Fix 'DoGetTextExtent - invalid DC' error

most likely this error happens only on certain wx backends.
GTK3+ on GNU/Linux is apparently one of them.
The problem is described in wxWidgets issue tracker.
http://trac.wxwidgets.org/ticket/12486

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platform:
Linux-4.16.0-2-rt-amd64-x86_64-with-debian-buster-sid

python-version:
2.7.15

traceback:
File "/home/developer/WorkData/PLC/beremiz/beremiz/ProjectController.py", line 1605, in DispatchDebugValuesProc
self.CallWeakcallables("__tick__", "NewDataAvailable", debug_ticks)
File "/home/developer/WorkData/PLC/beremiz/beremiz/ProjectController.py", line 1585, in CallWeakcallables
function(*cargs)
File "/home/developer/WorkData/PLC/beremiz/beremiz/editors/Viewer.py", line 1217, in NewDataAvailable
refresh_rect.Union(element.GetRedrawRect())
File "/home/developer/WorkData/PLC/beremiz/beremiz/graphics/GraphicCommons.py", line 1609, in GetRedrawRect
self.ValueSize = self.Parent.GetMiniTextExtent(self.ComputedValue)
File "/home/developer/WorkData/PLC/beremiz/beremiz/editors/Viewer.py", line 932, in GetMiniTextExtent
return self.MiniTextDC.GetTextExtent(text)
File "/usr/lib/python2.7/dist-packages/wx-3.0-gtk3/wx/_gdi.py", line 4127, in GetTextExtent
return _gdi_.DC_GetTextExtent(*args, **kwargs)
<class 'wx._core.PyAssertionError'>: C++ assertion "m_graphicContext" failed at ../src/common/dcgraph.cpp(1160) in DoGetTextExtent(): wxGCDC(cg)::DoGetTextExtent - invalid DC

wx-platform:
__WXGTK__

wx-version:
3.0.2.0

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traceback:
File "/home/developer/WorkData/PLC/beremiz/beremiz/controls/LogViewer.py", line 740, in OnMessageToolTipTimer
self.MessageToolTip.SetFont(self.Font)
File "/home/developer/WorkData/PLC/beremiz/beremiz/controls/CustomToolTip.py", line 75, in SetFont
self.RefreshTip()
File "/home/developer/WorkData/PLC/beremiz/beremiz/controls/CustomToolTip.py", line 158, in RefreshTip
self.SetClientSize(self.GetToolTipSize())
File "/home/developer/WorkData/PLC/beremiz/beremiz/controls/CustomToolTip.py", line 145, in GetToolTipSize
w, h = dc.GetTextExtent(line)
File "/usr/lib/python2.7/dist-packages/wx-3.0-gtk3/wx/_gdi.py", line 4127, in GetTextExtent
return _gdi_.DC_GetTextExtent(*args, **kwargs)
<class 'wx._core.PyAssertionError'>: C++ assertion "m_graphicContext" failed at ../src/common/dcgraph.cpp(1160) in DoGetTextExtent(): wxGCDC(cg)::DoGetTextExtent - invalid DC

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Fix size of ProjectDialog used by PLCOpenEditor

Disable scrolling for ProjectDialog, because otherwise very very small
windows is created.
This regression was introduced by 5701225 ("replaced normal panel with scrolled panel under project
properties").

Fix some compilation warnings for better ANSI C compliance

Customizable columns in VariableTables (i.e. can be monkey patched properly)

Merged

Customizable update of toolbar buttons (i.e. 'methods') according to PLCStatus

Fixed small typo in error message.

WAMP : complains about failure to start WAMP only if it was successfully imported.

WAMP: now config and secret given in project files always override those given in commandline. Also made extensions web customisations happen before registration of web interface.

Moved Wamp configuration file selection logic into runtime/wampclient.py. Added Wamp CRA secret file upload and download. Slightly reworked code for config and secret file loading and saving.

Added a way for extension to register dedicated URL under settings page URL (i.e. /settings/something)

Fixed a bit of everything in WAMP, and added web settings for that same extension.

Added some immutable field (platform) in default runtime web setting page, for the example.

Fix misc typos in exception handling code.

Fixed i18n related typo.

Fixed typo

Better logging of Nevow Server import in case of exception.

WampClient : Simplified, removed dead code, use exception for handling failures and misconfiguration, check existence of mandatory parameters.

Merged #2486, enhancements to WAMP client : auto reconnecting, wamp conf checking and saving, additional attributes for exposed calls, etc

Nevow based web interface now show simple Log message sending form for basic runtime, and allow extensions to add their own web settings.

Now, runtime extensions should be able to add their own settings to web configuration interface.

Embrio of setting form, just to test

#2486 Exception if custom protocol options are wrong.

#2486 ExposedCalls with register options as a dictionary.

#2486 Renaming functions.

#2486 Reconnect funtion in SaveWampClientConf function.

#2486 Modified reconnect function. Added 'active' parameter to wampconf.json file.

#2486 Adding reconnect funtion to WampClient. Global TransportFactory not needed anymore.

#2486 Added global TransportFactory, needed in WebInterface reconnecting function.

#2486 WampClient needs pyro.plcobj before registration calls.

#2486 Fix if protocol, register options are not present in wapmconf.json file.

#2486 Added ExposedProgressCalls list using details argument for registration progress calls.

#2486 Unnecessary variable removed.

#2486 Added option to use websocket register options. Added function getValidOptins to read options from wampconf.json.

#2486 Added option to use websocket protocol options.

#2486 Updated wamp test project to work with the latest Crossbar version.

#2486 Reset delay function added. It resets the delay and the retry counter on reconnect.

merge

merge

Fix compilation warning/error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]

merge

WxGlade HMI extension now does only instanciate wx object who's name match extension's name. If no object match the name and no code is provided in 'start' user python code section, then a warning is issued

BACnet : ensure that Init did happen before continuing with PLC startup.

Update list of files with strings for i18n and templates for translations

Add small contributing document with information about codestyle checking

Add argument to set list of source files to check

This is necessary, in case you want to use docker run in pretxncommit
Mercurial hook. Unfortunately for some reason if hg running in
container can't find just created commit defined by $HG_NODE. And it
throws error 'unknown revision'.

Here is example for hgrc.

[hooks]
pretxncommit.linter = hg status -m -n -a -n -I '**.py' --change $HG_NODE > files.lst && docker run --volume=$PWD:/beremiz --workdir="/beremiz" --volume=$PWD/../CanFestival-3:/CanFestival-3 --memory=1g --entrypoint=/beremiz/tests/tools/check_source.sh skvorl/beremiz-requirements --files-to-check files.lst

check_source.sh: handle case if there are no files to check

Fix linter errors