Dragging panel in produces ~wxWindowBase() error

[Tom Goddard]

Drag side view panel out. Then drag it back into Chimera on far right edge drop target produces this error on both Mac and Linux.

new frame callback raised error
Traceback (most recent call last):
File "/Users/goddard/ucsf/chimera2/Chimera2.app/Contents/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/chimera/core/graphics/view.py", line 411, in _draw_if_changed
cb()
File "/Users/goddard/ucsf/chimera2/Chimera2.app/Contents/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/chimera/core/structure.py", line 160, in _update_graphics_if_needed
c, s, se = self.gc_color, self.gc_shape, self.gc_select
File "/Users/goddard/ucsf/chimera2/Chimera2.app/Contents/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/chimera/core/molecule/molc.py", line 24, in get_prop
cget(self._c_pointer_ref, 1, v_ref)
wx._core.wxAssertionError: C++ assertion "GetEventHandler() == this" failed at /Users/goddard/ucsf/chimera2/build/tmp/wxPython_Phoenix-3.0.3.dev1719+62a2221/ext/wxWidgets/src/common/wincmn.cpp(478) in ~wxWindowBase(): any pushed event handlers must have been removed

[Tom Goddard]

Same error dragging mouse mode panel into main window on Mac.

[Eric Pettersen]

Had to make the wx.Timer() redraw callback us wx.CallAfter, since the Timer callback is apparently in a thread.