python3 中的 PyGTK、PyGObject 和 Pgi
PyGTK, PyGObject and Pgi in python3
在https://github.com/cztomczak/cefpython/blob/master/src/linux/binaries_64bit/kivy_.py中使用了pygtk和gtk。 （注意源码只在Linux测试，我用的是Windows）
当我尝试 pip install pygtk 时，出现错误
Collecting pygtk
Using cached pygtk-2.24.0.tar.bz2 (2.4 MB)
ERROR: Command errored out with exit status 1:
command: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\Users\jared\AppData\Local\Temp\pip-install-rle_vbsd\pygtk\setup.py'"'"'; __file__='"'"'C:\Users\jared\AppData\Local\Temp\pip-install-rle_vbsd\pygtk\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base 'C:\Users\jared\AppData\Local\Temp\pip-pip-egg-info-pex79haa'
cwd: C:\Users\jared\AppData\Local\Temp\pip-install-rle_vbsd\pygtk\
Complete output (1 lines):
ERROR: Could not import dsextras module: Make sure you have installed pygobject.
----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
于是，我又去了pip install pygobject，又报错了。
Collecting pygobject
Using cached PyGObject-3.38.0.tar.gz (712 kB)
Installing build dependencies ... error
ERROR: Command errored out with exit status 1:
command: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' 'c:\users\jared\appdata\local\programs\python\python37\lib\site-packages\pip' install --ignore-installed --no-user --prefix 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay' --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple -- setuptools wheel pycairo
cwd: None
Complete output (34 lines):
Collecting setuptools
Using cached setuptools-50.3.0-py3-none-any.whl (785 kB)
Collecting wheel
Using cached wheel-0.35.1-py2.py3-none-any.whl (33 kB)
Collecting pycairo
Using cached pycairo-1.19.1.tar.gz (205 kB)
Using legacy 'setup.py install' for pycairo, since package 'wheel' is not installed.
Installing collected packages: setuptools, wheel, pycairo
Running setup.py install for pycairo: started
Running setup.py install for pycairo: finished with status 'error'
ERROR: Command errored out with exit status 1:
command: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\setup.py'"'"'; __file__='"'"'C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\jared\AppData\Local\Temp\pip-record-kq9tlvv8\install-record.txt' --single-version-externally-managed --prefix 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay' --compile --install-headers 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay\Include\pycairo'
cwd: C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\
Complete output (18 lines):
running install
running build
running build_py
creating build
creating build\lib.win-amd64-3.7
creating build\lib.win-amd64-3.7\cairo
copying cairo\__init__.py -> build\lib.win-amd64-3.7\cairo
copying cairo\__init__.pyi -> build\lib.win-amd64-3.7\cairo
copying cairo\py.typed -> build\lib.win-amd64-3.7\cairo
running build_ext
building 'cairo._cairo' extension
creating build\temp.win-amd64-3.7
creating build\temp.win-amd64-3.7\Release
creating build\temp.win-amd64-3.7\Release\cairo
C:\Program Files (x86)\Microsoft Visual Studio19\BuildTools\VC\Tools\MSVC.27.29110\bin\HostX86\x64\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -DPYCAIRO_VERSION_MAJOR=1 -DPYCAIRO_VERSION_MINOR=19 -DPYCAIRO_VERSION_MICRO=1 -Ic:\users\jared\appdata\local\programs\python\python37\include -Ic:\users\jared\appdata\local\programs\python\python37\include "-IC:\Program Files (x86)\Microsoft Visual Studio19\BuildTools\VC\Tools\MSVC.27.29110\include" "-IC:\Program Files (x86)\Windows Kits\NETFXSDK.6.1\include\um" "-IC:\Program Files (x86)\Windows Kits\include.0.18362.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\include.0.18362.0\shared" "-IC:\Program Files (x86)\Windows Kits\include.0.18362.0\um" "-IC:\Program Files (x86)\Windows Kits\include.0.18362.0\winrt" "-IC:\Program Files (x86)\Windows Kits\include.0.18362.0\cppwinrt" /Tccairo/device.c /Fobuild\temp.win-amd64-3.7\Release\cairo/device.obj
device.c
C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\cairo\pycairo.h(37): fatal error C1083: Cannot open include file: 'cairo.h': No such file or directory
error: command 'C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\VC\Tools\MSVC\14.27.29110\bin\HostX86\x64\cl.exe' failed with exit status 2
----------------------------------------
ERROR: Command errored out with exit status 1: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\setup.py'"'"'; __file__='"'"'C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\jared\AppData\Local\Temp\pip-record-kq9tlvv8\install-record.txt' --single-version-externally-managed --prefix 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay' --compile --install-headers 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay\Include\pycairo' Check the logs for full command output.
----------------------------------------
ERROR: Command errored out with exit status 1: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' 'c:\users\jared\appdata\local\programs\python\python37\lib\site-packages\pip' install --ignore-installed --no-user --prefix 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay' --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple -- setuptools wheel pycairo Check the logs for full command output.
然后我参考了 Whosebug 上的一些帖子，他们告诉我 python3 中不再需要 gtk 并用 pgi 代替了它。 （不知道源码里的pygtk还是gtk应该换掉）于是试了一下pip install pgi，又报错
Collecting pgi
Using cached pgi-0.0.11.2.tar.gz (239 kB)
ERROR: Command errored out with exit status 1:
command: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\setup.py'"'"'; __file__='"'"'C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base 'C:\Users\jared\AppData\Local\Temp\pip-pip-egg-info-5e57ceft'
cwd: C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\
Complete output (21 lines):
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\setup.py", line 18, in <module>
import pgi
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\__init__.py", line 10, in <module>
from .importer import require_version, get_required_version
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\importer.py", line 15, in <module>
from .clib.gir import GIRepository
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\clib\gir\__init__.py", line 8, in <module>
from .giargument import GIArgument
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\clib\gir\giargument.py", line 9, in <module>
from ..glib import gboolean, gint8, guint8, gint16, guint16, gint32, guint32
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\clib\glib.py", line 16, in <module>
_glib = find_library("glib-2.0")
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\clib\_utils.py", line 99, in find_library
_internal[name] = cdll.LoadLibrary(_so_mapping[name])
File "c:\users\jared\appdata\local\programs\python\python37\lib\ctypes\__init__.py", line 442, in LoadLibrary
return self._dlltype(name)
File "c:\users\jared\appdata\local\programs\python\python37\lib\ctypes\__init__.py", line 364, in __init__
self._handle = _dlopen(self._name, mode)
OSError: [WinError 126] The specified module could not be found
----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
我不知道发生了什么。我希望有人能把我从这个无限的错误循环中拉出来。非常感谢。
首先我想说的是我使用的是 Xubuntu 20.04，所以 Linux.
为了使 kivy 示例正常工作，您需要将 pygtk 模块替换为 PyGobject 模块。所以安装它，这里是说明：
https://pygobject.readthedocs.io/en/latest/getting_started.html#windows-logo-windows
现在在这个文件中
https://github.com/cztomczak/cefpython/blob/master/src/linux/binaries_64bit/kivy_.py 您需要更改导入和其他一些内容。这是我的进口商品的样子
...
from cefpython3 import cefpython as cef
import gi # notice this line is added
# import pygtk # this one is commented out or you can delete it
from gi.repository import Gtk as gtk # this one is added
# import gtk # this one is commented out or you can delete it
import sys
...
from kivy.graphics.texture import Texture
from kivy.uix.boxlayout import BoxLayout
from kivy.base import EventLoop
# Global variables
g_switches = None
# PyGTK required
# pygtk.require('2.0') # this one is commented out or you can delete it
class BrowserLayout(BoxLayout):
...
我还需要修复传递给在第 208 行某处调用的 windowInfo.SetAsOffscreen 方法的参数（在我的例子中），查找 start_cef 方法定义。我根据这个 https://github.com/cztomczak/cefpython/blob/master/api/WindowInfo.md#setasoffscreen 将参数设置为 0，因为它提到：
You can pass 0 as parentWindowHandle, but then some things like context menus and plugins may not display correctly.
因此代码如下所示：
...
#popup widgets to work.
gtkwin = gtk.Window()
gtkwin.realize()
# WindowInfo offscreen flag
windowInfo = cef.WindowInfo()
windowInfo.SetAsOffscreen(0)
# Create Broswer and naviagte to empty page <= OnPaint won't get
# called yet
...
在https://github.com/cztomczak/cefpython/blob/master/src/linux/binaries_64bit/kivy_.py中使用了pygtk和gtk。 （注意源码只在Linux测试，我用的是Windows）
当我尝试 pip install pygtk 时，出现错误
Collecting pygtk
Using cached pygtk-2.24.0.tar.bz2 (2.4 MB)
ERROR: Command errored out with exit status 1:
command: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\Users\jared\AppData\Local\Temp\pip-install-rle_vbsd\pygtk\setup.py'"'"'; __file__='"'"'C:\Users\jared\AppData\Local\Temp\pip-install-rle_vbsd\pygtk\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base 'C:\Users\jared\AppData\Local\Temp\pip-pip-egg-info-pex79haa'
cwd: C:\Users\jared\AppData\Local\Temp\pip-install-rle_vbsd\pygtk\
Complete output (1 lines):
ERROR: Could not import dsextras module: Make sure you have installed pygobject.
----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
于是，我又去了pip install pygobject，又报错了。
Collecting pygobject
Using cached PyGObject-3.38.0.tar.gz (712 kB)
Installing build dependencies ... error
ERROR: Command errored out with exit status 1:
command: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' 'c:\users\jared\appdata\local\programs\python\python37\lib\site-packages\pip' install --ignore-installed --no-user --prefix 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay' --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple -- setuptools wheel pycairo
cwd: None
Complete output (34 lines):
Collecting setuptools
Using cached setuptools-50.3.0-py3-none-any.whl (785 kB)
Collecting wheel
Using cached wheel-0.35.1-py2.py3-none-any.whl (33 kB)
Collecting pycairo
Using cached pycairo-1.19.1.tar.gz (205 kB)
Using legacy 'setup.py install' for pycairo, since package 'wheel' is not installed.
Installing collected packages: setuptools, wheel, pycairo
Running setup.py install for pycairo: started
Running setup.py install for pycairo: finished with status 'error'
ERROR: Command errored out with exit status 1:
command: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\setup.py'"'"'; __file__='"'"'C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\jared\AppData\Local\Temp\pip-record-kq9tlvv8\install-record.txt' --single-version-externally-managed --prefix 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay' --compile --install-headers 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay\Include\pycairo'
cwd: C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\
Complete output (18 lines):
running install
running build
running build_py
creating build
creating build\lib.win-amd64-3.7
creating build\lib.win-amd64-3.7\cairo
copying cairo\__init__.py -> build\lib.win-amd64-3.7\cairo
copying cairo\__init__.pyi -> build\lib.win-amd64-3.7\cairo
copying cairo\py.typed -> build\lib.win-amd64-3.7\cairo
running build_ext
building 'cairo._cairo' extension
creating build\temp.win-amd64-3.7
creating build\temp.win-amd64-3.7\Release
creating build\temp.win-amd64-3.7\Release\cairo
C:\Program Files (x86)\Microsoft Visual Studio19\BuildTools\VC\Tools\MSVC.27.29110\bin\HostX86\x64\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -DPYCAIRO_VERSION_MAJOR=1 -DPYCAIRO_VERSION_MINOR=19 -DPYCAIRO_VERSION_MICRO=1 -Ic:\users\jared\appdata\local\programs\python\python37\include -Ic:\users\jared\appdata\local\programs\python\python37\include "-IC:\Program Files (x86)\Microsoft Visual Studio19\BuildTools\VC\Tools\MSVC.27.29110\include" "-IC:\Program Files (x86)\Windows Kits\NETFXSDK.6.1\include\um" "-IC:\Program Files (x86)\Windows Kits\include.0.18362.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\include.0.18362.0\shared" "-IC:\Program Files (x86)\Windows Kits\include.0.18362.0\um" "-IC:\Program Files (x86)\Windows Kits\include.0.18362.0\winrt" "-IC:\Program Files (x86)\Windows Kits\include.0.18362.0\cppwinrt" /Tccairo/device.c /Fobuild\temp.win-amd64-3.7\Release\cairo/device.obj
device.c
C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\cairo\pycairo.h(37): fatal error C1083: Cannot open include file: 'cairo.h': No such file or directory
error: command 'C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\VC\Tools\MSVC\14.27.29110\bin\HostX86\x64\cl.exe' failed with exit status 2
----------------------------------------
ERROR: Command errored out with exit status 1: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\setup.py'"'"'; __file__='"'"'C:\Users\jared\AppData\Local\Temp\pip-install-faiuku8y\pycairo\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\jared\AppData\Local\Temp\pip-record-kq9tlvv8\install-record.txt' --single-version-externally-managed --prefix 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay' --compile --install-headers 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay\Include\pycairo' Check the logs for full command output.
----------------------------------------
ERROR: Command errored out with exit status 1: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' 'c:\users\jared\appdata\local\programs\python\python37\lib\site-packages\pip' install --ignore-installed --no-user --prefix 'C:\Users\jared\AppData\Local\Temp\pip-build-env-t_0q3g_h\overlay' --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple -- setuptools wheel pycairo Check the logs for full command output.
然后我参考了 Whosebug 上的一些帖子，他们告诉我 python3 中不再需要 gtk 并用 pgi 代替了它。 （不知道源码里的pygtk还是gtk应该换掉）于是试了一下pip install pgi，又报错
Collecting pgi
Using cached pgi-0.0.11.2.tar.gz (239 kB)
ERROR: Command errored out with exit status 1:
command: 'c:\users\jared\appdata\local\programs\python\python37\python.exe' -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\setup.py'"'"'; __file__='"'"'C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base 'C:\Users\jared\AppData\Local\Temp\pip-pip-egg-info-5e57ceft'
cwd: C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\
Complete output (21 lines):
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\setup.py", line 18, in <module>
import pgi
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\__init__.py", line 10, in <module>
from .importer import require_version, get_required_version
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\importer.py", line 15, in <module>
from .clib.gir import GIRepository
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\clib\gir\__init__.py", line 8, in <module>
from .giargument import GIArgument
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\clib\gir\giargument.py", line 9, in <module>
from ..glib import gboolean, gint8, guint8, gint16, guint16, gint32, guint32
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\clib\glib.py", line 16, in <module>
_glib = find_library("glib-2.0")
File "C:\Users\jared\AppData\Local\Temp\pip-install-2znm3fjc\pgi\pgi\clib\_utils.py", line 99, in find_library
_internal[name] = cdll.LoadLibrary(_so_mapping[name])
File "c:\users\jared\appdata\local\programs\python\python37\lib\ctypes\__init__.py", line 442, in LoadLibrary
return self._dlltype(name)
File "c:\users\jared\appdata\local\programs\python\python37\lib\ctypes\__init__.py", line 364, in __init__
self._handle = _dlopen(self._name, mode)
OSError: [WinError 126] The specified module could not be found
----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
我不知道发生了什么。我希望有人能把我从这个无限的错误循环中拉出来。非常感谢。
首先我想说的是我使用的是 Xubuntu 20.04，所以 Linux.
为了使 kivy 示例正常工作，您需要将 pygtk 模块替换为 PyGobject 模块。所以安装它，这里是说明：
https://pygobject.readthedocs.io/en/latest/getting_started.html#windows-logo-windows
现在在这个文件中 https://github.com/cztomczak/cefpython/blob/master/src/linux/binaries_64bit/kivy_.py 您需要更改导入和其他一些内容。这是我的进口商品的样子
...
from cefpython3 import cefpython as cef
import gi # notice this line is added
# import pygtk # this one is commented out or you can delete it
from gi.repository import Gtk as gtk # this one is added
# import gtk # this one is commented out or you can delete it
import sys
...
from kivy.graphics.texture import Texture
from kivy.uix.boxlayout import BoxLayout
from kivy.base import EventLoop
# Global variables
g_switches = None
# PyGTK required
# pygtk.require('2.0') # this one is commented out or you can delete it
class BrowserLayout(BoxLayout):
...
我还需要修复传递给在第 208 行某处调用的 windowInfo.SetAsOffscreen 方法的参数（在我的例子中），查找 start_cef 方法定义。我根据这个 https://github.com/cztomczak/cefpython/blob/master/api/WindowInfo.md#setasoffscreen 将参数设置为 0，因为它提到：
You can pass 0 as parentWindowHandle, but then some things like context menus and plugins may not display correctly.
因此代码如下所示：
...
#popup widgets to work.
gtkwin = gtk.Window()
gtkwin.realize()
# WindowInfo offscreen flag
windowInfo = cef.WindowInfo()
windowInfo.SetAsOffscreen(0)
# Create Broswer and naviagte to empty page <= OnPaint won't get
# called yet
...