feat(ui): add a settings window

CHANGELOG.md

@@ -7,6 +7,13 @@ Release notes on GitHub are taken from the matching section here.
 
 ### Added
 
+- Added a settings window. Open it from the app menu (right-click Nightcap, then Settings) or with
+  `mocktail --settings`. It changes `config.yaml` and `fflags.json` for you, keeps your comments, and does
+  not save a value Nightcap could not start with. Changes apply the next time Nightcap starts. If Nightcap
+  is open when you change something, the window offers to restart it for you, with the same options and
+  environment it was started with. It opens on the main menu. Every `config.yaml` setting has a row,
+  including the device, the window size, the proxy, Fleasion and the update source. A setting you changed
+  from its default gets a button that resets it.
 - An asset overlay folder, `~/.local/share/mocktail/asset_overlay`. A file there replaces the file Roblox
   ships at the same path, such as a cursor, a font or a sky texture, and it stays in place when Roblox
   updates. The layout matches Sober's `asset_overlay` folder. `MOCKTAIL_ASSET_OVERLAY_DIR` moves it. Thanks to
@@ -26,6 +33,7 @@ Release notes on GitHub are taken from the matching section here.
 
 - Joining a game from a website link while already in a game no longer freezes Nightcap. It leaves the
   current game and joins the new one, and leaving that game returns to the home screen.
+- The loading window no longer gets a dock icon of its own. It now shows under Nightcap's icon.
 
 ### Changed
 

CMakeLists.txt

@@ -303,8 +303,11 @@ add_library(mocktail_runtime STATIC
   src/runtime/asset_overlay_names.cc
   src/runtime/runtime_config.cc
   src/runtime/runtime_config_bootstrap.cc
+  src/runtime/runtime_config_editor.cc
+  src/runtime/runtime_config_store.cc
   src/runtime/runtime_config_file.cc
   src/runtime/runtime_paths.cc
+  src/runtime/running_instance.cc
   src/runtime/session_log.cc
   src/runtime/single_instance_lock.cc
   src/runtime/startup_state_machine.cc
@@ -354,6 +357,8 @@ target_link_libraries(mocktail_runtime PRIVATE
 # Keep GTK out of the process that loads Android libraries.
 add_library(mocktail_failure_dialog_runtime STATIC
   src/runtime/failure_dialog.cc
+  src/runtime/helper_program.cc
+  src/runtime/settings_launcher.cc
 )
 add_library(Mocktail::FailureDialog ALIAS mocktail_failure_dialog_runtime)
 target_include_directories(mocktail_failure_dialog_runtime PUBLIC include)
@@ -365,9 +370,34 @@ mocktail_apply_compile_options(mocktail_failure_dialog_runtime)
 add_executable(mocktail_failure_dialog
   src/ui/mocktail_failure_dialog.cc
 )
+target_include_directories(mocktail_failure_dialog PRIVATE include)
 target_link_libraries(mocktail_failure_dialog PRIVATE PkgConfig::LIBADWAITA)
 mocktail_apply_compile_options(mocktail_failure_dialog)
 
+add_library(mocktail_settings_model STATIC
+  src/ui/settings_model.cc
+)
+add_library(Mocktail::SettingsModel ALIAS mocktail_settings_model)
+target_include_directories(mocktail_settings_model PUBLIC include)
+target_link_libraries(mocktail_settings_model PUBLIC
+  Mocktail::Runtime
+  mocktail_services
+)
+mocktail_apply_compile_options(mocktail_settings_model)
+
+add_executable(mocktail_settings
+  src/ui/mocktail_settings.cc
+)
+target_include_directories(mocktail_settings PRIVATE
+  ${MOCKTAIL_PLATFORM_GENERATED_INCLUDE_DIR}
+)
+target_link_libraries(mocktail_settings PRIVATE
+  Mocktail::SettingsModel
+  PkgConfig::LIBADWAITA
+  SDL3::SDL3
+)
+mocktail_apply_compile_options(mocktail_settings)
+
 add_library(mocktail_services STATIC
   src/services/http_client.cc
   src/services/auth_service.cc
@@ -669,6 +699,7 @@ install(TARGETS
     mocktail
     mocktail_updater
     mocktail_failure_dialog
+    mocktail_settings
     mocktail_webview_helper
     mocktail_audio_sdl
     mocktail_opensles
@@ -707,6 +738,9 @@ install(CODE "
   string(REPLACE \"Exec=env SDL_VIDEODRIVER=wayland,x11 mocktail %u\"
          \"Exec=env SDL_VIDEODRIVER=wayland,x11 \${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_BINDIR}/mocktail %u\"
          MOCKTAIL_DESKTOP_ENTRY \"\${MOCKTAIL_DESKTOP_ENTRY}\")
+  string(REPLACE \"Exec=mocktail --settings\"
+         \"Exec=\${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_BINDIR}/mocktail --settings\"
+         MOCKTAIL_DESKTOP_ENTRY \"\${MOCKTAIL_DESKTOP_ENTRY}\")
   file(WRITE \"${CMAKE_BINARY_DIR}/io.github.CoderDayton.nightcap.desktop\"
        \"\${MOCKTAIL_DESKTOP_ENTRY}\")
   file(INSTALL \"${CMAKE_BINARY_DIR}/io.github.CoderDayton.nightcap.desktop\"
@@ -810,7 +844,7 @@ set(CPACK_RPM_PACKAGE_CONFLICTS "${MOCKTAIL_PACKAGE_CONFLICTS}")
 include(CPack)
 
 add_dependencies(mocktail all_stubs)
-add_dependencies(mocktail mocktail_failure_dialog)
+add_dependencies(mocktail mocktail_failure_dialog mocktail_settings)
 add_dependencies(mocktail mocktail_webview_helper)
 
 if(BUILD_TESTING)

FAQ.md

@@ -4,8 +4,14 @@
 ## How do I turn Discord RPC off?
 
 RPC is on by default. It never signs in to Discord and never reads an
-account token. To turn it off, launch Nightcap once to create the config,
-then close it. Open `config.yaml`:
+account token.
+
+The quick way: open Settings (right-click Nightcap in the app menu, or run
+`mocktail --settings`), go to Discord, and switch off "Show activity in
+Discord". Then restart Nightcap.
+
+To do it by hand, launch Nightcap once to create the config, then close
+it. Open `config.yaml`:
 
 - Native / AppImage: `~/.config/mocktail/config.yaml`
 - Flatpak: `~/.var/app/io.github.CoderDayton.nightcap/config/mocktail/config.yaml`

Makefile

@@ -1,6 +1,6 @@
 # Modified by vii from komaruworld/mocktail. See README "About this fork".
 .DEFAULT_GOAL := all
-.PHONY: all build release debug test apk install register-url-handler release-runtime portable portable-test standalone appimage flatpak run-flatpak run run-smoke run-unlimited run-game run-input run-resize run-network auto-run run-gles run-angle update-roblox update-auto update-auto-launch payload-status payload-rollback support-bundle clean submodules help
+.PHONY: all build release debug test apk install register-url-handler release-runtime portable portable-test standalone appimage flatpak flatpak-build run-flatpak run run-smoke run-unlimited run-game run-input run-resize run-network auto-run run-gles run-angle update-roblox update-auto update-auto-launch payload-status payload-rollback support-bundle clean submodules help
 
 BUILD_DIR  := build
 BINARY     := $(BUILD_DIR)/mocktail
@@ -91,6 +91,13 @@ flatpak: ## Build and install the local x86-64 Flatpak
 		--manifest "$(FLATPAK_MANIFEST)" \
 		--jobs "$(FLATPAK_JOBS)"
 
+flatpak-build: ## Build the local Flatpak without installing it
+	@./scripts/build_flatpak.sh \
+		--no-install \
+		--build-dir "$(FLATPAK_BUILD_DIR)" \
+		--manifest "$(FLATPAK_MANIFEST)" \
+		--jobs "$(FLATPAK_JOBS)"
+
 run-flatpak: ## Run the installed Flatpak
 	@flatpak run io.github.CoderDayton.nightcap
 

README.md

@@ -128,6 +128,8 @@ removing the marker.
 
 Put a JSON object in `$XDG_CONFIG_HOME/mocktail/fflags.json` (usually
 `~/.config/mocktail/fflags.json`). Nightcap applies it on the next launch.
+The Advanced page of the [settings window](#settings) edits this file and
+does not save text that Nightcap could not load.
 
 PC profiles use the legacy Charts page by default to avoid the blank screen
 caused by `Color3` errors in the newer SDUI page. An explicit
@@ -149,7 +151,25 @@ it yourself turns the switching off and your value applies everywhere. See
 ```
 ## Settings
 
-Edit `~/.config/mocktail/config.yaml`. Useful options:
+Open the settings window from the app menu: right-click Nightcap and pick
+Settings. Or run:
+
+```sh
+mocktail --settings
+```
+
+With the Flatpak, run
+`flatpak run io.github.CoderDayton.nightcap --settings`. To open it with a
+key, bind that command to a keyboard shortcut in your desktop's settings. If
+Settings is missing from the menu right after you install, log out and back
+in.
+
+The window edits `~/.config/mocktail/config.yaml`. It keeps your comments
+and layout, saves each change at once, and does not save a value Nightcap
+could not start with. Changes apply the next time Nightcap starts. If
+Nightcap is open, the window offers to restart it, except in the Flatpak.
+
+You can also edit the file by hand. Useful options:
 
 - `graphics.frame_rate_limit: display` to unlock FPS to your monitor's rate.
 - `graphics.vsync: off` for the lowest lag, at the cost of tearing.
@@ -226,7 +246,8 @@ Roblox website links open the build tree copy without installing, run
 To build and install the Flatpak from source, install `flatpak-builder` and run
 `make flatpak`. It builds with 2 parallel jobs to keep memory use low. Pass
 `FLATPAK_JOBS=N` to `make flatpak`, or set `MOCKTAIL_FLATPAK_JOBS=N` for
-`scripts/build_flatpak.sh`, to change that.
+`scripts/build_flatpak.sh`, to change that. To build without installing, run
+`make flatpak-build`; the result stays in `build-flatpak/`.
 
 To run the same checks as CI before each commit and push, install
 [lefthook](https://github.com/evilmartians/lefthook) and run once:

docs/ROADMAP.md

@@ -4,26 +4,15 @@ What Nightcap is working toward, in priority order. Items move to
 [Shipped](#shipped) when they land on `main`. Open an issue to propose a
 change to this list.
 
-## 1. Settings UI
-
-Nightcap is configured by editing `~/.config/mocktail/config.yaml`. Most
-people never open it, so they never find the FPS unlock or the vsync switch.
-
-Goal: a small GTK4 settings window, reachable from the app menu and from a
-`--settings` flag, that reads and writes the same `config.yaml`.
-
-- Graphics tab: backend, frame rate limit, vsync, small texture upscale.
-- Input tab: the `input.raw_mouse` toggle and controller options.
-- Advanced tab: FFlag overrides with a plain text editor for `fflags.json`.
-- Discord tab: every field in the `discord_rpc` block, so a friend can see
-what you are playing and you can switch it all off in one click.
-- Changes apply on next launch. A restart button restarts Nightcap.
-
-Done when every option in `config/mocktail.example.yaml` that a player would
-touch can be set without a text editor.
+Nothing is queued right now.
 
 ## Shipped
 
+- Settings window, from the app menu or `mocktail --settings`: graphics,
+input, performance, audio, and Discord options, and a text editor for
+`fflags.json`. It edits the same `config.yaml`, keeps your comments, and
+does not save a value Nightcap could not start with. Changes apply on the
+next launch.
 - Lower input latency: frames are presented as soon as they are ready.
 - Controllers hot-plug without a restart, and a pad that is unplugged mid-game
 releases its held buttons and sticks instead of leaving them stuck.

include/mocktail/platform/application_id.h

@@ -0,0 +1,12 @@
+#ifndef MOCKTAIL_PLATFORM_APPLICATION_ID_H_
+#define MOCKTAIL_PLATFORM_APPLICATION_ID_H_
+
+namespace mocktail {
+namespace platform {
+
+inline constexpr char kApplicationId[] = "io.github.CoderDayton.nightcap";
+
+}
+}
+
+#endif

include/mocktail/platform/sdl_application_metadata.h

@@ -2,14 +2,14 @@
 #ifndef MOCKTAIL_PLATFORM_SDL_APPLICATION_METADATA_H_
 #define MOCKTAIL_PLATFORM_SDL_APPLICATION_METADATA_H_
 
+#include "mocktail/platform/application_id.h"
 #include "mocktail/status.h"
 
 namespace mocktail {
 namespace platform {
 
 inline constexpr char kMocktailApplicationName[] = "Nightcap";
-inline constexpr char kMocktailApplicationIdentifier[] =
-    "io.github.CoderDayton.nightcap";
+inline constexpr const char* kMocktailApplicationIdentifier = kApplicationId;
 
 // Configures the stable compositor identity before SDL initializes. The
 // identifier matches the installed desktop file and icon name so Wayland and

include/runtime/command_line.h

@@ -10,6 +10,8 @@ namespace runtime {
 enum class CommandMode {
   kRun,
   kHelp,
+  // Open the settings window in place of the game.
+  kSettings,
 };
 
 enum class WindowMode {

include/runtime/helper_program.h

@@ -0,0 +1,24 @@
+#ifndef MOCKTAIL_RUNTIME_HELPER_PROGRAM_H_
+#define MOCKTAIL_RUNTIME_HELPER_PROGRAM_H_
+
+#include <filesystem>
+#include <string_view>
+
+#include "runtime/environment.h"
+
+namespace mocktail {
+namespace runtime {
+
+// Path of the helper program `name`, or empty when there is none to run.
+// `override_variable` names it outright: it must be an absolute path to a
+// regular executable file, and nothing else is tried when it is set.
+// Otherwise the program is looked for under MOCKTAIL_PROJECT_ROOT/bin, then
+// beside this executable and in its install directories.
+std::filesystem::path FindHelperProgram(const Environment& environment,
+                                        std::string_view override_variable,
+                                        std::string_view name);
+
+}  // namespace runtime
+}  // namespace mocktail
+
+#endif

include/runtime/running_instance.h

@@ -0,0 +1,78 @@
+#ifndef MOCKTAIL_RUNTIME_RUNNING_INSTANCE_H_
+#define MOCKTAIL_RUNTIME_RUNNING_INSTANCE_H_
+
+#include <sys/types.h>
+
+#include <chrono>
+#include <filesystem>
+#include <optional>
+#include <string>
+#include <string_view>
+#include <vector>
+
+#include "runtime/environment.h"
+
+namespace mocktail {
+namespace runtime {
+
+inline constexpr char kInstanceLockVariable[] = "MOCKTAIL_INSTANCE_LOCK";
+inline constexpr char kRestartProgramVariable[] = "MOCKTAIL_RESTART_PROGRAM";
+
+// A Flatpak settings window runs in a sandbox of its own and cannot reach
+// the game.
+bool CanRestartFromSettings(const Environment& environment);
+
+std::optional<pid_t> FindFlockHolder(std::string_view proc_locks,
+                                     dev_t device, ino_t inode);
+
+struct RunningInstance {
+  bool running = false;
+  // 0 when Nightcap runs but this process cannot see it.
+  pid_t pid = 0;
+};
+
+RunningInstance FindRunningInstance(const std::filesystem::path& lock_file);
+
+// SIGTERM reaches Nightcap as SDL_EVENT_QUIT, the same as closing its window.
+bool StopRunningInstance(const std::filesystem::path& lock_file,
+                         std::chrono::milliseconds timeout,
+                         std::string* error);
+
+struct LaunchCommand {
+  std::vector<std::string> arguments;
+  // NAME=value entries.
+  std::vector<std::string> environment;
+  // Empty keeps this process's own.
+  std::filesystem::path working_directory;
+};
+
+// The arguments in /proc/<pid>/cmdline. Nightcap zeroes a join link after
+// reading it, since the link holds a one-time login ticket, so the zeroed
+// argument is dropped along with a --launch-uri or --launch-request-json
+// left without it.
+std::vector<std::string> ParseProcArguments(std::string_view cmdline);
+std::vector<std::string> ParseProcEnvironment(std::string_view variables);
+
+// Nothing when /proc cannot be read, as for another user's process.
+std::optional<LaunchCommand> ReadLaunchCommand(pid_t pid);
+
+// Starts `program` in a session of its own, so it keeps running after this
+// process exits. Empty arguments run it with just its path; an empty
+// environment passes this process's own. Signals start out with their
+// default handling, whatever this process ignores or blocks.
+bool StartDetached(const std::filesystem::path& program, std::string* error,
+                   const LaunchCommand& command = {});
+
+// Closes the running Nightcap and starts `program` with its arguments,
+// environment and working directory. Nothing is closed when its launch
+// cannot be read, since it could not be started the same way again. A
+// Nightcap that does not close within `timeout` may still close later.
+bool RestartRunningInstance(const std::filesystem::path& lock_file,
+                            const std::filesystem::path& program,
+                            std::chrono::milliseconds timeout,
+                            std::string* error);
+
+}  // namespace runtime
+}  // namespace mocktail
+
+#endif