am/applets: Add Applet superclass to describe a generic applet

Adds an Initialize and Execute methods which are used by the ILibraryAppletAccessor to start and control the applet.

src/core/CMakeLists.txt

@@ -150,6 +150,8 @@ add_library(core STATIC
     hle/service/am/applet_ae.h
     hle/service/am/applet_oe.cpp
     hle/service/am/applet_oe.h
+    hle/service/am/applets/applets.cpp
+    hle/service/am/applets/applets.h
     hle/service/am/idle.cpp
     hle/service/am/idle.h
     hle/service/am/omm.cpp

src/core/hle/service/am/applets/applets.cpp

@@ -0,0 +1,29 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/frontend/applets/software_keyboard.h"
+#include "core/hle/service/am/applets/applets.h"
+
+namespace Service::AM::Applets {
+
+std::shared_ptr<Frontend::SoftwareKeyboardApplet> software_keyboard =
+    std::make_shared<Frontend::DefaultSoftwareKeyboardApplet>();
+
+void Applet::Initialize(std::vector<std::shared_ptr<IStorage>> storage) {
+    storage_stack = std::move(storage);
+    initialized = true;
+}
+
+void RegisterSoftwareKeyboard(std::shared_ptr<Frontend::SoftwareKeyboardApplet> applet) {
+    if (applet == nullptr)
+        return;
+
+    software_keyboard = std::move(applet);
+}
+
+std::shared_ptr<Frontend::SoftwareKeyboardApplet> GetSoftwareKeyboard() {
+    return software_keyboard;
+}
+
+} // namespace Service::AM::Applets

src/core/hle/service/am/applets/applets.h

@@ -0,0 +1,46 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <vector>
+#include "common/swap.h"
+
+namespace Frontend {
+class SoftwareKeyboardApplet;
+}
+
+namespace Service::AM {
+
+class IStorage;
+
+namespace Applets {
+
+class Applet {
+public:
+    virtual void Initialize(std::vector<std::shared_ptr<IStorage>> storage);
+
+    virtual IStorage Execute() = 0;
+
+protected:
+    struct CommonArguments {
+        u32_le arguments_version;
+        u32_le size;
+        u32_le library_version;
+        u32_le theme_color;
+        u8 play_startup_sound;
+        u64_le system_tick;
+    };
+    static_assert(sizeof(CommonArguments) == 0x20, "CommonArguments has incorrect size.");
+
+    std::vector<std::shared_ptr<IStorage>> storage_stack;
+    bool initialized = false;
+};
+
+void RegisterSoftwareKeyboard(std::shared_ptr<Frontend::SoftwareKeyboardApplet> applet);
+std::shared_ptr<Frontend::SoftwareKeyboardApplet> GetSoftwareKeyboard();
+
+} // namespace Applets
+} // namespace Service::AM