feat(textarea): only send one event when updating text (#9852)

src/widgets/textarea/lv_textarea.c

@@ -65,7 +65,9 @@ static void auto_hide_characters(lv_obj_t * obj);
 static void auto_hide_characters_cancel(lv_obj_t * obj);
 static inline bool is_valid_but_non_printable_char(const uint32_t letter);
 static void lv_textarea_scroll_to_cusor_pos(lv_obj_t * obj, int32_t pos);
-
+static lv_result_t add_char(lv_obj_t * obj, uint32_t c);
+static void add_text(lv_obj_t * obj, const char * txt);
+static void set_cursor_pos_internal(lv_obj_t * obj, int32_t pos);
 /**********************
  *  STATIC VARIABLES
  **********************/
@@ -183,72 +185,11 @@ lv_obj_t * lv_textarea_create(lv_obj_t * parent)
 void lv_textarea_add_char(lv_obj_t * obj, uint32_t c)
 {
     LV_ASSERT_OBJ(obj, MY_CLASS);
-
-    lv_textarea_t * ta = (lv_textarea_t *)obj;
-
-    if(ta->one_line && (c == '\n' || c == '\r')) {
-        LV_LOG_INFO("Text area: line break ignored in one-line mode");
+    lv_result_t res = add_char(obj, c);
+    if(res != LV_RESULT_OK) {
         return;
     }
-
-    uint32_t u32_buf[2];
-    u32_buf[0] = c;
-    u32_buf[1] = 0;
-
-    const char * letter_buf = (char *)&u32_buf;
-
-    uint32_t c2 = c;
-#if LV_BIG_ENDIAN_SYSTEM
-    if(c != 0) while(*letter_buf == 0) ++letter_buf;
-
-    /*The byte order may or may not need to be swapped here to get correct c_uni below,
-      since lv_textarea_add_text is ordering bytes correctly before calling lv_textarea_add_char.
-      Assume swapping is needed if MSB is zero. May not be foolproof. */
-    if((c != 0) && ((c & 0xff000000) == 0)) {
-        c2 = ((c >> 24) & 0xff) | /*move byte 3 to byte 0*/
-             ((c << 8) & 0xff0000) | /*move byte 1 to byte 2*/
-             ((c >> 8) & 0xff00) | /*move byte 2 to byte 1*/
-             ((c << 24) & 0xff000000); /*byte 0 to byte 3*/
-    }
-#endif
-
-    lv_result_t res = insert_handler(obj, letter_buf);
-    if(res != LV_RESULT_OK) return;
-
-    uint32_t c_uni = lv_text_encoded_next((const char *)&c2, NULL);
-
-    if(char_is_accepted(obj, c_uni) == false) {
-        LV_LOG_INFO("Character is not accepted by the text area (too long text or not in the accepted list)");
-        return;
-    }
-
-    if(ta->pwd_mode) pwd_char_hider(obj); /*Make sure all the current text contains only '*'*/
-
-    /*If the textarea is empty, invalidate it to hide the placeholder*/
-    if(ta->placeholder_txt) {
-        const char * txt = lv_label_get_text(ta->label);
-        if(txt[0] == '\0') lv_obj_invalidate(obj);
-    }
-
-    lv_label_ins_text(ta->label, ta->cursor.pos, letter_buf); /*Insert the character*/
-    lv_textarea_clear_selection(obj); /*Clear selection*/
-
-    if(ta->pwd_mode) {
-        /*+2: the new char + \0*/
-        size_t realloc_size = lv_strlen(ta->pwd_tmp) + lv_strlen(letter_buf) + 1;
-        ta->pwd_tmp = lv_realloc(ta->pwd_tmp, realloc_size);
-        LV_ASSERT_MALLOC(ta->pwd_tmp);
-        if(ta->pwd_tmp == NULL) return;
-
-        lv_text_ins(ta->pwd_tmp, ta->cursor.pos, (const char *)letter_buf);
-
-        /*Auto hide characters*/
-        auto_hide_characters(obj);
-    }
-
-    /*Move the cursor after the new character*/
     lv_textarea_set_cursor_pos(obj, lv_textarea_get_cursor_pos(obj) + 1);
-
     lv_obj_send_event(obj, LV_EVENT_VALUE_CHANGED, NULL);
 }
 
@@ -263,11 +204,7 @@ void lv_textarea_add_text(lv_obj_t * obj, const char * txt)
 
     /*Add the character one-by-one if not all characters are accepted or there is character limit.*/
     if(lv_textarea_get_accepted_chars(obj) || lv_textarea_get_max_length(obj)) {
-        uint32_t i = 0;
-        while(txt[i] != '\0') {
-            uint32_t c = lv_text_encoded_next(txt, &i);
-            lv_textarea_add_char(obj, lv_text_unicode_to_encoded(c));
-        }
+        add_text(obj, txt);
         return;
     }
 
@@ -376,11 +313,7 @@ void lv_textarea_set_text(lv_obj_t * obj, const char * txt)
         if(ta->pwd_mode) {
             ta->pwd_tmp[0] = '\0'; /*Clear the password too*/
         }
-        uint32_t i = 0;
-        while(txt[i] != '\0') {
-            uint32_t c = lv_text_encoded_next(txt, &i);
-            lv_textarea_add_char(obj, lv_text_unicode_to_encoded(c));
-        }
+        add_text(obj, txt);
     }
     else {
         lv_label_set_text(ta->label, txt);
@@ -401,8 +334,6 @@ void lv_textarea_set_text(lv_obj_t * obj, const char * txt)
 
         pwd_char_hider(obj);
     }
-
-    lv_obj_send_event(obj, LV_EVENT_VALUE_CHANGED, NULL);
 }
 
 void lv_textarea_set_placeholder_text(lv_obj_t * obj, const char * txt)
@@ -437,17 +368,7 @@ void lv_textarea_set_placeholder_text(lv_obj_t * obj, const char * txt)
 void lv_textarea_set_cursor_pos(lv_obj_t * obj, int32_t pos)
 {
     LV_ASSERT_OBJ(obj, MY_CLASS);
-
-    lv_textarea_t * ta = (lv_textarea_t *)obj;
-    if((uint32_t)ta->cursor.pos == (uint32_t)pos) return;
-
-    uint32_t len = lv_text_get_encoded_length(lv_label_get_text(ta->label));
-
-    if(pos < 0) pos = len + pos;
-
-    if(pos > (int32_t)len || pos == LV_TEXTAREA_CURSOR_LAST) pos = len;
-
-    ta->cursor.pos = pos;
+    set_cursor_pos_internal(obj, pos);
 
     /*Position the label to make the cursor visible*/
     lv_obj_update_layout(obj);
@@ -1530,4 +1451,117 @@ static void lv_textarea_scroll_to_cusor_pos(lv_obj_t * obj, int32_t pos)
     refr_cursor_area(obj);
 }
 
+static void set_cursor_pos_internal(lv_obj_t * obj, int32_t pos)
+{
+    lv_textarea_t * ta = (lv_textarea_t *)obj;
+    if((uint32_t)ta->cursor.pos == (uint32_t)pos) return;
+
+    uint32_t len = lv_text_get_encoded_length(lv_label_get_text(ta->label));
+
+    if(pos < 0) pos = len + pos;
+
+    if(pos > (int32_t)len || pos == LV_TEXTAREA_CURSOR_LAST) pos = len;
+
+    ta->cursor.pos = pos;
+}
+
+static void add_text(lv_obj_t * obj, const char * txt)
+{
+    lv_textarea_t * ta = (lv_textarea_t *)obj;
+    uint32_t i = 0;
+    bool text_changed = false;
+    while(txt[i] != '\0') {
+        uint32_t c = lv_text_encoded_next(txt, &i);
+        lv_result_t res = add_char(obj, lv_text_unicode_to_encoded(c));
+        if(res != LV_RESULT_OK) {
+            continue;
+        }
+        set_cursor_pos_internal(obj, ta->cursor.pos + 1);
+        text_changed = true;
+    }
+
+    if(!text_changed) {
+        return;
+    }
+
+    lv_obj_update_layout(obj);
+    lv_textarea_scroll_to_cusor_pos(obj, ta->cursor.pos);
+    refr_cursor_area(obj);
+    /*Move the cursor after the new character*/
+    lv_obj_send_event(obj, LV_EVENT_VALUE_CHANGED, NULL);
+
+}
+static lv_result_t add_char(lv_obj_t * obj, uint32_t c)
+{
+    LV_ASSERT_OBJ(obj, MY_CLASS);
+
+    lv_textarea_t * ta = (lv_textarea_t *)obj;
+
+    if(ta->one_line && (c == '\n' || c == '\r')) {
+        LV_LOG_INFO("Text area: line break ignored in one-line mode");
+        return LV_RESULT_INVALID;
+    }
+
+    uint32_t u32_buf[2];
+    u32_buf[0] = c;
+    u32_buf[1] = 0;
+
+    const char * letter_buf = (char *)&u32_buf;
+
+    uint32_t c2 = c;
+#if LV_BIG_ENDIAN_SYSTEM
+    if(c != 0) while(*letter_buf == 0) ++letter_buf;
+
+    /*The byte order may or may not need to be swapped here to get correct c_uni below,
+      since lv_textarea_add_text is ordering bytes correctly before calling lv_textarea_add_char.
+      Assume swapping is needed if MSB is zero. May not be foolproof. */
+    if((c != 0) && ((c & 0xff000000) == 0)) {
+        c2 = ((c >> 24) & 0xff) | /*move byte 3 to byte 0*/
+             ((c << 8) & 0xff0000) | /*move byte 1 to byte 2*/
+             ((c >> 8) & 0xff00) | /*move byte 2 to byte 1*/
+             ((c << 24) & 0xff000000); /*byte 0 to byte 3*/
+    }
+#endif
+
+    lv_result_t res = insert_handler(obj, letter_buf);
+    if(res != LV_RESULT_OK) return res;
+
+    uint32_t c_uni = lv_text_encoded_next((const char *)&c2, NULL);
+
+    if(char_is_accepted(obj, c_uni) == false) {
+        LV_LOG_INFO("Character is not accepted by the text area (too long text or not in the accepted list)");
+        return LV_RESULT_INVALID;
+    }
+
+    if(ta->pwd_mode) pwd_char_hider(obj); /*Make sure all the current text contains only '*'*/
+
+    /*If the textarea is empty, invalidate it to hide the placeholder*/
+    if(ta->placeholder_txt) {
+        const char * txt = lv_label_get_text(ta->label);
+        if(txt[0] == '\0') lv_obj_invalidate(obj);
+    }
+
+    /* Try to allocate memory for pwd mode first, if we fail we don't insert the character either*/
+    if(ta->pwd_mode) {
+        /*+2: the new char + \0*/
+        size_t realloc_size = lv_strlen(ta->pwd_tmp) + lv_strlen(letter_buf) + 1;
+        char * pwd_tmp = lv_realloc(ta->pwd_tmp, realloc_size);
+        LV_ASSERT_MALLOC(pwd_tmp);
+        if(!pwd_tmp) return LV_RESULT_INVALID;
+        ta->pwd_tmp = pwd_tmp;
+    }
+
+
+    lv_label_ins_text(ta->label, ta->cursor.pos, letter_buf); /*Insert the character*/
+    lv_textarea_clear_selection(obj); /*Clear selection*/
+
+    if(ta->pwd_mode) {
+        lv_text_ins(ta->pwd_tmp, ta->cursor.pos, (const char *)letter_buf);
+
+        /*Auto hide characters*/
+        auto_hide_characters(obj);
+    }
+    return LV_RESULT_OK;
+}
+
 #endif

tests/src/test_cases/widgets/test_textarea.c

@@ -233,4 +233,85 @@ void test_textarea_properties(void)
 #endif
 }
 
+static uint32_t event_count;
+static void event_counter_cb(lv_event_t * e)
+{
+    LV_UNUSED(e);
+    event_count++;
+}
+
+void test_textarea_set_text_should_emit_value_changed_event_only_once(void)
+{
+
+    const char * accepted_list = "abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ!,";
+    const char * text = "Hello, World!";
+    const uint32_t text_len = 13U; /* strlen("Hello, World!") */
+
+    /* Test 1: with accepted_chars set */
+    event_count = 0;
+    lv_textarea_set_accepted_chars(textarea, accepted_list);
+    lv_obj_add_event_cb(textarea, event_counter_cb, LV_EVENT_VALUE_CHANGED, NULL);
+
+    lv_textarea_set_text(textarea, text);
+
+    TEST_ASSERT_EQUAL_STRING(text, lv_textarea_get_text(textarea));
+    TEST_ASSERT_EQUAL_UINT32(1U, event_count);
+
+    /* Test 2: with max_length set to exactly the text length — if set_text
+     * doesn't clear before re-adding chars, char_is_accepted sees the buffer
+     * as already full and rejects every character, leaving the textarea empty */
+    lv_obj_clean(active_screen);
+    textarea = lv_textarea_create(active_screen);
+
+    event_count = 0;
+    lv_textarea_set_max_length(textarea, text_len);
+    lv_obj_add_event_cb(textarea, event_counter_cb, LV_EVENT_VALUE_CHANGED, NULL);
+
+    lv_textarea_set_text(textarea, text);
+
+    TEST_ASSERT_EQUAL_STRING(text, lv_textarea_get_text(textarea));
+    TEST_ASSERT_EQUAL_UINT32(1U, event_count);
+
+    /* Test 3: with both accepted_chars and max_length set */
+    lv_obj_clean(active_screen);
+    textarea = lv_textarea_create(active_screen);
+
+    event_count = 0;
+    lv_textarea_set_accepted_chars(textarea, accepted_list);
+    lv_textarea_set_max_length(textarea, text_len);
+    lv_obj_add_event_cb(textarea, event_counter_cb, LV_EVENT_VALUE_CHANGED, NULL);
+
+    lv_textarea_set_text(textarea, text);
+
+    TEST_ASSERT_EQUAL_STRING(text, lv_textarea_get_text(textarea));
+    TEST_ASSERT_EQUAL_UINT32(1U, event_count);
+
+    /* Test 4: empty string — no characters to add, no event */
+    lv_obj_clean(active_screen);
+    textarea = lv_textarea_create(active_screen);
+
+    event_count = 0;
+    lv_textarea_set_accepted_chars(textarea, accepted_list);
+    lv_textarea_set_max_length(textarea, text_len);
+    lv_obj_add_event_cb(textarea, event_counter_cb, LV_EVENT_VALUE_CHANGED, NULL);
+
+    lv_textarea_set_text(textarea, "");
+
+    TEST_ASSERT_EQUAL_STRING("", lv_textarea_get_text(textarea));
+    TEST_ASSERT_EQUAL_UINT32(0U, event_count);
+
+    /* Test 5: all characters rejected by accepted_chars — no characters added, no event */
+    lv_obj_clean(active_screen);
+    textarea = lv_textarea_create(active_screen);
+
+    event_count = 0;
+    lv_textarea_set_accepted_chars(textarea, accepted_list);
+    lv_obj_add_event_cb(textarea, event_counter_cb, LV_EVENT_VALUE_CHANGED, NULL);
+
+    lv_textarea_set_text(textarea, "123"); /* digits not in accepted_list */
+
+    TEST_ASSERT_EQUAL_STRING("", lv_textarea_get_text(textarea));
+    TEST_ASSERT_EQUAL_UINT32(0U, event_count);
+}
+
 #endif