fix(buttonmatrix): use const arrays (#6765)

Co-authored-by: Julian Foad <julian@foad.me.uk>

src/widgets/buttonmatrix/lv_buttonmatrix.c

@@ -51,7 +51,7 @@ static bool button_is_popover(lv_buttonmatrix_ctrl_t ctrl_bits);
 static bool button_is_checkable(lv_buttonmatrix_ctrl_t ctrl_bits);
 static bool button_get_checked(lv_buttonmatrix_ctrl_t ctrl_bits);
 static uint32_t get_button_from_point(lv_obj_t * obj, lv_point_t * p);
-static void allocate_button_areas_and_controls(const lv_obj_t * obj, const char ** map);
+static void allocate_button_areas_and_controls(const lv_obj_t * obj, const char * const * map);
 static void invalidate_button_area(const lv_obj_t * obj, uint32_t btn_idx);
 static void make_one_button_checked(lv_obj_t * obj, uint32_t btn_idx);
 static bool has_popovers_in_top_row(lv_obj_t * obj);
@@ -60,7 +60,7 @@ static bool has_popovers_in_top_row(lv_obj_t * obj);
  *  STATIC VARIABLES
  **********************/
 #if LV_WIDGETS_HAS_DEFAULT_VALUE
-static const char * lv_buttonmatrix_def_map[] = {"Btn1", "Btn2", "Btn3", "\n", "Btn4", "Btn5", ""};
+static const char * const lv_buttonmatrix_def_map[] = {"Btn1", "Btn2", "Btn3", "\n", "Btn4", "Btn5", ""};
 #endif
 
 const lv_obj_class_t lv_buttonmatrix_class = {
@@ -96,7 +96,7 @@ lv_obj_t * lv_buttonmatrix_create(lv_obj_t * parent)
  * Setter functions
  *====================*/
 
-void lv_buttonmatrix_set_map(lv_obj_t * obj, const char * map[])
+void lv_buttonmatrix_set_map(lv_obj_t * obj, const char * const map[])
 {
     LV_ASSERT_OBJ(obj, MY_CLASS);
     if(map == NULL) return;
@@ -125,7 +125,7 @@ void lv_buttonmatrix_set_map(lv_obj_t * obj, const char * map[])
      *(A button can be 1,2,3... unit wide)*/
     uint32_t txt_tot_i = 0; /*Act. index in the str map*/
     uint32_t btn_tot_i = 0; /*Act. index of button areas*/
-    const char ** map_row = map;
+    const char * const * map_row = map;
 
     /*Count the units and the buttons in a line*/
     uint32_t row;
@@ -295,7 +295,7 @@ void lv_buttonmatrix_set_one_checked(lv_obj_t * obj, bool en)
  * Getter functions
  *====================*/
 
-const char ** lv_buttonmatrix_get_map(const lv_obj_t * obj)
+const char * const * lv_buttonmatrix_get_map(const lv_obj_t * obj)
 {
     LV_ASSERT_OBJ(obj, MY_CLASS);
 
@@ -813,7 +813,7 @@ static void draw_main(lv_event_t * e)
  * @param obj pointer to button matrix object
  * @param map_p pointer to a string array
  */
-static void allocate_button_areas_and_controls(const lv_obj_t * obj, const char ** map)
+static void allocate_button_areas_and_controls(const lv_obj_t * obj, const char * const * map)
 {
     lv_buttonmatrix_t * btnm = (lv_buttonmatrix_t *)obj;
     btnm->row_cnt = 1;
@@ -1029,7 +1029,7 @@ static bool has_popovers_in_top_row(lv_obj_t * obj)
         return false;
     }
 
-    const char ** map_row = btnm->map_p;
+    const char * const * map_row = btnm->map_p;
     uint32_t btn_cnt = 0;
 
     while(map_row[btn_cnt] && lv_strcmp(map_row[btn_cnt], "\n") != 0 && map_row[btn_cnt][0] != '\0') {

src/widgets/buttonmatrix/lv_buttonmatrix.h

@@ -73,7 +73,7 @@ lv_obj_t * lv_buttonmatrix_create(lv_obj_t * parent);
  * @param obj       pointer to a button matrix object
  * @param map       pointer a string array. The last string has to be: "". Use "\n" to make a line break.
  */
-void lv_buttonmatrix_set_map(lv_obj_t * obj, const char * map[]);
+void lv_buttonmatrix_set_map(lv_obj_t * obj, const char * const map[]);
 
 /**
  * Set the button control map (hidden, disabled etc.) for a button matrix.
@@ -155,7 +155,7 @@ void lv_buttonmatrix_set_one_checked(lv_obj_t * obj, bool en);
  * @param obj       pointer to a button matrix object
  * @return          the current map
  */
-const char ** lv_buttonmatrix_get_map(const lv_obj_t * obj);
+const char * const * lv_buttonmatrix_get_map(const lv_obj_t * obj);
 
 /**
  * Get the index of the lastly "activated" button by the user (pressed, released, focused etc)

src/widgets/buttonmatrix/lv_buttonmatrix_private.h

@@ -30,7 +30,7 @@ extern "C" {
 /** Data of button matrix */
 struct lv_buttonmatrix_t {
     lv_obj_t obj;
-    const char ** map_p;                 /**< Pointer to the current map */
+    const char * const * map_p;          /**< Pointer to the current map */
     lv_area_t * button_areas;            /**< Array of areas of buttons */
     lv_buttonmatrix_ctrl_t * ctrl_bits;  /**< Array of control bytes */
     uint32_t btn_cnt;                    /**< Number of button in 'map_p'(Handled by the library) */

src/widgets/keyboard/lv_keyboard.c

@@ -176,19 +176,19 @@ static const lv_buttonmatrix_ctrl_t default_kb_ctrl_num_map[] = {
     1, 1, 1, 1, 1
 };
 
-static const char * * kb_map[10] = {
-    (const char * *)default_kb_map_lc,
-    (const char * *)default_kb_map_uc,
-    (const char * *)default_kb_map_spec,
-    (const char * *)default_kb_map_num,
-    (const char * *)default_kb_map_lc,
-    (const char * *)default_kb_map_lc,
-    (const char * *)default_kb_map_lc,
-    (const char * *)default_kb_map_lc,
+static const char * const * kb_map[10] = {
+    default_kb_map_lc,
+    default_kb_map_uc,
+    default_kb_map_spec,
+    default_kb_map_num,
+    default_kb_map_lc,
+    default_kb_map_lc,
+    default_kb_map_lc,
+    default_kb_map_lc,
 #if LV_USE_ARABIC_PERSIAN_CHARS == 1
-    (const char * *)default_kb_map_ar,
+    default_kb_map_ar,
 #endif
-    (const char * *)NULL
+    NULL
 };
 static const lv_buttonmatrix_ctrl_t * kb_ctrl[10] = {
     default_kb_ctrl_lc_map,
@@ -269,7 +269,7 @@ void lv_keyboard_set_popovers(lv_obj_t * obj, bool en)
     lv_keyboard_update_ctrl_map(obj);
 }
 
-void lv_keyboard_set_map(lv_obj_t * obj, lv_keyboard_mode_t mode, const char * map[],
+void lv_keyboard_set_map(lv_obj_t * obj, lv_keyboard_mode_t mode, const char * const map[],
                          const lv_buttonmatrix_ctrl_t ctrl_map[])
 {
     LV_ASSERT_OBJ(obj, MY_CLASS);
@@ -410,7 +410,7 @@ void lv_keyboard_def_event_cb(lv_event_t * e)
     }
 }
 
-const char ** lv_keyboard_get_map_array(const lv_obj_t * kb)
+const char * const * lv_keyboard_get_map_array(const lv_obj_t * kb)
 {
     return lv_buttonmatrix_get_map(kb);
 }

src/widgets/keyboard/lv_keyboard.h

@@ -107,7 +107,7 @@ void lv_keyboard_set_popovers(lv_obj_t * kb, bool en);
  * @param ctrl_map  See 'lv_buttonmatrix_set_ctrl_map()' for more info.
 
  */
-void lv_keyboard_set_map(lv_obj_t * kb, lv_keyboard_mode_t mode, const char * map[],
+void lv_keyboard_set_map(lv_obj_t * kb, lv_keyboard_mode_t mode, const char * const map[],
                          const lv_buttonmatrix_ctrl_t ctrl_map[]);
 
 /*=====================
@@ -140,7 +140,7 @@ bool lv_keyboard_get_popovers(const lv_obj_t * obj);
  * @param kb        pointer to a keyboard object
  * @return          the current map
  */
-const char ** lv_keyboard_get_map_array(const lv_obj_t * kb);
+const char * const * lv_keyboard_get_map_array(const lv_obj_t * kb);
 
 /**
  * Get the index of the lastly "activated" button by the user (pressed, released, focused etc)

tests/src/test_cases/widgets/test_btnmatrix.c

@@ -25,7 +25,7 @@ void tearDown(void)
 
 void test_button_matrix_creation(void)
 {
-    const char ** map;
+    const char * const * map;
 
     /* Verify the default map. */
     map = lv_buttonmatrix_get_map(btnm);
@@ -39,7 +39,7 @@ void test_button_matrix_creation(void)
 
 void test_button_matrix_set_map_works(void)
 {
-    const char ** ret_map;
+    const char * const * ret_map;
     static const char * exp_map[] = {"A", "B", "\n", "C", "D", ""};
 
     lv_buttonmatrix_set_map(btnm, exp_map);