Subject: Re: QTreeView setFirstColumnSpanned?

[Tomaz Canabrava]

On Sun, Jun 9, 2013 at 5:43 PM, Tomaz Canabrava <tcanabrava at kde.org> wrote:
> On Sun, Jun 9, 2013 at 5:24 PM, Linus Torvalds
> <torvalds at linux-foundation.org> wrote:
>> On Sun, Jun 9, 2013 at 11:03 AM, Amit Chaudhuri
>> <amit.k.chaudhuri at gmail.com> wrote:
>>>
>>> QTreeView has a protected virtual method for drawing a row.  I've not had
>>> time to look at the code for that in any detail, but it sounds like an
>>> invitation to sub-class and get any row specific behaviour we wish to have.
>>>
>>> So we might consider something like this:
>>>
>>> - sub-class QTreeView
>>
>> We already do this (DiveListView).
>>
>>> - re-implement drawRow
>>
>> Ok, I did that, easy enough.
>>
>>> - in our drawRow, test ( isTrip() )
>>
>> Done.
>>
>>> - compose the custom string we want to display from trip data "fields"
>>
>> Done (ok, for now I just take the name).
>>
>>> - display trip in our custom manner
>>
>> .. but this is a *bitch*.
>>
>> Why? The drawRow() function seems to be complex as hell. It has to
>> know all the insane private details of the QTreeView. It needs to do
>> all the background color selection (possibly alternating), the "is
>> this row selected" stuff, yadda yadda. Looking at the sources of the
>> *normal* drawRow(), this is very painful.
>>
>> But maybe there is some shortcut that I don't know about.
>>
>>> - else do the usual - 'cos it's not a trip
>>
>> Well, that's the trivial case.
>>
>> Anyway, the appended patch does everything *except* for the actual
>> drawing of the string. Which looks insanely complex to somebody that
>> doesn't know Qt. Can anybody fill in the missing blanks (literally:
>> there is a comment like
>>
>>      /* Draw 'trip->name' here ! */
>>
>> but since it doesn't do it, the trip rows end up being blank).
>>
>>                    Linus
>
> Nonono - don't reimplement drawRow unless you *really* have a reason
> too ( like, almost never ), or wanted to create your widget from
> scratch.
>
> From what I understood, Linus wants the Trips to have 2 or 3 Columns,
> and Dives to have more, right?
> this should be treated on the models, not on the TreeView.
>
> Linus - I'm in a Cooking festival now - so cant really hack, but in
> the DiveTripModels class inside models.h / cpp there is a method named
> columnCount() that returns the amount of columns for a specific item,
> you need to change *there*, if you want to make Dives and Trips to
> behave differently.
>
> Since the original returns 'COLUMNS' ( the enum value ), it's prepared
> to only have COLUMNS rows, change that and profit.
>
> ( or maybe not... I'll tinker with that on the next week to see the
> possibilities. )
>
> T


Linus,

Can you provide a dummy screenshoot on what you are trying to achive?

T