check_versions()

sys.excepthook = cef.ExceptHook # To shutdown all CEF processes on error

if os.path.exists(SCREENSHOT_PATH):

print("[screenshot.py] Remove old screenshot")

os.remove(SCREENSHOT_PATH)

command_line_arguments()

# Off-screen-rendering requires setting "windowless_rendering_enabled"

# option.

settings = {

"windowless_rendering_enabled": True,

}

switches = {

# GPU acceleration is not supported in OSR mode, so must disable

# it using these Chromium switches (Issues #240 and #463)

"disable-gpu": "",

"disable-gpu-compositing": "",

# Tweaking OSR performance by setting the same Chromium flags

# as in upstream cefclient (Issue #240).

"enable-begin-frame-scheduling": "",

"disable-surfaces": "", # This is required for PDF ext to work

}

browser_settings = {

# Tweaking OSR performance (Issue #240)

"windowless_frame_rate": 30, # Default frame rate in CEF is 30

}

cef.Initialize(settings=settings, switches=switches)

create_browser(browser_settings)

cef.MessageLoop()

cef.Shutdown()

print("[screenshot.py] Opening screenshot with default application")

print("[screenshot.py] CEF Python {ver}".format(ver=cef.__version__))

print("[screenshot.py] Python {ver} {arch}".format(

ver=platform.python_version(), arch=platform.architecture()[0]))

print("[screenshot.py] Pillow {ver}".format(ver=PILLOW_VERSION))

if len(sys.argv) == 4:

url = sys.argv[1]

width = int(sys.argv[2])

height = int(sys.argv[3])

if url.startswith("http://") or url.startswith("https://"):

global URL

URL = url

else:

print("[screenshot.py] Error: Invalid url argument")

sys.exit(1)

if width > 0 and height > 0:

global VIEWPORT_SIZE

VIEWPORT_SIZE = (width, height)

else:

print("[screenshot.py] Error: Invalid width and height")

sys.exit(1)

elif len(sys.argv) > 1:

print("[screenshot.py] Error: Expected arguments: url width height")

# Create browser in off-screen-rendering mode (windowless mode)

# by calling SetAsOffscreen method. In such mode parent window

# handle can be NULL (0).

parent_window_handle = 0

window_info = cef.WindowInfo()

window_info.SetAsOffscreen(parent_window_handle)

print("[screenshot.py] Viewport size: {size}"

.format(size=str(VIEWPORT_SIZE)))

print("[screenshot.py] Loading url: {url}"

.format(url=URL))

browser = cef.CreateBrowserSync(window_info=window_info,

settings=settings,

url=URL)

browser.SetClientHandler(LoadHandler())

browser.SetClientHandler(RenderHandler())

browser.SendFocusEvent(True)

# You must call WasResized at least once to let know CEF that

# viewport size is available and that OnPaint may be called.

# Browser object provides GetUserData/SetUserData methods

# for storing custom data associated with browser. The

# "OnPaint.buffer_string" data is set in RenderHandler.OnPaint.

buffer_string = browser.GetUserData("OnPaint.buffer_string")

if not buffer_string:

raise Exception("buffer_string is empty, OnPaint never called?")

image = Image.frombytes("RGBA", VIEWPORT_SIZE, buffer_string,

"raw", "RGBA", 0, 1)

image.save(SCREENSHOT_PATH, "PNG")

if sys.platform.startswith("darwin"):

subprocess.call(("open", path))

elif os.name == "nt":

# noinspection PyUnresolvedReferences

os.startfile(path)

elif os.name == "posix":

# Important note:

# Do not close browser nor exit app from OnLoadingStateChange

# OnLoadError or OnPaint events. Closing browser during these

# events may result in unexpected behavior. Use cef.PostTask

# function to call exit_app from these events.

print("[screenshot.py] Close browser and exit app")

browser.CloseBrowser()

def OnLoadingStateChange(self, browser, is_loading, **_):

"""Called when the loading state has changed."""

if not is_loading:

# Loading is complete

sys.stdout.write(os.linesep)

print("[screenshot.py] Web page loading is complete")

save_screenshot(browser)

# See comments in exit_app() why PostTask must be used

cef.PostTask(cef.TID_UI, exit_app, browser)

def OnLoadError(self, browser, frame, error_code, failed_url, **_):

"""Called when the resource load for a navigation fails

if not frame.IsMain():

# We are interested only in loading main url.

# Ignore any errors during loading of other frames.

return

print("[screenshot.py] ERROR: Failed to load url: {url}"

.format(url=failed_url))

print("[screenshot.py] Error code: {code}"

.format(code=error_code))

# See comments in exit_app() why PostTask must be used

def __init__(self):

self.OnPaint_called = False

def GetViewRect(self, rect_out, **_):

"""Called to retrieve the view rectangle which is relative

# rect_out --> [x, y, width, height]

rect_out.extend([0, 0, VIEWPORT_SIZE[0], VIEWPORT_SIZE[1]])

return True

def OnPaint(self, browser, element_type, paint_buffer, **_):

"""Called when an element should be painted."""

if self.OnPaint_called:

sys.stdout.write(".")

sys.stdout.flush()

else:

sys.stdout.write("[screenshot.py] OnPaint")

self.OnPaint_called = True

if element_type == cef.PET_VIEW:

# Buffer string is a huge string, so for performance

# reasons it would be better not to copy this string.

# I think that Python makes a copy of that string when

# passing it to SetUserData.

buffer_string = paint_buffer.GetString(mode="rgba",

origin="top-left")

# Browser object provides GetUserData/SetUserData methods

# for storing custom data associated with browser.

browser.SetUserData("OnPaint.buffer_string", buffer_string)

else: