diff --git a/README.md b/README.md
index c24d4de..c42bd7d 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,11 @@ The Game of Fifteen (also called 15-puzzle, Gem Puzzle, Boss Puzzle, Mystic Squa
+
+
+
+
Report a bug or request a feature
----------------
diff --git a/linux/.gitignore b/linux/.gitignore
new file mode 100644
index 0000000..d3896c9
--- /dev/null
+++ b/linux/.gitignore
@@ -0,0 +1 @@
+flutter/ephemeral
diff --git a/linux/CMakeLists.txt b/linux/CMakeLists.txt
new file mode 100644
index 0000000..07a3d9b
--- /dev/null
+++ b/linux/CMakeLists.txt
@@ -0,0 +1,98 @@
+cmake_minimum_required(VERSION 3.10)
+project(runner LANGUAGES CXX)
+
+set(BINARY_NAME "fifteenpuzzle")
+set(APPLICATION_ID "com.artemchep.fifteenpuzzle")
+
+cmake_policy(SET CMP0063 NEW)
+
+set(CMAKE_INSTALL_RPATH "$ORIGIN/lib")
+
+# Configure build options.
+if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
+ set(CMAKE_BUILD_TYPE "Debug" CACHE
+ STRING "Flutter build mode" FORCE)
+ set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS
+ "Debug" "Profile" "Release")
+endif()
+
+# Compilation settings that should be applied to most targets.
+function(APPLY_STANDARD_SETTINGS TARGET)
+ target_compile_features(${TARGET} PUBLIC cxx_std_14)
+ target_compile_options(${TARGET} PRIVATE -Wall -Werror)
+ target_compile_options(${TARGET} PRIVATE "$<$>:-O3>")
+ target_compile_definitions(${TARGET} PRIVATE "$<$>:NDEBUG>")
+endfunction()
+
+set(FLUTTER_MANAGED_DIR "${CMAKE_CURRENT_SOURCE_DIR}/flutter")
+
+# Flutter library and tool build rules.
+add_subdirectory(${FLUTTER_MANAGED_DIR})
+
+# System-level dependencies.
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(GTK REQUIRED IMPORTED_TARGET gtk+-3.0)
+
+add_definitions(-DAPPLICATION_ID="${APPLICATION_ID}")
+
+# Application build
+add_executable(${BINARY_NAME}
+ "main.cc"
+ "my_application.cc"
+ "${FLUTTER_MANAGED_DIR}/generated_plugin_registrant.cc"
+)
+apply_standard_settings(${BINARY_NAME})
+target_link_libraries(${BINARY_NAME} PRIVATE flutter)
+target_link_libraries(${BINARY_NAME} PRIVATE PkgConfig::GTK)
+add_dependencies(${BINARY_NAME} flutter_assemble)
+
+# Generated plugin build rules, which manage building the plugins and adding
+# them to the application.
+include(flutter/generated_plugins.cmake)
+
+
+# === Installation ===
+# By default, "installing" just makes a relocatable bundle in the build
+# directory.
+set(BUILD_BUNDLE_DIR "${PROJECT_BINARY_DIR}/bundle")
+if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+ set(CMAKE_INSTALL_PREFIX "${BUILD_BUNDLE_DIR}" CACHE PATH "..." FORCE)
+endif()
+
+# Start with a clean build bundle directory every time.
+install(CODE "
+ file(REMOVE_RECURSE \"${BUILD_BUNDLE_DIR}/\")
+ " COMPONENT Runtime)
+
+set(INSTALL_BUNDLE_DATA_DIR "${CMAKE_INSTALL_PREFIX}/data")
+set(INSTALL_BUNDLE_LIB_DIR "${CMAKE_INSTALL_PREFIX}/lib")
+
+install(TARGETS ${BINARY_NAME} RUNTIME DESTINATION "${CMAKE_INSTALL_PREFIX}"
+ COMPONENT Runtime)
+
+install(FILES "${FLUTTER_ICU_DATA_FILE}" DESTINATION "${INSTALL_BUNDLE_DATA_DIR}"
+ COMPONENT Runtime)
+
+install(FILES "${FLUTTER_LIBRARY}" DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+ COMPONENT Runtime)
+
+if(PLUGIN_BUNDLED_LIBRARIES)
+ install(FILES "${PLUGIN_BUNDLED_LIBRARIES}"
+ DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+ COMPONENT Runtime)
+endif()
+
+# Fully re-copy the assets directory on each build to avoid having stale files
+# from a previous install.
+set(FLUTTER_ASSET_DIR_NAME "flutter_assets")
+install(CODE "
+ file(REMOVE_RECURSE \"${INSTALL_BUNDLE_DATA_DIR}/${FLUTTER_ASSET_DIR_NAME}\")
+ " COMPONENT Runtime)
+install(DIRECTORY "${PROJECT_BUILD_DIR}/${FLUTTER_ASSET_DIR_NAME}"
+ DESTINATION "${INSTALL_BUNDLE_DATA_DIR}" COMPONENT Runtime)
+
+# Install the AOT library on non-Debug builds only.
+if(NOT CMAKE_BUILD_TYPE MATCHES "Debug")
+ install(FILES "${AOT_LIBRARY}" DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+ COMPONENT Runtime)
+endif()
diff --git a/linux/flutter/CMakeLists.txt b/linux/flutter/CMakeLists.txt
new file mode 100644
index 0000000..4f48a7c
--- /dev/null
+++ b/linux/flutter/CMakeLists.txt
@@ -0,0 +1,88 @@
+cmake_minimum_required(VERSION 3.10)
+
+set(EPHEMERAL_DIR "${CMAKE_CURRENT_SOURCE_DIR}/ephemeral")
+
+# Configuration provided via flutter tool.
+include(${EPHEMERAL_DIR}/generated_config.cmake)
+
+# TODO: Move the rest of this into files in ephemeral. See
+# https://github.com/flutter/flutter/issues/57146.
+
+# Serves the same purpose as list(TRANSFORM ... PREPEND ...),
+# which isn't available in 3.10.
+function(list_prepend LIST_NAME PREFIX)
+ set(NEW_LIST "")
+ foreach(element ${${LIST_NAME}})
+ list(APPEND NEW_LIST "${PREFIX}${element}")
+ endforeach(element)
+ set(${LIST_NAME} "${NEW_LIST}" PARENT_SCOPE)
+endfunction()
+
+# === Flutter Library ===
+# System-level dependencies.
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(GTK REQUIRED IMPORTED_TARGET gtk+-3.0)
+pkg_check_modules(GLIB REQUIRED IMPORTED_TARGET glib-2.0)
+pkg_check_modules(GIO REQUIRED IMPORTED_TARGET gio-2.0)
+pkg_check_modules(BLKID REQUIRED IMPORTED_TARGET blkid)
+
+set(FLUTTER_LIBRARY "${EPHEMERAL_DIR}/libflutter_linux_gtk.so")
+
+# Published to parent scope for install step.
+set(FLUTTER_LIBRARY ${FLUTTER_LIBRARY} PARENT_SCOPE)
+set(FLUTTER_ICU_DATA_FILE "${EPHEMERAL_DIR}/icudtl.dat" PARENT_SCOPE)
+set(PROJECT_BUILD_DIR "${PROJECT_DIR}/build/" PARENT_SCOPE)
+set(AOT_LIBRARY "${PROJECT_DIR}/build/lib/libapp.so" PARENT_SCOPE)
+
+list(APPEND FLUTTER_LIBRARY_HEADERS
+ "fl_basic_message_channel.h"
+ "fl_binary_codec.h"
+ "fl_binary_messenger.h"
+ "fl_dart_project.h"
+ "fl_engine.h"
+ "fl_json_message_codec.h"
+ "fl_json_method_codec.h"
+ "fl_message_codec.h"
+ "fl_method_call.h"
+ "fl_method_channel.h"
+ "fl_method_codec.h"
+ "fl_method_response.h"
+ "fl_plugin_registrar.h"
+ "fl_plugin_registry.h"
+ "fl_standard_message_codec.h"
+ "fl_standard_method_codec.h"
+ "fl_string_codec.h"
+ "fl_value.h"
+ "fl_view.h"
+ "flutter_linux.h"
+)
+list_prepend(FLUTTER_LIBRARY_HEADERS "${EPHEMERAL_DIR}/flutter_linux/")
+add_library(flutter INTERFACE)
+target_include_directories(flutter INTERFACE
+ "${EPHEMERAL_DIR}"
+)
+target_link_libraries(flutter INTERFACE "${FLUTTER_LIBRARY}")
+target_link_libraries(flutter INTERFACE
+ PkgConfig::GTK
+ PkgConfig::GLIB
+ PkgConfig::GIO
+ PkgConfig::BLKID
+)
+add_dependencies(flutter flutter_assemble)
+
+# === Flutter tool backend ===
+# _phony_ is a non-existent file to force this command to run every time,
+# since currently there's no way to get a full input/output list from the
+# flutter tool.
+add_custom_command(
+ OUTPUT ${FLUTTER_LIBRARY} ${FLUTTER_LIBRARY_HEADERS}
+ ${CMAKE_CURRENT_BINARY_DIR}/_phony_
+ COMMAND ${CMAKE_COMMAND} -E env
+ ${FLUTTER_TOOL_ENVIRONMENT}
+ "${FLUTTER_ROOT}/packages/flutter_tools/bin/tool_backend.sh"
+ linux-x64 ${CMAKE_BUILD_TYPE}
+)
+add_custom_target(flutter_assemble DEPENDS
+ "${FLUTTER_LIBRARY}"
+ ${FLUTTER_LIBRARY_HEADERS}
+)
diff --git a/linux/flutter/generated_plugin_registrant.cc b/linux/flutter/generated_plugin_registrant.cc
new file mode 100644
index 0000000..026851f
--- /dev/null
+++ b/linux/flutter/generated_plugin_registrant.cc
@@ -0,0 +1,13 @@
+//
+// Generated file. Do not edit.
+//
+
+#include "generated_plugin_registrant.h"
+
+#include
+
+void fl_register_plugins(FlPluginRegistry* registry) {
+ g_autoptr(FlPluginRegistrar) url_launcher_linux_registrar =
+ fl_plugin_registry_get_registrar_for_plugin(registry, "UrlLauncherPlugin");
+ url_launcher_plugin_register_with_registrar(url_launcher_linux_registrar);
+}
diff --git a/linux/flutter/generated_plugin_registrant.h b/linux/flutter/generated_plugin_registrant.h
new file mode 100644
index 0000000..9bf7478
--- /dev/null
+++ b/linux/flutter/generated_plugin_registrant.h
@@ -0,0 +1,13 @@
+//
+// Generated file. Do not edit.
+//
+
+#ifndef GENERATED_PLUGIN_REGISTRANT_
+#define GENERATED_PLUGIN_REGISTRANT_
+
+#include
+
+// Registers Flutter plugins.
+void fl_register_plugins(FlPluginRegistry* registry);
+
+#endif // GENERATED_PLUGIN_REGISTRANT_
diff --git a/linux/flutter/generated_plugins.cmake b/linux/flutter/generated_plugins.cmake
new file mode 100644
index 0000000..1fc8ed3
--- /dev/null
+++ b/linux/flutter/generated_plugins.cmake
@@ -0,0 +1,16 @@
+#
+# Generated file, do not edit.
+#
+
+list(APPEND FLUTTER_PLUGIN_LIST
+ url_launcher_linux
+)
+
+set(PLUGIN_BUNDLED_LIBRARIES)
+
+foreach(plugin ${FLUTTER_PLUGIN_LIST})
+ add_subdirectory(flutter/ephemeral/.plugin_symlinks/${plugin}/linux plugins/${plugin})
+ target_link_libraries(${BINARY_NAME} PRIVATE ${plugin}_plugin)
+ list(APPEND PLUGIN_BUNDLED_LIBRARIES $)
+ list(APPEND PLUGIN_BUNDLED_LIBRARIES ${${plugin}_bundled_libraries})
+endforeach(plugin)
diff --git a/linux/main.cc b/linux/main.cc
new file mode 100644
index 0000000..058e617
--- /dev/null
+++ b/linux/main.cc
@@ -0,0 +1,10 @@
+#include "my_application.h"
+
+int main(int argc, char** argv) {
+ // Only X11 is currently supported.
+ // Wayland support is being developed: https://github.com/flutter/flutter/issues/57932.
+ gdk_set_allowed_backends("x11");
+
+ g_autoptr(MyApplication) app = my_application_new();
+ return g_application_run(G_APPLICATION(app), argc, argv);
+}
diff --git a/linux/my_application.cc b/linux/my_application.cc
new file mode 100644
index 0000000..2712215
--- /dev/null
+++ b/linux/my_application.cc
@@ -0,0 +1,46 @@
+#include "my_application.h"
+
+#include
+
+#include "flutter/generated_plugin_registrant.h"
+
+struct _MyApplication {
+ GtkApplication parent_instance;
+};
+
+G_DEFINE_TYPE(MyApplication, my_application, GTK_TYPE_APPLICATION)
+
+// Implements GApplication::activate.
+static void my_application_activate(GApplication* application) {
+ GtkWindow* window =
+ GTK_WINDOW(gtk_application_window_new(GTK_APPLICATION(application)));
+ GtkHeaderBar *header_bar = GTK_HEADER_BAR(gtk_header_bar_new());
+ gtk_widget_show(GTK_WIDGET(header_bar));
+ gtk_header_bar_set_title(header_bar, "fifteenpuzzle");
+ gtk_header_bar_set_show_close_button(header_bar, TRUE);
+ gtk_window_set_titlebar(window, GTK_WIDGET(header_bar));
+ gtk_window_set_default_size(window, 720, 480);
+ gtk_widget_show(GTK_WIDGET(window));
+
+ g_autoptr(FlDartProject) project = fl_dart_project_new();
+
+ FlView* view = fl_view_new(project);
+ gtk_widget_show(GTK_WIDGET(view));
+ gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(view));
+
+ fl_register_plugins(FL_PLUGIN_REGISTRY(view));
+
+ gtk_widget_grab_focus(GTK_WIDGET(view));
+}
+
+static void my_application_class_init(MyApplicationClass* klass) {
+ G_APPLICATION_CLASS(klass)->activate = my_application_activate;
+}
+
+static void my_application_init(MyApplication* self) {}
+
+MyApplication* my_application_new() {
+ return MY_APPLICATION(g_object_new(my_application_get_type(),
+ "application-id", APPLICATION_ID,
+ nullptr));
+}
diff --git a/linux/my_application.h b/linux/my_application.h
new file mode 100644
index 0000000..72271d5
--- /dev/null
+++ b/linux/my_application.h
@@ -0,0 +1,18 @@
+#ifndef FLUTTER_MY_APPLICATION_H_
+#define FLUTTER_MY_APPLICATION_H_
+
+#include
+
+G_DECLARE_FINAL_TYPE(MyApplication, my_application, MY, APPLICATION,
+ GtkApplication)
+
+/**
+ * my_application_new:
+ *
+ * Creates a new Flutter-based application.
+ *
+ * Returns: a new #MyApplication.
+ */
+MyApplication* my_application_new();
+
+#endif // FLUTTER_MY_APPLICATION_H_
diff --git a/snap/gui/fifteenpuzzle.desktop b/snap/gui/fifteenpuzzle.desktop
new file mode 100644
index 0000000..b3a0705
--- /dev/null
+++ b/snap/gui/fifteenpuzzle.desktop
@@ -0,0 +1,10 @@
+[Desktop Entry]
+Name=Game of Fifteen
+Comment=The Game of Fifteen is a sliding puzzle game
+Icon=${SNAP}/meta/gui/fifteenpuzzle.png
+Exec=fifteenpuzzle %U
+Terminal=false
+Type=Application
+Categories=Games;
+Keywords=Flutter;Puzzle;
+StartupNotify=false
diff --git a/snap/gui/fifteenpuzzle.png b/snap/gui/fifteenpuzzle.png
new file mode 100644
index 0000000..89b44f0
Binary files /dev/null and b/snap/gui/fifteenpuzzle.png differ
diff --git a/snap/snapcraft.yaml b/snap/snapcraft.yaml
new file mode 100644
index 0000000..ad588a4
--- /dev/null
+++ b/snap/snapcraft.yaml
@@ -0,0 +1,36 @@
+name: fifteenpuzzle
+adopt-info: fifteenpuzzle
+summary: Game of Fifteen
+description: |
+ The Game of Fifteen (also called 15-puzzle, Gem Puzzle, Boss Puzzle, Mystic
+ Square and many others) is a sliding puzzle that consists of a frame of
+ numbered square tiles in random order with one tile missing.
+grade: stable
+confinement: strict
+base: core18
+
+architectures:
+ - build-on: amd64
+
+slots:
+ # for GtkApplication registration
+ transporter:
+ interface: dbus
+ bus: session
+ name: com.artemchep.fifteenpuzzle
+
+apps:
+ fifteenpuzzle:
+ command: bin/fifteenpuzzle
+ extensions: [flutter-master]
+
+parts:
+ fifteenpuzzle:
+ source: .
+ plugin: flutter
+ flutter-target: lib/main.dart
+ override-pull: |
+ snapcraftctl pull
+ snapcraftctl set-version $(git describe --tags --abbrev=7)
+ build-packages:
+ - git