chore: minor fixed in XML and observer related codes

docs/src/details/auxiliary-modules/observer/observer.rst

@@ -372,7 +372,7 @@ integer value:
     - Drop-Down
     - Roller
     - Slider
-    - Scale Section Min/Max value
++    - Scale Section Min/Max values
 
 Any number of Observers can be created for a single Widget, each bound to ONE of
 the above properties.
@@ -521,6 +521,9 @@ The only difference is that in the bind function both the spangroup and the span
 
  :cpp:expr:`lv_spangroup_bind_span_text(spangroup, span1, &subject, format_string)`
 
+Note that before calling :cpp:expr:`lv_spangroup_delete_span` :cpp:expr:`lv_observer_remove`
+needs to be called manually as LVGL can't remove the binding automatically.
+
 Arc Widgets
 ~~~~~~~~~~~
 
@@ -578,10 +581,10 @@ Scale's Section
 
 This method of subscribing to an integer Subject affects a Section of a Scale Widget's integer
 minimum or maximum values directly.  Note that this is a one way binding (Subject ==> Widget)
-as the Scale Section's are not interactive.
+as the Scale Section's boundaries are not interactive.
 (Requires :c:macro:`LV_USE_SCALE` to be configured to ``1``.)
 
-It support only integer subjects.
+It supports only integer subjects.
 
 - :cpp:expr:`lv_scale_bind_section_min_value(scale, section1, &subject)`
 - :cpp:expr:`lv_scale_bind_section_max_value(scale, section1, &subject)`

examples/others/xml/view.xml

@@ -9,17 +9,26 @@
 		<style name="btn_pr_style" bg_opa="255"/>
 	</styles>
 
-	<view extends="lv_obj" name="main" width="280" height="content" style_bg_color="#light_blue">
+	<view extends="lv_obj" name="main" width="280" height="content" style_bg_color="#light_blue"
-		<lv_label text-translated="tiger"/>
+        style_layout="grid" style_grid_column_dsc_array="100 fr(1)" style_grid_row_dsc_array="50 200"
-		<my_card title="Card 1" name="card1"
+
-				 y="30"
+    >
-				 btn_rel_style="btn_style"
+        <lv_obj style_grid_cell_column_pos="0" style_grid_cell_column_span="1" style_grid_cell_x_align="stretch"
-				 btn_pr_style="btn_pr_style"/>
+                style_grid_cell_row_pos="0" style_grid_cell_row_span="1"  style_grid_cell_y_align="stretch">
+            <lv_label text="0/0"/>
+        </lv_obj>
+        <lv_obj style_grid_cell_column_pos="0" style_grid_cell_column_span="1" style_grid_cell_x_align="stretch"
+                style_grid_cell_row_pos="1" style_grid_cell_row_span="1"  style_grid_cell_y_align="stretch">
+            <lv_label text="0/1"/>
+        </lv_obj>
+        <lv_obj style_grid_cell_column_pos="1" style_grid_cell_column_span="1" style_grid_cell_x_align="stretch"
+                style_grid_cell_row_pos="0" style_grid_cell_row_span="1"  style_grid_cell_y_align="stretch">
+            <lv_label text="1/0"/>
+        </lv_obj>
+        <lv_obj style_grid_cell_column_pos="1" style_grid_cell_column_span="1" style_grid_cell_x_align="stretch"
+                style_grid_cell_row_pos="1" style_grid_cell_row_span="1"  style_grid_cell_y_align="stretch">
+            <lv_label text="1/1"/>
+        </lv_obj>
 
-		<my_card y="125"
-				 bg_color="0xffaaaa"
-				 action="Apply"
-				 btn_rel_style="btn_style"
-				 btn_pr_style="btn_pr_style"/>
 	</view>
 </component>

src/others/observer/lv_observer.h

@@ -548,7 +548,7 @@ lv_observer_t * lv_label_bind_text(lv_obj_t * obj, lv_subject_t * subject, const
 #if LV_USE_LABEL
 
 /**
- * Bind an integer, string, or pointer Subject to a Label.
+ * Bind an integer, string, or pointer Subject to a Spangroup's Span.
  * @param obj       pointer to Spangroup
  * @param span      pointer to Span
  * @param subject   pointer to Subject
@@ -607,7 +607,7 @@ lv_observer_t * lv_dropdown_bind_value(lv_obj_t * obj, lv_subject_t * subject);
 
 /**
  * Bind an integer subject to a scales section minimum value
- * @param obj       pointer to an Scale
+ * @param obj       pointer to a Scale
  * @param section   pointer to a Scale section
  * @param subject   pointer to a Subject
  * @return          pointer to newly-created Observer

src/others/xml/lv_xml_style.c

@@ -290,7 +290,7 @@ lv_result_t lv_xml_style_register(lv_xml_component_scope_t * scope, const char *
                 if(value[c] == ' ') item_cnt++;
             }
 
-            int32_t * dsc_array = lv_malloc((item_cnt + 1) * sizeof(int32_t)); /*+1 for LV_GRID_TEMPLATE_LAST*/
+            int32_t * dsc_array = lv_malloc((item_cnt + 2) * sizeof(int32_t)); /*+2 for LV_GRID_TEMPLATE_LAST*/
 
             char * value_buf = (char *)value;
             item_cnt = 0;

src/others/xml/lv_xml_widget.h

@@ -16,7 +16,6 @@ extern "C" {
 #include "../../misc/lv_types.h"
 #if LV_USE_XML
 
-#include "lv_xml.h"
 #include "lv_xml_utils.h"
 
 /**********************

src/others/xml/parsers/lv_xml_obj_parser.c

@@ -900,7 +900,7 @@ static void apply_styles(lv_xml_parser_state_t * state, lv_obj_t * obj, const ch
             if(value[i] == ' ') item_cnt++;
         }
 
-        int32_t * dsc_array = lv_malloc((item_cnt + 1) * sizeof(int32_t)); /*+1 for LV_GRID_TEMPLATE_LAST*/
+        int32_t * dsc_array = lv_malloc((item_cnt + 2) * sizeof(int32_t)); /*+2 for LV_GRID_TEMPLATE_LAST*/
 
         char * value_buf = (char *)value;
         item_cnt = 0;

src/others/xml/parsers/lv_xml_spangroup_parser.c

@@ -25,7 +25,6 @@
  **********************/
 
 static lv_span_overflow_t spangroup_overflow_to_enum(const char * txt);
-static void free_fmt_event_cb(lv_event_t * e);
 
 /**********************
  *  STATIC VARIABLES
@@ -97,7 +96,7 @@ void lv_xml_spangroup_span_apply(lv_xml_parser_state_t * state, const char ** at
             const char * fmt = lv_xml_get_value_of(attrs, "bind_text-fmt");
             if(fmt) {
                 fmt = lv_strdup(fmt);
-                lv_obj_add_event_cb(spangroup, free_fmt_event_cb, LV_EVENT_DELETE, (void *) fmt);
+                lv_obj_add_event_cb(spangroup, lv_event_free_user_data_cb, LV_EVENT_DELETE, (void *) fmt);
             }
             lv_spangroup_bind_span_text(spangroup, span, subject, fmt);
         }
@@ -117,10 +116,4 @@ static lv_span_overflow_t spangroup_overflow_to_enum(const char * txt)
     return 0; /*Return 0 in lack of a better option. */
 }
 
-static void free_fmt_event_cb(lv_event_t * e)
-{
-    void * fmt = lv_event_get_user_data(e);
-    lv_free(fmt);
-}
-
 #endif /* LV_USE_XML */

src/others/xml/parsers/lv_xml_textarea_parser.c

@@ -56,7 +56,7 @@ void lv_xml_textarea_apply(lv_xml_parser_state_t * state, const char ** attrs)
 
 
         if(lv_streq("text", name)) lv_textarea_set_text(item, value);
-        else if(lv_streq("placeholder", name)) lv_textarea_set_placeholder_text(item, value);
+        else if(lv_streq("placeholder_text", name)) lv_textarea_set_placeholder_text(item, value);
         else if(lv_streq("one_line", name)) lv_textarea_set_one_line(item, lv_xml_to_bool(value));
         else if(lv_streq("password_mode", name)) lv_textarea_set_password_mode(item, lv_xml_to_bool(value));
         else if(lv_streq("password_show_time", name)) lv_textarea_set_password_show_time(item, lv_xml_atoi(value));

src/widgets/label/lv_label.h

@@ -97,7 +97,7 @@ void lv_label_set_text(lv_obj_t * obj, const char * text);
  * @code
  * lv_label_set_text_fmt(label1, "%d user", user_num);
  * @endcode
- * @note It ignores `LV_USE_ARABIC_PERSIAN_CHARS`
+ * @note If `LV_USE_ARABIC_PERSIAN_CHARS` is enabled the text will be modified to have the correct Arabic characters in it.
  */
 void lv_label_set_text_fmt(lv_obj_t * obj, const char * fmt, ...) LV_FORMAT_ATTRIBUTE(2, 3);
 

src/widgets/span/lv_span.c

@@ -209,11 +209,14 @@ void lv_span_set_text_fmt(lv_span_t * span, const char * fmt, ...)
     va_start(args, fmt);
     char * text = lv_text_set_text_vfmt(fmt, args);
     LV_ASSERT_MALLOC(text);
-    if(text == NULL) return;
+    if(text == NULL) {
+        va_end(args);
+        return;
+    }
 
     va_end(args);
 
-    if(span->txt == NULL && span->static_flag) {
+    if(span->txt && !span->static_flag) {
         lv_free(span->txt);
     }
 
@@ -267,11 +270,14 @@ void lv_spangroup_set_span_text_fmt(lv_obj_t * obj, lv_span_t * span, const char
     va_start(args, fmt);
     char * text = lv_text_set_text_vfmt(fmt, args);
     LV_ASSERT_MALLOC(text);
-    if(text == NULL) return;
+    if(text == NULL) {
+        va_end(args);
+        return;
+    }
 
     va_end(args);
 
-    if(span->txt == NULL && span->static_flag) {
+    if(span->txt && !span->static_flag) {
         lv_free(span->txt);
     }
 

src/widgets/span/lv_span.h

@@ -75,6 +75,9 @@ lv_span_t * lv_spangroup_add_span(lv_obj_t * obj);
  * Remove the span from the spangroup and free memory.
  * @param obj   pointer to a spangroup object.
  * @param span  pointer to a span.
+ * @note        Note that before calling `lv_spangroup_delete_span`
+ *              `lv_observer_remove` needs to be called manually as LVGL can't remove the
+ *              binding automatically.
  */
 void lv_spangroup_delete_span(lv_obj_t * obj, lv_span_t * span);
 
@@ -100,7 +103,7 @@ void lv_span_set_text(lv_span_t * span, const char * text);
  * @param span  pointer to a span.
  * @param fmt   `printf`-like format string
  */
-void lv_span_set_text_fmt(lv_span_t * span, const char * fmt, ...);
+void lv_span_set_text_fmt(lv_span_t * span, const char * fmt, ...) LV_FORMAT_ATTRIBUTE(2, 3);
 
 /**
  * Set a static text. It will not be saved by the span so the 'text' variable
@@ -136,7 +139,7 @@ void lv_spangroup_set_span_text_static(lv_obj_t * obj, lv_span_t * span, const c
  * @param span  pointer to a span.
  * @param fmt   `printf`-like format string
  */
-void lv_spangroup_set_span_text_fmt(lv_obj_t * obj, lv_span_t * span, const char * fmt, ...);
+void lv_spangroup_set_span_text_fmt(lv_obj_t * obj, lv_span_t * span, const char * fmt, ...) LV_FORMAT_ATTRIBUTE(3, 4);
 
 /**
  * Set a static text. It will not be saved by the span so the 'text' variable

xmls/lv_spangroup.xml

@@ -1,35 +1,35 @@
 <!--
 Example
 <lv_spangroup mode="fixed">
-	<lv_spangroup-span text="hello " style="red"/>
+    <lv_spangroup-span text="hello " style="red"/>
-	<lv_spangroup-span text="world" style="blue"/>
+    <lv_spangroup-span text="world" style="blue"/>
 </lv_spangroup>
 -->
 
 <widget>
-	<api>
+    <api>
-		<enumdef name="lv_span_overflow">
+        <enumdef name="lv_span_overflow">
-			<enum name="clip" help=""/>
+            <enum name="clip" help=""/>
-			<enum name="ellipses" help=""/>
+            <enum name="ellipses" help=""/>
-		</enumdef>
+        </enumdef>
 
-		<enumdef name="lv_span_mode">
+        <enumdef name="lv_span_mode">
-			<enum name="fixed" help=""/>
+            <enum name="fixed" help=""/>
-			<enum name="expand" help=""/>
+            <enum name="expand" help=""/>
-			<enum name="break" help=""/>
+            <enum name="break" help=""/>
-		</enumdef>
+        </enumdef>
 
-	    <prop name="overflow" type="enum:lv_span_overflow" help=""/>
+        <prop name="overflow" type="enum:lv_span_overflow" help=""/>
-	    <prop name="max_lines" type="int" help=""/>
+        <prop name="max_lines" type="int" help=""/>
-	    <prop name="indent" type="int" help=""/>
+        <prop name="indent" type="int" help=""/>
 
-		<element name="span" type="lv_span" access="add">
+        <element name="span" type="lv_span" access="add">
-			<prop name="text" type="string" help=""/>
+            <prop name="text" type="string" help=""/>
-			<prop name="style" type="style" help=""/>
+            <prop name="style" type="style" help=""/>
-    	    <prop name="bind_text" help="">
+            <prop name="bind_text" help="">
                 <param name="bind_text" type="subject"/>
                 <param name="fmt" type="string" default="NULL"/>
             </prop>
-		</element>
+        </element>
-	</api>
+    </api>
 </widget>