[PySide] Internal C++ object (PySide.QtWebKit.QWebFrame) already deleted; but I'm saving it as an attribute to avoid this exact issue
Jorge Araya Navarro
elcorreo at deshackra.com
Thu Nov 6 06:04:41 CET 2014
I need some help figuring out how to solve this error. As I described it on SO[1]:
I'm working on a project where I use a modified `QWebView`. I'm getting this error:
Traceback (most recent call last):
File "/home/jorge/coders/universal-scraper/src/customwebview.py", line 63, in mouseMoveEvent
hittestresult = self.currentframe.hitTestContent(event.pos())
RuntimeError: Internal C++ object (PySide.QtWebKit.QWebFrame) already deleted.
I have read about [PySide pitfalls](http://qt-project.org/wiki/PySide_Pitfalls) already, and I've been
saving that `QtWebKit.QWebFrame` as an attribute of my modified `QWebView` **from the beggining of the
project** with the method `setframeafterloadfinished` which is called when the page finishes loading,
the problem raised after some majors changes on my modified `QWebView`.
Here is the source code showing what I changed:
diff -r 916f0091fee8 src/customwebview.py
--- a/src/customwebview.py Thu Oct 30 19:54:57 2014 -0600
+++ b/src/customwebview.py Mon Nov 03 20:22:51 2014 -0600
@@ -4,6 +4,7 @@
from PySide.QtWebKit import QWebView
from PySide import QtCore, QtGui
+from . import webelementinfo
class CustomQWebView(QWebView):
@@ -12,19 +13,16 @@
""" Init the custom class
"""
super(CustomQWebView, self).__init__(*args, **kwargs)
- self.colors = {0: QtGui.QColor(255, 165, 0),
- 1: QtGui.QColor(135, 206, 235),
- 2: QtGui.QColor(135, 235, 164),
- 3: QtGui.QColor(235, 135, 206),
- 4: QtGui.QColor(235, 164, 135)}
- self.colorfill = None
+ self.colors = {0: QtGui.QColor(255, 165, 0, 127),
+ 1: QtGui.QColor(135, 206, 235, 127),
+ 2: QtGui.QColor(135, 235, 164, 127),
+ 3: QtGui.QColor(235, 135, 206, 127),
+ 4: QtGui.QColor(235, 164, 135, 127)}
+ self.color = None
self.currentframe = None
- self.lastelement = None
- self.lastelementboundingrect = None
+ self.element = None
self.loadFinished.connect(self.setframeafterloadfinished)
- self.pen = QtGui.QPen()
- self.pen.setWidth(2)
- self.drawrects = False
+ self.selectCommentsArea()
@QtCore.Slot()
def selectCommentsArea(self):
@@ -63,11 +61,15 @@
if self.drawrects:
if self.currentframe:
hittestresult = self.currentframe.hitTestContent(event.pos())
- element = hittestresult.element()
- if self.lastelement != element:
- self.lastelement = element
- self.lastelementboundingrect = hittestresult.boundingRect()
- self.update()
+ element = webelementinfo.WebElement(
+ hittestresult, self.color, self)
+ if not self.element:
+ self.element = element
+ elif self.element != element:
+ self.element = element
+
+ # FIXME: self.update should draw rects from WebElements too.
+ self.update()
@QtCore.Slot(QtGui.QPaintEvent)
def paintEvent(self, event):
@@ -76,22 +78,8 @@
if self.drawrects:
# then the rectangle
- if self.lastelementboundingrect:
- painter = QtGui.QPainter(self)
- painter.setPen(self.defaultpen)
- # This rectangles takes into account any offset of the scroll
- # bar so the rectangle can be drawn correctly
- rect = QtCore.QRect()
- rect.setRect(self.lastelementboundingrect.x() -
- self.currentframe.scrollPosition().x(),
- self.lastelementboundingrect.y() -
- self.currentframe.scrollPosition().y(),
- self.lastelementboundingrect.width(),
- self.lastelementboundingrect.height())
- # painter.drawRect(QtCore.QRectF(self.lastelementcurrectrect))
- painter.drawRect(QtCore.QRectF(rect))
- painter.fillRect(
- QtCore.QRectF(rect), self.colorfill)
+ if self.element:
+ self.element.update()
def setframeafterloadfinished(self):
self.currentframe = self.page().mainFrame()
@@ -109,15 +97,7 @@
commentary text.
"""
self.drawrects = True
- self.colorfill = self.colors[forarea]
- self.colorfill.setAlpha(128)
-
- colorborder = self.colors[forarea]
- self.pen.setColor(colorborder)
+ self.color = self.colors[forarea]
# defines what we are looking to select
self.selecttype = forarea
and here it is again but complete, **and functional** (just be sure to put the file
`webelementinfo.py` in the same directory as this code before running a test):
#!/usr/bin/env python2
# coding: utf-8
# VENI, SANCTE SPIRITUS
from PySide.QtWebKit import QWebView
from PySide import QtCore, QtGui
try:
from . import webelementinfo
except ValueError:
import webelementinfo
class CustomQWebView(QWebView):
def __init__(self, *args, **kwargs):
""" Init the custom class
"""
super(CustomQWebView, self).__init__(*args, **kwargs)
self.colors = {0: QtGui.QColor(255, 165, 0, 127),
1: QtGui.QColor(135, 206, 235, 127),
2: QtGui.QColor(135, 235, 164, 127),
3: QtGui.QColor(235, 135, 206, 127),
4: QtGui.QColor(235, 164, 135, 127)}
self.color = None
self.currentframe = None
self.element = None
self.loadFinished.connect(self.setframeafterloadfinished)
self.selectCommentsArea()
@QtCore.Slot()
def selectCommentsArea(self):
""" For selecting the comment area
"""
self.setup_rectcolor_area(0)
@QtCore.Slot(QtGui.QMouseEvent)
def mouseMoveEvent(self, event):
super(CustomQWebView, self).mouseMoveEvent(event)
if self.drawrects:
if self.currentframe:
hittestresult = self.currentframe.hitTestContent(event.pos())
element = webelementinfo.WebElement(
hittestresult, self.color, self)
if not self.element:
self.element = element
elif self.element != element:
self.element = element
# FIXME: self.update should draw rects from WebElements too.
self.update()
@QtCore.Slot(QtGui.QPaintEvent)
def paintEvent(self, event):
# draw the content first
super(CustomQWebView, self).paintEvent(event)
if self.drawrects:
# then the rectangle
if self.element:
self.element.update()
def setframeafterloadfinished(self):
self.currentframe = self.page().mainFrame()
def setup_rectcolor_area(self, forarea):
"""Called when we want to select certain area of a web site
This method set-up the painter to a giving color so web elements are
drawn with a rect on top. Also activates the flag to allow painting
inside CustomQWebView.
:param int forarea: For which area we are going to set the painter\\
valid values are: 0 for Comments area, 1 for comment box, 2 for\\
commentator's user name, 3 for comment date and time, 4 for\\
commentary text.
"""
self.drawrects = True
self.color = self.colors[forarea]
# defines what we are looking to select
self.selecttype = forarea
if __name__ == "__main__":
app = QtGui.QApplication([])
mainwn = QtGui.QMainWindow()
mainwn.resize(800, 696)
centralwidget = QtGui.QWidget(mainwn)
centralwidget.resize(800, 600)
gridlayout = QtGui.QGridLayout(centralwidget)
web = CustomQWebView(parent=centralwidget)
gridlayout.addWidget(web, 0, 0, 1)
web.setUrl(QtCore.QUrl("http://duckduckgo.com"))
mainwn.show()
app.exec_()
Here is the other file that have the definition of that new class `WebElement` that I write and start
to use:
#!/usr/bin/env python2
# coding: utf-8
# VENI, SANCTE SPIRITUS
from PySide.QtWebKit import QWebElement, QWebHitTestResult
from PySide import QtGui
from PySide import QtCore
class WebElement(QtCore.QObject):
""" Holds information of webelements
"""
def __eq__(self, other):
if isinstance(other, WebElement):
return (self.web_element == other.web_element and
self.getrect() == other.getrect())
else:
raise ValueError("Not same objects")
def __ne__(self, other):
if isinstance(other, WebElement):
return (self.web_element != other.web_element and
self.getrect() != other.getrect())
else:
raise ValueError("Not same objects")
def __init__(self, hittestresult, color, parent=None):
super(WebElement, self).__init__(parent)
if (not isinstance(hittestresult, QWebHitTestResult) and
not isinstance(hittestresult, QWebElement)):
raise ValueError(
"Argument passed for 'hittestresult' is not"
" QtWebkit.QWenHitTestResult or QtWebkit.QWebElement instance"
)
if not isinstance(color, QtGui.QColor):
raise ValueError(
"Argument passed for 'color' is not QtGui.QColor instance"
)
try:
self.frame = hittestresult.frame()
except AttributeError:
self.frame = hittestresult.webFrame()
self.frame_scroll_x = self.frame.scrollPosition().x()
self.frame_scroll_y = self.frame.scrollPosition().y()
try:
rect = hittestresult.boundingRect()
except AttributeError:
rect = hittestresult.geometry()
self.element_rect_x = rect.x()
self.element_rect_y = rect.y()
self.element_rect_w = rect.width()
self.element_rect_h = rect.height()
try:
self.web_element = hittestresult.element()
except AttributeError:
self.web_element = hittestresult
self.color = color
self.color_darker = color.darker()
self.color_darker.setAlpha(255)
self.pen = QtGui.QPen(self.color_darker)
self.pen.setWidth(2)
#self.painter = QtGui.QPainter(self.parent)
self.painter = QtGui.QPainter()
self.painter.setPen(self.pen)
def update(self):
""" draw the rect for this element in the CustomQWebView
"""
rect = self.getrect()
rectf = QtCore.QRectF(rect)
self.painter.fillRect(rectf, self.color)
self.painter.drawRect(rectf)
def getrect(self):
""" Return the rect for this WebElement
"""
self.frame_scroll_x = self.frame.scrollPosition().x()
self.frame_scroll_y = self.frame.scrollPosition().y()
rect = QtCore.QRect()
rect.setRect(self.element_rect_x - self.frame_scroll_x,
self.element_rect_y - self.frame_scroll_y,
self.element_rect_w, self.element_rect_h)
return rect
My project should work right as if I didn't change anything, however, with these changes it
doesn't. What am I doing wrong? Am I missing something about `QWebFrame`s?
[1]: http://stackoverflow.com/q/26726878/2020214
--
Pax et bonum.
Jorge Araya Navarro.
ES: Diseñador Publicitario, Programador Python y colaborador en Parabola GNU/Linux-libre
EN: Ads Designer, Python programmer and contributor Parabola GNU/Linux-libre
EO: Anonco grafikisto, Pitino programalingvo programisto kai kontribuanto en Parabola GNU/Linux-libre
https://es.gravatar.com/shackra
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