Use databinding for the top bar. It's so nice now!

src/app_console/app_console.cpp

@@ -336,7 +336,6 @@ void RegisterDbDump() {
   esp_console_cmd_register(&cmd);
 }
 
-#if CONFIG_APPTRACE_ENABLE
 int CmdTasks(int argc, char** argv) {
   if (!configUSE_TRACE_FACILITY) {
     std::cout << "configUSE_TRACE_FACILITY must be enabled" << std::endl;
@@ -446,7 +445,6 @@ void RegisterTasks() {
                         .argtable = NULL};
   esp_console_cmd_register(&cmd);
 }
-#endif
 
 int CmdHeaps(int argc, char** argv) {
   static const std::pmr::string usage = "usage: heaps";
@@ -638,9 +636,7 @@ auto AppConsole::RegisterExtraComponents() -> void {
   RegisterDbTracks();
   RegisterDbIndex();
   RegisterDbDump();
-#if CONFIG_APPTRACE_ENABLE
   RegisterTasks();
-#endif
 
   RegisterHeaps();
 

src/battery/battery.cpp

@@ -77,15 +77,16 @@ auto Battery::Update() -> void {
                      *charge_state == ChargeStatus::kChargingFast ||
                      *charge_state == ChargeStatus::kFullCharge;
 
-  if (!state_ || state_->is_charging != is_charging ||
+  if (state_ && state_->is_charging == is_charging &&
-      state_->percent != percent) {
+      state_->percent == percent) {
-    EmitEvent();
+    return;
   }
 
   state_ = BatteryState{
       .percent = percent,
       .is_charging = is_charging,
   };
+  EmitEvent();
 }
 
 auto Battery::State() -> std::optional<BatteryState> {
@@ -94,8 +95,15 @@ auto Battery::State() -> std::optional<BatteryState> {
 }
 
 auto Battery::EmitEvent() -> void {
-  events::System().Dispatch(system_fsm::BatteryStateChanged{});
+  auto state = state_;
-  events::Ui().Dispatch(system_fsm::BatteryStateChanged{});
+  if (!state) {
+    return;
+  }
+  system_fsm::BatteryStateChanged ev{
+      .new_state = *state,
+  };
+  events::System().Dispatch(ev);
+  events::Ui().Dispatch(ev);
 }
 
 }  // namespace battery

src/system_fsm/include/system_events.hpp

@@ -8,6 +8,7 @@
 
 #include <memory>
 
+#include "battery.hpp"
 #include "database.hpp"
 #include "service_locator.hpp"
 #include "tinyfsm.hpp"
@@ -54,7 +55,9 @@ struct HasPhonesChanged : tinyfsm::Event {
 };
 
 struct ChargingStatusChanged : tinyfsm::Event {};
-struct BatteryStateChanged : tinyfsm::Event {};
+struct BatteryStateChanged : tinyfsm::Event {
+  battery::Battery::BatteryState new_state;
+};
 
 struct BluetoothDevicesChanged : tinyfsm::Event {};
 

src/ui/include/model_top_bar.hpp

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2023 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#pragma once
+
+#include "battery.hpp"
+#include "bindey/property.h"
+
+#include "track.hpp"
+
+namespace ui {
+namespace models {
+
+struct TopBar {
+  bindey::property<battery::Battery::BatteryState> battery_state;
+
+  // Shared with the Playback model
+  bindey::property<bool>& is_playing;
+  bindey::property<std::optional<database::TrackId>>& current_track;
+};
+
+}  // namespace models
+}  // namespace ui

src/ui/include/screen.hpp

@@ -16,6 +16,7 @@
 #include "core/lv_obj_tree.h"
 #include "event_binding.hpp"
 #include "lvgl.h"
+#include "model_top_bar.hpp"
 #include "nod/nod.hpp"
 #include "widget_top_bar.hpp"
 
@@ -37,8 +38,6 @@ class Screen {
    */
   virtual auto Tick() -> void {}
 
-  auto UpdateTopBar(const widgets::TopBar::State& state) -> void;
-
   auto root() -> lv_obj_t* { return root_; }
   auto content() -> lv_obj_t* { return content_; }
 
@@ -52,8 +51,9 @@ class Screen {
   }
 
  protected:
-  auto CreateTopBar(lv_obj_t* parent, const widgets::TopBar::Configuration&)
+  auto CreateTopBar(lv_obj_t* parent,
-      -> widgets::TopBar*;
+                    const widgets::TopBar::Configuration&,
+                    models::TopBar& model) -> widgets::TopBar*;
 
   std::pmr::vector<bindey::scoped_binding> data_bindings_;
   std::pmr::vector<std::unique_ptr<EventBinding>> event_bindings_;
@@ -78,7 +78,9 @@ class Screen {
 
 class MenuScreen : public Screen {
  public:
-  MenuScreen(const std::pmr::string& title, bool show_back_button = true);
+  MenuScreen(models::TopBar&,
+             const std::pmr::string& title,
+             bool show_back_button = true);
 };
 
 }  // namespace ui

src/ui/include/screen_menu.hpp

@@ -12,6 +12,7 @@
 #include "index.hpp"
 #include "lvgl.h"
 
+#include "model_top_bar.hpp"
 #include "screen.hpp"
 #include "screen_settings.hpp"
 
@@ -20,7 +21,7 @@ namespace screens {
 
 class Menu : public MenuScreen {
  public:
-  explicit Menu(std::vector<database::IndexInfo> indexes);
+  explicit Menu(models::TopBar&, std::vector<database::IndexInfo> indexes);
   ~Menu();
 
  private:

src/ui/include/screen_playing.hpp

@@ -18,6 +18,7 @@
 #include "database.hpp"
 #include "future_fetcher.hpp"
 #include "model_playback.hpp"
+#include "model_top_bar.hpp"
 #include "screen.hpp"
 #include "track.hpp"
 #include "track_queue.hpp"
@@ -31,7 +32,8 @@ namespace screens {
  */
 class Playing : public Screen {
  public:
-  explicit Playing(models::Playback& playback_model,
+  explicit Playing(models::TopBar&,
+                   models::Playback& playback_model,
                    std::weak_ptr<database::Database> db,
                    audio::TrackQueue& queue);
   ~Playing();

src/ui/include/screen_settings.hpp

@@ -18,6 +18,7 @@
 #include "index.hpp"
 #include "lvgl.h"
 
+#include "model_top_bar.hpp"
 #include "nvs.hpp"
 #include "screen.hpp"
 
@@ -26,12 +27,12 @@ namespace screens {
 
 class Settings : public MenuScreen {
  public:
-  Settings();
+  Settings(models::TopBar&);
 };
 
 class Bluetooth : public MenuScreen {
  public:
-  Bluetooth(drivers::Bluetooth& bt, drivers::NvsStorage& nvs);
+  Bluetooth(models::TopBar&, drivers::Bluetooth& bt, drivers::NvsStorage& nvs);
 
   auto ChangeEnabledState(bool enabled) -> void;
   auto RefreshDevicesList() -> void;
@@ -53,7 +54,7 @@ class Bluetooth : public MenuScreen {
 
 class Headphones : public MenuScreen {
  public:
-  Headphones(drivers::NvsStorage& nvs);
+  Headphones(models::TopBar&, drivers::NvsStorage& nvs);
 
   auto ChangeMaxVolume(uint8_t index) -> void;
   auto ChangeCustomVolume(int8_t diff) -> void;
@@ -71,7 +72,9 @@ class Headphones : public MenuScreen {
 
 class Appearance : public MenuScreen {
  public:
-  Appearance(drivers::NvsStorage& nvs, drivers::Display& display);
+  Appearance(models::TopBar&,
+             drivers::NvsStorage& nvs,
+             drivers::Display& display);
 
   auto ChangeBrightness(uint_fast8_t) -> void;
   auto CommitBrightness() -> void;
@@ -86,22 +89,22 @@ class Appearance : public MenuScreen {
 
 class InputMethod : public MenuScreen {
  public:
-  InputMethod();
+  InputMethod(models::TopBar&);
 };
 
 class Storage : public MenuScreen {
  public:
-  Storage();
+  Storage(models::TopBar&);
 };
 
 class FirmwareUpdate : public MenuScreen {
  public:
-  FirmwareUpdate();
+  FirmwareUpdate(models::TopBar&);
 };
 
 class About : public MenuScreen {
  public:
-  About();
+  About(models::TopBar&);
 };
 
 }  // namespace screens

src/ui/include/screen_track_browser.hpp

@@ -14,6 +14,7 @@
 #include "lvgl.h"
 
 #include "database.hpp"
+#include "model_top_bar.hpp"
 #include "screen.hpp"
 
 namespace ui {
@@ -22,6 +23,7 @@ namespace screens {
 class TrackBrowser : public Screen {
  public:
   TrackBrowser(
+      models::TopBar&,
       std::weak_ptr<database::Database> db,
       const std::pmr::string& title,
       std::future<database::Result<database::IndexRecord>*>&& initial_page);

src/ui/include/ui_fsm.hpp

@@ -17,6 +17,7 @@
 #include "gpios.hpp"
 #include "lvgl_task.hpp"
 #include "model_playback.hpp"
+#include "model_top_bar.hpp"
 #include "nvs.hpp"
 #include "relative_wheel.hpp"
 #include "screen_playing.hpp"
@@ -82,7 +83,6 @@ class UiState : public tinyfsm::Fsm<UiState> {
  protected:
   void PushScreen(std::shared_ptr<Screen>);
   void PopScreen();
-  void UpdateTopBar();
 
   static std::unique_ptr<UiTask> sTask;
   static std::shared_ptr<system_fsm::ServiceLocator> sServices;
@@ -94,8 +94,7 @@ class UiState : public tinyfsm::Fsm<UiState> {
   static std::shared_ptr<Modal> sCurrentModal;
 
   static models::Playback sPlaybackModel;
-
+  static models::TopBar sTopBarModel;
-  static bindey::property<battery::Battery::BatteryState> sPropBatteryState;
 };
 
 namespace states {

src/ui/include/widget_top_bar.hpp

@@ -9,9 +9,11 @@
 #include <cstdint>
 #include <string>
 
+#include "bindey/binding.h"
 #include "lvgl.h"
 
 #include "memory_resource.hpp"
+#include "model_top_bar.hpp"
 
 namespace ui {
 
@@ -24,33 +26,18 @@ class TopBar {
     std::pmr::string title;
   };
 
-  enum class PlaybackState {
+  explicit TopBar(lv_obj_t* parent,
-    kIdle,
+                  const Configuration& config,
-    kPaused,
+                  models::TopBar& model);
-    kPlaying,
-  };
-
-  struct State {
-    PlaybackState playback_state;
-    uint_fast8_t battery_percent;
-    bool is_charging;
-  };
-
-  explicit TopBar(lv_obj_t* parent, const Configuration& config);
 
   auto root() -> lv_obj_t* { return container_; }
   auto button() -> lv_obj_t* { return back_button_; }
 
-  auto Update(const State&) -> void;
-
  private:
-  lv_obj_t* container_;
+  std::vector<bindey::scoped_binding> bindings_;
 
+  lv_obj_t* container_;
   lv_obj_t* back_button_;
-  lv_obj_t* title_;
-  lv_obj_t* playback_;
-  lv_obj_t* battery_;
-  lv_obj_t* charging_;
 };
 
 }  // namespace widgets

src/ui/screen.cpp

@@ -12,6 +12,7 @@
 #include "core/lv_obj_tree.h"
 #include "misc/lv_area.h"
 #include "misc/lv_color.h"
+#include "model_top_bar.hpp"
 #include "widget_top_bar.hpp"
 
 namespace ui {
@@ -40,24 +41,20 @@ Screen::~Screen() {
   lv_obj_del(root_);
 }
 
-auto Screen::UpdateTopBar(const widgets::TopBar::State& state) -> void {
-  if (top_bar_) {
-    top_bar_->Update(state);
-  }
-}
-
 auto Screen::CreateTopBar(lv_obj_t* parent,
-                          const widgets::TopBar::Configuration& config)
+                          const widgets::TopBar::Configuration& config,
-    -> widgets::TopBar* {
+                          models::TopBar& model) -> widgets::TopBar* {
   assert(top_bar_ == nullptr);
-  top_bar_ = std::make_unique<widgets::TopBar>(parent, config);
+  top_bar_ = std::make_unique<widgets::TopBar>(parent, config, model);
   if (top_bar_->button()) {
     lv_group_add_obj(group_, top_bar_->button());
   }
   return top_bar_.get();
 }
 
-MenuScreen::MenuScreen(const std::pmr::string& title, bool show_back_button)
+MenuScreen::MenuScreen(models::TopBar& top_bar_model,
+                       const std::pmr::string& title,
+                       bool show_back_button)
     : Screen() {
   lv_group_set_wrap(group_, false);
 
@@ -70,7 +67,7 @@ MenuScreen::MenuScreen(const std::pmr::string& title, bool show_back_button)
       .show_back_button = show_back_button,
       .title = title.c_str(),
   };
-  CreateTopBar(content_, config);
+  CreateTopBar(content_, config, top_bar_model);
 
   content_ = lv_obj_create(content_);
   lv_obj_set_flex_grow(content_, 1);

src/ui/screen_menu.cpp

@@ -18,6 +18,7 @@
 #include "hal/lv_hal_disp.h"
 #include "index.hpp"
 #include "misc/lv_area.h"
+#include "model_top_bar.hpp"
 #include "ui_events.hpp"
 #include "ui_fsm.hpp"
 #include "widget_top_bar.hpp"
@@ -45,8 +46,8 @@ static void index_click_cb(lv_event_t* ev) {
   events::Ui().Dispatch(internal::IndexSelected{.index = *index});
 }
 
-Menu::Menu(std::vector<database::IndexInfo> indexes)
+Menu::Menu(models::TopBar& top_bar, std::vector<database::IndexInfo> indexes)
-    : MenuScreen(" ", false), indexes_(indexes) {
+    : MenuScreen(top_bar, " ", false), indexes_(indexes) {
   lv_obj_t* list = lv_list_create(content_);
   lv_obj_set_size(list, lv_pct(100), lv_pct(100));
 

src/ui/screen_playing.cpp

@@ -37,6 +37,7 @@
 #include "misc/lv_color.h"
 #include "misc/lv_txt.h"
 #include "model_playback.hpp"
+#include "model_top_bar.hpp"
 #include "track.hpp"
 #include "ui_events.hpp"
 #include "ui_fsm.hpp"
@@ -101,7 +102,8 @@ auto Playing::next_up_label(lv_obj_t* parent, const std::pmr::string& text)
   return button;
 }
 
-Playing::Playing(models::Playback& playback_model,
+Playing::Playing(models::TopBar& top_bar_model,
+                 models::Playback& playback_model,
                  std::weak_ptr<database::Database> db,
                  audio::TrackQueue& queue)
     : db_(db),
@@ -158,7 +160,7 @@ Playing::Playing(models::Playback& playback_model,
       .show_back_button = true,
       .title = "Now Playing",
   };
-  CreateTopBar(above_fold_container, config);
+  CreateTopBar(above_fold_container, config, top_bar_model);
 
   lv_obj_t* info_container = lv_obj_create(above_fold_container);
   lv_obj_set_layout(info_container, LV_LAYOUT_FLEX);

src/ui/screen_settings.cpp

@@ -29,6 +29,7 @@
 #include "index.hpp"
 #include "misc/lv_anim.h"
 #include "misc/lv_area.h"
+#include "model_top_bar.hpp"
 #include "nvs.hpp"
 #include "screen.hpp"
 #include "ui_events.hpp"
@@ -64,7 +65,7 @@ static void sub_menu(lv_obj_t* list,
                       reinterpret_cast<void*>(static_cast<uintptr_t>(page)));
 }
 
-Settings::Settings() : MenuScreen("Settings") {
+Settings::Settings(models::TopBar& bar) : MenuScreen(bar, "Settings") {
   lv_obj_t* list = lv_list_create(content_);
   lv_obj_set_size(list, lv_pct(100), lv_pct(100));
 
@@ -113,8 +114,10 @@ static auto select_device_cb(lv_event_t* ev) {
   instance->OnDeviceSelected(lv_obj_get_index(ev->target));
 }
 
-Bluetooth::Bluetooth(drivers::Bluetooth& bt, drivers::NvsStorage& nvs)
+Bluetooth::Bluetooth(models::TopBar& bar,
-    : MenuScreen("Bluetooth"), bt_(bt), nvs_(nvs) {
+                     drivers::Bluetooth& bt,
+                     drivers::NvsStorage& nvs)
+    : MenuScreen(bar, "Bluetooth"), bt_(bt), nvs_(nvs) {
   lv_obj_t* toggle_container = settings_container(content_);
   lv_obj_t* toggle_label = lv_label_create(toggle_container);
   lv_label_set_text(toggle_label, "Enable");
@@ -268,8 +271,8 @@ static void decrease_vol_limit_cb(lv_event_t* ev) {
   instance->ChangeCustomVolume(-2);
 }
 
-Headphones::Headphones(drivers::NvsStorage& nvs)
+Headphones::Headphones(models::TopBar& bar, drivers::NvsStorage& nvs)
-    : MenuScreen("Headphones"), nvs_(nvs), custom_limit_(0) {
+    : MenuScreen(bar, "Headphones"), nvs_(nvs), custom_limit_(0) {
   uint16_t reference = drivers::wm8523::kLineLevelReferenceVolume;
   index_to_level_.push_back(reference - (10 * 4));
   index_to_level_.push_back(reference + (6 * 4));
@@ -377,8 +380,10 @@ static auto brightness_str(uint_fast8_t percent) -> std::string {
   return std::to_string(percent) + "%";
 }
 
-Appearance::Appearance(drivers::NvsStorage& nvs, drivers::Display& display)
+Appearance::Appearance(models::TopBar& bar,
-    : MenuScreen("Appearance"), nvs_(nvs), display_(display) {
+                       drivers::NvsStorage& nvs,
+                       drivers::Display& display)
+    : MenuScreen(bar, "Appearance"), nvs_(nvs), display_(display) {
   lv_obj_t* toggle_container = settings_container(content_);
   lv_obj_t* toggle_label = lv_label_create(toggle_container);
   lv_obj_set_flex_grow(toggle_label, 1);
@@ -417,7 +422,8 @@ auto Appearance::CommitBrightness() -> void {
   nvs_.ScreenBrightness(current_brightness_);
 }
 
-InputMethod::InputMethod() : MenuScreen("Input Method") {
+InputMethod::InputMethod(models::TopBar& bar)
+    : MenuScreen(bar, "Input Method") {
   lv_obj_t* wheel_label = lv_label_create(content_);
   lv_label_set_text(wheel_label, "What does the wheel do?");
   lv_obj_t* wheel_dropdown = lv_dropdown_create(content_);
@@ -431,7 +437,7 @@ InputMethod::InputMethod() : MenuScreen("Input Method") {
   lv_group_add_obj(group_, buttons_dropdown);
 }
 
-Storage::Storage() : MenuScreen("Storage") {
+Storage::Storage(models::TopBar& bar) : MenuScreen(bar, "Storage") {
   label_pair(content_, "Storage Capacity:", "32 GiB");
   label_pair(content_, "Currently Used:", "6 GiB");
   label_pair(content_, "DB Size:", "1.2 MiB");
@@ -446,7 +452,8 @@ Storage::Storage() : MenuScreen("Storage") {
   lv_group_add_obj(group_, reset_btn);
 }
 
-FirmwareUpdate::FirmwareUpdate() : MenuScreen("Firmware Update") {
+FirmwareUpdate::FirmwareUpdate(models::TopBar& bar)
+    : MenuScreen(bar, "Firmware Update") {
   label_pair(content_, "ESP32 FW:", "vIDKLOL");
   label_pair(content_, "SAMD21 FW:", "vIDKLOL");
 
@@ -461,7 +468,7 @@ FirmwareUpdate::FirmwareUpdate() : MenuScreen("Firmware Update") {
   lv_group_add_obj(group_, flash_samd_btn);
 }
 
-About::About() : MenuScreen("About") {
+About::About(models::TopBar& bar) : MenuScreen(bar, "About") {
   lv_obj_t* label = lv_label_create(content_);
   lv_label_set_text(label, "Some licenses or whatever");
 }

src/ui/screen_track_browser.cpp

@@ -16,6 +16,7 @@
 #include "font/lv_symbol_def.h"
 #include "lvgl.h"
 #include "misc/lv_anim.h"
+#include "model_top_bar.hpp"
 #include "screen_menu.hpp"
 
 #include "core/lv_event.h"
@@ -59,6 +60,7 @@ static void item_select_cb(lv_event_t* ev) {
 }
 
 TrackBrowser::TrackBrowser(
+    models::TopBar& top_bar_model,
     std::weak_ptr<database::Database> db,
     const std::pmr::string& title,
     std::future<database::Result<database::IndexRecord>*>&& initial_page)
@@ -83,7 +85,7 @@ TrackBrowser::TrackBrowser(
       .show_back_button = true,
       .title = title,
   };
-  auto top_bar = CreateTopBar(content_, config);
+  auto top_bar = CreateTopBar(content_, config, top_bar_model);
   back_button_ = top_bar->button();
 
   list_ = lv_list_create(content_);

src/ui/ui_fsm.cpp

@@ -54,8 +54,9 @@ std::shared_ptr<Screen> UiState::sCurrentScreen;
 std::shared_ptr<Modal> UiState::sCurrentModal;
 
 models::Playback UiState::sPlaybackModel;
-
+models::TopBar UiState::sTopBarModel{{},
-bindey::property<battery::Battery::BatteryState> UiState::sPropBatteryState;
+                                     UiState::sPlaybackModel.is_playing,
+                                     UiState::sPlaybackModel.current_track};
 
 auto UiState::InitBootSplash(drivers::IGpios& gpios) -> bool {
   // Init LVGL first, since the display driver registers itself with LVGL.
@@ -75,7 +76,6 @@ void UiState::PushScreen(std::shared_ptr<Screen> screen) {
     sScreens.push(sCurrentScreen);
   }
   sCurrentScreen = screen;
-  UpdateTopBar();
 }
 
 void UiState::PopScreen() {
@@ -84,7 +84,6 @@ void UiState::PopScreen() {
   }
   sCurrentScreen = sScreens.top();
   sScreens.pop();
-  UpdateTopBar();
 }
 
 void UiState::react(const system_fsm::KeyLockChanged& ev) {
@@ -93,14 +92,8 @@ void UiState::react(const system_fsm::KeyLockChanged& ev) {
                                    : std::shared_ptr<TouchWheelEncoder>());
 }
 
-void UiState::react(const system_fsm::BatteryStateChanged&) {
+void UiState::react(const system_fsm::BatteryStateChanged& ev) {
-  if (!sServices) {
+  sTopBarModel.battery_state.set(ev.new_state);
-    return;
-  }
-  auto state = sServices->battery().State();
-  if (state) {
-    sPropBatteryState.set(*state);
-  }
 }
 
 void UiState::react(const audio::PlaybackStarted&) {
@@ -117,34 +110,11 @@ void UiState::react(const audio::PlaybackUpdate& ev) {
 }
 
 void UiState::react(const audio::QueueUpdate&) {
-  ESP_LOGI(kTag, "current changed!");
   auto& queue = sServices->track_queue();
   sPlaybackModel.current_track.set(queue.GetCurrent());
   sPlaybackModel.upcoming_tracks.set(queue.GetUpcoming(10));
 }
 
-void UiState::UpdateTopBar() {
-  auto battery_state = sServices->battery().State();
-  bool has_queue = sServices->track_queue().GetCurrent().has_value();
-  bool is_playing = audio::AudioState::is_in_state<audio::states::Playback>();
-
-  widgets::TopBar::State state{
-      .playback_state = widgets::TopBar::PlaybackState::kIdle,
-      .battery_percent = static_cast<uint_fast8_t>(
-          battery_state.has_value() ? battery_state->percent : 100),
-      .is_charging = !battery_state.has_value() || battery_state->is_charging,
-  };
-
-  if (has_queue) {
-    state.playback_state = is_playing ? widgets::TopBar::PlaybackState::kPlaying
-                                      : widgets::TopBar::PlaybackState::kPaused;
-  }
-
-  if (sCurrentScreen) {
-    sCurrentScreen->UpdateTopBar(state);
-  }
-}
-
 namespace states {
 
 void Splash::exit() {
@@ -242,7 +212,8 @@ void Browse::entry() {
     if (!db) {
       return;
     }
-    sCurrentScreen = std::make_shared<screens::Menu>(db->GetIndexes());
+    sCurrentScreen =
+        std::make_shared<screens::Menu>(sTopBarModel, db->GetIndexes());
     sBrowseFirstEntry = false;
   }
 }
@@ -253,7 +224,8 @@ void Browse::react(const system_fsm::StorageMounted& ev) {
     if (!db) {
       return;
     }
-    sCurrentScreen = std::make_shared<screens::Menu>(db->GetIndexes());
+    sCurrentScreen =
+        std::make_shared<screens::Menu>(sTopBarModel, db->GetIndexes());
     sBrowseFirstEntry = false;
   }
 }
@@ -267,31 +239,32 @@ void Browse::react(const internal::ShowSettingsPage& ev) {
   std::shared_ptr<screens::Bluetooth> bt_screen;
   switch (ev.page) {
     case internal::ShowSettingsPage::Page::kRoot:
-      screen.reset(new screens::Settings());
+      screen.reset(new screens::Settings(sTopBarModel));
       break;
     case internal::ShowSettingsPage::Page::kBluetooth:
-      bt_screen = std::make_shared<screens::Bluetooth>(sServices->bluetooth(),
+      bt_screen = std::make_shared<screens::Bluetooth>(
-                                                       sServices->nvs());
+          sTopBarModel, sServices->bluetooth(), sServices->nvs());
       screen = bt_screen;
       bluetooth_screen_ = bt_screen;
       break;
     case internal::ShowSettingsPage::Page::kHeadphones:
-      screen.reset(new screens::Headphones(sServices->nvs()));
+      screen.reset(new screens::Headphones(sTopBarModel, sServices->nvs()));
       break;
     case internal::ShowSettingsPage::Page::kAppearance:
-      screen.reset(new screens::Appearance(sServices->nvs(), *sDisplay));
+      screen.reset(
+          new screens::Appearance(sTopBarModel, sServices->nvs(), *sDisplay));
       break;
     case internal::ShowSettingsPage::Page::kInput:
-      screen.reset(new screens::InputMethod());
+      screen.reset(new screens::InputMethod(sTopBarModel));
       break;
     case internal::ShowSettingsPage::Page::kStorage:
-      screen.reset(new screens::Storage());
+      screen.reset(new screens::Storage(sTopBarModel));
       break;
     case internal::ShowSettingsPage::Page::kFirmwareUpdate:
-      screen.reset(new screens::FirmwareUpdate());
+      screen.reset(new screens::FirmwareUpdate(sTopBarModel));
       break;
     case internal::ShowSettingsPage::Page::kAbout:
-      screen.reset(new screens::About());
+      screen.reset(new screens::About(sTopBarModel));
       break;
   }
   if (screen) {
@@ -323,7 +296,7 @@ void Browse::react(const internal::RecordSelected& ev) {
     auto query = db->GetPage(&cont.value());
     std::pmr::string title = record->text().value_or("TODO");
     PushScreen(std::make_shared<screens::TrackBrowser>(
-        sServices->database(), title, std::move(query)));
+        sTopBarModel, sServices->database(), title, std::move(query)));
   }
 }
 
@@ -336,7 +309,7 @@ void Browse::react(const internal::IndexSelected& ev) {
   ESP_LOGI(kTag, "selected index %s", ev.index.name.c_str());
   auto query = db->GetTracksByIndex(ev.index, kRecordsPerPage);
   PushScreen(std::make_shared<screens::TrackBrowser>(
-      sServices->database(), ev.index.name, std::move(query)));
+      sTopBarModel, sServices->database(), ev.index.name, std::move(query)));
 }
 
 void Browse::react(const internal::BackPressed& ev) {
@@ -354,8 +327,9 @@ static std::shared_ptr<screens::Playing> sPlayingScreen;
 
 void Playing::entry() {
   ESP_LOGI(kTag, "push playing screen");
-  sPlayingScreen.reset(new screens::Playing(
+  sPlayingScreen.reset(new screens::Playing(sTopBarModel, sPlaybackModel,
-      sPlaybackModel, sServices->database(), sServices->track_queue()));
+                                            sServices->database(),
+                                            sServices->track_queue()));
   PushScreen(sPlayingScreen);
 }
 

src/ui/widget_top_bar.cpp

@@ -5,13 +5,16 @@
  */
 
 #include "widget_top_bar.hpp"
+#include "battery.hpp"
 #include "core/lv_group.h"
 #include "core/lv_obj.h"
 #include "event_queue.hpp"
 #include "extra/layouts/flex/lv_flex.h"
 #include "font/lv_symbol_def.h"
 #include "font_symbols.hpp"
+#include "model_top_bar.hpp"
 #include "themes.hpp"
+#include "track.hpp"
 #include "ui_events.hpp"
 #include "ui_fsm.hpp"
 #include "widgets/lv_img.h"
@@ -34,7 +37,9 @@ static void back_click_cb(lv_event_t* ev) {
   events::Ui().Dispatch(internal::BackPressed{});
 }
 
-TopBar::TopBar(lv_obj_t* parent, const Configuration& config) {
+TopBar::TopBar(lv_obj_t* parent,
+               const Configuration& config,
+               models::TopBar& model) {
   container_ = lv_obj_create(parent);
   lv_obj_set_size(container_, lv_pct(100), 20);
   lv_obj_set_flex_flow(container_, LV_FLEX_FLOW_ROW);
@@ -54,49 +59,51 @@ TopBar::TopBar(lv_obj_t* parent, const Configuration& config) {
     back_button_ = nullptr;
   }
 
-  title_ = lv_label_create(container_);
+  lv_obj_t* title_ = lv_label_create(container_);
   lv_label_set_text(title_, config.title.c_str());
   lv_obj_set_flex_grow(title_, 1);
 
-  playback_ = lv_img_create(container_);
+  lv_obj_t* playback = lv_img_create(container_);
-  battery_ = lv_img_create(container_);
-  charging_ = lv_label_create(container_);
 
-  themes::Theme::instance()->ApplyStyle(container_, themes::Style::kTopBar);
+  bindings_.push_back(model.is_playing.onChangedAndNow([=](bool is_playing) {
-}
+    lv_img_set_src(playback, is_playing ? &kIconPlay : &kIconPause);
+  }));
+  bindings_.push_back(model.current_track.onChangedAndNow(
+      [=](const std::optional<database::TrackId>& id) {
+        if (id) {
+          lv_obj_clear_flag(playback, LV_OBJ_FLAG_HIDDEN);
+        } else {
+          lv_obj_add_flag(playback, LV_OBJ_FLAG_HIDDEN);
+        }
+      }));
 
-auto TopBar::Update(const State& state) -> void {
+  lv_obj_t* battery = lv_img_create(container_);
-  switch (state.playback_state) {
+  lv_obj_t* charging = lv_label_create(container_);
-    case PlaybackState::kIdle:
-      lv_img_set_src(playback_, NULL);
-      break;
-    case PlaybackState::kPaused:
-      lv_img_set_src(playback_, &kIconPause);
-      break;
-    case PlaybackState::kPlaying:
-      lv_img_set_src(playback_, &kIconPlay);
-      break;
-  }
 
-  if (state.is_charging) {
+  bindings_.push_back(model.battery_state.onChangedAndNow(
-    lv_label_set_text(charging_, "+");
+      [=](const battery::Battery::BatteryState& state) {
-  } else {
+        if (state.is_charging) {
-    lv_label_set_text(charging_, "");
+          lv_label_set_text(charging, "+");
-  }
+        } else {
+          lv_label_set_text(charging, "");
+        }
 
-  if (state.battery_percent >= 95) {
+        if (state.percent >= 95) {
-    lv_img_set_src(battery_, &kIconBatteryFull);
+          lv_img_set_src(battery, &kIconBatteryFull);
-  } else if (state.battery_percent >= 75) {
+        } else if (state.percent >= 75) {
-    lv_img_set_src(battery_, &kIconBattery80);
+          lv_img_set_src(battery, &kIconBattery80);
-  } else if (state.battery_percent >= 55) {
+        } else if (state.percent >= 55) {
-    lv_img_set_src(battery_, &kIconBattery60);
+          lv_img_set_src(battery, &kIconBattery60);
-  } else if (state.battery_percent >= 35) {
+        } else if (state.percent >= 35) {
-    lv_img_set_src(battery_, &kIconBattery40);
+          lv_img_set_src(battery, &kIconBattery40);
-  } else if (state.battery_percent >= 15) {
+        } else if (state.percent >= 15) {
-    lv_img_set_src(battery_, &kIconBattery20);
+          lv_img_set_src(battery, &kIconBattery20);
-  } else {
+        } else {
-    lv_img_set_src(battery_, &kIconBatteryEmpty);
+          lv_img_set_src(battery, &kIconBatteryEmpty);
-  }
+        }
+      }));
+
+  themes::Theme::instance()->ApplyStyle(container_, themes::Style::kTopBar);
 }
 
 }  // namespace widgets