[Development] New class for QtWidgets: ColumnResizer

[Aurélien Gâteau]

Oswald Buddenhagen wrote:

> On Fri, Jun 13, 2014 at 10:39:34AM +0200, Aurélien Gâteau wrote:
>> Oswald Buddenhagen wrote:
>> > On Thu, Jun 12, 2014 at 04:08:17PM +0200, Aurélien Gâteau wrote:
>> >> Olivier Goffart wrote:
>> >> > But just wondering if it would not be better to have that as an API
>> >> > within QGridLayout such as
>> >> >   QGridLayout::setAlignedWith(QGridLayout*)
>> >> 
>> >> The class works with QFormLayout as well, so I don't think moving the
>> >> feature into QGridLayout would be a good idea.
>> >> 
>> > they have a common base class, you know ...
>> > 
>> >   QLayout::linkDimension(QLayout *other, Qt::Orientation orientation =
>> >   Qt::Horizontal)
>> > 
>> > (the second parameter is actually a flag field).
>> > 
>> > and for more fine-grained control one could consider (not sure this
>> > makes sense):
>> > 
>> >   QLayoutItem::linkDimension(QLayoutItem *other, Qt::Orientation
>> >   orientation = Qt::Horizontal)
>> 
>> What is missing from what you propose is the notion of column or row:
>> ColumnResizer lets you limit resizing to one column only so for example
>> if you have two 3-columns QGridLayouts stacked on top of each other then
>> you can link the first column widths while leaving each layout decide how
>> they want to size the 2 other columns.
>> 
> linking layout items would do exactly that, no? obviously, in a grid
> layout, linking an item's width constrains the whole column's width.
> of course one could argue that this is less elegant.
> 
>> What about this instead?
>> 
>>     QLayout::linkDimension(QLayout *other, int index, Qt::Orientation
>> orientation = Qt::Vertical);
>> 
> could work, i guess.
> 
> the default orientation is meant to link the width, as i think that's
> the by far more common case. whether one calls that horizontal or
> vertical is an awesome bikeshed, as we have seen in various discussions
> about splitters. my thinking was "width is horizontal on the screen".

I see how orientation is confusing for splitters because the widgets use one 
orientation while the splitter use the other, but here everything is using 
the same orientation, so I would find it surprising that the orientation to 
align two elements which are stacked vertically is "horizontal". Maybe the 
easiest way to avoid bikeshed and ambiguity is to have two methods: 
linkColumn() and linkRow()?

Aurélien