Re: [Pythoncard-users] wxSafeYield and findfiles

[Kevin A. <al...@se...>]

On Oct 5, 2004, at 2:19 PM, Alex Tweedly wrote:

>
>  Two questions ....
>
>  1. Is this a bug ?
>  I think there's a bug in that findfiles only does a yield when it=20
> successfully finds the string that you're searching for. If you do a=20=

> findfiles for some string that never occurs, the window is=20
> non-responsive until the search is complete.
>
>  The "inner loop" is
> =A0=A0=A0=A0=A0=A0=A0 for dir in self.dirpattern.split(';'):
>  =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 for filename in util.dirwalk(dir, =
patterns, self.recurse):
>  =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 if =
self.SearchFile(filename):
>  =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 found +=3D =
1
>  =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =
self.statusBar.text =3D "Files found: %d" % found
>  =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 if =
self.stopSearching:
>  =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =
break
>  =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =
wx.SafeYield(self)
>
>
> I think the wx.SafeYield(self) should be outside the "if" block, so=20
> that it occurs for each file.

Fixed

>  2. What's the best way to protect yourself from recursive SafeYield=20=

> calls ?
>  In this case it would be easy enough - just add a flag (or re-use=20
> StopSearching) which is set at the start of the search, and reset at=20=

> the (normal) end; then the menu handler can check for a search already=20=

> in progress, and avoid starting another.=A0 Since SafeYield is only=20
> called within the search, this would fix it for findfiles.

That should have been a wx.SafeYield(self, True) call, the second arg=20
is yieldIfNeeded.

>  But in the general case, there could be SafeYield calls within many=20=

> different processing loops. Is there a way to tell if you are "already=20=

> yielded" ?=A0
>
>  (btw - is wx.SafeYield" documented somewhere ? )
>

wx.SafeYield is a wxPython method, so it is documented in the new=20
wxPython-specific docs, but you can also look at the help for it in the=20=

shell, just type wx.SafeYield( and it should popup. It is a bit=20
confusing to know when to use wx.Yield, wx.SafeYield, or=20
wx.YieldIfNeeded. In the case of findfiles you want to be able to click=20=

a Cancel button to end the search, so I added one of those as well as=20
be able to start viewing a file or make other changes before the search=20=

of all of the files is done so wx.SafeYield seems like the right choice=20=

and setting the yieldIfNeeded flag to True should prevent a recursive=20
call problem. That's about as far as my knowledge goes, so further=20
questions should go to wxPython-users.

ka