api: Add get screenshot operation

The *GET /screen/{name}/screenshot* path operation returns a screenshot
of the specified screen as a PNG image.  If a value is specified for one
or more of `height`, `width`, or `ratio`, then the image will be resized
accordingly.

svc/poetry.lock

@@ -1,6 +1,6 @@
 [[package]]
 name = "aiomarionette"
-version = "0.0.1.post1"
+version = "0.0.2"
 description = "Firefox Marionette client for asyncio"
 category = "main"
 optional = false
@@ -224,6 +224,18 @@ category = "dev"
 optional = false
 python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,>=2.7"
 
+[[package]]
+name = "pillow"
+version = "9.1.0"
+description = "Python Imaging Library (Fork)"
+category = "main"
+optional = false
+python-versions = ">=3.7"
+
+[package.extras]
+docs = ["olefile", "sphinx (>=2.4)", "sphinx-copybutton", "sphinx-issues (>=3.0.1)", "sphinx-removed-in", "sphinx-rtd-theme (>=1.0)", "sphinxext-opengraph"]
+tests = ["check-manifest", "coverage", "defusedxml", "markdown2", "olefile", "packaging", "pyroma", "pytest", "pytest-cov", "pytest-timeout"]
+
 [[package]]
 name = "platformdirs"
 version = "2.5.2"
@@ -411,7 +423,7 @@ python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,>=2.7"
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.10"
-content-hash = "e27fe7faf85bdfce0d97bed53d029fd335a0fffa63fa16930f8708535dea7532"
+content-hash = "45f12ccd35375c54bb22e148e216c82fa6f4b51a2fc457650d0af8febdcabf88"
 
 [metadata.files]
 aiomarionette = []
@@ -617,6 +629,46 @@ pathspec = [
     {file = "pathspec-0.9.0-py2.py3-none-any.whl", hash = "sha256:7d15c4ddb0b5c802d161efc417ec1a2558ea2653c2e8ad9c19098201dc1c993a"},
     {file = "pathspec-0.9.0.tar.gz", hash = "sha256:e564499435a2673d586f6b2130bb5b95f04a3ba06f81b8f895b651a3c76aabb1"},
 ]
+pillow = [
+    {file = "Pillow-9.1.0-cp310-cp310-macosx_10_9_x86_64.whl", hash = "sha256:af79d3fde1fc2e33561166d62e3b63f0cc3e47b5a3a2e5fea40d4917754734ea"},
+    {file = "Pillow-9.1.0-cp310-cp310-macosx_11_0_arm64.whl", hash = "sha256:55dd1cf09a1fd7c7b78425967aacae9b0d70125f7d3ab973fadc7b5abc3de652"},
+    {file = "Pillow-9.1.0-cp310-cp310-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:66822d01e82506a19407d1afc104c3fcea3b81d5eb11485e593ad6b8492f995a"},
+    {file = "Pillow-9.1.0-cp310-cp310-manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:a5eaf3b42df2bcda61c53a742ee2c6e63f777d0e085bbc6b2ab7ed57deb13db7"},
+    {file = "Pillow-9.1.0-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:01ce45deec9df310cbbee11104bae1a2a43308dd9c317f99235b6d3080ddd66e"},
+    {file = "Pillow-9.1.0-cp310-cp310-musllinux_1_1_x86_64.whl", hash = "sha256:aea7ce61328e15943d7b9eaca87e81f7c62ff90f669116f857262e9da4057ba3"},
+    {file = "Pillow-9.1.0-cp310-cp310-win32.whl", hash = "sha256:7a053bd4d65a3294b153bdd7724dce864a1d548416a5ef61f6d03bf149205160"},
+    {file = "Pillow-9.1.0-cp310-cp310-win_amd64.whl", hash = "sha256:97bda660702a856c2c9e12ec26fc6d187631ddfd896ff685814ab21ef0597033"},
+    {file = "Pillow-9.1.0-cp37-cp37m-macosx_10_9_x86_64.whl", hash = "sha256:21dee8466b42912335151d24c1665fcf44dc2ee47e021d233a40c3ca5adae59c"},
+    {file = "Pillow-9.1.0-cp37-cp37m-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:6b6d4050b208c8ff886fd3db6690bf04f9a48749d78b41b7a5bf24c236ab0165"},
+    {file = "Pillow-9.1.0-cp37-cp37m-manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:5cfca31ab4c13552a0f354c87fbd7f162a4fafd25e6b521bba93a57fe6a3700a"},
+    {file = "Pillow-9.1.0-cp37-cp37m-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:ed742214068efa95e9844c2d9129e209ed63f61baa4d54dbf4cf8b5e2d30ccf2"},
+    {file = "Pillow-9.1.0-cp37-cp37m-win32.whl", hash = "sha256:c9efef876c21788366ea1f50ecb39d5d6f65febe25ad1d4c0b8dff98843ac244"},
+    {file = "Pillow-9.1.0-cp37-cp37m-win_amd64.whl", hash = "sha256:de344bcf6e2463bb25179d74d6e7989e375f906bcec8cb86edb8b12acbc7dfef"},
+    {file = "Pillow-9.1.0-cp38-cp38-macosx_10_9_x86_64.whl", hash = "sha256:17869489de2fce6c36690a0c721bd3db176194af5f39249c1ac56d0bb0fcc512"},
+    {file = "Pillow-9.1.0-cp38-cp38-macosx_11_0_arm64.whl", hash = "sha256:25023a6209a4d7c42154073144608c9a71d3512b648a2f5d4465182cb93d3477"},
+    {file = "Pillow-9.1.0-cp38-cp38-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:8782189c796eff29dbb37dd87afa4ad4d40fc90b2742704f94812851b725964b"},
+    {file = "Pillow-9.1.0-cp38-cp38-manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:463acf531f5d0925ca55904fa668bb3461c3ef6bc779e1d6d8a488092bdee378"},
+    {file = "Pillow-9.1.0-cp38-cp38-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:3f42364485bfdab19c1373b5cd62f7c5ab7cc052e19644862ec8f15bb8af289e"},
+    {file = "Pillow-9.1.0-cp38-cp38-musllinux_1_1_x86_64.whl", hash = "sha256:3fddcdb619ba04491e8f771636583a7cc5a5051cd193ff1aa1ee8616d2a692c5"},
+    {file = "Pillow-9.1.0-cp38-cp38-win32.whl", hash = "sha256:4fe29a070de394e449fd88ebe1624d1e2d7ddeed4c12e0b31624561b58948d9a"},
+    {file = "Pillow-9.1.0-cp38-cp38-win_amd64.whl", hash = "sha256:c24f718f9dd73bb2b31a6201e6db5ea4a61fdd1d1c200f43ee585fc6dcd21b34"},
+    {file = "Pillow-9.1.0-cp39-cp39-macosx_10_9_x86_64.whl", hash = "sha256:fb89397013cf302f282f0fc998bb7abf11d49dcff72c8ecb320f76ea6e2c5717"},
+    {file = "Pillow-9.1.0-cp39-cp39-macosx_11_0_arm64.whl", hash = "sha256:c870193cce4b76713a2b29be5d8327c8ccbe0d4a49bc22968aa1e680930f5581"},
+    {file = "Pillow-9.1.0-cp39-cp39-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:69e5ddc609230d4408277af135c5b5c8fe7a54b2bdb8ad7c5100b86b3aab04c6"},
+    {file = "Pillow-9.1.0-cp39-cp39-manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:35be4a9f65441d9982240e6966c1eaa1c654c4e5e931eaf580130409e31804d4"},
+    {file = "Pillow-9.1.0-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:82283af99c1c3a5ba1da44c67296d5aad19f11c535b551a5ae55328a317ce331"},
+    {file = "Pillow-9.1.0-cp39-cp39-musllinux_1_1_x86_64.whl", hash = "sha256:a325ac71914c5c043fa50441b36606e64a10cd262de12f7a179620f579752ff8"},
+    {file = "Pillow-9.1.0-cp39-cp39-win32.whl", hash = "sha256:a598d8830f6ef5501002ae85c7dbfcd9c27cc4efc02a1989369303ba85573e58"},
+    {file = "Pillow-9.1.0-cp39-cp39-win_amd64.whl", hash = "sha256:0c51cb9edac8a5abd069fd0758ac0a8bfe52c261ee0e330f363548aca6893595"},
+    {file = "Pillow-9.1.0-pp37-pypy37_pp73-macosx_10_9_x86_64.whl", hash = "sha256:a336a4f74baf67e26f3acc4d61c913e378e931817cd1e2ef4dfb79d3e051b481"},
+    {file = "Pillow-9.1.0-pp37-pypy37_pp73-manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:eb1b89b11256b5b6cad5e7593f9061ac4624f7651f7a8eb4dfa37caa1dfaa4d0"},
+    {file = "Pillow-9.1.0-pp37-pypy37_pp73-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:255c9d69754a4c90b0ee484967fc8818c7ff8311c6dddcc43a4340e10cd1636a"},
+    {file = "Pillow-9.1.0-pp38-pypy38_pp73-macosx_10_9_x86_64.whl", hash = "sha256:5a3ecc026ea0e14d0ad7cd990ea7f48bfcb3eb4271034657dc9d06933c6629a7"},
+    {file = "Pillow-9.1.0-pp38-pypy38_pp73-manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:c5b0ff59785d93b3437c3703e3c64c178aabada51dea2a7f2c5eccf1bcf565a3"},
+    {file = "Pillow-9.1.0-pp38-pypy38_pp73-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:c7110ec1701b0bf8df569a7592a196c9d07c764a0a74f65471ea56816f10e2c8"},
+    {file = "Pillow-9.1.0-pp38-pypy38_pp73-win_amd64.whl", hash = "sha256:8d79c6f468215d1a8415aa53d9868a6b40c4682165b8cb62a221b1baa47db458"},
+    {file = "Pillow-9.1.0.tar.gz", hash = "sha256:f401ed2bbb155e1ade150ccc63db1a4f6c1909d3d378f7d1235a44e90d75fb97"},
+]
 platformdirs = [
     {file = "platformdirs-2.5.2-py3-none-any.whl", hash = "sha256:027d8e83a2d7de06bbac4e5ef7e023c02b863d7ea5d079477e722bb41ab25788"},
     {file = "platformdirs-2.5.2.tar.gz", hash = "sha256:58c8abb07dcb441e6ee4b11d8df0ac856038f944ab98b7be6b27b2a3c7feef19"},

svc/pyproject.toml

@@ -11,6 +11,7 @@ fastapi = "^0.75.1"
 uvicorn = "^0.17.6"
 python-multipart = "^0.0.5"
 aiomarionette = {path = "../../aiomarionette", develop = true}
+Pillow = "^9.1.0"
 
 [tool.poetry.dev-dependencies]
 black = "^22.3.0"

svc/src/hudctrl/api.py

@@ -1,6 +1,9 @@
+import io
 import logging
+from typing import Optional
 
 import fastapi
+from PIL import Image
 
 from .hud import HUDService, NoMonitorConfig
 from .xrandr import MonitorConfig
@@ -19,6 +22,10 @@ app = fastapi.FastAPI(
 svc = HUDService()
 
 
+class PNGImageResponse(fastapi.Response):
+    media_type = 'image/png'
+
+
 @app.post(
     '/display/up',
     response_class=fastapi.Response,
@@ -89,6 +96,36 @@ async def refresh_screen(name: str):
         ) from None
 
 
+@app.get(
+    '/screen/{name}/screenshot',
+    response_class=PNGImageResponse,
+)
+async def get_screenshot(
+    name: str,
+    height: Optional[int] = fastapi.Query(None),
+    width: Optional[int] = fastapi.Query(None),
+    ratio: Optional[float] = fastapi.Query(None),
+):
+    response = PNGImageResponse()
+    data = await svc.take_screenshot(name)
+    if height or width:
+        buf = io.BytesIO(data)
+        img = Image.open(buf)
+        if ratio is None:
+            ratio = max(img.size[0] / max(img.size[1], 1), 1)
+        if height and not width:
+            width = int(height * ratio)
+        elif width and not height:
+            height = int(width / ratio)
+        assert height and width
+        img = img.resize((width, height))
+        buf = io.BytesIO()
+        img.save(buf, format='png')
+        data = buf.getvalue()
+    response.body = data
+    return response
+
+
 @app.on_event('shutdown')
 async def on_shutdown():
     await svc.shutdown()

svc/src/hudctrl/hud.py

@@ -1,4 +1,5 @@
 import asyncio
+import base64
 import json
 import logging
 from pathlib import Path
@@ -133,3 +134,10 @@ class HUDService:
     async def startup(self) -> None:
         loop = asyncio.get_running_loop()
         await loop.run_in_executor(None, self.load_urls)
+
+    async def take_screenshot(self, screen: str) -> bytes:
+        assert self.marionette
+        handle = self.windows[screen]
+        await self.marionette.switch_to_window(handle)
+        data = await self.marionette.take_screenshot()
+        return base64.b64decode(data)