Files
Kiwy-Signage/windows/test_webview2_embed.py
ske087 9f5409685d Embedded WebView2 engine for web links (Windows)
Web links previously launched a separate Chrome/Edge kiosk process, which
caused the whole class of bugs in the tracker: the browser opening behind the
player, being handed off to an already-running instance and exiting instantly,
fighting for foreground/z-order, and leaking msedge.exe/chrome.exe processes
that were never closed.

WebView2 renders as a CHILD HWND of Kivy's own SDL window instead, so there is
no separate top-level browser to open behind the player, nothing to hand the
URL off to, no z-order contest, and no leaked browser process.

Windows/webview2_browser.py
  - Environment -> controller -> navigate, driven through pythonnet.
  - Async .NET Tasks are polled from Kivy's Clock. Calling GetAwaiter()
    .GetResult() would deadlock: the continuation needs the same thread's
    message pump.
  - The controller is a .NET IntPtr, not a Python int (CreateAsync overloads
    do not match otherwise).
  - NavigationCompleted is tracked so a page that never loads can be told
    apart from one that did. This matters on a closed network: an unreachable
    host paints a Chromium error page, and without this the player would show
    a blank/error screen for the item's whole slot instead of skipping it.
  - is_alive() reports True while starting up. Start-up is async, so a
    controller that does not exist yet is not a dead browser; treating it as
    one made the first web link after a cold start be skipped instantly.

Windows/webview2_runtime.py
  - Detects the Runtime (registry pv value, SDK probe as fallback) and
    installs it silently when missing, unelevated, which produces a per-user
    install and therefore never raises a UAC prompt on the signage display.
  - Success is decided by RE-READING the installed version, not by the
    installer exit code: Edge Update returns a non-zero HRESULT
    (-2147219416) when the Runtime is already current, which is not a failure.
  - On a closed network the online bootstrapper can never succeed, so it fails
    fast with an actionable message instead of hanging for the full timeout.
  - Failed attempts are cooldown-gated so a broken machine does not re-run an
    installer on every start.

Offline hardening
  - Browser arguments disable component updates, field trials, safe-browsing
    list fetches, translate and other internet chatter. On an isolated LAN
    each of those would otherwise have to time out, costing start-up latency.
    Pages on the local server are unaffected.

Engine order (best first): WebView2 -> CEF -> Chrome/Edge subprocess. CEF has
no wheels past Python 3.9 so it is dormant on this build; the subprocess engine
remains only as a last resort.

Also fixes the reason the Windows adapters were never used at all:
SignagePlayer.__init__ assigned self.weblink_adapter_factory = None, which
shadowed the CLASS attribute that run_win.py injects. play_weblink() therefore
fell back to the generic adapter, whose find_browser() uses shutil.which() and
finds nothing on Windows because Chrome/Edge are not on PATH. The instance
attribute is now only set when the class attribute is absent.

Verified: windows/test_webview2_embed.py, test_webview2_navigation.py and
test_webview2_offline.py all pass (a locally served page renders with all
internet traffic disabled), and the packaged exe reports
"weblink_launch engine=webview2-embedded" -> "weblink_launched" on every cycle
with no leaked browser processes.
2026-09-13 10:14:18 +03:00

170 lines
5.0 KiB
Python

"""Standalone harness for windows/webview2_browser.py — no Kivy, no player.
Creates a plain Win32 window, embeds WebView2 in it via the same
WebView2Browser class the player uses, navigates to a page, checks that the
page actually becomes visible, then resizes and tears down.
Run: windows\\venv\\Scripts\\python.exe windows\\test_webview2_embed.py
Exit code 0 = embedded engine works.
"""
import ctypes
import os
import sys
import time
from pathlib import Path
sys.path.insert(0, str(Path(__file__).resolve().parent))
URL = os.environ.get('KIWY_TEST_URL', 'https://example.com/')
user32 = ctypes.windll.user32
kernel32 = ctypes.windll.kernel32
WNDPROC = ctypes.WINFUNCTYPE(
ctypes.c_int64,
ctypes.c_void_p, # HWND
ctypes.c_uint, # UINT msg
ctypes.c_void_p, # WPARAM
ctypes.c_void_p, # LPARAM
)
_messages = []
@WNDPROC
def _wnd_proc(hwnd, msg, wparam, lparam):
_messages.append(msg)
if msg == 0x0002: # WM_DESTROY
user32.PostQuitMessage(0)
return 0
user32.DefWindowProcW.restype = ctypes.c_int64
user32.DefWindowProcW.argtypes = [
ctypes.c_void_p, ctypes.c_uint, ctypes.c_void_p, ctypes.c_void_p,
]
return user32.DefWindowProcW(hwnd, msg, wparam, lparam)
def _make_window(width=1280, height=720):
"""Register a class and create a visible top-level window."""
hinstance = kernel32.GetModuleHandleW(None)
class_name = 'KiwyWebView2Test'
class WNDCLASSEX(ctypes.Structure):
_fields_ = [
('cbSize', ctypes.c_uint),
('style', ctypes.c_uint),
('lpfnWndProc', WNDPROC),
('cbClsExtra', ctypes.c_int),
('cbWndExtra', ctypes.c_int),
('hInstance', ctypes.c_void_p),
('hIcon', ctypes.c_void_p),
('hCursor', ctypes.c_void_p),
('hbrBackground', ctypes.c_void_p),
('lpszMenuName', ctypes.c_wchar_p),
('lpszClassName', ctypes.c_wchar_p),
('hIconSm', ctypes.c_void_p),
]
wc = WNDCLASSEX()
wc.cbSize = ctypes.sizeof(WNDCLASSEX)
wc.style = 0x0002 | 0x0001 # CS_HREDRAW | CS_VREDRAW
wc.lpfnWndProc = _wnd_proc
wc.hInstance = hinstance
wc.hbrBackground = ctypes.c_void_p(6) # COLOR_WINDOW+1
wc.lpszClassName = class_name
user32.RegisterClassExW(ctypes.byref(wc))
hwnd = user32.CreateWindowExW(
0,
class_name,
'Kiwy WebView2 Embed Test',
0x00CF0000 | 0x10000000, # WS_OVERLAPPEDWINDOW | WS_VISIBLE
100, 100, width, height,
0, 0, hinstance, 0,
)
if not hwnd:
raise RuntimeError(f'CreateWindowExW failed (err={kernel32.GetLastError()})')
user32.UpdateWindow(hwnd)
return hwnd
def _pump(seconds):
"""Pump Win32 messages — WebView2 needs this to deliver its callbacks."""
deadline = time.monotonic() + seconds
while time.monotonic() < deadline:
msg = ctypes.wintypes.MSG() if hasattr(ctypes, 'wintypes') else None
import ctypes.wintypes as wt
msg = wt.MSG()
while user32.PeekMessageW(ctypes.byref(msg), None, 0, 0, 1):
user32.TranslateMessage(ctypes.byref(msg))
user32.DispatchMessageW(ctypes.byref(msg))
time.sleep(0.02)
def main():
print('=' * 68)
print(' WebView2 embedded-engine test')
print('=' * 68)
from webview2_browser import WebView2Browser
print(f'SDK dir : {WebView2Browser.__module__}')
available = WebView2Browser.is_available()
print(f'available: {available}')
if not available:
print(f'REASON: {WebView2Browser._import_error}')
return 1
hwnd = _make_window()
print(f'window : hwnd=0x{hwnd:x}')
browser = WebView2Browser(hwnd_provider=lambda: hwnd)
started = time.monotonic()
ok = browser.show(URL)
print(f'show() : {ok}')
if not ok:
print(f'FAILED : {browser.failed_reason}')
return 1
# Drive the Kivy-style Clock poll manually while pumping messages.
visible = False
while time.monotonic() - started < 25:
browser._tick(0) # consume the async task
_pump(0.1)
if browser.failed_reason:
print(f'FAILED : {browser.failed_reason}')
return 1
if browser.is_showing():
visible = True
break
print(f'visible : {visible} after {time.monotonic() - started:.1f}s')
if not visible:
print('FAILED : page never became visible')
return 1
# Resize to the signage resolution and confirm it is applied.
browser.resize(1920, 1080)
_pump(1.0)
print(f'resized : 1920x1080 (bounds={browser._size})')
# Hide, then re-show to prove the controller survives a transition.
browser.hide()
_pump(0.5)
print(f'after hide -> is_showing={browser.is_showing()}')
browser.show(URL)
_pump(2.0)
print(f'after re-show -> is_showing={browser.is_showing()}')
browser.shutdown()
print('shutdown: ok')
print('=' * 68)
print(' RESULT: PASS')
print('=' * 68)
return 0
if __name__ == '__main__':
sys.exit(main())