class _WebkitRendererHelper(QObject):
"""This helper class is doing the real work. It is required to
allow WebkitRenderer.render() to be called "asynchronously"
(but always from Qt's GUI thread).
"""
def __init__(self, parent):
"""Copies the properties from the parent (WebkitRenderer) object,
creates the required instances of QWebPage, QWebView and QMainWindow
and registers some Slots.
"""
QObject.__init__(self)
# Copy properties from parent
for key, value in parent.__dict__.items():
setattr(self, key, value)
# Create and connect required PyQt4 objects
self._page = QWebPage()
self._view = QWebView()
self._view.setPage(self._page)
self._window = QMainWindow()
self._window.setCentralWidget(self._view)
# Import QWebSettings
for key, value in self.qWebSettings.iteritems():
self._page.settings().setAttribute(key, value)
# Connect required event listeners
self.connect(
self._page, SIGNAL("loadFinished(bool)"),
self._on_load_finished
)
self.connect(
self._page, SIGNAL("loadStarted()"),
self._on_load_started
)
self.connect(
self._page.networkAccessManager(),
SIGNAL("sslErrors(QNetworkReply *,const QList<QSslError>&)"),
self._on_ssl_errors
)
self.connect(
self._page.networkAccessManager(),
SIGNAL("finished(QNetworkReply *)"), self._on_each_reply
)
# The way we will use this, it seems to be unesseccary to have
# Scrollbars enabled.
self._page.mainFrame().setScrollBarPolicy(
Qt.Horizontal, Qt.ScrollBarAlwaysOff
)
self._page.mainFrame().setScrollBarPolicy(
Qt.Vertical, Qt.ScrollBarAlwaysOff
)
self._page.settings().setUserStyleSheetUrl(
QUrl("data:text/css,html,body{overflow-y:hidden !important;}")
)
# Show this widget
self._window.show()
def __del__(self):
"""Clean up Qt4 objects. """
self._window.close()
del self._window
del self._view
del self._page
def render(self, url):
"""The real worker. Loads the page (_load_page) and awaits
the end of the given 'delay'. While it is waiting outstanding
QApplication events are processed.
After the given delay, the Window or Widget (depends
on the value of 'grabWholeWindow' is drawn into a QPixmap
and postprocessed (_post_process_image).
"""
self._load_page(url, self.width, self.height, self.timeout)
# Wait for end of timer. In this time, process
# other outstanding Qt events.
if self.wait > 0:
if self.logger:
self.logger.debug("Waiting %d seconds " % self.wait)
waitToTime = time.time() + self.wait
while time.time() < waitToTime and QApplication.hasPendingEvents():
QApplication.processEvents()
if self.renderTransparentBackground:
# Another possible drawing solution
image = QImage(self._page.viewportSize(), QImage.Format_ARGB32)
image.fill(QColor(255, 0, 0, 0).rgba())
# http://ariya.blogspot.com/2009/04/transparent-qwebview-and-qwebpage.html
palette = self._view.palette()
palette.setBrush(QPalette.Base, Qt.transparent)
self._page.setPalette(palette)
self._view.setAttribute(Qt.WA_OpaquePaintEvent, False)
painter = QPainter(image)
painter.setBackgroundMode(Qt.TransparentMode)
self._page.mainFrame().render(painter)
painter.end()
else:
if self.grabWholeWindow:
# Note that this does not fully ensure that the
# window still has the focus when the screen is
# grabbed. This might result in a race condition.
self._view.activateWindow()
image = QPixmap.grabWindow(self._window.winId())
else:
image = QPixmap.grabWidget(self._window)
return self._post_process_image(image)
def _load_page(self, url, width, height, timeout):
"""
This method implements the logic for retrieving and displaying
the requested page.
"""
# This is an event-based application. So we have to wait until
# "loadFinished(bool)" raised.
cancelAt = time.time() + timeout
self.__loading = True
self.__loadingResult = False # Default
# TODO: fromEncoded() needs to be used in some situations. Some
# sort of flag should be passed in to WebkitRenderer maybe?
#self._page.mainFrame().load(QUrl.fromEncoded(url))
self._page.mainFrame().load(QUrl(url))
while self.__loading:
if timeout > 0 and time.time() >= cancelAt:
raise RuntimeError("Request timed out on %s" % url)
while QApplication.hasPendingEvents() and self.__loading:
QCoreApplication.processEvents()
if self.logger:
self.logger.debug("Processing result")
if not self.__loading_result:
if self.logger:
self.logger.warning("Failed to load %s" % url)
raise BadURLException("Failed to load %s" % url)
# Set initial viewport (the size of the "window")
size = self._page.mainFrame().contentsSize()
if self.logger:
self.logger.debug("contentsSize: %s", size)
if width > 0:
size.setWidth(width)
if height > 0:
size.setHeight(height)
self._window.resize(size)
def _post_process_image(self, qImage):
"""If 'scaleToWidth' or 'scaleToHeight' are set to a value
greater than zero this method will scale the image
using the method defined in 'scaleRatio'.
"""
if self.scaleToWidth > 0 or self.scaleToHeight > 0:
# Scale this image
if self.scaleRatio == 'keep':
ratio = Qt.KeepAspectRatio
elif self.scaleRatio in ['expand', 'crop']:
ratio = Qt.KeepAspectRatioByExpanding
else: # 'ignore'
ratio = Qt.IgnoreAspectRatio
qImage = qImage.scaled(
self.scaleToWidth, self.scaleToHeight, ratio
)
if self.scaleRatio == 'crop':
qImage = qImage.copy(
0, 0, self.scaleToWidth, self.scaleToHeight
)
return qImage
def _on_each_reply(self, reply):
"""Logs each requested uri"""
self.logger.debug("Received %s" % (reply.url().toString()))
# Eventhandler for "loadStarted()" signal
def _on_load_started(self):
"""Slot that sets the '__loading' property to true."""
if self.logger:
self.logger.debug("loading started")
self.__loading = True
# Eventhandler for "loadFinished(bool)" signal
def _on_load_finished(self, result):
"""Slot that sets the '__loading' property to false and stores
the result code in '__loading_result'.
"""
if self.logger:
self.logger.debug("loading finished with result %s", result)
self.__loading = False
self.__loading_result = result
# Eventhandler for "sslErrors(QNetworkReply *,const QList<QSslError>&)"
# signal.
def _on_ssl_errors(self, reply, errors):
"""Slot that writes SSL warnings into the log but ignores them."""
for e in errors:
if self.logger:
self.logger.warn("SSL: " + e.errorString())
reply.ignoreSslErrors()
class WebkitRenderer(QObject):
# Initializes the QWebPage object and registers some slots
def __init__(self):
QObject.__init__(self)
logging.debug("Initializing class %s", self.__class__.__name__)
self._page = QWebPage()
self.connect(self._page, SIGNAL("loadFinished(bool)"), self.__on_load_finished)
self.connect(self._page, SIGNAL("loadStarted()"), self.__on_load_started)
self.connect(self._page.networkAccessManager(), SIGNAL("sslErrors(QNetworkReply *,const QList<QSslError>&)"), self.__on_ssl_errors)
# The way we will use this, it seems to be unesseccary to have Scrollbars enabled
self._page.mainFrame().setScrollBarPolicy(Qt.Horizontal, Qt.ScrollBarAlwaysOff)
self._page.mainFrame().setScrollBarPolicy(Qt.Vertical, Qt.ScrollBarAlwaysOff)
# Helper for multithreaded communication through signals
self.__loading = False
self.__loading_result = False
# Loads "url" and renders it.
# Returns QImage-object on success.
def render(self, url, width=0, height=0, timeout=0):
logging.debug("render(%s, timeout=%d)", url, timeout)
# This is an event-based application. So we have to wait until
# "loadFinished(bool)" raised.
cancelAt = time.time() + timeout
self._page.mainFrame().load(QUrl(url))
while self.__loading:
if timeout > 0 and time.time() >= cancelAt:
raise RuntimeError("Request timed out")
QCoreApplication.processEvents()
logging.debug("Processing result")
if self.__loading_result == False:
raise RuntimeError("Failed to load %s" % url)
# Set initial viewport (the size of the "window")
size = self._page.mainFrame().contentsSize()
logging.debug("contentsSize: %s", size)
if width > 0:
size.setWidth(width)
if height > 0:
size.setHeight(height)
self._page.setViewportSize(size)
# Paint this frame into an image
image = QImage(self._page.viewportSize(), QImage.Format_ARGB32)
painter = QPainter(image)
self._page.mainFrame().render(painter)
painter.end()
return image
# Eventhandler for "loadStarted()" signal
def __on_load_started(self):
logging.debug("loading started")
self.__loading = True
# Eventhandler for "loadFinished(bool)" signal
def __on_load_finished(self, result):
logging.debug("loading finished with result %s", result)
self.__loading = False
self.__loading_result = result
# Eventhandler for "sslErrors(QNetworkReply *,const QList<QSslError>&)" signal
def __on_ssl_errors(self, reply, errors):
logging.warn("ssl error")
#self.__loading = False
#self.__loading_result = result
reply.ignoreSslErrors()
