update

.cargo/config.toml

@@ -0,0 +1,5 @@
+# CEF symbols are resolved at runtime from the dlopen'd framework
+# (see cef_host::load_framework_if_bundled), so the linker must tolerate
+# undefined cef_* symbols.
+[target.'cfg(target_os = "macos")']
+rustflags = ["-C", "link-arg=-Wl,-undefined,dynamic_lookup"]

Cargo.lock

@@ -347,7 +347,7 @@ version = "0.38.0+1.3.281"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0bb44936d800fea8f016d7f2311c6a4f97aebd5dc86f09906139ec848cf3a46f"
 dependencies = [
- "libloading",
+ "libloading 0.8.9",
 ]
 
 [[package]]
@@ -668,6 +668,7 @@ dependencies = [
 name = "browser"
 version = "0.1.0"
 dependencies = [
+ "cef",
  "egui",
  "egui-wgpu",
  "egui-winit",
@@ -680,6 +681,8 @@ dependencies = [
  "objc2-quartz-core 0.3.2",
  "pollster",
  "rustls",
+ "serde",
+ "serde_json",
  "servo",
  "url",
  "wgpu",
@@ -759,6 +762,15 @@ version = "1.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc652a48c352aef3ea3aed32080501cf3ef6ed5da78602a020c991775b0aff04"
 
+[[package]]
+name = "bzip2"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f3a53fac24f34a81bc9954b5d6cfce0c21e18ec6959f44f56e8e90e4bb7c346c"
+dependencies = [
+ "libbz2-rs-sys",
+]
+
 [[package]]
 name = "calendrical_calculations"
 version = "0.1.3"
@@ -820,6 +832,39 @@ dependencies = [
  "wayland-client",
 ]
 
+[[package]]
+name = "camino"
+version = "1.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb1307f12aa967b5a58416e87b3653360e0fd614a016b6e970db08fecbb1b80d"
+dependencies = [
+ "serde_core",
+]
+
+[[package]]
+name = "cargo-platform"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd0061da739915fae12ea00e16397555ed4371a6bb285431aab930f61b0aa4ba"
+dependencies = [
+ "serde",
+ "serde_core",
+]
+
+[[package]]
+name = "cargo_metadata"
+version = "0.23.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ef987d17b0a113becdd19d3d0022d04d7ef41f9efe4f3fb63ac44ba61df3ade9"
+dependencies = [
+ "camino",
+ "cargo-platform",
+ "semver",
+ "serde",
+ "serde_json",
+ "thiserror 2.0.20",
+]
+
 [[package]]
 name = "cbc"
 version = "0.2.1"
@@ -841,6 +886,38 @@ dependencies = [
  "shlex 2.0.1",
 ]
 
+[[package]]
+name = "cef"
+version = "151.7.0+151.3.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c96acc058418aaf5dbcb95420677eb053032acc9b8af224079fb091a3043d899"
+dependencies = [
+ "anyhow",
+ "cargo_metadata",
+ "cef-dll-sys",
+ "clap",
+ "libloading 0.9.0",
+ "objc2 0.6.4",
+ "plist",
+ "semver",
+ "serde",
+ "serde_json",
+ "thiserror 2.0.20",
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "cef-dll-sys"
+version = "151.7.0+151.3.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "043cf920289eeaa8e6b4d7f1701ef28e07e0cdaa7c8acf54e6008e9b61435a4c"
+dependencies = [
+ "anyhow",
+ "cmake",
+ "download-cef",
+ "serde_json",
+]
+
 [[package]]
 name = "cexpr"
 version = "0.6.0"
@@ -942,9 +1019,49 @@ checksum = "157a8ba7b480713b56f4c09fd13fc3e0a22a5dfab8097ba61cbc5feef950788a"
 dependencies = [
  "glob",
  "libc",
- "libloading",
+ "libloading 0.8.9",
 ]
 
+[[package]]
+name = "clap"
+version = "4.6.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "473c7e07f409a8d772161724aa8db6a765a2532a70f9667eeb7b49d3d02fbdca"
+dependencies = [
+ "clap_builder",
+ "clap_derive",
+]
+
+[[package]]
+name = "clap_builder"
+version = "4.6.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b48fea5a88e9ae728a2dcbedbfc0e730f7d60da42e1cb049a83c9fb8b789889"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "clap_lex",
+ "strsim",
+]
+
+[[package]]
+name = "clap_derive"
+version = "4.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d012d2b9d65aca7f18f4d9878a045bc17899bba951561ba5ec3c2ba1eed9a061"
+dependencies = [
+ "heck 0.5.0",
+ "proc-macro2",
+ "quote",
+ "syn 3.0.3",
+]
+
+[[package]]
+name = "clap_lex"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
+
 [[package]]
 name = "clipboard-win"
 version = "5.4.1"
@@ -1049,6 +1166,18 @@ dependencies = [
  "crossbeam-utils",
 ]
 
+[[package]]
+name = "console"
+version = "0.16.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4fe5f465a4f6fee88fad41b85d990f84c835335e85b5d9e6e63e0d06d28cba7c"
+dependencies = [
+ "encode_unicode",
+ "libc",
+ "unicode-width",
+ "windows-sys 0.61.2",
+]
+
 [[package]]
 name = "const-oid"
 version = "0.10.2"
@@ -1087,10 +1216,29 @@ version = "0.18.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1a373e3602691c3cdea496d2f0ee5935151e6168fe87739483c463db1b2f2f87"
 dependencies = [
+ "percent-encoding",
  "time",
  "version_check",
 ]
 
+[[package]]
+name = "cookie_store"
+version = "0.22.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "15b2c103cf610ec6cae3da84a766285b42fd16aad564758459e6ecf128c75206"
+dependencies = [
+ "cookie 0.18.2",
+ "document-features",
+ "idna",
+ "indexmap",
+ "log",
+ "serde",
+ "serde_derive",
+ "serde_json",
+ "time",
+ "url",
+]
+
 [[package]]
 name = "core-foundation"
 version = "0.9.4"
@@ -1586,7 +1734,7 @@ version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ab8ecd87370524b461f8557c119c405552c396ed91fc0a8eec68679eab26f94a"
 dependencies = [
- "libloading",
+ "libloading 0.8.9",
 ]
 
 [[package]]
@@ -1604,6 +1752,26 @@ version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "75b325c5dbd37f80359721ad39aca5a29fb04c89279657cffdda8736d0c0b9d2"
 
+[[package]]
+name = "download-cef"
+version = "2.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c169adf067a787e1f1c58ed62906a557de85388bee4b54fb878b722ff606b113"
+dependencies = [
+ "bzip2",
+ "clap",
+ "fs-err",
+ "indicatif",
+ "regex",
+ "semver",
+ "serde",
+ "serde_json",
+ "sha1_smol",
+ "tar",
+ "thiserror 2.0.20",
+ "ureq",
+]
+
 [[package]]
 name = "dpi"
 version = "0.1.2"
@@ -1830,6 +1998,12 @@ version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "edd0f118536f44f5ccd48bcb8b111bdc3de888b58c74639dfb034a357d0f206d"
 
+[[package]]
+name = "encode_unicode"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34aa73646ffb006b8f5147f3dc182bd4bcb190227ce861fc4a4844bf8e3cb2c0"
+
 [[package]]
 name = "encoding_c"
 version = "0.9.8"
@@ -2235,6 +2409,15 @@ dependencies = [
  "pkg-config",
 ]
 
+[[package]]
+name = "fs-err"
+version = "3.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b91aa448ca50d7e79433bdf3ee8d99215430d2ec02ade5aefab2a073a1822e8a"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "fs_extra"
 version = "1.3.0"
@@ -3487,6 +3670,19 @@ dependencies = [
  "hashbrown 0.17.1",
 ]
 
+[[package]]
+name = "indicatif"
+version = "0.18.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9433806cd6b4ec1aba79c021c7e4c58fb4c3b9977c085062e611ac929998fb0c"
+dependencies = [
+ "console",
+ "portable-atomic",
+ "unicode-width",
+ "unit-prefix",
+ "web-time",
+]
+
 [[package]]
 name = "inout"
 version = "0.2.2"
@@ -3746,7 +3942,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6aae1df220ece3c0ada96b8153459b67eebe9ae9212258bb0134ae60416fdf76"
 dependencies = [
  "libc",
- "libloading",
+ "libloading 0.8.9",
  "pkg-config",
 ]
 
@@ -3781,6 +3977,12 @@ version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7a79a3332a6609480d7d0c9eab957bca6b455b91bb84e66d19f5ff66294b85b8"
 
+[[package]]
+name = "libbz2-rs-sys"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34b357333733e8260735ba5894eb928c02ecc69c78715f01a8019e7fa7f2db4c"
+
 [[package]]
 name = "libc"
 version = "0.2.189"
@@ -3807,6 +4009,16 @@ dependencies = [
  "windows-link 0.2.1",
 ]
 
+[[package]]
+name = "libloading"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "754ca22de805bb5744484a5b151a9e1a8e837d5dc232c2d7d8c2e3492edc8b60"
+dependencies = [
+ "cfg-if",
+ "windows-link 0.2.1",
+]
+
 [[package]]
 name = "libm"
 version = "0.2.16"
@@ -5107,6 +5319,19 @@ dependencies = [
  "smallvec",
 ]
 
+[[package]]
+name = "plist"
+version = "1.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da1d65da6dd5d1e44199ac0f58712d241c0f439f80adea8924d832384087f85"
+dependencies = [
+ "base64 0.22.1",
+ "indexmap",
+ "quick-xml",
+ "serde",
+ "time",
+]
+
 [[package]]
 name = "png"
 version = "0.18.1"
@@ -5827,6 +6052,7 @@ dependencies = [
  "aws-lc-rs",
  "log",
  "once_cell",
+ "ring",
  "rustls-pki-types",
  "rustls-webpki",
  "subtle",
@@ -6044,6 +6270,10 @@ name = "semver"
 version = "1.0.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a7852d02fc848982e0c167ef163aaff9cd91dc640ba85e263cb1ce46fae51cd"
+dependencies = [
+ "serde",
+ "serde_core",
+]
 
 [[package]]
 name = "seq-macro"
@@ -7867,6 +8097,17 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "socks"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0c3dbbd9ae980613c6dd8e28a9407b50509d3803b57624d5dfe8315218cd58b"
+dependencies = [
+ "byteorder",
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "speexdsp-resampler"
 version = "0.1.0"
@@ -7972,6 +8213,12 @@ dependencies = [
  "quote",
 ]
 
+[[package]]
+name = "strsim"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
+
 [[package]]
 name = "strum"
 version = "0.28.0"
@@ -8870,6 +9117,12 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39ec24b3121d976906ece63c9daad25b85969647682eee313cb5779fdd69e14e"
 
+[[package]]
+name = "unit-prefix"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "81e544489bf3d8ef66c953931f56617f423cd4b5494be343d9b9d3dda037b9a3"
+
 [[package]]
 name = "universal-hash"
 version = "0.6.1"
@@ -8886,6 +9139,39 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ecb6da28b8a351d773b68d5825ac39017e680750f980f3a1a85cd8dd28a47c1"
 
+[[package]]
+name = "ureq"
+version = "3.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "972d7902c8735f2695410b8aed7df6ed12a47394aa1c8d7af49f0497b731a94d"
+dependencies = [
+ "base64 0.23.1",
+ "cookie_store",
+ "flate2",
+ "log",
+ "percent-encoding",
+ "rustls",
+ "rustls-pki-types",
+ "serde",
+ "serde_json",
+ "socks",
+ "ureq-proto",
+ "utf8-zero",
+ "webpki-roots",
+]
+
+[[package]]
+name = "ureq-proto"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da5f78b09e6941e1a0f2e30e695e4b120377b54d5e0aec11b594bb57b3971613"
+dependencies = [
+ "base64 0.23.1",
+ "http 1.5.0",
+ "httparse",
+ "log",
+]
+
 [[package]]
 name = "url"
 version = "2.5.8"
@@ -8945,6 +9231,12 @@ version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c8232dd3cdaed5356e0f716d285e4b40b932ac434100fe9b7e0e8e935b9e6246"
 
+[[package]]
+name = "utf8-zero"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8c0a043c9540bae7c578c88f91dda8bd82e59ae27c21baca69c8b191aaf5a6e"
+
 [[package]]
 name = "utf8_iter"
 version = "1.0.4"
@@ -9566,7 +9858,7 @@ dependencies = [
  "js-sys",
  "khronos-egl",
  "libc",
- "libloading",
+ "libloading 0.8.9",
  "log",
  "naga",
  "naga-types",
@@ -10204,7 +10496,7 @@ dependencies = [
  "as-raw-xcb-connection",
  "gethostname",
  "libc",
- "libloading",
+ "libloading 0.8.9",
  "once_cell",
  "rustix 1.1.4",
  "x11rb-protocol",

Cargo.toml

@@ -4,6 +4,9 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+cef = "151"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
 egui = "0.36.1"
 egui-wgpu = "0.36.1"
 egui-winit = "0.36.1"

scripts/bundle.sh

@@ -0,0 +1,95 @@
+#!/bin/sh
+# Build Fox and assemble Fox.app with the CEF framework + helper bundles.
+#
+#   scripts/bundle.sh [debug|release]
+#
+# The CEF distribution must be exported first:
+#   cargo install export-cef-dir --version 151.7.0+151.3.23 && export-cef-dir
+set -e
+
+PROFILE="${1:-debug}"
+cd "$(dirname "$0")/.."
+
+export CEF_PATH="${CEF_PATH:-$HOME/.local/share/cef}"
+DIST="$CEF_PATH"
+FRAMEWORK="Chromium Embedded Framework.framework"
+
+if [ "$PROFILE" = "release" ]; then
+    cargo build --release
+    BIN="target/release/browser"
+else
+    cargo build
+    BIN="target/debug/browser"
+fi
+
+APP="target/bundle/Fox.app"
+CONTENTS="$APP/Contents"
+rm -rf "$APP"
+mkdir -p "$CONTENTS/MacOS" "$CONTENTS/Frameworks"
+
+cp "$BIN" "$CONTENTS/MacOS/browser"
+ditto "$DIST/$FRAMEWORK" "$CONTENTS/Frameworks/$FRAMEWORK"
+
+cat > "$CONTENTS/Info.plist" <<'PLIST'
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"
+  "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>CFBundleDevelopmentRegion</key><string>en</string>
+    <key>CFBundleExecutable</key><string>browser</string>
+    <key>CFBundleIconFile</key><string></string>
+    <key>CFBundleIdentifier</key><string>dev.fox.browser</string>
+    <key>CFBundleInfoDictionaryVersion</key><string>6.0</string>
+    <key>CFBundleName</key><string>Fox</string>
+    <key>CFBundleDisplayName</key><string>Fox</string>
+    <key>CFBundlePackageType</key><string>APPL</string>
+    <key>CFBundleShortVersionString</key><string>0.2.0</string>
+    <key>CFBundleVersion</key><string>0.2.0</string>
+    <key>LSMinimumSystemVersion</key><string>11.0</string>
+    <key>NSHighResolutionCapable</key><true/>
+    <key>NSPrincipalClass</key><string>NSApplication</string>
+</dict>
+</plist>
+PLIST
+
+# Chromium on macOS launches child processes (GPU/renderer/network/utility)
+# from dedicated .app bundles. We reuse the Fox binary itself as the helper
+# executable — CEF child processes are dispatched via --type= arguments, which
+# our bootstrap() already understands.
+make_helper () {
+    HELPER_NAME="$1"
+    HELPER_ID="$2"
+    HELPER_DIR="$CONTENTS/Frameworks/$HELPER_NAME.app"
+    mkdir -p "$HELPER_DIR/Contents/MacOS"
+    cp "$BIN" "$HELPER_DIR/Contents/MacOS/$HELPER_NAME"
+    cat > "$HELPER_DIR/Contents/Info.plist" <<PLIST
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"
+  "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>CFBundleDevelopmentRegion</key><string>en</string>
+    <key>CFBundleExecutable</key><string>$HELPER_NAME</string>
+    <key>CFBundleIdentifier</key><string>$HELPER_ID</string>
+    <key>CFBundleInfoDictionaryVersion</key><string>6.0</string>
+    <key>CFBundleName</key><string>$HELPER_NAME</string>
+    <key>CFBundlePackageType</key><string>APPL</string>
+    <key>CFBundleShortVersionString</key><string>0.2.0</string>
+    <key>CFBundleVersion</key><string>0.2.0</string>
+    <key>LSMinimumSystemVersion</key><string>11.0</string>
+    <key>NSSupportsAutomaticGraphicsSwitching</key><true/>
+</dict>
+</plist>
+PLIST
+}
+
+make_helper "Fox Helper"            "dev.fox.browser.helper"
+make_helper "Fox Helper (Renderer)" "dev.fox.browser.helper.renderer"
+make_helper "Fox Helper (GPU)"      "dev.fox.browser.helper.gpu"
+make_helper "Fox Helper (Plugin)"   "dev.fox.browser.helper.plugin"
+make_helper "Fox Helper (Alerts)"   "dev.fox.browser.helper.alerts"
+
+codesign --force --deep --sign - "$APP"
+
+echo "Built $APP"

scripts/run-dev.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+# Build and run Fox in dev mode.
+#
+#   scripts/run-dev.sh [extra cargo args...]
+#
+# On macOS the app must run from a .app bundle (CEF needs its framework
+# resources, so a bare target/debug binary cannot start). This script
+# therefore bundles first, then launches Fox.app with console output visible.
+#
+# The CEF distribution must be exported once:
+#   cargo install export-cef-dir --version 151.7.0+151.3.23
+#   export-cef-dir            # installs to ~/.local/share/cef
+set -e
+
+cd "$(dirname "$0")/.."
+
+export CEF_PATH="${CEF_PATH:-$HOME/.local/share/cef}"
+
+scripts/bundle.sh "${FOX_PROFILE:-debug}"
+
+exec ./target/bundle/Fox.app/Contents/MacOS/browser "$@"

src/main.rs

@@ -1,16 +1,21 @@
 mod app;
+mod cef_host;
 mod servo_host;
+mod settings;
 
 use std::error::Error;
+use std::process::ExitCode;
 
 use app::BrowserApp;
 
 #[derive(Debug)]
 pub enum UserEvent {
     RepaintAfter(std::time::Duration),
+    /// CEF asked for a message-loop pass after this delay.
+    PumpCef(std::time::Duration),
 }
 
-fn main() -> Result<(), Box<dyn Error>> {
+fn main() -> Result<ExitCode, Box<dyn Error>> {
     // Note: logging is initialized by `Servo::setup_logging()` — do not install
     // another logger here or it will panic with `SetLoggerError`.
 
@@ -18,13 +23,27 @@ fn main() -> Result<(), Box<dyn Error>> {
         .install_default()
         .expect("Failed to install crypto provider");
 
+    // The CEF handshake must happen before winit creates an NSApplication:
+    // when this binary is re-executed as a CEF helper process, bootstrap()
+    // runs the child-process loop to completion and returns false.
+    if !cef_host::bootstrap() {
+        return Ok(ExitCode::SUCCESS);
+    }
+
+    if cef_host::run_probe() {
+        return Ok(ExitCode::SUCCESS);
+    }
+
     let event_loop = winit::event_loop::EventLoop::<UserEvent>::with_user_event()
         .build()
         .expect("Failed to create event loop");
 
     let proxy = event_loop.create_proxy();
-    let mut app = BrowserApp::new(proxy);
+    cef_host::set_pump_proxy(proxy.clone());
+
+    let settings = settings::Settings::load();
+    let mut app = BrowserApp::new(proxy, settings);
 
     event_loop.run_app(&mut app)?;
-    Ok(())
+    Ok(ExitCode::SUCCESS)
 }

src/servo_host.rs

@@ -1,7 +1,6 @@
 use std::cell::RefCell;
 use std::rc::Rc;
 
-use egui::TextureHandle;
 use keyboard_types::{Code, Key, KeyState, Location, Modifiers, NamedKey};
 use servo::{
     DevicePoint, EventLoopWaker, InputEvent, KeyboardEvent as ServoKeyboardEvent, LoadStatus,
@@ -124,7 +123,7 @@ impl Engine {
         self.servo.spin_event_loop();
     }
 
-    pub fn create_tab(&self, url: Url, hidpi_scale: f32) -> Tab {
+    pub fn create_tab(&self, url: Url, hidpi_scale: f32) -> ServoPage {
         let size = self.window_context.size();
         let offscreen: Rc<OffscreenRenderingContext> =
             Rc::new(self.window_context.offscreen_context(size));
@@ -137,45 +136,27 @@ impl Engine {
             .delegate(delegate)
             .build();
         webview.notify_theme_change(Theme::Light);
-        Tab::new(webview)
+        ServoPage::new(webview)
     }
 }
 
-pub struct Tab {
+/// Engine-side handle for one Servo tab. UI state (title, texture, …) lives in
+/// `app::Tab`; this only carries what Servo needs.
+pub struct ServoPage {
     pub webview: WebView,
     pub id: WebViewId,
-    pub title: String,
-    pub url_string: String,
-    pub status_text: Option<String>,
-    pub loading: bool,
-    pub animating: bool,
-    pub dirty: bool,
-    pub texture: Option<TextureHandle>,
-    /// Hash of the last uploaded frame — skips redundant GPU texture uploads.
-    pub last_frame_hash: u64,
-    /// Time of the last GPU->CPU readback — throttles readback frequency.
-    pub last_paint: std::time::Instant,
 }
 
-impl Tab {
+impl ServoPage {
-    fn new(webview: WebView) -> Tab {
+    fn new(webview: WebView) -> ServoPage {
-        Tab {
+        ServoPage {
             id: webview.id(),
             webview,
-            title: String::from("New Tab"),
-            url_string: String::new(),
-            status_text: None,
-            loading: true,
-            animating: false,
-            dirty: true,
-            texture: None,
-            last_frame_hash: 0,
-            last_paint: std::time::Instant::now() - std::time::Duration::from_secs(1),
         }
     }
 
-    pub fn adopt(webview: WebView) -> Tab {
+    pub fn adopt(webview: WebView) -> ServoPage {
-        Tab::new(webview)
+        Self::new(webview)
     }
 }
 

src/settings.rs

@@ -0,0 +1,50 @@
+use serde::{Deserialize, Serialize};
+use std::path::PathBuf;
+
+/// Which browser engine renders a tab.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum EngineKind {
+    #[default]
+    Chromium,
+    Servo,
+}
+
+impl EngineKind {
+    pub fn label(self) -> &'static str {
+        match self {
+            EngineKind::Chromium => "Chromium",
+            EngineKind::Servo => "Servo",
+        }
+    }
+}
+
+#[derive(Clone, Debug, Default, Serialize, Deserialize)]
+pub struct Settings {
+    pub default_engine: EngineKind,
+}
+
+impl Settings {
+    pub fn load() -> Settings {
+        let Some(text) = std::fs::read_to_string(Self::path()).ok() else {
+            return Settings::default();
+        };
+        serde_json::from_str(&text).unwrap_or_default()
+    }
+
+    pub fn save(&self) {
+        let path = Self::path();
+        if let Some(parent) = path.parent() {
+            let _ = std::fs::create_dir_all(parent);
+        }
+        if let Ok(json) = serde_json::to_string_pretty(self) {
+            let _ = std::fs::write(path, json);
+        }
+    }
+
+    fn path() -> PathBuf {
+        let home = std::env::var("HOME").unwrap_or_else(|_| ".".to_owned());
+        PathBuf::from(home)
+            .join("Library/Application Support/Fox/settings.json")
+    }
+}