Itemviews - ScrollPerItem, ScrollPerPixel

Benjamin Meyer ben at
Fri Jun 6 11:30:56 BST 2008

On Jun 5, 2008, at 2:33 AM, Rafael Fernández López wrote:

> Hi there,
> Those who are used to itemviews know that we have to set some flags  
> to them
> for they working "properly". We have been discussing on IRC whether  
> itemviews
> should have a ScrollPerItem or ScrollPerPixel scrolling mode.
> The default in Qt is ScrollPerItem, but somehow this looks like a  
> bit 90's,
> and doesn't let the user easily "track the movements".
> This is specially critical, since the usage of itemviews have been  
> extended to
> the maximum, as for example, what a combobox shows when being  
> opened, is an
> item view.
> For example, I was asked to add smooth scrolling to the config  
> dialog of
> plasma (backgrounds and themes), and had to do something like:
> combo->view()- 
> >setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);
> what is pretty crazy all over the system.
> And there seems to be users that prefer ScrollPerItem to  
> ScrollPerPixel.
> Given this situation, I propose the next (4.2, of course):
> 1) Create a new entry on KGlobalSettings. Something like:
> 	static QAbstractItemView::ScrollMode itemViewsScrollMode();
> 2) We have 3 different approaches at this point:
> 	2.a) Do let the developer read this value. Bad stuff: We only gain  
> the
>             possibility of configuration, but we can't assure total
>             integration in the system, we would have to trust the  
> developer,
>             and he could miss this value, what could be very  
> understandable.
> 	2.b) Create KAbstractItemView, KListView, KTreeView, KTableView.  
> All of those
> 	     will read on their constructor this value, and automatically  
> set the 	
>             value. We should always use K's classes on this case. We  
> already
>             have this rule. Problem: crazyness, probably impossible  
> changes
>             because of BIC.
> 	2.c) Add on kstyle.cpp, on the polish() method, the call to this  
> method
>             reading the value of the setting. Problem: would only  
> work with
>             KStyles, not with QStyles.

  Where is option 2.d) give a patch to tt to add a style option?

-Benjamin Meyer

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