[wxPython-users] how to scroll wx.Window horizontally?

[Robin Dunn]

Pan Xingzhi wrote:
> Robin,
> 
>     Nice to hear from you again in 2008. Thank you for the direction.
> 
>     I kept asking questions about scrolling because I feel that
> scrolling in wxPython is a little bit weird, but to accomplish my task
> I have to thoroughly understand what's going on. There is something
> unusual but I couldn't tell, until I took some time to think about it,
> inside and out. Then I realized that in wxPython, both containers and
> non-containers can have scrolling ability (though it seems that
> wxPython do not emphasize the difference between the two). So my
> questions came again. I put my understandings below, please correct me
> if I'm wrong:
> 
>     1. For non-container widgets like wx.TreeCtrl, by default,
> scrollbars show up when the virtual size gets larger than the client
> size.

Yes, in general.  More specifically, widgets like this manage their own 
scrollbars internally, and wx doesn't really have access to them[*]. 
The can be considered as an implementation detail that just happens to 
be used inside the "black box" that is the widget.

[*] The exception of course is if the widget is implemented generically 
using wx itself, but you can't depend on that because for a particular 
widget it may be native on some platforms and generic on others.


>     2. The virtual size of non-containers is decided by the content of
> the non-container widget, e.g., the text in the TextCtrl, items in a
> TreeCtrl.

Yes.

>     3. For containers, the virtual size is calculated from the size
> (*not* virtual size) and position of its children (suppose we don't
> use sizers).

No.  You need to explicitly set the virtual size, although sizers can be 
used to help with this.

>     4. The condition for scrollbars of containers to show up is the
> same as non-containers.

Scrollbars will be shown if the virtual size is greater than the client 
size.

> 
>     Btw, you guys really should rename wx.ScrolledWindow to
> ScrolledPanel or something. After all it's a container. A beginner
> would easily think ScrolledWIndow as a direct child of wx.Window.
> (However I found a wx.lib.scrolledpanel.ScrolledPanel already occupied
> the name.)

Yep, this was discussed in the past, but nothing was done because there 
wasn't a clean migration path that made sense that would also preserve 
backwards compatibility.


-- 
Robin Dunn
Software Craftsman
http://wxPython.org  Java give you jitters?  Relax with wxPython!