refactor app code (#93)

AppEsp32/Source/HelloWorld/HelloWorld.cpp

@@ -1,7 +1,7 @@
 #include "lvgl.h"
 #include "lvgl/Toolbar.h"
 
-static void app_show(tt::app::App app, lv_obj_t* parent) {
+static void app_show(tt::app::App& app, lv_obj_t* parent) {
     lv_obj_t* toolbar = tt::lvgl::toolbar_create(parent, app);
     lv_obj_align(toolbar, LV_ALIGN_TOP_MID, 0, 0);
 
@@ -14,5 +14,5 @@ extern const tt::app::Manifest hello_world_app = {
     .id = "HelloWorld",
     .name = "Hello World",
     .type = tt::app::TypeUser,
-    .on_show = &app_show,
+    .onShow = &app_show,
 };

AppSim/Source/HelloWorld/hello_world.cpp

@@ -1,6 +1,6 @@
 #include "lvgl/Toolbar.h"
 
-static void app_show(tt::app::App app, lv_obj_t* parent) {
+static void app_show(tt::app::App& app, lv_obj_t* parent) {
     lv_obj_t* toolbar = tt::lvgl::toolbar_create(parent, app);
     lv_obj_align(toolbar, LV_ALIGN_TOP_MID, 0, 0);
 
@@ -13,5 +13,5 @@ extern const tt::app::Manifest hello_world_app = {
     .id = "HelloWorld",
     .name = "Hello World",
     .type = tt::app::TypeUser,
-    .on_show = &app_show
+    .onShow = &app_show
 };

Tactility/Private/app/AppInstance.h

@@ -0,0 +1,66 @@
+#pragma once
+
+#include "app/App.h"
+#include "app/Manifest.h"
+#include "Bundle.h"
+#include "Mutex.h"
+
+namespace tt::app {
+
+typedef enum {
+    StateInitial, // App is being activated in loader
+    StateStarted, // App is in memory
+    StateShowing, // App view is created
+    StateHiding,  // App view is destroyed
+    StateStopped  // App is not in memory
+} State;
+
+/**
+ * Thread-safe app instance.
+ */
+class AppInstance : public App {
+
+private:
+
+    Mutex mutex = Mutex(MutexTypeNormal);
+    const Manifest& manifest;
+    State state = StateInitial;
+    Flags flags = { .showStatusbar = true };
+    /** @brief Optional parameters to start the app with
+     * When these are stored in the app struct, the struct takes ownership.
+     * Do not mutate after app creation.
+     */
+    tt::Bundle parameters;
+    /** @brief @brief Contextual data related to the running app's instance
+     * The app can attach its data to this.
+     * The lifecycle is determined by the on_start and on_stop methods in the AppManifest.
+     * These manifest methods can optionally allocate/free data that is attached here.
+     */
+    void* _Nullable data = nullptr;
+
+public:
+
+    AppInstance(const Manifest& manifest) :
+        manifest(manifest) {}
+
+    AppInstance(const Manifest& manifest, const Bundle& parameters) :
+        manifest(manifest),
+        parameters(parameters) {}
+
+    ~AppInstance() {}
+
+    void setState(State state);
+    State getState() const;
+
+    const Manifest& getManifest() const;
+
+    Flags getFlags() const;
+    void setFlags(Flags flags);
+
+    _Nullable void* getData() const;
+    void setData(void* data);
+
+    const Bundle& getParameters() const;
+};
+
+} // namespace

Tactility/Private/service/loader/Loader_i.h

@@ -1,11 +1,13 @@
 #pragma once
 
 #include "app/Manifest.h"
+#include "app/AppInstance.h"
 #include "MessageQueue.h"
 #include "Pubsub.h"
 #include "Thread.h"
 #include "service/gui/ViewPort.h"
 #include "service/loader/Loader.h"
+#include <stack>
 
 #ifdef ESP_PLATFORM
 #include "freertos/FreeRTOS.h"
@@ -108,8 +110,7 @@ struct Loader {
     PubSub* pubsub_external;
     MessageQueue queue = MessageQueue(1, sizeof(LoaderMessage));
     Mutex* mutex;
-    int8_t app_stack_index;
+    std::stack<app::AppInstance*> app_stack;
-    app::App app_stack[APP_STACK_SIZE];
 };
 
 } // namespace

Tactility/Source/Tactility.cpp

@@ -76,11 +76,11 @@ static const std::vector<const app::Manifest*> system_apps = {
 static void register_system_apps() {
     TT_LOG_I(TAG, "Registering default apps");
     for (const auto& app_manifest: system_apps) {
-        app_manifest_registry_add(app_manifest);
+        addApp(app_manifest);
     }
 
     if (getConfiguration()->hardware->power != nullptr) {
-        app_manifest_registry_add(&app::power::manifest);
+        addApp(&app::power::manifest);
     }
 }
 
@@ -89,7 +89,7 @@ static void register_user_apps(const app::Manifest* const apps[TT_CONFIG_APPS_LI
     for (size_t i = 0; i < TT_CONFIG_APPS_LIMIT; i++) {
         const app::Manifest* manifest = apps[i];
         if (manifest != nullptr) {
-            app_manifest_registry_add(manifest);
+            addApp(manifest);
         } else {
             // reached end of list
             break;
@@ -129,8 +129,6 @@ void init(const Configuration* config) {
 
     lvgl::init(config->hardware);
 
-    app::app_manifest_registry_init();
-
     // Note: the order of starting apps and services is critical!
     // System services are registered first so the apps below can find them if needed
     register_and_start_system_services();

Tactility/Source/app/App.cpp

@@ -1,102 +0,0 @@
-#include "app/App.h"
-
-namespace tt::app {
-
-#define TAG "app"
-
-void AppInstance::setState(State newState) {
-    mutex.acquire(TtWaitForever);
-    state = newState;
-    mutex.release();
-}
-
-State AppInstance::getState() {
-    mutex.acquire(TtWaitForever);
-    auto result = state;
-    mutex.release();
-    return result;
-}
-
-/** TODO: Make this thread-safe.
- * In practice, the bundle is writeable, so someone could be writing to it
- * while it is being accessed from another thread.
- * Consider creating MutableBundle vs Bundle.
- * Consider not exposing bundle, but expose `app_get_bundle_int(key)` methods with locking in it.
- */
-const Manifest& AppInstance::getManifest() {
-    return manifest;
-}
-
-Flags AppInstance::getFlags() {
-    mutex.acquire(TtWaitForever);
-    auto result = flags;
-    mutex.release();
-    return result;
-}
-
-void AppInstance::setFlags(Flags newFlags) {
-    mutex.acquire(TtWaitForever);
-    flags = newFlags;
-    mutex.release();
-}
-
-_Nullable void* AppInstance::getData() {
-    mutex.acquire(TtWaitForever);
-    auto result = data;
-    mutex.release();
-    return result;
-}
-
-void AppInstance::setData(void* newData) {
-    mutex.acquire(TtWaitForever);
-    data = newData;
-    mutex.release();
-}
-
-const Bundle& AppInstance::getParameters() {
-    return parameters;
-}
-
-App tt_app_alloc(const Manifest& manifest, const Bundle& parameters) {
-    auto* instance = new AppInstance(manifest, parameters);
-    return static_cast<App>(instance);
-}
-
-void tt_app_free(App app) {
-    auto* instance = static_cast<AppInstance*>(app);
-    delete instance;
-}
-
-void tt_app_set_state(App app, State state) {
-    static_cast<AppInstance*>(app)->setState(state);
-}
-
-State tt_app_get_state(App app) {
-    return static_cast<AppInstance*>(app)->getState();
-}
-
-const Manifest& tt_app_get_manifest(App app) {
-    return static_cast<AppInstance*>(app)->getManifest();
-}
-
-Flags tt_app_get_flags(App app) {
-    return static_cast<AppInstance*>(app)->getFlags();
-}
-
-void tt_app_set_flags(App app, Flags flags) {
-    return static_cast<AppInstance*>(app)->setFlags(flags);
-}
-
-void* tt_app_get_data(App app) {
-    return static_cast<AppInstance*>(app)->getData();
-}
-
-void tt_app_set_data(App app, void* data) {
-    return static_cast<AppInstance*>(app)->setData(data);
-}
-
-const Bundle& tt_app_get_parameters(App app) {
-    return static_cast<AppInstance*>(app)->getParameters();
-}
-
-} // namespace

Tactility/Source/app/App.h

@@ -2,98 +2,28 @@
 
 #include "Manifest.h"
 #include "Bundle.h"
-#include "Mutex.h"
 
 namespace tt::app {
 
-typedef enum {
-    StateInitial, // App is being activated in loader
-    StateStarted, // App is in memory
-    StateShowing, // App view is created
-    StateHiding,  // App view is destroyed
-    StateStopped  // App is not in memory
-} State;
-
 typedef union {
     struct {
-        bool show_statusbar : 1;
+        bool showStatusbar : 1;
     };
     unsigned char flags;
 } Flags;
 
-
+/**
-class AppInstance {
+ * A limited representation of the application instance.
-
+ * Do not store references or pointers to these!
-private:
+ */
-
+class App {
-    Mutex mutex = Mutex(MutexTypeNormal);
-    const Manifest& manifest;
-    State state = StateInitial;
-    Flags flags = { .show_statusbar = true };
-    /** @brief Optional parameters to start the app with
-     * When these are stored in the app struct, the struct takes ownership.
-     * Do not mutate after app creation.
-     */
-    tt::Bundle parameters;
-    /** @brief @brief Contextual data related to the running app's instance
-     * The app can attach its data to this.
-     * The lifecycle is determined by the on_start and on_stop methods in the AppManifest.
-     * These manifest methods can optionally allocate/free data that is attached here.
-     */
-    void* _Nullable data = nullptr;
-
 public:
-
+    virtual ~App() {};
-    AppInstance(const Manifest& manifest) :
+    virtual const Manifest& getManifest() const = 0;
-        manifest(manifest) {}
+    virtual _Nullable void* getData() const = 0;
-
+    virtual void setData(void* data) = 0;
-    AppInstance(const Manifest& manifest, const Bundle& parameters) :
+    virtual const Bundle& getParameters() const = 0;
-        manifest(manifest),
+    virtual Flags getFlags() const = 0;
-        parameters(parameters) {}
-
-    void setState(State state);
-    State getState();
-
-    const Manifest& getManifest();
-
-    Flags getFlags();
-    void setFlags(Flags flags);
-
-    _Nullable void* getData();
-    void setData(void* data);
-
-    const Bundle& getParameters();
 };
 
-/** @brief Create an app
+}
- * @param manifest
- * @param parameters optional bundle. memory ownership is transferred to App
- * @return
- */
-[[deprecated("use class")]]
-App tt_app_alloc(const Manifest& manifest, const Bundle& parameters);
-[[deprecated("use class")]]
-void tt_app_free(App app);
-
-[[deprecated("use class")]]
-void tt_app_set_state(App app, State state);
-[[deprecated("use class")]]
-State tt_app_get_state(App app);
-
-[[deprecated("use class")]]
-const Manifest& tt_app_get_manifest(App app);
-
-[[deprecated("use class")]]
-Flags tt_app_get_flags(App app);
-[[deprecated("use class")]]
-void tt_app_set_flags(App app, Flags flags);
-
-[[deprecated("use class")]]
-void* _Nullable tt_app_get_data(App app);
-[[deprecated("use class")]]
-void tt_app_set_data(App app, void* data);
-
-[[deprecated("use class")]]
-const Bundle& tt_app_get_parameters(App app);
-
-} // namespace

Tactility/Source/app/AppInstance.cpp

@@ -0,0 +1,60 @@
+#include "app/AppInstance.h"
+
+namespace tt::app {
+
+#define TAG "app"
+
+void AppInstance::setState(State newState) {
+    mutex.acquire(TtWaitForever);
+    state = newState;
+    mutex.release();
+}
+
+State AppInstance::getState() const {
+    mutex.acquire(TtWaitForever);
+    auto result = state;
+    mutex.release();
+    return result;
+}
+
+/** TODO: Make this thread-safe.
+ * In practice, the bundle is writeable, so someone could be writing to it
+ * while it is being accessed from another thread.
+ * Consider creating MutableBundle vs Bundle.
+ * Consider not exposing bundle, but expose `app_get_bundle_int(key)` methods with locking in it.
+ */
+const Manifest& AppInstance::getManifest() const {
+    return manifest;
+}
+
+Flags AppInstance::getFlags() const {
+    mutex.acquire(TtWaitForever);
+    auto result = flags;
+    mutex.release();
+    return result;
+}
+
+void AppInstance::setFlags(Flags newFlags) {
+    mutex.acquire(TtWaitForever);
+    flags = newFlags;
+    mutex.release();
+}
+
+_Nullable void* AppInstance::getData() const {
+    mutex.acquire(TtWaitForever);
+    auto result = data;
+    mutex.release();
+    return result;
+}
+
+void AppInstance::setData(void* newData) {
+    mutex.acquire(TtWaitForever);
+    data = newData;
+    mutex.release();
+}
+
+const Bundle& AppInstance::getParameters() const {
+    return parameters;
+}
+
+} // namespace

Tactility/Source/app/Manifest.h

@@ -8,7 +8,7 @@ typedef struct _lv_obj_t lv_obj_t;
 
 namespace tt::app {
 
-typedef void* App;
+class App;
 
 typedef enum {
     /** A desktop app sits at the root of the app stack managed by the Loader service */
@@ -23,10 +23,11 @@ typedef enum {
     TypeUser
 } Type;
 
-typedef void (*AppOnStart)(App app);
+
-typedef void (*AppOnStop)(App app);
+typedef void (*AppOnStart)(App& app);
-typedef void (*AppOnShow)(App app, lv_obj_t* parent);
+typedef void (*AppOnStop)(App& app);
-typedef void (*AppOnHide)(App app);
+typedef void (*AppOnShow)(App& app, lv_obj_t* parent);
+typedef void (*AppOnHide)(App& app);
 
 typedef struct Manifest {
     /**
@@ -52,26 +53,26 @@ typedef struct Manifest {
     /**
      * Non-blocking method to call when app is started.
      */
-    const AppOnStart on_start = nullptr;
+    const AppOnStart onStart = nullptr;
 
     /**
      * Non-blocking method to call when app is stopped.
      */
-    const AppOnStop _Nullable on_stop = nullptr;
+    const AppOnStop _Nullable onStop = nullptr;
 
     /**
      * Non-blocking method to create the GUI
      */
-    const AppOnShow _Nullable on_show = nullptr;
+    const AppOnShow _Nullable onShow = nullptr;
 
     /**
      * Non-blocking method, called before gui is destroyed
      */
-    const AppOnHide _Nullable on_hide = nullptr;
+    const AppOnHide _Nullable onHide = nullptr;
 } AppManifest;
 
 struct {
-    bool operator()(const Manifest* a, const Manifest* b) const { return a->name < b->name; }
+    bool operator()(const Manifest* left, const Manifest* right) const { return left->name < right->name; }
 } SortAppManifestByName;
 
 } // namespace

Tactility/Source/app/ManifestRegistry.cpp

@@ -3,52 +3,38 @@
 #include "TactilityCore.h"
 #include <unordered_map>
 
-#define TAG "app_registry"
+#define TAG "app"
 
 namespace tt::app {
 
 typedef std::unordered_map<std::string, const Manifest*> AppManifestMap;
 
 static AppManifestMap app_manifest_map;
-static Mutex* hash_mutex = nullptr;
+static Mutex hash_mutex(MutexTypeNormal);
 
-static void app_registry_lock() {
+void addApp(const Manifest* manifest) {
-    tt_assert(hash_mutex != nullptr);
+    TT_LOG_I(TAG, "Registering manifest %s", manifest->id.c_str());
-    tt_mutex_acquire(hash_mutex, TtWaitForever);
-}
 
-static void app_registry_unlock() {
+    hash_mutex.acquire(TtWaitForever);
-    tt_assert(hash_mutex != nullptr);
-    tt_mutex_release(hash_mutex);
-}
-
-void app_manifest_registry_init() {
-    tt_assert(hash_mutex == nullptr);
-    hash_mutex = tt_mutex_alloc(MutexTypeNormal);
-}
-void app_manifest_registry_add(const Manifest* manifest) {
-    TT_LOG_I(TAG, "adding %s", manifest->id.c_str());
-
-    app_registry_lock();
     app_manifest_map[manifest->id] = manifest;
-    app_registry_unlock();
+    hash_mutex.release();
 }
 
-_Nullable const Manifest * app_manifest_registry_find_by_id(const std::string& id) {
+_Nullable const Manifest * findAppById(const std::string& id) {
-    app_registry_lock();
+    hash_mutex.acquire(TtWaitForever);
     auto iterator = app_manifest_map.find(id);
     _Nullable const Manifest* result = iterator != app_manifest_map.end() ? iterator->second : nullptr;
-    app_registry_unlock();
+    hash_mutex.release();
     return result;
 }
 
-std::vector<const Manifest*> app_manifest_registry_get() {
+std::vector<const Manifest*> getApps() {
     std::vector<const Manifest*> manifests;
-    app_registry_lock();
+    hash_mutex.acquire(TtWaitForever);
     for (const auto& item: app_manifest_map) {
         manifests.push_back(item.second);
     }
-    app_registry_unlock();
+    hash_mutex.release();
     return manifests;
 }
 

Tactility/Source/app/ManifestRegistry.h

@@ -6,10 +6,8 @@
 
 namespace tt::app {
 
-void app_manifest_registry_init();
+void addApp(const Manifest* manifest);
-void app_manifest_registry_add(const Manifest* manifest);
+const Manifest _Nullable* findAppById(const std::string& id);
-void app_manifest_registry_remove(const Manifest* manifest);
+std::vector<const Manifest*> getApps();
-const Manifest _Nullable* app_manifest_registry_find_by_id(const std::string& id);
-std::vector<const Manifest*> app_manifest_registry_get();
 
 } // namespace

Tactility/Source/app/desktop/Desktop.cpp

@@ -23,12 +23,12 @@ static void create_app_widget(const Manifest* manifest, void* parent) {
     lv_obj_add_event_cb(btn, &on_app_pressed, LV_EVENT_CLICKED, (void*)manifest);
 }
 
-static void desktop_show(TT_UNUSED App app, lv_obj_t* parent) {
+static void desktop_show(TT_UNUSED App& app, lv_obj_t* parent) {
     lv_obj_t* list = lv_list_create(parent);
     lv_obj_set_size(list, LV_PCT(100), LV_PCT(100));
     lv_obj_center(list);
 
-    auto manifests = app_manifest_registry_get();
+    auto manifests = getApps();
     std::sort(manifests.begin(), manifests.end(), SortAppManifestByName);
 
     lv_list_add_text(list, "User");
@@ -50,7 +50,7 @@ extern const Manifest manifest = {
     .id = "Desktop",
     .name = "Desktop",
     .type = TypeDesktop,
-    .on_show = &desktop_show,
+    .onShow = &desktop_show,
 };
 
 } // namespace

Tactility/Source/app/display/Display.cpp

@@ -67,7 +67,7 @@ static void on_orientation_set(lv_event_t* event) {
     }
 }
 
-static void app_show(App app, lv_obj_t* parent) {
+static void app_show(App& app, lv_obj_t* parent) {
     lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
 
     lvgl::toolbar_create(parent, app);
@@ -89,7 +89,7 @@ static void app_show(App app, lv_obj_t* parent) {
     lv_obj_set_width(brightness_slider, LV_PCT(50));
     lv_obj_align(brightness_slider, LV_ALIGN_TOP_RIGHT, -8, 0);
     lv_slider_set_range(brightness_slider, 0, 255);
-    lv_obj_add_event_cb(brightness_slider, slider_event_cb, LV_EVENT_VALUE_CHANGED, NULL);
+    lv_obj_add_event_cb(brightness_slider, slider_event_cb, LV_EVENT_VALUE_CHANGED, nullptr);
 
     const Configuration* config = getConfiguration();
     hal::SetBacklightDuty set_backlight_duty = config->hardware->display.setBacklightDuty;
@@ -115,7 +115,7 @@ static void app_show(App app, lv_obj_t* parent) {
     lv_dropdown_set_selected(orientation_dropdown, orientation_selected);
 }
 
-static void app_hide(TT_UNUSED App app) {
+static void app_hide(TT_UNUSED App& app) {
     if (backlight_duty_set) {
         preferences_set_backlight_duty(backlight_duty);
     }
@@ -126,10 +126,10 @@ extern const Manifest manifest = {
     .name = "Display",
     .icon = TT_ASSETS_APP_ICON_DISPLAY_SETTINGS,
     .type = TypeSettings,
-    .on_start = nullptr,
+    .onStart = nullptr,
-    .on_stop = nullptr,
+    .onStop = nullptr,
-    .on_show = &app_show,
+    .onShow = &app_show,
-    .on_hide = &app_hide
+    .onHide = &app_hide
 };
 
 } // namespace

Tactility/Source/app/files/Files.cpp

@@ -180,8 +180,8 @@ static void update_views(Data* data) {
 
 // region Lifecycle
 
-static void on_show(App app, lv_obj_t* parent) {
+static void on_show(App& app, lv_obj_t* parent) {
-    auto* data = static_cast<Data*>(tt_app_get_data(app));
+    auto* data = static_cast<Data*>(app.getData());
 
     lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
 
@@ -196,7 +196,7 @@ static void on_show(App app, lv_obj_t* parent) {
     update_views(data);
 }
 
-static void on_start(App app) {
+static void on_start(App& app) {
     auto* data = data_alloc();
     // PC platform is bound to current work directory because of the LVGL file system mapping
     if (get_platform() == PlatformPc) {
@@ -211,11 +211,11 @@ static void on_start(App app) {
         data_set_entries_for_path(data, "/");
     }
 
-    tt_app_set_data(app, data);
+    app.setData(data);
 }
 
-static void on_stop(App app) {
+static void on_stop(App& app) {
-    auto* data = static_cast<Data*>(tt_app_get_data(app));
+    auto* data = static_cast<Data*>(app.getData());
     data_free(data);
 }
 
@@ -226,9 +226,9 @@ extern const Manifest manifest = {
     .name = "Files",
     .icon = TT_ASSETS_APP_ICON_FILES,
     .type = TypeSystem,
-    .on_start = &on_start,
+    .onStart = &on_start,
-    .on_stop = &on_stop,
+    .onStop = &on_stop,
-    .on_show = &on_show,
+    .onShow = &on_show,
 };
 
 } // namespace

Tactility/Source/app/gpio/Gpio.cpp

@@ -120,8 +120,8 @@ static void task_stop(Gpio* gpio) {
 
 // region App lifecycle
 
-static void app_show(App app, lv_obj_t* parent) {
+static void app_show(App& app, lv_obj_t* parent) {
-    auto* gpio = static_cast<Gpio*>(tt_app_get_data(app));
+    auto* gpio = (Gpio*)app.getData();
 
     lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
     lv_obj_t* toolbar = lvgl::toolbar_create(parent, app);
@@ -176,27 +176,26 @@ static void app_show(App app, lv_obj_t* parent) {
     task_start(gpio);
 }
 
-static void on_hide(App app) {
+static void on_hide(App& app) {
-    auto* gpio = static_cast<Gpio*>(tt_app_get_data(app));
+    auto* gpio = (Gpio*)app.getData();
     task_stop(gpio);
 }
 
-static void on_start(App app) {
+static void on_start(App& app) {
-    auto* gpio = static_cast<Gpio*>(malloc(sizeof(Gpio)));
+    auto* gpio = new Gpio {
-    *gpio = (Gpio) {
         .lv_pins = { nullptr },
         .pin_states = { 0 },
         .thread = nullptr,
         .mutex = tt_mutex_alloc(MutexTypeNormal),
         .thread_interrupted = true,
     };
-    tt_app_set_data(app, gpio);
+    app.setData(gpio);
 }
 
-static void on_stop(App app) {
+static void on_stop(App& app) {
-    auto* gpio = static_cast<Gpio*>(tt_app_get_data(app));
+    auto* gpio = (Gpio*)app.getData();
     tt_mutex_free(gpio->mutex);
-    free(gpio);
+    delete gpio;
 }
 
 // endregion App lifecycle
@@ -205,10 +204,10 @@ extern const Manifest manifest = {
     .id = "Gpio",
     .name = "GPIO",
     .type = TypeSystem,
-    .on_start = &on_start,
+    .onStart = &on_start,
-    .on_stop = &on_stop,
+    .onStop = &on_stop,
-    .on_show = &app_show,
+    .onShow = &app_show,
-    .on_hide = &on_hide
+    .onHide = &on_hide
 };
 
 } // namespace

Tactility/Source/app/i2csettings/I2cSettings.cpp

@@ -69,7 +69,7 @@ static void show(lv_obj_t* parent, const hal::i2c::Configuration& configuration)
     }
 }
 
-static void on_show(App app, lv_obj_t* parent) {
+static void on_show(App& app, lv_obj_t* parent) {
     lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
     lvgl::toolbar_create(parent, app);
 
@@ -90,7 +90,7 @@ extern const Manifest manifest = {
     .name = "I2C",
     .icon = TT_ASSETS_APP_ICON_I2C_SETTINGS,
     .type = TypeSettings,
-    .on_show = &on_show
+    .onShow = &on_show
 };
 
 } // namespace

Tactility/Source/app/imageviewer/ImageViewer.cpp

@@ -8,7 +8,7 @@ namespace tt::app::imageviewer {
 
 #define TAG "image_viewer"
 
-static void on_show(App app, lv_obj_t* parent) {
+static void on_show(App& app, lv_obj_t* parent) {
     lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
     lvgl::toolbar_create(parent, app);
 
@@ -22,7 +22,7 @@ static void on_show(App app, lv_obj_t* parent) {
     lv_obj_t* image = lv_img_create(wrapper);
     lv_obj_align(image, LV_ALIGN_CENTER, 0, 0);
 
-    const Bundle& bundle = tt_app_get_parameters(app);
+    const Bundle& bundle = app.getParameters();
     std::string file_argument;
     if (bundle.optString(IMAGE_VIEWER_FILE_ARGUMENT, file_argument)) {
         std::string prefixed_path = "A:" + file_argument;
@@ -35,7 +35,7 @@ extern const Manifest manifest = {
     .id = "ImageViewer",
     .name = "Image Viewer",
     .type = TypeHidden,
-    .on_show = &on_show
+    .onShow = &on_show
 };
 
 } // namespace

Tactility/Source/app/power/Power.cpp

@@ -53,7 +53,7 @@ static void on_power_enabled_change(lv_event_t* event) {
     }
 }
 
-static void app_show(App app, lv_obj_t* parent) {
+static void app_show(App& app, lv_obj_t* parent) {
     lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
 
     lvgl::toolbar_create(parent, app);
@@ -64,7 +64,7 @@ static void app_show(App app, lv_obj_t* parent) {
     lv_obj_set_flex_grow(wrapper, 1);
     lv_obj_set_flex_flow(wrapper, LV_FLEX_FLOW_COLUMN);
 
-    auto* data = static_cast<AppData*>(tt_app_get_data(app));
+    auto* data = static_cast<AppData*>(app.getData());
 
     // Top row: enable/disable
     lv_obj_t* switch_container = lv_obj_create(wrapper);
@@ -90,21 +90,21 @@ static void app_show(App app, lv_obj_t* parent) {
     data->update_timer->start(ms_to_ticks(1000));
 }
 
-static void app_hide(TT_UNUSED App app) {
+static void app_hide(TT_UNUSED App& app) {
-    auto* data = static_cast<AppData*>(tt_app_get_data(app));
+    auto* data = static_cast<AppData*>(app.getData());
     data->update_timer->stop();
 }
 
-static void app_start(App app) {
+static void app_start(App& app) {
     auto* data = new AppData();
     data->update_timer = new Timer(Timer::TypePeriodic, &app_update_ui, data);
     data->power = getConfiguration()->hardware->power;
     assert(data->power != nullptr); // The Power app only shows up on supported devices
-    tt_app_set_data(app, data);
+    app.setData(data);
 }
 
-static void app_stop(App app) {
+static void app_stop(App& app) {
-    auto* data = static_cast<AppData*>(tt_app_get_data(app));
+    auto* data = static_cast<AppData*>(app.getData());
     delete data->update_timer;
     delete data;
 }
@@ -114,10 +114,10 @@ extern const Manifest manifest = {
     .name = "Power",
     .icon = TT_ASSETS_APP_ICON_POWER_SETTINGS,
     .type = TypeSettings,
-    .on_start = &app_start,
+    .onStart = &app_start,
-    .on_stop = &app_stop,
+    .onStop = &app_stop,
-    .on_show = &app_show,
+    .onShow = &app_show,
-    .on_hide = &app_hide
+    .onHide = &app_hide
 };
 
 } // namespace

Tactility/Source/app/screenshot/Screenshot.cpp

@@ -2,18 +2,18 @@
 
 namespace tt::app::screenshot {
 
-static void on_show(App app, lv_obj_t* parent) {
+static void on_show(App& app, lv_obj_t* parent) {
-    auto* ui = static_cast<ScreenshotUi*>(tt_app_get_data(app));
+    auto* ui = static_cast<ScreenshotUi*>(app.getData());
     create_ui(app, ui, parent);
 }
 
-static void on_start(App app) {
+static void on_start(App& app) {
     auto* ui = static_cast<ScreenshotUi*>(malloc(sizeof(ScreenshotUi)));
-    tt_app_set_data(app, ui);
+    app.setData(ui);
 }
 
-static void on_stop(App app) {
+static void on_stop(App& app) {
-    auto* ui = static_cast<ScreenshotUi*>(tt_app_get_data(app));
+    auto* ui = static_cast<ScreenshotUi*>(app.getData());
     free(ui);
 }
 
@@ -22,9 +22,9 @@ extern const Manifest manifest = {
     .name = "_Screenshot", // So it gets put at the bottom of the desktop and becomes less visible on small screen devices
     .icon = LV_SYMBOL_IMAGE,
     .type = TypeSystem,
-    .on_start = &on_start,
+    .onStart = &on_start,
-    .on_stop = &on_stop,
+    .onStop = &on_stop,
-    .on_show = &on_show,
+    .onShow = &on_show,
 };
 
 } // namespace

Tactility/Source/app/screenshot/ScreenshotUi.cpp

@@ -153,7 +153,7 @@ static void create_timer_settings_ui(ScreenshotUi* ui, lv_obj_t* parent) {
     lv_label_set_text(delay_unit_label, "seconds");
 }
 
-void create_ui(App app, ScreenshotUi* ui, lv_obj_t* parent) {
+void create_ui(const App& app, ScreenshotUi* ui, lv_obj_t* parent) {
     lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
     lv_obj_t* toolbar = lvgl::toolbar_create(parent, app);
     lv_obj_align(toolbar, LV_ALIGN_TOP_MID, 0, 0);

Tactility/Source/app/screenshot/ScreenshotUi.h

@@ -13,6 +13,6 @@ typedef struct {
     lv_obj_t* delay_textarea;
 } ScreenshotUi;
 
-void create_ui(App app, ScreenshotUi* ui, lv_obj_t* parent);
+void create_ui(const App& app, ScreenshotUi* ui, lv_obj_t* parent);
 
 } // namespace

Tactility/Source/app/settings/Settings.cpp

@@ -24,7 +24,7 @@ static void create_app_widget(const Manifest* manifest, void* parent) {
     lv_obj_add_event_cb(btn, &on_app_pressed, LV_EVENT_CLICKED, (void*)manifest);
 }
 
-static void on_show(App app, lv_obj_t* parent) {
+static void on_show(App& app, lv_obj_t* parent) {
     lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
 
     lvgl::toolbar_create(parent, app);
@@ -33,7 +33,7 @@ static void on_show(App app, lv_obj_t* parent) {
     lv_obj_set_width(list, LV_PCT(100));
     lv_obj_set_flex_grow(list, 1);
 
-    auto manifests = app_manifest_registry_get();
+    auto manifests = getApps();
     std::sort(manifests.begin(), manifests.end(), SortAppManifestByName);
     for (const auto& manifest: manifests) {
         if (manifest->type == TypeSettings) {
@@ -47,10 +47,10 @@ extern const Manifest manifest = {
     .name = "Settings",
     .icon = TT_ASSETS_APP_ICON_SETTINGS,
     .type = TypeSystem,
-    .on_start = nullptr,
+    .onStart = nullptr,
-    .on_stop = nullptr,
+    .onStop = nullptr,
-    .on_show = &on_show,
+    .onShow = &on_show,
-    .on_hide = nullptr
+    .onHide = nullptr
 };
 
 } // namespace

Tactility/Source/app/systeminfo/SystemInfo.cpp

@@ -65,7 +65,7 @@ static void add_memory_bar(lv_obj_t* parent, const char* label, size_t used, siz
     lv_obj_set_style_text_align(bottom_label, LV_TEXT_ALIGN_RIGHT, 0);
 }
 
-static void on_show(App app, lv_obj_t* parent) {
+static void on_show(App& app, lv_obj_t* parent) {
     lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
     lvgl::toolbar_create(parent, app);
 
@@ -106,9 +106,9 @@ extern const Manifest manifest = {
     .name = "System Info",
     .icon = TT_ASSETS_APP_ICON_SYSTEM_INFO,
     .type = TypeSystem,
-    .on_start = nullptr,
+    .onStart = nullptr,
-    .on_stop = nullptr,
+    .onStop = nullptr,
-    .on_show = &on_show
+    .onShow = &on_show
 };
 
 } // namespace

Tactility/Source/app/textviewer/TextViewer.cpp

@@ -9,7 +9,7 @@
 
 namespace tt::app::textviewer {
 
-static void on_show(App app, lv_obj_t* parent) {
+static void on_show(App& app, lv_obj_t* parent) {
     lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);
     lvgl::toolbar_create(parent, app);
 
@@ -22,7 +22,7 @@ static void on_show(App app, lv_obj_t* parent) {
 
     lv_obj_t* label = lv_label_create(wrapper);
     lv_obj_align(label, LV_ALIGN_CENTER, 0, 0);
-    const Bundle& bundle = tt_app_get_parameters(app);
+    const Bundle& bundle = app.getParameters();
     std::string file_argument;
     if (bundle.optString(TEXT_VIEWER_FILE_ARGUMENT, file_argument)) {
         std::string prefixed_path = "A:" + file_argument;
@@ -35,7 +35,7 @@ extern const Manifest manifest = {
     .id = "TextViewer",
     .name = "Text Viewer",
     .type = TypeHidden,
-    .on_show = &on_show
+    .onShow = &on_show
 };
 
 } // namespace

Tactility/Source/app/wificonnect/WifiConnect.cpp

@@ -101,8 +101,8 @@ static void event_callback(const void* message, void* context) {
     request_view_update(wifi);
 }
 
-static void app_show(App app, lv_obj_t* parent) {
+static void app_show(App& app, lv_obj_t* parent) {
-    auto* wifi = static_cast<WifiConnect*>(tt_app_get_data(app));
+    auto* wifi = static_cast<WifiConnect*>(app.getData());
 
     lock(wifi);
     wifi->view_enabled = true;
@@ -111,8 +111,8 @@ static void app_show(App app, lv_obj_t* parent) {
     unlock(wifi);
 }
 
-static void app_hide(App app) {
+static void app_hide(App& app) {
-    auto* wifi = static_cast<WifiConnect*>(tt_app_get_data(app));
+    auto* wifi = static_cast<WifiConnect*>(app.getData());
     // No need to lock view, as this is called from within Gui's LVGL context
     view_destroy(&wifi->view);
     lock(wifi);
@@ -120,16 +120,15 @@ static void app_hide(App app) {
     unlock(wifi);
 }
 
-static void app_start(App app) {
+static void app_start(App& app) {
     auto* wifi_connect = wifi_connect_alloc();
-    tt_app_set_data(app, wifi_connect);
+    app.setData(wifi_connect);
 }
 
-static void app_stop(App app) {
+static void app_stop(App& app) {
-    auto* wifi = static_cast<WifiConnect*>(tt_app_get_data(app));
+    auto* wifi = static_cast<WifiConnect*>(app.getData());
     tt_assert(wifi != nullptr);
     wifi_connect_free(wifi);
-    tt_app_set_data(app, nullptr);
 }
 
 extern const Manifest manifest = {
@@ -137,10 +136,10 @@ extern const Manifest manifest = {
     .name = "Wi-Fi Connect",
     .icon = LV_SYMBOL_WIFI,
     .type = TypeSettings,
-    .on_start = &app_start,
+    .onStart = &app_start,
-    .on_stop = &app_stop,
+    .onStop = &app_stop,
-    .on_show = &app_show,
+    .onShow = &app_show,
-    .on_hide = &app_hide
+    .onHide = &app_hide
 };
 
 } // namespace

Tactility/Source/app/wificonnect/WifiConnectView.cpp

@@ -113,7 +113,7 @@ void view_create_bottom_buttons(WifiConnect* wifi, lv_obj_t* parent) {
 }
 
 // TODO: Standardize dialogs
-void view_create(App app, void* wifi, lv_obj_t* parent) {
+void view_create(const App& app, void* wifi, lv_obj_t* parent) {
     WifiConnect* wifi_connect = (WifiConnect*)wifi;
     WifiConnectView* view = &wifi_connect->view;
 
@@ -195,7 +195,7 @@ void view_create(App app, void* wifi, lv_obj_t* parent) {
     service::gui::keyboard_add_textarea(view->password_textarea);
 
     // Init from app parameters
-    const Bundle& bundle = tt_app_get_parameters(app);
+    const Bundle& bundle = app.getParameters();
     std::string ssid;
     if (bundle.optString(WIFI_CONNECT_PARAM_SSID, ssid)) {
         lv_textarea_set_text(view->ssid_textarea, ssid.c_str());

Tactility/Source/app/wificonnect/WifiConnectView.h

@@ -20,7 +20,7 @@ typedef struct {
     lv_group_t* group;
 } WifiConnectView;
 
-void view_create(App app, void* wifi, lv_obj_t* parent);
+void view_create(const App& app, void* wifi, lv_obj_t* parent);
 void view_update(WifiConnectView* view, WifiConnectBindings* bindings, WifiConnectState* state);
 void view_destroy(WifiConnectView* view);
 

Tactility/Source/app/wifimanage/WifiManage.cpp

@@ -116,8 +116,8 @@ static void wifi_manage_event_callback(const void* message, void* context) {
     request_view_update(wifi);
 }
 
-static void app_show(App app, lv_obj_t* parent) {
+static void app_show(App& app, lv_obj_t* parent) {
-    auto* wifi = (WifiManage*)tt_app_get_data(app);
+    auto* wifi = (WifiManage*)app.getData();
 
     PubSub* wifi_pubsub = service::wifi::get_pubsub();
     wifi->wifi_subscription = tt_pubsub_subscribe(wifi_pubsub, &wifi_manage_event_callback, wifi);
@@ -144,8 +144,8 @@ static void app_show(App app, lv_obj_t* parent) {
     }
 }
 
-static void app_hide(App app) {
+static void app_hide(App& app) {
-    auto* wifi = (WifiManage*)tt_app_get_data(app);
+    auto* wifi = (WifiManage*)app.getData();
     lock(wifi);
     PubSub* wifi_pubsub = service::wifi::get_pubsub();
     tt_pubsub_unsubscribe(wifi_pubsub, wifi->wifi_subscription);
@@ -154,16 +154,15 @@ static void app_hide(App app) {
     unlock(wifi);
 }
 
-static void app_start(App app) {
+static void app_start(App& app) {
     WifiManage* wifi = wifi_manage_alloc();
-    tt_app_set_data(app, wifi);
+    app.setData(wifi);
 }
 
-static void app_stop(App app) {
+static void app_stop(App& app) {
-    auto* wifi = (WifiManage*)tt_app_get_data(app);
+    auto* wifi = (WifiManage*)app.getData();
     tt_assert(wifi != nullptr);
     wifi_manage_free(wifi);
-    tt_app_set_data(app, nullptr);
 }
 
 extern const Manifest manifest = {
@@ -171,10 +170,10 @@ extern const Manifest manifest = {
     .name = "Wi-Fi",
     .icon = LV_SYMBOL_WIFI,
     .type = TypeSettings,
-    .on_start = &app_start,
+    .onStart = &app_start,
-    .on_stop = &app_stop,
+    .onStop = &app_stop,
-    .on_show = &app_show,
+    .onShow = &app_show,
-    .on_hide = &app_hide
+    .onHide = &app_hide
 };
 
 } // namespace

Tactility/Source/app/wifimanage/WifiManageView.cpp

@@ -129,7 +129,7 @@ static void update_connected_ap(WifiManageView* view, WifiManageState* state, TT
 
 // region Main
 
-void view_create(App app, WifiManageView* view, WifiManageBindings* bindings, lv_obj_t* parent) {
+void view_create(const App& app, WifiManageView* view, WifiManageBindings* bindings, lv_obj_t* parent) {
     view->root = parent;
 
     lv_obj_set_flex_flow(parent, LV_FLEX_FLOW_COLUMN);

Tactility/Source/app/wifimanage/WifiManageView.h

@@ -17,7 +17,7 @@ typedef struct {
     lv_obj_t* connected_ap_label;
 } WifiManageView;
 
-void view_create(App app, WifiManageView* view, WifiManageBindings* bindings, lv_obj_t* parent);
+void view_create(const App& app, WifiManageView* view, WifiManageBindings* bindings, lv_obj_t* parent);
 void view_update(WifiManageView* view, WifiManageBindings* bindings, WifiManageState* state);
 
 } // namespace

Tactility/Source/lvgl/Toolbar.cpp

@@ -86,9 +86,8 @@ lv_obj_t* toolbar_create(lv_obj_t* parent, const std::string& title) {
     return obj;
 }
 
-lv_obj_t* toolbar_create(lv_obj_t* parent, app::App app) {
+lv_obj_t* toolbar_create(lv_obj_t* parent, const app::App& app) {
-    const app::Manifest& manifest = app::tt_app_get_manifest(app);
+    lv_obj_t* toolbar = toolbar_create(parent, app.getManifest().name);
-    lv_obj_t* toolbar = toolbar_create(parent, manifest.name);
     toolbar_set_nav_action(toolbar, LV_SYMBOL_CLOSE, &stop_app, nullptr);
     return toolbar;
 }

Tactility/Source/lvgl/Toolbar.h

@@ -19,7 +19,7 @@ typedef struct {
 } ToolbarAction;
 
 lv_obj_t* toolbar_create(lv_obj_t* parent, const std::string& title);
-lv_obj_t* toolbar_create(lv_obj_t* parent, app::App app);
+lv_obj_t* toolbar_create(lv_obj_t* parent, const app::App& app);
 void toolbar_set_title(lv_obj_t* obj, const std::string& title);
 void toolbar_set_nav_action(lv_obj_t* obj, const char* icon, lv_event_cb_t callback, void* user_data);
 uint8_t toolbar_add_action(lv_obj_t* obj, const char* icon, const char* text, lv_event_cb_t callback, void* user_data);

Tactility/Source/service/gui/Gui.cpp

@@ -20,13 +20,12 @@ static int32_t gui_main(void*);
 
 Gui* gui = nullptr;
 
-typedef void (*PubSubCallback)(const void* message, void* context);
 void loader_callback(const void* message, TT_UNUSED void* context) {
     auto* event = static_cast<const loader::LoaderEvent*>(message);
     if (event->type == loader::LoaderEventTypeApplicationShowing) {
-        app::App* app = event->app_showing.app;
+        app::App& app = event->app_showing.app;
-        const app::Manifest& app_manifest = app::tt_app_get_manifest(app);
+        const app::Manifest& app_manifest = app.getManifest();
-        show_app(app, app_manifest.on_show, app_manifest.on_hide);
+        show_app(app, app_manifest.onShow, app_manifest.onHide);
     } else if (event->type == loader::LoaderEventTypeApplicationHiding) {
         hide_app();
     }
@@ -83,7 +82,7 @@ void request_draw() {
     thread_flags_set(thread_id, GUI_THREAD_FLAG_DRAW);
 }
 
-void show_app(app::App app, ViewPortShowCallback on_show, ViewPortHideCallback on_hide) {
+void show_app(app::App& app, ViewPortShowCallback on_show, ViewPortHideCallback on_hide) {
     lock();
     tt_check(gui->app_view_port == nullptr);
     gui->app_view_port = view_port_alloc(app, on_show, on_hide);

Tactility/Source/service/gui/Gui.h

@@ -14,7 +14,7 @@ typedef struct Gui Gui;
  * @param on_show
  * @param on_hide
  */
-void show_app(app::App app, ViewPortShowCallback on_show, ViewPortHideCallback on_hide);
+void show_app(app::App& app, ViewPortShowCallback on_show, ViewPortHideCallback on_hide);
 
 /**
  * Hide the current app's viewport.

Tactility/Source/service/gui/GuiDraw.cpp

@@ -9,7 +9,7 @@ namespace tt::service::gui {
 
 #define TAG "gui"
 
-static lv_obj_t* create_app_views(Gui* gui, lv_obj_t* parent, app::App app) {
+static lv_obj_t* create_app_views(Gui* gui, lv_obj_t* parent, app::App& app) {
     lvgl::obj_set_style_bg_blacken(parent);
 
     lv_obj_t* vertical_container = lv_obj_create(parent);
@@ -19,8 +19,8 @@ static lv_obj_t* create_app_views(Gui* gui, lv_obj_t* parent, app::App app) {
     lvgl::obj_set_style_bg_blacken(vertical_container);
 
     // TODO: Move statusbar into separate ViewPort
-    app::Flags flags = app::tt_app_get_flags(app);
+    app::Flags flags = app.getFlags();
-    if (flags.show_statusbar) {
+    if (flags.showStatusbar) {
         lvgl::statusbar_create(vertical_container);
     }
 
@@ -49,7 +49,7 @@ void redraw(Gui* gui) {
 
         ViewPort* view_port = gui->app_view_port;
         if (view_port != nullptr) {
-            app::App app = view_port->app;
+            app::App& app = view_port->app;
             lv_obj_t* container = create_app_views(gui, gui->lvgl_parent, app);
             view_port_show(view_port, container);
         } else {

Tactility/Source/service/gui/ViewPort.cpp

@@ -9,35 +9,35 @@ namespace tt::service::gui {
 #define TAG "viewport"
 
 ViewPort* view_port_alloc(
-    app::App app,
+    app::App& app,
     ViewPortShowCallback on_show,
     ViewPortHideCallback on_hide
 ) {
-    auto* view_port = static_cast<ViewPort*>(malloc(sizeof(ViewPort)));
+    return new ViewPort(
-    view_port->app = app;
+        app,
-    view_port->on_show = on_show;
+        on_show,
-    view_port->on_hide = on_hide;
+        on_hide
-    return view_port;
+    );
 }
 
 void view_port_free(ViewPort* view_port) {
     tt_assert(view_port);
-    free(view_port);
+    delete view_port;
 }
 
 void view_port_show(ViewPort* view_port, lv_obj_t* parent) {
     tt_assert(view_port);
     tt_assert(parent);
-    if (view_port->on_show) {
+    if (view_port->onShow) {
         lvgl::obj_set_style_no_padding(parent);
-        view_port->on_show(view_port->app, parent);
+        view_port->onShow(view_port->app, parent);
     }
 }
 
 void view_port_hide(ViewPort* view_port) {
     tt_assert(view_port);
-    if (view_port->on_hide) {
+    if (view_port->onHide) {
-        view_port->on_hide(view_port->app);
+        view_port->onHide(view_port->app);
     }
 }
 

Tactility/Source/service/gui/ViewPort.h

@@ -8,16 +8,21 @@ namespace tt::service::gui {
 /** ViewPort Draw callback
  * @warning    called from GUI thread
  */
-typedef void (*ViewPortShowCallback)(app::App app, lv_obj_t* parent);
+typedef void (*ViewPortShowCallback)(app::App& app, lv_obj_t* parent);
-typedef void (*ViewPortHideCallback)(app::App app);
+typedef void (*ViewPortHideCallback)(app::App& app);
 
 // TODO: Move internally, use handle publicly
 
-typedef struct {
+typedef struct ViewPort {
-    app::App app;
+    app::App& app;
-    ViewPortShowCallback on_show;
+    ViewPortShowCallback onShow;
-    ViewPortHideCallback _Nullable on_hide;
+    ViewPortHideCallback _Nullable onHide;
-    bool app_toolbar;
+
+    ViewPort(
+        app::App& app,
+        ViewPortShowCallback on_show,
+        ViewPortHideCallback _Nullable on_hide
+    ) : app(app), onShow(on_show), onHide(on_hide) {}
 } ViewPort;
 
 /** ViewPort allocator
@@ -30,7 +35,7 @@ typedef struct {
  * @return     ViewPort instance
  */
 ViewPort* view_port_alloc(
-    app::App app,
+    app::App& app,
     ViewPortShowCallback on_show,
     ViewPortHideCallback on_hide
 );

Tactility/Source/service/loader/Loader.cpp

@@ -1,4 +1,5 @@
 #include "Tactility.h"
+#include <Mutex.h>
 #include "app/Manifest.h"
 #include "app/ManifestRegistry.h"
 #include "service/Manifest.h"
@@ -39,8 +40,6 @@ static Loader* loader_alloc() {
         nullptr
     );
     loader_singleton->mutex = tt_mutex_alloc(MutexTypeRecursive);
-    loader_singleton->app_stack_index = -1;
-    memset(loader_singleton->app_stack, 0, sizeof(app::App) * APP_STACK_SIZE);
     return loader_singleton;
 }
 
@@ -100,14 +99,12 @@ void stop_app() {
     loader_singleton->queue.put(&message, TtWaitForever);
 }
 
-app::App _Nullable get_current_app() {
+app::App* _Nullable get_current_app() {
     tt_assert(loader_singleton);
     loader_lock();
-    app::App app = (loader_singleton->app_stack_index >= 0)
+    app::AppInstance* app = loader_singleton->app_stack.top();
-        ? loader_singleton->app_stack[loader_singleton->app_stack_index]
-        : nullptr;
     loader_unlock();
-    return app;
+    return dynamic_cast<app::App*>(app);
 }
 
 PubSub* get_pubsub() {
@@ -135,9 +132,9 @@ static const char* app_state_to_string(app::State state) {
     }
 }
 
-static void app_transition_to_state(app::App app, app::State state) {
+static void app_transition_to_state(app::AppInstance& app, app::State state) {
-    const app::Manifest& manifest = app::tt_app_get_manifest(app);
+    const app::Manifest& manifest = app.getManifest();
-    const app::State old_state = app::tt_app_get_state(app);
+    const app::State old_state = app.getState();
 
     TT_LOG_I(
         TAG,
@@ -149,42 +146,42 @@ static void app_transition_to_state(app::App app, app::State state) {
 
     switch (state) {
         case app::StateInitial:
-            tt_app_set_state(app, app::StateInitial);
+            app.setState(app::StateInitial);
             break;
         case app::StateStarted:
-            if (manifest.on_start != nullptr) {
+            if (manifest.onStart != nullptr) {
-                manifest.on_start(app);
+                manifest.onStart(app);
             }
-            tt_app_set_state(app, app::StateStarted);
+            app.setState(app::StateStarted);
             break;
         case app::StateShowing: {
             LoaderEvent event_showing = {
                 .type = LoaderEventTypeApplicationShowing,
                 .app_showing = {
-                    .app = static_cast<app::App*>(app)
+                    .app = dynamic_cast<app::App&>(app)
                 }
             };
             tt_pubsub_publish(loader_singleton->pubsub_external, &event_showing);
-            tt_app_set_state(app, app::StateShowing);
+            app.setState(app::StateShowing);
             break;
         }
         case app::StateHiding: {
             LoaderEvent event_hiding = {
                 .type = LoaderEventTypeApplicationHiding,
                 .app_hiding = {
-                    .app = static_cast<app::App*>(app)
+                    .app = dynamic_cast<app::App&>(app)
                 }
             };
             tt_pubsub_publish(loader_singleton->pubsub_external, &event_hiding);
-            tt_app_set_state(app, app::StateHiding);
+            app.setState(app::StateHiding);
             break;
         }
         case app::StateStopped:
-            if (manifest.on_stop) {
+            if (manifest.onStop) {
-                manifest.on_stop(app);
+                manifest.onStop(app);
             }
-            app::tt_app_set_data(app, nullptr);
+            app.setData(nullptr);
-            tt_app_set_state(app, app::StateStopped);
+            app.setState(app::StateStopped);
             break;
     }
 }
@@ -197,27 +194,18 @@ static LoaderStatus loader_do_start_app_with_manifest(
 
     loader_lock();
 
-    if (loader_singleton->app_stack_index >= (APP_STACK_SIZE - 1)) {
+    auto previous_app = !loader_singleton->app_stack.empty() ? loader_singleton->app_stack.top() : nullptr;
-        TT_LOG_E(TAG, "failed to start app: stack limit of %d reached", APP_STACK_SIZE);
+    auto new_app = new app::AppInstance(*manifest, bundle);
-        return LoaderStatusErrorInternal;
+    loader_singleton->app_stack.push(new_app);
-    }
+    app_transition_to_state(*new_app, app::StateInitial);
-
+    app_transition_to_state(*new_app, app::StateStarted);
-    int8_t previous_index = loader_singleton->app_stack_index;
-    loader_singleton->app_stack_index++;
-
-    app::App app = tt_app_alloc(*manifest, bundle);
-    tt_check(loader_singleton->app_stack[loader_singleton->app_stack_index] == nullptr);
-    loader_singleton->app_stack[loader_singleton->app_stack_index] = app;
-    app_transition_to_state(app, app::StateInitial);
-    app_transition_to_state(app, app::StateStarted);
 
     // We might have to hide the previous app first
-    if (previous_index != -1) {
+    if (previous_app != nullptr) {
-        app::App previous_app = loader_singleton->app_stack[previous_index];
+        app_transition_to_state(*previous_app, app::StateHiding);
-        app_transition_to_state(previous_app, app::StateHiding);
     }
 
-    app_transition_to_state(app, app::StateShowing);
+    app_transition_to_state(*new_app, app::StateShowing);
 
     loader_unlock();
 
@@ -227,7 +215,7 @@ static LoaderStatus loader_do_start_app_with_manifest(
     LoaderEvent event_external = {
         .type = LoaderEventTypeApplicationStarted,
         .app_started = {
-            .app = static_cast<app::App*>(app)
+            .app = dynamic_cast<app::App&>(*new_app)
         }
     };
     tt_pubsub_publish(loader_singleton->pubsub_external, &event_external);
@@ -241,7 +229,7 @@ static LoaderStatus do_start_by_id(
 ) {
     TT_LOG_I(TAG, "Start by id %s", id.c_str());
 
-    const app::Manifest* manifest = app::app_manifest_registry_find_by_id(id);
+    const app::Manifest* manifest = app::findAppById(id);
     if (manifest == nullptr) {
         return LoaderStatusErrorUnknownApp;
     } else {
@@ -253,38 +241,40 @@ static LoaderStatus do_start_by_id(
 static void do_stop_app() {
     loader_lock();
 
-    int8_t current_app_index = loader_singleton->app_stack_index;
+    size_t original_stack_size = loader_singleton->app_stack.size();
 
-    if (current_app_index == -1) {
+    if (original_stack_size == 0) {
         loader_unlock();
         TT_LOG_E(TAG, "Stop app: no app running");
         return;
     }
 
-    if (current_app_index == 0) {
+    if (original_stack_size == 1) {
         loader_unlock();
         TT_LOG_E(TAG, "Stop app: can't stop root app");
         return;
     }
 
     // Stop current app
-    app::App app_to_stop = loader_singleton->app_stack[current_app_index];
+    app::AppInstance* app_to_stop = loader_singleton->app_stack.top();
-    const app::Manifest& manifest = app::tt_app_get_manifest(app_to_stop);
+    const app::Manifest& manifest = app_to_stop->getManifest();
-    app_transition_to_state(app_to_stop, app::StateHiding);
+    app_transition_to_state(*app_to_stop, app::StateHiding);
-    app_transition_to_state(app_to_stop, app::StateStopped);
+    app_transition_to_state(*app_to_stop, app::StateStopped);
 
-    app::tt_app_free(app_to_stop);
+    loader_singleton->app_stack.pop();
-    loader_singleton->app_stack[current_app_index] = nullptr;
+    delete app_to_stop;
-    loader_singleton->app_stack_index--;
 
 #ifdef ESP_PLATFORM
     TT_LOG_I(TAG, "Free heap: %zu", heap_caps_get_free_size(MALLOC_CAP_INTERNAL));
 #endif
 
     // Resume previous app
-    tt_assert(loader_singleton->app_stack[loader_singleton->app_stack_index] != nullptr);
+    if (original_stack_size > 1) {
-    app::App app_to_resume = loader_singleton->app_stack[loader_singleton->app_stack_index];
+
-    app_transition_to_state(app_to_resume, app::StateShowing);
+    }
+    app::AppInstance* app_to_resume = loader_singleton->app_stack.top();
+    tt_assert(app_to_resume);
+    app_transition_to_state(*app_to_resume, app::StateShowing);
 
     loader_unlock();
 
@@ -294,7 +284,7 @@ static void do_stop_app() {
     LoaderEvent event_external = {
         .type = LoaderEventTypeApplicationStopped,
         .app_stopped = {
-            .manifest = &manifest
+            .manifest = manifest
         }
     };
     tt_pubsub_publish(loader_singleton->pubsub_external, &event_external);

Tactility/Source/service/loader/Loader.h

@@ -24,19 +24,19 @@ typedef enum {
 } LoaderEventType;
 
 typedef struct {
-    app::App* app;
+    app::App& app;
 } LoaderEventAppStarted;
 
 typedef struct {
-    app::App* app;
+    app::App& app;
 } LoaderEventAppShowing;
 
 typedef struct {
-    app::App* app;
+    app::App& app;
 } LoaderEventAppHiding;
 
 typedef struct {
-    const app::Manifest* manifest;
+    const app::Manifest& manifest;
 } LoaderEventAppStopped;
 
 typedef struct {
@@ -63,7 +63,7 @@ LoaderStatus start_app(const std::string& id, bool blocking, const Bundle& bundl
  */
 void stop_app();
 
-app::App _Nullable get_current_app();
+app::App* _Nullable get_current_app();
 
 /**
  * @brief PubSub for LoaderEvent

Tactility/Source/service/screenshot/ScreenshotTask.cpp

@@ -98,9 +98,9 @@ static int32_t screenshot_task(void* context) {
                 break; // Interrupted loop
             }
         } else if (data->work.type == TASK_WORK_TYPE_APPS) {
-            app::App _Nullable app = loader::get_current_app();
+            app::App* _Nullable app = loader::get_current_app();
             if (app) {
-                const app::Manifest& manifest = app::tt_app_get_manifest(app);
+                const app::Manifest& manifest = app->getManifest();
                 if (manifest.id != last_app_id) {
                     delay_ms(100);
                     last_app_id = manifest.id;
@@ -125,7 +125,7 @@ static int32_t screenshot_task(void* context) {
 
 static void task_start(ScreenshotTaskData* data) {
     task_lock(data);
-    tt_check(data->thread == NULL);
+    tt_check(data->thread == nullptr);
     data->thread = new Thread(
         "screenshot",
         8192,