✨ feat: Add i18n support and fix application icon

- Add APP_ICON constant to config.py for proper icon loading
- Update i18n.py with correct text domain (biglinux-swap)
- Add translation function import to all UI files:
  - application.py
  - window.py
  - utils.py
  - ui/unified_view.py
  - ui/components.py
- Replace local gettext implementation in utils.py with centralized i18n module
- Update application.py to use APP_ICON in about dialog

Author: talesam

src/biglinux_swap/application.py

@@ -16,7 +16,8 @@
 gi.require_version("Adw", "1")
 from gi.repository import Adw, Gio, GLib
 
-from biglinux_swap.config import APP_ID, APP_NAME, APP_VERSION
+from biglinux_swap.config import APP_ICON, APP_ID, APP_NAME, APP_VERSION
+from biglinux_swap.i18n import _
 from biglinux_swap.services import ConfigService, MeminfoService, SwapService
 from biglinux_swap.window import SwapWindow
 
@@ -153,7 +154,7 @@ def _on_about(
         about.set_issue_url(
             "https://github.com/biglinux/biglinux-systemd-swap-gui/issues"
         )
-        about.set_application_icon(APP_ID)
+        about.set_application_icon(APP_ICON)
 
         about.set_developers(
             [

src/biglinux_swap/config.py

@@ -27,6 +27,8 @@
 APP_DEVELOPER = "BigLinux Team"
 APP_WEBSITE = "https://github.com/biglinux/biglinux-systemd-swap-gui"
 APP_ISSUE_URL = f"{APP_WEBSITE}/issues"
+APP_ICON = "biglinux-swap"
+
 
 # =============================================================================
 # Window Configuration
@@ -305,7 +307,7 @@ class DiscardPolicy(Enum):
 class ZswapConfig:
     """Zswap configuration."""
 
-    compressor: Compressor = Compressor.ZSTD
+    compressor: Compressor = Compressor.LZ4
     max_pool_percent: int = ZSWAP_MAX_POOL_DEFAULT
     zpool: str = "zsmalloc"
     shrinker_enabled: bool = True
@@ -432,7 +434,7 @@ def from_dict(cls, data: dict[str, Any]) -> SwapConfig:
         if "zswap" in data:
             zs = data["zswap"]
             config.zswap = ZswapConfig(
-                compressor=Compressor(zs.get("compressor", "zstd")),
+                compressor=Compressor(zs.get("compressor", "lz4")),
                 max_pool_percent=zs.get("max_pool_percent", ZSWAP_MAX_POOL_DEFAULT),
                 zpool=zs.get("zpool", "zsmalloc"),
                 shrinker_enabled=zs.get("shrinker_enabled", True),

src/biglinux_swap/i18n.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# i18n.py - Utilities for translation support
+#
+import gettext
+import os
+from typing import Callable
+
+# Determine locale directory (works in AppImage and system install)
+locale_dir = "/usr/share/locale"  # Default for system install
+
+# Check if we're in an AppImage
+if "APPIMAGE" in os.environ or "APPDIR" in os.environ:
+    # Running from AppImage
+    # i18n.py is in: src/biglinux_swap/i18n.py
+    # We need to get to: usr/share/locale
+    script_dir = os.path.dirname(os.path.abspath(__file__))  # src/biglinux_swap
+    src_dir = os.path.dirname(script_dir)  # src
+    appdir_root = os.path.dirname(src_dir)  # AppDir root (squashfs-root)
+    appimage_locale = os.path.join(appdir_root, "usr", "share", "locale")  # usr/share/locale
+
+    if os.path.isdir(appimage_locale):
+        locale_dir = appimage_locale
+
+# Configure the translation text domain for biglinux-swap
+gettext.bindtextdomain("biglinux-swap", locale_dir)
+gettext.textdomain("biglinux-swap")
+
+# Export _ directly as the translation function with explicit type
+_: Callable[[str], str] = gettext.gettext

src/biglinux_swap/services.py

@@ -65,21 +65,69 @@ def __init__(self) -> None:
         self._config: SwapConfig | None = None
 
     def load(self) -> SwapConfig:
-        """Load configuration from system files."""
+        """Load configuration from system files.
+        
+        Priority:
+        1. /etc/systemd/swap.conf (user config)
+        2. /usr/share/systemd-swap/swap-default.conf (defaults)
+        3. Current kernel values from /sys/module/zswap/parameters/ (fallback)
+        """
         config = SwapConfig()
 
+        # Track which values were explicitly set in config files
+        explicitly_set: set[str] = set()
+
         if DEFAULT_CONFIG.exists():
             default_values = self._parse_config_file(DEFAULT_CONFIG)
+            explicitly_set.update(default_values.keys())
             config = self._apply_values(config, default_values)
 
         if CONFIG_FILE.exists():
             user_values = self._parse_config_file(CONFIG_FILE)
+            explicitly_set.update(user_values.keys())
             config = self._apply_values(config, user_values)
 
+        # Read current kernel values for parameters not explicitly configured
+        self._apply_kernel_values(config, explicitly_set)
+
         self._config = config
         logger.info("Configuration loaded")
         return config
 
+    def _apply_kernel_values(
+        self, config: SwapConfig, explicitly_set: set[str]
+    ) -> None:
+        """Read current kernel values for parameters not in config files.
+        
+        This ensures the GUI shows the actual system state, not hardcoded defaults.
+        """
+        zswap_params = Path("/sys/module/zswap/parameters")
+
+        # Read zswap compressor from kernel if not in config
+        if "zswap_compressor" not in explicitly_set and zswap_params.is_dir():
+            compressor_path = zswap_params / "compressor"
+            if compressor_path.exists():
+                try:
+                    kernel_compressor = compressor_path.read_text().strip()
+                    with contextlib.suppress(ValueError):
+                        config.zswap.compressor = Compressor(kernel_compressor)
+                        logger.debug(
+                            "Using kernel zswap compressor: %s", kernel_compressor
+                        )
+                except OSError:
+                    pass
+
+        # Read zswap max_pool_percent from kernel if not in config
+        if "zswap_max_pool_percent" not in explicitly_set and zswap_params.is_dir():
+            pool_path = zswap_params / "max_pool_percent"
+            if pool_path.exists():
+                try:
+                    kernel_pool = pool_path.read_text().strip()
+                    config.zswap.max_pool_percent = int(kernel_pool)
+                    logger.debug("Using kernel zswap max_pool_percent: %s", kernel_pool)
+                except (OSError, ValueError):
+                    pass
+
     def get(self) -> SwapConfig:
         """Get current config, loading if necessary."""
         if self._config is None:

src/biglinux_swap/ui/components.py

@@ -15,6 +15,9 @@
 gi.require_version("Adw", "1")
 from gi.repository import Adw, Gtk
 
+from biglinux_swap.i18n import _
+
+
 
 def create_preferences_group(
     title: str,

src/biglinux_swap/ui/settings_view.py

@@ -192,7 +192,6 @@ def _setup_ui(self) -> None:
             "Compressor",
             subtitle="Compression algorithm",
             options=compressor_names,
-            selected_index=1,  # zstd
             on_selected=self._on_zswap_compressor_changed,
         )
         self._zswap_expander.add_row(self._zswap_compressor_combo)

src/biglinux_swap/ui/unified_view.py

@@ -68,6 +68,8 @@
 )
 from biglinux_swap.ui.memory_chart import MemoryChartWidget
 from biglinux_swap.utils import TooltipHelper
+from biglinux_swap.i18n import _
+
 
 if TYPE_CHECKING:
     from biglinux_swap.services import (

src/biglinux_swap/utils.py

@@ -8,8 +8,6 @@
 from __future__ import annotations
 
 import contextlib
-import gettext
-import locale
 import logging
 import shutil
 import subprocess
@@ -24,6 +22,7 @@
 from gi.repository import Adw, Gdk, GLib, Gtk
 
 from biglinux_swap.config import CONFIG_PATH
+from biglinux_swap.i18n import _
 
 logger = logging.getLogger(__name__)
 
@@ -157,23 +156,9 @@ def run_as_root(command: list[str]) -> tuple[bool, str, str]:
 
 
 # =============================================================================
-# Internationalization
+# X11 Detection Helper
 # =============================================================================
 
-LOCALE_DIR = Path("/usr/share/locale")
-DOMAIN = "biglinux-swap"
-
-with contextlib.suppress(locale.Error):
-    locale.setlocale(locale.LC_ALL, "")
-
-try:
-    translation = gettext.translation(DOMAIN, LOCALE_DIR, fallback=True)
-    _ = translation.gettext
-except Exception:
-
-    def _(text: str) -> str:
-        return text
-
 
 def _is_x11_backend() -> bool:
     """Check if running on X11 backend."""
@@ -190,6 +175,7 @@ def _is_x11_backend() -> bool:
 # Tooltip Texts
 # =============================================================================
 
+
 TOOLTIPS = {
     # Mode selection
     "mode_auto": _(

src/biglinux_swap/window.py

@@ -23,6 +23,8 @@
     enable_systemd_swap,
     stop_systemd_swap,
 )
+from biglinux_swap.i18n import _
+
 
 if TYPE_CHECKING:
     from biglinux_swap.services import ConfigService, MeminfoService, SwapService