Add support for BLE notification (ANS client).

Work In Progress!!!

src/DisplayApp/Screens/Modal.cpp

@@ -26,6 +26,8 @@ bool Modal::OnButtonPushed() {
 }
 
 void Modal::Show() {
+  if(isVisible) return;
+  isVisible = true;
   lv_style_copy(&modal_style, &lv_style_plain_color);
   modal_style.body.main_color = modal_style.body.grad_color = LV_COLOR_BLACK;
   modal_style.body.opa = LV_OPA_50;
@@ -63,6 +65,7 @@ void Modal::Hide() {
   /* Delete the parent modal background */
   lv_obj_del_async(lv_obj_get_parent(mbox));
   mbox = NULL; /* happens before object is actually deleted! */
+  isVisible = false;
 }
 
 void Modal::mbox_event_cb(lv_obj_t *obj, lv_event_t evt) {
@@ -79,3 +82,37 @@ void Modal::OnEvent(lv_obj_t *event_obj, lv_event_t evt) {
 //    Hide();
   }
 }
+
+void Modal::Show(const std::string& message) {
+  if(isVisible) return;
+  this->message = message;
+  isVisible = true;
+  lv_style_copy(&modal_style, &lv_style_plain_color);
+  modal_style.body.main_color = modal_style.body.grad_color = LV_COLOR_BLACK;
+  modal_style.body.opa = LV_OPA_50;
+
+  obj = lv_obj_create(lv_scr_act(), NULL);
+  lv_obj_set_style(obj, &modal_style);
+  lv_obj_set_pos(obj, 0, 0);
+  lv_obj_set_size(obj, LV_HOR_RES, LV_VER_RES);
+  lv_obj_set_opa_scale_enable(obj, true); /* Enable opacity scaling for the animation */
+
+  static const char * btns2[] = {"Ok", ""};
+
+  /* Create the message box as a child of the modal background */
+  mbox = lv_mbox_create(obj, NULL);
+  lv_mbox_add_btns(mbox, btns2);
+  lv_mbox_set_text(mbox, message.data());
+  lv_obj_align(mbox, NULL, LV_ALIGN_CENTER, 0, 0);
+  lv_obj_set_event_cb(mbox, Modal::mbox_event_cb);
+
+  mbox->user_data = this;
+
+  /* Fade the message box in with an animation */
+  lv_anim_t a;
+  lv_anim_init(&a);
+  lv_anim_set_time(&a, 500, 0);
+  lv_anim_set_values(&a, LV_OPA_TRANSP, LV_OPA_COVER);
+  lv_anim_set_exec_cb(&a, obj, (lv_anim_exec_xcb_t)lv_obj_set_opa_scale);
+  lv_anim_create(&a);
+}

src/DisplayApp/Screens/Modal.h

@@ -23,6 +23,7 @@ namespace Pinetime {
           ~Modal() override;
 
           void Show();
+          void Show(const std::string& message);
           void Hide();
 
           bool Refresh() override;
@@ -37,6 +38,8 @@ namespace Pinetime {
           lv_obj_t *mbox;
           lv_obj_t *info;
           bool running = true;
+          bool isVisible = false;
+          std::string message;
 
       };
     }