remove_style_apply);
+    lv_xml_widget_register("lv_obj-remove_style_all", lv_obj_xml_remove_style_all_create,
+                           lv_obj_xml_remove_style_all_apply);
+
     lv_xml_widget_register("lv_obj-event_cb", lv_obj_xml_event_cb_create, lv_obj_xml_event_cb_apply);
     lv_xml_widget_register("lv_obj-subject_set_int", lv_obj_xml_subject_set_create, lv_obj_xml_subject_set_apply);
     lv_xml_widget_register("lv_obj-subject_set_string", lv_obj_xml_subject_set_create, lv_obj_xml_subject_set_apply);
@@ -119,6 +123,7 @@ void lv_xml_init(void)
                            lv_obj_xml_screen_load_event_apply);
     lv_xml_widget_register("lv_obj-screen_create_event", lv_obj_xml_screen_create_event_create,
                            lv_obj_xml_screen_create_event_apply);
+
     lv_xml_widget_register("lv_obj-bind_flag_if_eq", lv_obj_xml_bind_flag_create, lv_obj_xml_bind_flag_apply);
     lv_xml_widget_register("lv_obj-bind_flag_if_not_eq", lv_obj_xml_bind_flag_create, lv_obj_xml_bind_flag_apply);
     lv_xml_widget_register("lv_obj-bind_flag_if_gt", lv_obj_xml_bind_flag_create, lv_obj_xml_bind_flag_apply);
diff --git a/src/others/xml/parsers/lv_xml_obj_parser.c b/src/others/xml/parsers/lv_xml_obj_parser.c
index 542a252da0..81191ef9e4 100644
--- a/src/others/xml/parsers/lv_xml_obj_parser.c
+++ b/src/others/xml/parsers/lv_xml_obj_parser.c
@@ -34,6 +34,7 @@ typedef struct {
  **********************/
 static lv_obj_flag_t flag_to_enum(const char * txt);
 static void apply_styles(lv_xml_parser_state_t * state, lv_obj_t * obj, const char * name, const char * value);
+static lv_style_selector_t get_selector(const char * str);
 static void free_user_data_event_cb(lv_event_t * e);
 static void screen_create_on_trigger_event_cb(lv_event_t * e);
 static void screen_load_on_trigger_event_cb(lv_event_t * e);
@@ -173,29 +174,56 @@ void lv_obj_xml_style_apply(lv_xml_parser_state_t * state, const char ** attrs)
         return;
     }
 
-    lv_style_selector_t selector = 0;
     const char * selector_str = lv_xml_get_value_of(attrs, "selector");
-    if(selector_str) {
-        char buf[256];
-        lv_strncpy(buf, selector_str, sizeof(buf));
-
-        char * bufp = buf;
-        const char * next = lv_xml_split_str(&bufp, '|');
-
-        while(next) {
-            /* Handle different states and parts */
-            selector |= lv_xml_style_state_to_enum(next);
-            selector |= lv_xml_style_part_to_enum(next);
-
-            /* Move to the next token */
-            next = lv_xml_split_str(&bufp, '|');
-        }
-    }
+    lv_style_selector_t selector = get_selector(selector_str);
 
     void * item = lv_xml_state_get_parent(state);
     lv_obj_add_style(item, &xml_style->style, selector);
 }
 
+void * lv_obj_xml_remove_style_create(lv_xml_parser_state_t * state, const char ** attrs)
+{
+    LV_UNUSED(attrs);
+    void * item = lv_xml_state_get_parent(state);
+    return item;
+}
+
+void lv_obj_xml_remove_style_apply(lv_xml_parser_state_t * state, const char ** attrs)
+{
+
+    const char * style_str = lv_xml_get_value_of(attrs, "name");
+    const char * selector_str = lv_xml_get_value_of(attrs, "selector");
+
+    lv_style_t * style = NULL;
+    if(style_str) {
+        lv_xml_style_t * xml_style = lv_xml_get_style_by_name(&state->scope, style_str);
+        if(xml_style == NULL) {
+            LV_LOG_WARN("No style found with name `%s`", style_str);
+            return;
+        }
+        style = &xml_style->style;
+    }
+
+    lv_style_selector_t selector = get_selector(selector_str);
+
+    void * item = lv_xml_state_get_item(state);
+    lv_obj_remove_style(item, style, selector);
+}
+
+void * lv_obj_xml_remove_style_all_create(lv_xml_parser_state_t * state, const char ** attrs)
+{
+    LV_UNUSED(attrs);
+    void * item = lv_xml_state_get_parent(state);
+    return item;
+}
+
+void lv_obj_xml_remove_style_all_apply(lv_xml_parser_state_t * state, const char ** attrs)
+{
+    LV_UNUSED(attrs);
+    void * item = lv_xml_state_get_item(state);
+    lv_obj_remove_style_all(item);
+}
+
 void * lv_obj_xml_event_cb_create(lv_xml_parser_state_t * state, const char ** attrs)
 {
     LV_UNUSED(attrs);
@@ -724,6 +752,28 @@ static void apply_styles(lv_xml_parser_state_t * state, lv_obj_t * obj, const ch
     else SET_STYLE_IF(grid_cell_y_align, lv_xml_grid_align_to_enum(value));
 }
 
+static lv_style_selector_t get_selector(const char * str)
+{
+    if(str == NULL) return 0;
+    lv_style_selector_t selector = 0;
+    char buf[256];
+    lv_strncpy(buf, str, sizeof(buf));
+
+    char * bufp = buf;
+    const char * next = lv_xml_split_str(&bufp, '|');
+
+    while(next) {
+        /* Handle different states and parts */
+        selector |= lv_xml_style_state_to_enum(next);
+        selector |= lv_xml_style_part_to_enum(next);
+
+        /* Move to the next token */
+        next = lv_xml_split_str(&bufp, '|');
+    }
+
+    return selector;
+}
+
 static void free_user_data_event_cb(lv_event_t * e)
 {
     lv_free(lv_event_get_user_data(e));
diff --git a/src/others/xml/parsers/lv_xml_obj_parser.h b/src/others/xml/parsers/lv_xml_obj_parser.h
index d5771fb075..28b462c2ed 100644
--- a/src/others/xml/parsers/lv_xml_obj_parser.h
+++ b/src/others/xml/parsers/lv_xml_obj_parser.h
@@ -30,6 +30,12 @@ void lv_xml_obj_apply(lv_xml_parser_state_t * state, const char ** attrs);
 void * lv_obj_xml_style_create(lv_xml_parser_state_t * state, const char ** attrs);
 void lv_obj_xml_style_apply(lv_xml_parser_state_t * state, const char ** attrs);
 
+void * lv_obj_xml_remove_style_create(lv_xml_parser_state_t * state, const char ** attrs);
+void lv_obj_xml_remove_style_apply(lv_xml_parser_state_t * state, const char ** attrs);
+
+void * lv_obj_xml_remove_style_all_create(lv_xml_parser_state_t * state, const char ** attrs);
+void lv_obj_xml_remove_style_all_apply(lv_xml_parser_state_t * state, const char ** attrs);
+
 void * lv_obj_xml_event_cb_create(lv_xml_parser_state_t * state, const char ** attrs);
 void lv_obj_xml_event_cb_apply(lv_xml_parser_state_t * state, const char ** attrs);
 
diff --git a/tests/src/test_cases/xml/test_xml_screen_event.c b/tests/src/test_cases/xml/test_xml_screen_event.c
index c1e52d6c6c..a8ff4119a6 100644
--- a/tests/src/test_cases/xml/test_xml_screen_event.c
+++ b/tests/src/test_cases/xml/test_xml_screen_event.c
@@ -1,4 +1,4 @@
-#if LV_BUILD_TEST || 1
+#if LV_BUILD_TEST
 #include "../lvgl.h"
 
 #include "unity/unity.h"
diff --git a/tests/src/test_cases/xml/test_xml_style.c b/tests/src/test_cases/xml/test_xml_style.c
index bbb4bdc152..87ce12cd25 100644
--- a/tests/src/test_cases/xml/test_xml_style.c
+++ b/tests/src/test_cases/xml/test_xml_style.c
@@ -1,4 +1,4 @@
-#if LV_BUILD_TEST
+#if LV_BUILD_TEST || 1
 #include "../lvgl.h"
 
 #include "unity/unity.h"
@@ -138,7 +138,48 @@ void test_xml_style_same_name(void)
     lv_xml_component_register_from_data("comp1", comp1);
     lv_obj_t * obj = lv_xml_create(lv_screen_active(), "comp1", NULL);
     TEST_ASSERT_EQUAL(20, lv_obj_get_style_bg_opa(obj, 0));
+}
 
+
+
+void test_xml_style_remove(void)
+{
+    const char * comp1 =
+        "<component>"
+        "  <styles>"
+        "    <style name=\"s1\" bg_opa=\"100\" border_width=\"2\"/>"
+        "    <style name=\"s2\" bg_color=\"0xff0000\"/>"
+        "  </styles>"
+        ""
+        "  <view extends=\"lv_slider\">"
+        "     <remove_style/>"
+        "     <remove_style selector=\"knob\"/>"
+        "     <style name=\"s1\" selector=\"knob|pressed\"/>"
+        "     <style name=\"s2\" selector=\"knob|pressed\"/>"
+        "     <remove_style name=\"s2\" selector=\"knob|pressed\"/>"
+        "     <remove_style name=\"s3\"/>"
+        "  </view>"
+        "</component>";
+
+    lv_xml_component_register_from_data("comp1", comp1);
+    lv_obj_t * obj = lv_xml_create(lv_screen_active(), "comp1", NULL);
+
+    /*The first remove_style removed the main style, so the radius should be the default 0*/
+    TEST_ASSERT_EQUAL(0, lv_obj_get_style_radius(obj, 0));
+
+    /*Styles are removed from the knob in the default state*/
+    TEST_ASSERT_EQUAL(0, lv_obj_get_style_radius(obj, LV_PART_KNOB));
+
+    lv_obj_add_state(obj, LV_STATE_PRESSED);
+    lv_test_wait(1000); /*Wait for transitions*/
+
+    /*s1 sets bg_opa=100 in pressed state*/
+    TEST_ASSERT_EQUAL(100, lv_obj_get_style_bg_opa(obj, LV_PART_KNOB));
+
+    /*s2 is added and removed so the red bg_color shouldn't be applied*/
+    TEST_ASSERT_NOT_EQUAL_COLOR(lv_color_hex(0xff0000), lv_obj_get_style_bg_color(obj, LV_PART_KNOB));
+
+    lv_xml_component_unregister("comp1");
 }
 
 #endif
diff --git a/tests/unity/unity_support.h b/tests/unity/unity_support.h
index 9c4304f111..9643d30c95 100644
--- a/tests/unity/unity_support.h
+++ b/tests/unity/unity_support.h
@@ -33,6 +33,11 @@ extern "C" {
 #  define TEST_ASSERT_EQUAL_COLOR32(c1, c2)                   TEST_ASSERT_TRUE(lv_color32_eq(c1, c2))
 #  define TEST_ASSERT_EQUAL_COLOR32_MESSAGE(c1, c2, msg)      TEST_ASSERT_TRUE(lv_color32_eq(c1, c2), msg)
 
+#  define TEST_ASSERT_NOT_EQUAL_COLOR(c1, c2)                   TEST_ASSERT_FALSE(lv_color_eq(c1, c2))
+#  define TEST_ASSERT_NOT_EQUAL_COLOR_MESSAGE(c1, c2, msg)      TEST_ASSERT_FALSE(lv_color_eq(c1, c2), msg)
+
+#  define TEST_ASSERT_NOT_EQUAL_COLOR32(c1, c2)                   TEST_ASSERT_FALSE(lv_color32_eq(c1, c2))
+#  define TEST_ASSERT_NOT_EQUAL_COLOR32_MESSAGE(c1, c2, msg)      TEST_ASSERT_FALSE(lv_color32_eq(c1, c2), msg)
 
 #  define TEST_ASSERT_MEM_LEAK_LESS_THAN(prev_usage, threshold)  TEST_ASSERT_LESS_OR_EQUAL(threshold, LV_ABS((int64_t)(prev_usage) - (int64_t)lv_test_get_free_mem()));
 
diff --git a/xmls/lv_obj.xml b/xmls/lv_obj.xml
index cac48ed498..d3a294f80f 100644
--- a/xmls/lv_obj.xml
+++ b/xmls/lv_obj.xml
@@ -44,6 +44,13 @@ Example
             <arg name="selector" type="selector+" default="0"/>
         </element>
 
+        <element name="remove_style" access="custom" type="void">
+            <arg name="name" type="style" default="NULL"/>
+            <arg name="selector" type="selector+" default="0"/>
+        </element>
+
+        <element name="remove_style_all" access="custom" type="void"/>
+
         <element name="event_cb" access="add">
             <arg name="name" type="string"/>
             <arg name="trigger" type="lv_event" default="clicked"/>