Qt5 Support

[corranwebster]

Now we have a released Pyface with Qt5 support, it makes sense to see what is needed to support Qt5.

This PR:

• Integrates PyQt5 into the CI testing system.
• Fixes mouse wheel support.
• Fixes dangling NativeScrollbar references on qt4.

[codecov-io]

Codecov Report

Merging #302 into master will increase coverage by 0.05%.
The diff coverage is 86.95%.

@@            Coverage Diff             @@
##           master     #302      +/-   ##
==========================================
+ Coverage    33.6%   33.65%   +0.05%     
==========================================
  Files         206      206              
  Lines       18278    18298      +20     
  Branches     2407     2411       +4     
==========================================
+ Hits         6142     6159      +17     
- Misses      11744    11747       +3     
  Partials      392      392

Impacted Files	Coverage Δ
enable/wx/base_window.py	0% <0%> (ø)	⬆️
enable/qt4/base_window.py	53.39% <100%> (+1.94%)	⬆️
enable/events.py	75.53% <100%> (+0.26%)	⬆️
enable/qt4/scrollbar.py	77.22% <100%> (+0.38%)	⬆️

---

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[jwiggins]

In general LGTM

[jwiggins]

I feel like this code should be in a pyface testing support module... But I don't see any such module in pyface.

[corranwebster]

Pyface doesn't really do any testing at the level of individual mouse events (things are usually driven at the level of signals and slots), so we haven't had a need to put anything like this into Pyface.

For now it's probably good enough to have it as part of enable.tests.qt4; if we find that we are repeating this a lot we might want to create a enable.qt4.testing.* utility method.

[jwiggins]

Sounds good to me

[corranwebster]

I think this is good to merge.

[kitchoi]

Apparently the two tests on wx are failing (but the job has been allowed to fail on CI):

======================================================================
FAIL: test_horizontal_mouse_wheel (enable.tests.wx.mouse_wheel_test_case.MouseWheelTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/travis/.edm/envs/enable-test-2.7-wx-pillow/lib/python2.7/site-packages/enable-4.7.1.dev15-py2.7-linux-x86_64.egg/enable/tests/wx/mouse_wheel_test_case.py", line 82, in test_horizontal_mouse_wheel
    self.assertEqual(self.tool.event.mouse_wheel_delta, (200, 0))
AssertionError: <undefined> != (200, 0)
======================================================================
FAIL: test_vertical_mouse_wheel (enable.tests.wx.mouse_wheel_test_case.MouseWheelTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/travis/.edm/envs/enable-test-2.7-wx-pillow/lib/python2.7/site-packages/enable-4.7.1.dev15-py2.7-linux-x86_64.egg/enable/tests/wx/mouse_wheel_test_case.py", line 63, in test_vertical_mouse_wheel
    self.assertEqual(self.tool.event.mouse_wheel_delta, (0, 200))
AssertionError: <undefined> != (0, 200)

The CI job for wx is very close to passing. If we can require wx job to pass, we will be able to catch these more easily.

I tried to fix these by assigning the mouse_wheel_delta to the event object where they are defined. However the values are not the expected value. I get (1.0, 0) for horizontal case, and (0, 1.0) for vertical case.