wxGTK: wxScrolledWindow in a wxNotebook has refresh problems

[robind]

wxGTK 2.2.x from CVS and also the released 2.2.2
gtk+ 1.2.8 and also 1.2.6

On the 2.2 branch (I havn't tried this on the main branch yet) if you have a
wxHtmlWindow as a wxNotebook page, then partially cover the window with
another and then raise the orginial window, then the covered portion of the
wxHtmlWindow is not refreshed correctly. The background colour is the
notebook's background, not the html page's. The text is drawn correctly.

If I put a wxPanel under the wxHtmlWindow and make that the notebook
page then it refreses correctly.

[robind]

I experimented around a bit and found that a very simple wxScrolledWindow
could duplicate the bug. Here it is in Python:

class MyCanvas(wxScrolledWindow):

def init(self, parent, id = -1, size = wxDefaultSize):

wxScrolledWindow.init(self, parent, id, wxPoint(0, 0),

size, wxSUNKEN_BORDER)

self.SetBackgroundColour(wxNamedColor("WHITE"))

Make an instance of one of these be a wxNotebook page and when it gets covered
by another window, or when it scrolls then the background colour is not refreshed
properly.

[robind]

I just checked to see if maybe this has been fixed (perhaps
as a side effect of some other fix...) It's not. Now that
we can upload images I'll do so.

[robind]

screenshot of notebook bg colour refresh problem

[robind]

I've just found another example of this or a related
problem. If a wxStyleTextCtrl is a notebook page then on
wxGTK it has serious flicker problems, and large portions
of the window are refreshed when they don't need to be.

[robind]

Oops, I forgot to mention below that yet again, putting a
wxPanel under the wxStyleTextCtrl makes things work MUCH
better.

[nwmoriarty]

The same problem appears to be true for wxTreeCtrl. My simple example
work find on Windows but had similar problems to the other windows
mentioned. A wxPanel behind the wxTreeCtrl solved the problem. Fixing
this bug would greatly simplify my GUIs.

[terrelshumway]

similar/same problem with wxMSW on win2k: (wxPython 2.3.2.1
py22-hybrid) except that adding the wxPanel underneath does
not fix the problem.

See http://wxidle.sourceforge.net/bugfiles/216861.zip for
code and screen-shot.

[robind]

The problem mentioned below on MSW is a bit different and
has already been fixed for the next release.

[robind]

Robert just checked in a change which fixes this for wxGTK
as well!

[robind]

Reopening this bug since the bug showed up on a different
machine just as it was before.

[echuck]

Here's a small program that demonstrates the problem with
the background color. Scrolling and HTML aren't even required:

from wxPython.wx import *

color = wxColor(85, 170, 255)

class MyPanel(wxPanel):

def init(self, *posArgs, **kwArgs):

wxPanel.init(self, *posArgs, **kwArgs)
self.SetBackgroundColour(color)
wxStaticText(self, -1, "Hello, world.")

app = wxPySimpleApp()
frame = wxFrame(None, -1, "")

nb = wxNotebook(frame, -1)

if 1:

# put MyPanel directly in the notebook
# cannot change background color
p = MyPanel(nb, -1)
nb.AddPage(p, "foo")
p.SetBackgroundColour(color) # futile attempt to force the

issue
else:

# wrap MyPanel in an arbitrary second panel
# now background color change is respected.
p = wxPanel(nb, -1)
p2 = MyPanel(p, -1)
if 1:

# make the inner panel fill the outer
sizer = wxBoxSizer(wxHORIZONTAL)
sizer.Add(p2, 1, wxEXPAND)
p.SetSizer(sizer)

nb.AddPage(p, "foo")

frame.Show(1)
app.MainLoop()

[ghazel]

The example below has the same problem (wxGTK, even CVS
HEAD 2.5 as of 20031028 or so), and wrapping it in any
amount of sizers does not change it.

<br>from wxPython.wx import *
<br>
<br>app = wxPySimpleApp()
<br>frame = wxFrame(None, -1, "")
<br>
<br>nb = wxNotebook(frame, -1)
<br>
<br>#if 1:
<br>
<br># put MyPanel directly in the notebook
<br># cannot change background color
<br>p = wxPanel(nb, -1)
<br>
<br>text=wxTextCtrl(p, -1,
<br> "Should be white text\non black background",
<br> wxDefaultPosition,
<br> wxDefaultSize,
<br> style=wxTE_MULTILINE)
<br># futile attempt to force the issue
<br>text.SetBackgroundColour(wxBLACK)
<br>text.SetForegroundColour(wxWHITE)
<br>sizer = wxBoxSizer(wxHORIZONTAL)
<br>sizer.Add(text, 1, wxEXPAND)
<br>p.SetSizer(sizer)
<br>nb.AddPage(p, "foo")
<br>
<br>#else:
<br>
<br># wrap wxPanel in an arbitrary second panel
<br># background color change still not respected.
<br>p2 = wxPanel(nb, -1)
<br>p3 = wxPanel(p2, -1)
<br>if 1:
<br> # make the inner panel fill the outer
<br> sizer2 = wxBoxSizer(wxHORIZONTAL)
<br> sizer2.Add(p3, 1, wxEXPAND)
<br> p2.SetSizer(sizer2)
<br> text=wxTextCtrl(p3, -1,
<br> "Still should be white text\non black
background",
<br> wxDefaultPosition,
<br> wxDefaultSize,
<br> style=wxTE_MULTILINE)
<br> # futile attempt to force the issue
<br> text.SetBackgroundColour(wxBLACK)
<br> text.SetForegroundColour(wxWHITE)
<br> # make the textctrl fill the inner panel
<br> sizer3 = wxBoxSizer(wxHORIZONTAL)
<br> sizer3.Add(text, 1, wxEXPAND)
<br> p3.SetSizer(sizer3)
<br>
<br>nb.AddPage(p2, "foo2")
<br>
<br>frame.Show(1)
<br>app.MainLoop()

[ghazel]

ew- sorry about all the <br>s

[ghazel]

So I think I made a little progress towards finding another
work-around:
In most cases, calling SetBackgroundColour() after
frame.Show(true) or notebook.AddPage() (or both) allowed
the colour change to take effect.
I don't know what this implies (overwriting or maybe the
object doesn't exist yet?) but it seems significant.

Hope this helps..

[roebling]

I think this was fixed recently with the background style
changes. At least I cannot reproduce this anymore in C++.