Fix dual-mode printers (SC03h) and add desktop and web apps

README.md

@@ -20,7 +20,7 @@ $ pip install -r requirements.txt
 ```bash
 $ ./print.py --help
 usage: print.py [-h] [-l {debug,info,warn,error}] [-b {mean-threshold,floyd-steinberg,atkinson,halftone,none}] [-s] [-d DEVICE] [-e ENERGY]
-                filename
+                [-S SPEED] filename
 
 prints an image on your cat thermal printer
 
@@ -40,8 +40,64 @@ options:
                         services.
   -e ENERGY, --energy ENERGY
                         Thermal energy. Between 0x0000 (light) and 0xffff (darker, default).
+  -S SPEED, --speed SPEED
+                        Print speed. Higher values print slower and darker. The official app uses 10 for the SC03h.
 ```
 
+# Desktop app (AppImage)
+
+There is also a GTK 4 desktop app (in Spanish) in `catprinter_gui/`. It
+stays connected to the printer, shows its battery level and prints images,
+PDFs, office documents (through LibreOffice) and text files with a preview
+of the exact dots that will be printed.
+
+It runs on the system's Python and GTK, so on Debian/Ubuntu you need:
+
+```bash
+$ sudo apt install python3-gi python3-gi-cairo gir1.2-gtk-4.0 gir1.2-adw-1 poppler-utils
+```
+
+Build the AppImage (about 1 MB) and run it:
+
+```bash
+$ ./appimage/build.sh
+$ ./dist/CatPrinter-*-x86_64.AppImage
+```
+
+From the app menu, "Integrar con Archivos y el menú de apps" (or
+`--instalar` on the command line) copies the AppImage to `~/.local/bin` and
+adds it to the application menu, to "Open With" and to the context menu of
+Files. For a top-level entry in that context menu, also install
+`python3-nautilus` and restart Files with `nautilus -q`.
+
+# Web app
+
+`docs/` contains a web app (in Spanish) that prints from the browser through
+Web Bluetooth, with the same processing and print settings as the desktop
+app. It is a PWA: it can be installed, works offline once loaded, appears in
+the Android share sheet and, when installed on the desktop, in "Open With".
+
+Publish it with GitHub Pages (Settings → Pages → Deploy from a branch →
+`main`, `/docs`). Web Bluetooth needs Chrome, Edge or Opera on Windows,
+macOS, Android or ChromeOS; on other browsers the page explains the
+alternatives. To try it locally, serve `docs/` over `http://localhost`.
+
+# Dual-mode printers (SC03h)
+
+Some printers, like the SC03h, also offer classic Bluetooth. BlueZ may then
+try to connect over classic Bluetooth and fail with
+`br-connection-profile-unavailable`. To fix it:
+
+- Don't pair the printer in the system's Bluetooth settings. If you did,
+  remove it there: these printers don't need pairing.
+- With BlueZ 5.80 or newer, set `Experimental = true` in the `[General]`
+  section of `/etc/bluetooth/main.conf` and run
+  `sudo systemctl restart bluetooth`. This lets catprinter ask BlueZ to use
+  Bluetooth Low Energy for the printer.
+
+If prints come out blank, charge the printer: with a low battery it feeds
+the paper but doesn't heat the print head.
+
 # Example
 ```bash
 % ./print.py --show-preview test.png

appimage/AppRun

@@ -0,0 +1,22 @@
+#!/bin/sh
+# Runs the app with the system's Python and GTK; the AppImage only bundles
+# pure Python code.
+HERE="$(dirname "$(readlink -f "$0")")"
+
+fail() {
+    if command -v zenity >/dev/null 2>&1; then
+        zenity --error --title="Impresora térmica" --text="$1" 2>/dev/null
+    elif command -v notify-send >/dev/null 2>&1; then
+        notify-send "Impresora térmica" "$1"
+    fi
+    echo "$1" >&2
+    exit 1
+}
+
+command -v python3 >/dev/null 2>&1 || fail "Falta Python 3. Instálalo con: sudo apt install python3"
+python3 -c 'import gi, cairo; gi.require_version("Gtk", "4.0"); gi.require_version("Adw", "1")' 2>/dev/null ||
+    fail "Faltan bibliotecas de GTK. Instálalas con:
+sudo apt install python3-gi python3-gi-cairo gir1.2-gtk-4.0 gir1.2-adw-1"
+
+export PYTHONPATH="$HERE/usr/share/catprinter:$HERE/usr/share/catprinter/vendor"
+exec python3 -s -m catprinter_gui "$@"

appimage/build.sh

@@ -0,0 +1,58 @@
+#!/bin/sh
+# Builds dist/CatPrinter-<version>-x86_64.AppImage.
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+BUILD="$ROOT/build/appimage"
+APPDIR="$BUILD/AppDir"
+APP_ID=io.github.catprinter.Gui
+APPIMAGETOOL_VERSION=1.9.1
+TOOL="$BUILD/tools/appimagetool-$APPIMAGETOOL_VERSION-x86_64.AppImage"
+TOOL_URL="https://github.com/AppImage/appimagetool/releases/download/$APPIMAGETOOL_VERSION/appimagetool-x86_64.AppImage"
+VERSION="$(cd "$ROOT" && python3 -c 'import catprinter_gui; print(catprinter_gui.VERSION)')"
+OUTPUT="$ROOT/dist/CatPrinter-$VERSION-x86_64.AppImage"
+
+rm -rf "$APPDIR"
+mkdir -p "$APPDIR/usr/share/catprinter" "$BUILD/tools" "$ROOT/dist"
+
+# App code. img.py needs OpenCV and is only used by the command line tool.
+for pkg in catprinter catprinter_gui; do
+    cp -r "$ROOT/$pkg" "$APPDIR/usr/share/catprinter/"
+done
+find "$APPDIR" -name __pycache__ -prune -exec rm -rf {} +
+rm -f "$APPDIR/usr/share/catprinter/catprinter/img.py"
+
+python3 -m pip install --quiet --no-compile \
+    --target "$APPDIR/usr/share/catprinter/vendor" -r "$ROOT/appimage/requirements.txt"
+rm -rf "$APPDIR/usr/share/catprinter/vendor/bin"
+if find "$APPDIR/usr/share/catprinter/vendor" -name '*.so' | grep -q .; then
+    echo "Error: bundled dependencies must be pure Python" >&2
+    exit 1
+fi
+
+cp "$ROOT/appimage/AppRun" "$APPDIR/AppRun"
+cp "$ROOT/catprinter_gui/data/$APP_ID.svg" "$APPDIR/$APP_ID.svg"
+ln -sf "$APP_ID.svg" "$APPDIR/.DirIcon"
+mkdir -p "$APPDIR/usr/share/icons/hicolor/scalable/apps" "$APPDIR/usr/share/applications"
+cp "$ROOT/catprinter_gui/data/$APP_ID.svg" "$APPDIR/usr/share/icons/hicolor/scalable/apps/"
+cat > "$APPDIR/$APP_ID.desktop" <<DESKTOP
+[Desktop Entry]
+Type=Application
+Name=Impresora térmica
+Comment=Imprime imágenes, PDF, documentos y texto en tu impresora térmica
+Exec=catprinter %F
+Icon=$APP_ID
+Terminal=false
+Categories=Graphics;Utility;
+DESKTOP
+cp "$APPDIR/$APP_ID.desktop" "$APPDIR/usr/share/applications/"
+
+if [ ! -x "$TOOL" ]; then
+    echo "Downloading appimagetool $APPIMAGETOOL_VERSION..."
+    curl -fL -o "$TOOL" "$TOOL_URL"
+    chmod +x "$TOOL"
+fi
+# Build next to the output and rename, so a running copy is not overwritten.
+ARCH=x86_64 "$TOOL" --appimage-extract-and-run --no-appstream "$APPDIR" "$OUTPUT.tmp"
+mv -f "$OUTPUT.tmp" "$OUTPUT"
+echo "Built $OUTPUT"

appimage/requirements.txt

@@ -0,0 +1,4 @@
+# Bundled in the AppImage. Only pure Python packages, so the AppImage works
+# with whatever Python 3 version the system has.
+bleak==0.14.3
+dbus-next==0.2.3