Implement custom, opt-in hit-testing handlers for objects (#1318)

src/lv_core/lv_indev.c

@@ -1034,25 +1034,7 @@ lv_obj_t * lv_indev_search_obj(lv_obj_t * obj, lv_point_t *point)
     lv_obj_t * found_p = NULL;
 
     /*If the point is on this object check its children too*/
-#if LV_USE_EXT_CLICK_AREA == LV_EXT_CLICK_AREA_TINY
+    if(lv_obj_hittest(obj, point)) {
-    lv_area_t ext_area;
-    ext_area.x1 = obj->coords.x1 - obj->ext_click_pad_hor;
-    ext_area.x2 = obj->coords.x2 + obj->ext_click_pad_hor;
-    ext_area.y1 = obj->coords.y1 - obj->ext_click_pad_ver;
-    ext_area.y2 = obj->coords.y2 + obj->ext_click_pad_ver;
-
-    if(lv_area_is_point_on(&ext_area, point)) {
-#elif LV_USE_EXT_CLICK_AREA == LV_EXT_CLICK_AREA_FULL
-    lv_area_t ext_area;
-    ext_area.x1 = obj->coords.x1 - obj->ext_click_pad.x1;
-    ext_area.x2 = obj->coords.x2 + obj->ext_click_pad.x2;
-    ext_area.y1 = obj->coords.y1 - obj->ext_click_pad.y1;
-    ext_area.y2 = obj->coords.y2 + obj->ext_click_pad.y2;
-
-    if(lv_area_is_point_on(&ext_area, point)) {
-#else
-    if(lv_area_is_point_on(&obj->coords, point)) {
-#endif
         lv_obj_t * i;
 
         LV_LL_READ(obj->child_ll, i)

src/lv_core/lv_obj.c

@@ -201,6 +201,7 @@ lv_obj_t * lv_obj_create(lv_obj_t * parent, const lv_obj_t * copy)
         new_obj->group_p = NULL;
 #endif
         /*Set attributes*/
+        new_obj->adv_hittest  = 0;
         new_obj->click        = 0;
         new_obj->drag         = 0;
         new_obj->drag_throw   = 0;
@@ -1275,6 +1276,17 @@ void lv_obj_set_hidden(lv_obj_t * obj, bool en)
     par->signal_cb(par, LV_SIGNAL_CHILD_CHG, obj);
 }
 
+/**
+ * Set whether advanced hit-testing is enabled on an object
+ * @param obj pointer to an object
+ * @param en true: advanced hit-testing is enabled
+ */
+void lv_obj_set_adv_hittest(lv_obj_t * obj, bool en) {
+    LV_ASSERT_OBJ(obj, LV_OBJX_NAME);
+
+    obj->adv_hittest = en == false ? 0 : 1;
+}
+
 /**
  * Enable or disable the clicking of an object
  * @param obj pointer to an object
@@ -2053,6 +2065,18 @@ bool lv_obj_get_hidden(const lv_obj_t * obj)
     return obj->hidden == 0 ? false : true;
 }
 
+/**
+ * Get whether advanced hit-testing is enabled on an object
+ * @param obj pointer to an object
+ * @return true: advanced hit-testing is enabled
+ */
+bool lv_obj_get_adv_hittest(const lv_obj_t * obj)
+{
+    LV_ASSERT_OBJ(obj, LV_OBJX_NAME);
+
+    return obj->adv_hittest == 0 ? false : true;
+}
+
 /**
  * Get the click enable attribute of an object
  * @param obj pointer to an object
@@ -2368,6 +2392,45 @@ bool lv_obj_is_focused(const lv_obj_t * obj)
  * OTHER FUNCTIONS
  *------------------*/
 
+/**
+ * Hit-test an object given a particular point in screen space.
+ * @param obj object to hit-test
+ * @param point screen-space point
+ * @return true if the object is considered under the point
+ */
+bool lv_obj_hittest(lv_obj_t * obj, lv_point_t * point) {
+#if LV_USE_EXT_CLICK_AREA == LV_EXT_CLICK_AREA_TINY
+    lv_area_t ext_area;
+    ext_area.x1 = obj->coords.x1 - obj->ext_click_pad_hor;
+    ext_area.x2 = obj->coords.x2 + obj->ext_click_pad_hor;
+    ext_area.y1 = obj->coords.y1 - obj->ext_click_pad_ver;
+    ext_area.y2 = obj->coords.y2 + obj->ext_click_pad_ver;
+
+    if(!lv_area_is_point_on(&ext_area, point, 0)) {
+#elif LV_USE_EXT_CLICK_AREA == LV_EXT_CLICK_AREA_FULL
+    lv_area_t ext_area;
+    ext_area.x1 = obj->coords.x1 - obj->ext_click_pad.x1;
+    ext_area.x2 = obj->coords.x2 + obj->ext_click_pad.x2;
+    ext_area.y1 = obj->coords.y1 - obj->ext_click_pad.y1;
+    ext_area.y2 = obj->coords.y2 + obj->ext_click_pad.y2;
+
+    if(!lv_area_is_point_on(&ext_area, point, 0)) {
+#else
+    if(!lv_area_is_point_on(&obj->coords, point, 0)) {
+#endif
+        return false;
+    }
+    if(obj->adv_hittest) {
+        lv_hit_test_info_t hit_info;
+        hit_info.point = point;
+        hit_info.result = true;
+        obj->signal_cb(obj, LV_SIGNAL_HIT_TEST, &hit_info);
+        if(!hit_info.result)
+            return false;
+    }
+    return true;
+}
+
 /**
  * Used in the signal callback to handle `LV_SIGNAL_GET_TYPE` signal
  * @param obj pointer to an object

src/lv_core/lv_obj.h

@@ -128,6 +128,7 @@ enum {
     LV_SIGNAL_GET_TYPE, /**< LittlevGL needs to retrieve the object's type */
 
     /*Input device related*/
+    LV_SIGNAL_HIT_TEST,          /**< Advanced hit-testing */
     LV_SIGNAL_PRESSED,           /**< The object has been pressed*/
     LV_SIGNAL_PRESSING,          /**< The object is being pressed (called continuously while pressing)*/
     LV_SIGNAL_PRESS_LOST,        /**< User is still pressing but slid cursor/finger off of the object */
@@ -225,7 +226,8 @@ typedef struct _lv_obj_t
     uint8_t parent_event : 1;   /**< 1: Send the object's events to the parent too. */
     lv_drag_dir_t drag_dir : 3; /**<  Which directions the object can be dragged in */
     lv_bidi_dir_t base_dir : 2; /**< Base direction of texts related to this object */
-    uint8_t reserved : 3;       /**<  Reserved for future use*/
+    uint8_t adv_hittest : 1;    /**< 1: Use advanced hit-testing (slower) */
+    uint8_t reserved : 2;       /**<  Reserved for future use*/
     uint8_t protect;            /**< Automatically happening actions can be prevented. 'OR'ed values from
                                    `lv_protect_t`*/
     lv_opa_t opa_scale;         /**< Scale down the opacity by this factor. Effects all children as well*/
@@ -263,6 +265,12 @@ typedef struct
                                                ... [x]: "lv_obj" */
 } lv_obj_type_t;
 
+typedef struct _lv_hit_test_info_t
+{
+    lv_point_t *point;
+    bool result;
+} lv_hit_test_info_t;
+
 /**********************
  * GLOBAL PROTOTYPES
  **********************/
@@ -466,6 +474,13 @@ void lv_obj_report_style_mod(lv_style_t * style);
  */
 void lv_obj_set_hidden(lv_obj_t * obj, bool en);
 
+/**
+ * Set whether advanced hit-testing is enabled on an object
+ * @param obj pointer to an object
+ * @param en true: advanced hit-testing is enabled
+ */
+void lv_obj_set_adv_hittest(lv_obj_t * obj, bool en);
+
 /**
  * Enable or disable the clicking of an object
  * @param obj pointer to an object
@@ -808,6 +823,13 @@ const lv_style_t * lv_obj_get_style(const lv_obj_t * obj);
  */
 bool lv_obj_get_hidden(const lv_obj_t * obj);
 
+/**
+ * Get whether advanced hit-testing is enabled on an object
+ * @param obj pointer to an object
+ * @return true: advanced hit-testing is enabled
+ */
+bool lv_obj_get_adv_hittest(const lv_obj_t * obj);
+
 /**
  * Get the click enable attribute of an object
  * @param obj pointer to an object
@@ -914,6 +936,8 @@ lv_event_cb_t lv_obj_get_event_cb(const lv_obj_t * obj);
  * Other get
  *-----------------*/
 
+bool lv_obj_hittest(lv_obj_t * obj, lv_point_t * point);
+
 /**
  * Get the ext pointer
  * @param obj pointer to an object

src/lv_misc/lv_area.c

@@ -27,6 +27,8 @@
  *  STATIC PROTOTYPES
  **********************/
 
+static bool lv_point_within_circle(const lv_area_t * area, const lv_point_t * p);
+
 /**********************
  *  STATIC VARIABLES
  **********************/
@@ -148,15 +150,62 @@ void lv_area_join(lv_area_t * a_res_p, const lv_area_t * a1_p, const lv_area_t *
  * @param p_p pointer to a point
  * @return false:the point is out of the area
  */
-bool lv_area_is_point_on(const lv_area_t * a_p, const lv_point_t * p_p)
+bool lv_area_is_point_on(const lv_area_t * a_p, const lv_point_t * p_p, lv_coord_t radius)
 {
-    bool is_on = false;
+    /*First check the basic area*/
-
+    bool is_on_rect = false;
     if((p_p->x >= a_p->x1 && p_p->x <= a_p->x2) && ((p_p->y >= a_p->y1 && p_p->y <= a_p->y2))) {
-        is_on = true;
+        is_on_rect = true;
     }
-
+    if(!is_on_rect)
-    return is_on;
+        return false;
+    /*Now handle potential rounded rectangles*/
+    if(radius <= 0) {
+        /*No radius, it is within the rectangle*/
+        return true;
+    }
+    lv_coord_t max_radius = LV_MATH_MIN(lv_area_get_width(a_p) / 2, lv_area_get_height(a_p) / 2);
+    if(radius > max_radius)
+        radius = max_radius;
+    
+    /*Check if it's in one of the corners*/
+    lv_area_t corner_area;
+    /*Top left*/
+    corner_area.x1 = a_p->x1;
+    corner_area.x2 = a_p->x1 + radius;
+    corner_area.y1 = a_p->y1;
+    corner_area.y2 = a_p->y1 + radius;
+    if(lv_area_is_point_on(&corner_area, p_p, 0)) {
+        corner_area.x2 += radius;
+        corner_area.y2 += radius;
+        return lv_point_within_circle(&corner_area, p_p);
+    }
+    /*Bottom left*/
+    corner_area.y1 = a_p->y2 - radius;
+    corner_area.y2 = a_p->y2;
+    if(lv_area_is_point_on(&corner_area, p_p, 0)) {
+        corner_area.x2 += radius;
+        corner_area.y1 -= radius;
+        return lv_point_within_circle(&corner_area, p_p);
+    }
+    /*Bottom right*/
+    corner_area.x1 = a_p->x2 - radius;
+    corner_area.x2 = a_p->x2;
+    if(lv_area_is_point_on(&corner_area, p_p, 0)) {
+        corner_area.x1 -= radius;
+        corner_area.y1 -= radius;
+        return lv_point_within_circle(&corner_area, p_p);
+    }
+    /*Top right*/
+    corner_area.y1 = a_p->y1;
+    corner_area.y2 = a_p->y1 + radius;
+    if(lv_area_is_point_on(&corner_area, p_p, 0)) {
+        corner_area.x1 -= radius;
+        corner_area.y2 += radius;
+        return lv_point_within_circle(&corner_area, p_p);
+    }
+    /*Not within corners*/
+    return false;
 }
 
 /**
@@ -208,3 +257,24 @@ void lv_area_increment(lv_area_t * a_p, const lv_coord_t amount)
 /**********************
  *   STATIC FUNCTIONS
  **********************/
+
+static bool lv_point_within_circle(const lv_area_t * area, const lv_point_t * p)
+{
+    lv_coord_t r = (area->x2 - area->x1) / 2;
+
+    /* Circle center */
+    lv_coord_t cx = area->x1 + r;
+    lv_coord_t cy = area->y1 + r;
+    
+    /*Simplify the code by moving everything to (0, 0) */
+    lv_coord_t px = p->x - cx;
+    lv_coord_t py = p->y - cy;
+
+    int32_t r_sqrd = r*r;
+    int32_t dist = (px*px) + (py*py);
+    
+    if(dist <= r_sqrd)
+        return true;
+    else
+        return false;
+}

src/lv_misc/lv_area.h

@@ -148,9 +148,10 @@ void lv_area_join(lv_area_t * a_res_p, const lv_area_t * a1_p, const lv_area_t *
  * Check if a point is on an area
  * @param a_p pointer to an area
  * @param p_p pointer to a point
+ * @param radius radius of area (e.g. for rounded rectangle)
  * @return false:the point is out of the area
  */
-bool lv_area_is_point_on(const lv_area_t * a_p, const lv_point_t * p_p);
+bool lv_area_is_point_on(const lv_area_t * a_p, const lv_point_t * p_p, lv_coord_t radius);
 
 /**
  * Check if two area has common parts

src/lv_objx/lv_btnm.c

@@ -1056,7 +1056,7 @@ static uint16_t get_button_from_point(lv_obj_t * btnm, lv_point_t * p)
         btn_area.y1 += btnm_cords.y1;
         btn_area.x2 += btnm_cords.x1;
         btn_area.y2 += btnm_cords.y1;
-        if(lv_area_is_point_on(&btn_area, p) != false) {
+        if(lv_area_is_point_on(&btn_area, p, 0) != false) {
             break;
         }
     }

src/lv_objx/lv_calendar.c

@@ -508,7 +508,7 @@ static lv_res_t lv_calendar_signal(lv_obj_t * calendar, lv_signal_t sign, void *
         lv_indev_get_point(indev, &p);
 
         /*If the header is pressed mark an arrow as pressed*/
-        if(lv_area_is_point_on(&header_area, &p)) {
+        if(lv_area_is_point_on(&header_area, &p, 0)) {
             if(p.x < header_area.x1 + lv_area_get_width(&header_area) / 2) {
                 if(ext->btn_pressing != -1) lv_obj_invalidate(calendar);
                 ext->btn_pressing = -1;
@@ -605,7 +605,7 @@ static bool calculate_touched_day(lv_obj_t * calendar, const lv_point_t * touche
     days_area.y1 =
         calendar->coords.y1 + get_header_height(calendar) + get_day_names_height(calendar) - style_bg->body.padding.top;
 
-    if(lv_area_is_point_on(&days_area, touched_point)) {
+    if(lv_area_is_point_on(&days_area, touched_point, 0)) {
         lv_coord_t w  = (days_area.x2 - days_area.x1 + 1) / 7;
         lv_coord_t h  = (days_area.y2 - days_area.y1 + 1) / 6;
         uint8_t x_pos = 0;

src/lv_objx/lv_cpicker.c

@@ -57,6 +57,7 @@
  **********************/
 static lv_design_res_t lv_cpicker_design(lv_obj_t * cpicker, const lv_area_t * clip_area, lv_design_mode_t mode);
 static lv_res_t lv_cpicker_signal(lv_obj_t * cpicker, lv_signal_t sign, void * param);
+static bool lv_cpicker_hit(lv_obj_t * cpicker, const lv_point_t * p);
 
 static void draw_rect_grad(lv_obj_t * cpicker, const lv_area_t * mask, lv_opa_t opa_scale);
 static void draw_disc_grad(lv_obj_t * cpicker, const lv_area_t * mask, lv_opa_t opa_scale);
@@ -889,11 +890,33 @@ static lv_res_t lv_cpicker_signal(lv_obj_t * cpicker, lv_signal_t sign, void * p
             res = lv_event_send(cpicker, LV_EVENT_VALUE_CHANGED, NULL);
             if(res != LV_RES_OK) return res;
         }
+    } else if(sign == LV_SIGNAL_HIT_TEST) {
+        lv_hit_test_info_t *info = param;
+        info->result = lv_cpicker_hit(cpicker, info->point);
     }
 
     return res;
 }
 
+static bool lv_cpicker_hit(lv_obj_t * cpicker, const lv_point_t * p)
+{
+    lv_cpicker_ext_t * ext = (lv_cpicker_ext_t *)lv_obj_get_ext_attr(cpicker);
+    if(ext->type != LV_CPICKER_TYPE_DISC || ext->preview)
+        return true;
+    const lv_style_t * style_main = lv_cpicker_get_style(cpicker, LV_CPICKER_STYLE_MAIN);
+    lv_area_t area_mid;
+    lv_area_copy(&area_mid, &cpicker->coords);
+    area_mid.x1 += style_main->line.width;
+    area_mid.y1 += style_main->line.width;
+    area_mid.x2 -= style_main->line.width;
+    area_mid.y2 -= style_main->line.width;
+    
+    if(lv_area_is_point_on(&area_mid, p, LV_RADIUS_CIRCLE))
+        return false;
+    
+    return true;
+}
+
 static void next_color_mode(lv_obj_t * cpicker)
 {
     lv_cpicker_ext_t * ext = lv_obj_get_ext_attr(cpicker);