Replace the stock Flutter launcher icon, add a Linux desktop icon

Adopt the shared icon family (python_pkg/app_icons in testsAndMisc): a
charcoal #1B1D21 field carrying a deep-purple checklist glyph, deep purple
being this app's own theme seedColor. Two ticked-off rows rather than a lone
checkmark, so it reads as a notes app and not as a generic "done" badge.

Android gains the adaptive-icon layers the project never had, including an
Android 13 monochrome layer.

Linux needs separate handling: Flutter's GTK runner never sets a window icon,
so my_application.cc now calls gtk_window_set_icon_name and
install_desktop_entry.sh populates the hicolor theme from the pre-rendered
PNGs in linux/icons (committed, so the installer needs no image tooling).
StartupWMClass is the APPLICATION_ID rather than the binary name - verified
with xprop against a running window, where WM_CLASS is the GApplication id.

No Dart code changes, so test coverage is unaffected.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

android/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+  <background android:drawable="@color/ic_launcher_background"/>
+  <foreground>
+      <inset
+          android:drawable="@drawable/ic_launcher_foreground"
+          android:inset="16%" />
+  </foreground>
+  <monochrome>
+      <inset
+          android:drawable="@drawable/ic_launcher_monochrome"
+          android:inset="16%" />
+  </monochrome>
+</adaptive-icon>

android/app/src/main/res/values/colors.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="ic_launcher_background">#1B1D21</color>
+</resources>

assets/icon/icon.svg

@@ -0,0 +1,9 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="1024" height="1024" viewBox="0 0 1024 1024">
+  <rect width="1024" height="1024" fill="#1B1D21"/>
+  <g fill="none" stroke="#7E57C2" stroke-width="72" stroke-linecap="round" stroke-linejoin="round" transform="translate(0,8)">
+    <path d="M 272 372 L 346 446 L 478 314"/>
+    <path d="M 594 400 L 752 400"/>
+    <path d="M 272 620 L 346 694 L 478 562"/>
+    <path d="M 594 648 L 752 648"/>
+  </g>
+</svg>

assets/icon/icon_foreground.svg

@@ -0,0 +1,8 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="1024" height="1024" viewBox="0 0 1024 1024">
+  <g fill="none" stroke="#7E57C2" stroke-width="72" stroke-linecap="round" stroke-linejoin="round" transform="translate(0,8)">
+    <path d="M 272 372 L 346 446 L 478 314"/>
+    <path d="M 594 400 L 752 400"/>
+    <path d="M 272 620 L 346 694 L 478 562"/>
+    <path d="M 594 648 L 752 648"/>
+  </g>
+</svg>

assets/icon/icon_monochrome.svg

@@ -0,0 +1,8 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="1024" height="1024" viewBox="0 0 1024 1024">
+  <g fill="none" stroke="#FFFFFF" stroke-width="72" stroke-linecap="round" stroke-linejoin="round" transform="translate(0,8)">
+    <path d="M 272 372 L 346 446 L 478 314"/>
+    <path d="M 594 400 L 752 400"/>
+    <path d="M 272 620 L 346 694 L 478 562"/>
+    <path d="M 594 648 L 752 648"/>
+  </g>
+</svg>

linux/install_desktop_entry.sh

@@ -0,0 +1,118 @@
+#!/bin/bash
+
+# ============================================================================
+# Install the todo launcher icon and .desktop entry for the Linux desktop.
+#
+# Flutter's GTK runner has no icon of its own: my_application.cc calls
+# gtk_window_set_icon_name("todo"), which resolves through the hicolor icon
+# theme. This script is what puts the icon into that theme, plus a .desktop
+# entry so the app appears in application menus.
+#
+# Icon PNGs are pre-rendered and committed under linux/icons/, so this script
+# needs no image tooling at run time. Regenerate them with:
+#   PYTHONPATH=~/testsAndMisc python3 -m python_pkg.app_icons \
+#       generate --app todo --linux-out linux/icons
+# ============================================================================
+
+set -euo pipefail
+
+SCRIPT_NAME="$(basename "$0")"
+LINUX_DIR="$(cd "$(dirname "$0")" && pwd)"
+REPO_DIR="$(dirname "$LINUX_DIR")"
+readonly SCRIPT_NAME LINUX_DIR REPO_DIR
+readonly ICON_NAME="todo"
+readonly BINARY_NAME="todo"
+# GTK derives WM_CLASS from the GApplication id in linux/CMakeLists.txt,
+# not from the binary name; verified with xprop on the running window.
+readonly WM_CLASS="dev.kuhy.todo"
+readonly ICON_SRC_DIR="$LINUX_DIR/icons"
+readonly ICON_THEME_DIR="${XDG_DATA_HOME:-$HOME/.local/share}/icons/hicolor"
+readonly DESKTOP_DIR="${XDG_DATA_HOME:-$HOME/.local/share}/applications"
+readonly BUNDLE_BIN="$REPO_DIR/build/linux/x64/release/bundle/$BINARY_NAME"
+
+usage() {
+    echo "Usage: $SCRIPT_NAME"
+    echo "Installs the todo icon into the hicolor theme and writes a .desktop entry."
+    exit 0
+}
+
+validate_requirements() {
+    if [[ ! -d "$ICON_SRC_DIR" ]]; then
+        echo "Error: $ICON_SRC_DIR is missing; regenerate the icons first" >&2
+        exit 1
+    fi
+}
+
+ensure_theme_index() {
+    # A user-local hicolor tree created from scratch has no index.theme, and
+    # without it gtk-update-icon-cache refuses to build a cache ("No theme
+    # index file"). Seed it from the system theme when one is available.
+    local system_index="/usr/share/icons/hicolor/index.theme"
+    if [[ ! -f "$ICON_THEME_DIR/index.theme" && -f "$system_index" ]]; then
+        install -Dm644 "$system_index" "$ICON_THEME_DIR/index.theme"
+    fi
+}
+
+install_icons() {
+    local size_dir size icon
+    for size_dir in "$ICON_SRC_DIR"/*/; do
+        size="$(basename "$size_dir")"
+        icon="$size_dir$ICON_NAME.png"
+        [[ -f "$icon" ]] || continue
+        install -Dm644 "$icon" \
+            "$ICON_THEME_DIR/${size}x${size}/apps/$ICON_NAME.png"
+    done
+    # Refresh the theme cache so GTK picks the icon up without a re-login.
+    # Harmless if the tool is absent: the icon still resolves, just slower.
+    if command -v gtk-update-icon-cache >/dev/null; then
+        gtk-update-icon-cache --quiet --force "$ICON_THEME_DIR" || true
+    fi
+}
+
+install_desktop_entry() {
+    mkdir -p "$DESKTOP_DIR"
+    # StartupWMClass must match the window's actual WM class, or the taskbar
+    # shows a generic icon for the running window even though the launcher
+    # entry itself looks right.
+    cat > "$DESKTOP_DIR/$ICON_NAME.desktop" <<EOF
+[Desktop Entry]
+Type=Application
+Name=todo
+Comment=Offline-first, CRDT-synced notes
+Exec=$BUNDLE_BIN
+Icon=$ICON_NAME
+Terminal=false
+Categories=Utility;TextEditor;
+StartupWMClass=$WM_CLASS
+EOF
+    if command -v update-desktop-database >/dev/null; then
+        update-desktop-database "$DESKTOP_DIR" || true
+    fi
+}
+
+main() {
+    validate_requirements
+    ensure_theme_index
+    install_icons
+    install_desktop_entry
+    echo "Installed $ICON_NAME icon into $ICON_THEME_DIR"
+    echo "Installed $DESKTOP_DIR/$ICON_NAME.desktop"
+    if [[ ! -x "$BUNDLE_BIN" ]]; then
+        echo "Note: $BUNDLE_BIN does not exist yet."
+        echo "      Run 'flutter build linux --release' to make the entry launchable."
+    fi
+}
+
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        -h|--help)
+            usage
+            ;;
+        *)
+            echo "Unknown option: $1" >&2
+            exit 1
+            ;;
+    esac
+done
+
+main "$@"

linux/runner/my_application.cc

@@ -54,6 +54,11 @@ static void my_application_activate(GApplication* application) {
 
   gtk_window_set_default_size(window, 1280, 720);
 
+  // Resolved from the hicolor icon theme, which linux/install_desktop_entry.sh
+  // populates from linux/icons/. Without this the GTK runner shows a generic
+  // placeholder in the taskbar, since Flutter never sets a window icon itself.
+  gtk_window_set_icon_name(window, "todo");
+
   g_autoptr(FlDartProject) project = fl_dart_project_new();
   fl_dart_project_set_dart_entrypoint_arguments(
       project, self->dart_entrypoint_arguments);

pubspec.lock

@@ -1,6 +1,14 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  archive:
+    dependency: transitive
+    description:
+      name: archive
+      sha256: a96e8b390886ee8abb49b7bd3ac8df6f451c621619f52a26e815fdcf568959ff
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.0.9"
   args:
     dependency: transitive
     description:
@@ -41,6 +49,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.4.0"
+  checked_yaml:
+    dependency: transitive
+    description:
+      name: checked_yaml
+      sha256: "959525d3162f249993882720d52b7e0c833978df229be20702b33d48d91de70f"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.4"
+  cli_util:
+    dependency: transitive
+    description:
+      name: cli_util
+      sha256: ff6785f7e9e3c38ac98b2fb035701789de90154024a75b6cb926445e83197d1c
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.4.2"
   clock:
     dependency: transitive
     description:
@@ -223,6 +247,14 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_launcher_icons:
+    dependency: "direct dev"
+    description:
+      name: flutter_launcher_icons
+      sha256: "10f13781741a2e3972126fae08393d3c4e01fa4cd7473326b94b72cf594195e7"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.14.4"
   flutter_lints:
     dependency: "direct dev"
     description:
@@ -321,6 +353,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "4.1.2"
+  image:
+    dependency: transitive
+    description:
+      name: image
+      sha256: "6300175e00616bbc832e2fc91bfa4d776af5402c81c7151bee6905bb08473c52"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.9.1"
   jni:
     dependency: transitive
     description:
@@ -337,6 +377,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.0.1"
+  json_annotation:
+    dependency: transitive
+    description:
+      name: json_annotation
+      sha256: "2a743920d81b7910627f68ee2c9ac1fc0bfee32b9fc3403587d7c6791ca12f80"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.12.0"
   leak_tracker:
     dependency: transitive
     description:
@@ -489,6 +537,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.3.0"
+  petitparser:
+    dependency: transitive
+    description:
+      name: petitparser
+      sha256: "91bd59303e9f769f108f8df05e371341b15d59e995e6806aefab827b58336675"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.0.2"
   platform:
     dependency: transitive
     description:
@@ -513,6 +569,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.5.2"
+  posix:
+    dependency: transitive
+    description:
+      name: posix
+      sha256: "185ef7606574f789b40f289c233efa52e96dead518aed988e040a10737febb07"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.5.0"
   process_run:
     dependency: transitive
     description:
@@ -846,6 +910,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.1.0"
+  xml:
+    dependency: transitive
+    description:
+      name: xml
+      sha256: "67f0aff7be013d107995e9b75bf4e7f2c3ef2dfdb2c8e68024bba0a7fd5756a4"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.0.1"
   yaml:
     dependency: transitive
     description:

pubspec.yaml

@@ -57,6 +57,9 @@ dependencies:
   # libsecret) instead of plaintext SharedPreferences.
   flutter_secure_storage: ^10.3.1
 dev_dependencies:
+  # Generates the Android launcher icons from assets/icon/ (see
+  # python_pkg/app_icons in testsAndMisc for the shared style).
+  flutter_launcher_icons: ^0.14.4
   flutter_test:
     sdk: flutter
 
@@ -117,3 +120,15 @@ flutter:
   #
   # For details regarding fonts from package dependencies,
   # see https://flutter.dev/to/font-from-package
+
+# Launcher icon generation. Source art is produced by the shared generator:
+#   PYTHONPATH=~/testsAndMisc python3 -m python_pkg.app_icons generate --app <key>
+# then run: dart run flutter_launcher_icons
+flutter_launcher_icons:
+  android: true
+  ios: false
+  image_path: "assets/icon/icon.png"
+  adaptive_icon_background: "#1B1D21"
+  adaptive_icon_foreground: "assets/icon/icon_foreground.png"
+  adaptive_icon_monochrome: "assets/icon/icon_monochrome.png"
+  min_sdk_android: 21