[PySide] custom table sorting

[Aaron Richiger]

Hello Frank

Regarding your custom table sorting problem, there are at least two options:

a) Using QTableWidget()
Recommended for small, "stupid", static tables only. As soon as larger 
data, databases or manipulations (sorting, filtering, editing) appear, 
use option b)! But if you still want to go this way, I could imagine the 
following:
     1) Store each row of the table in an appropriate datastructure, 
sort this datastructure
     2) Remove all widgets from your TableWidgetItem
     3) Refill the table from the sorted datastructure

b) Using QTableModel()/ QTableView()/ Controller: (The following only 
covers the case without database. If you have an underlying database, 
similar solutions are provided by QSqlTableModel and others).
I highly recommend this approach, but as other mentioned, it's a little 
bit harder to dive into, but if you are familiar with the MVC pattern 
from other languages or apps, it's not a too big deal. Checkboxes, 
comboboxes (QSqlTableModel) are already on board, if you need other 
widgets, just create them by using QStyledItemDelegate(). The same for 
sorting, filtering. The main work is not done any longer on the view, 
but in the model class (compared to option a)). I wrote a little example 
showing an MVC table with sortable checkboxes (but without custom 
delegates):

http://pastebin.com/rw9ipbit

It's far from completeness to keep the example short, but could be a 
starting or inspiration point.

Have a nice day!
Aaron


> will do, thanks
>
> On 7/04/12 9:27 PM, Sebastian Elsner wrote:
>> I recommend reading the appropriate chapters in  this book:
>> http://www.qtrac.eu/pyqtbook.html
>> and have a look this ressource: http://www.yasinuludag.com/blog/
>> also download a version of PyQt, it has all original Qt examples
>> (including the model view thingies) translated to python, which helps a
>> lot and is a good starting point.
>>
>> Am 07.04.2012 02:00, schrieb Frank Rueter | OHUfx:
>>> Hi Sebastian,
>>>
>>> thanks again for your help. I couldn't get the sorting to work even
>>> though the widgets in each column were always the same type.
>>> You are probably totally right that this won't be very scalable, I just
>>> wanted to get a grip on it first before diving into the
>>> QTableView/QTableModel solution, which I think I won't be able to avoid.
>>> These tables can indeed grow very large.
>>> I shall read up on this though and try and do it properly. ;)
>>>
>>>
>>> Cheers,
>>> frank
>>>
>>>
>>> On 6/04/12 10:03 PM, Sebastian Elsner wrote:
>>>> Hi,
>>>>
>>>> assuming the checkboxes and the combo boxes are different data types
>>>> (bool, vs, string) and thus displayed in different columns, sorting
>>>> should happen automatically when you setSortingEnabled(True). Please
>>>> note that you have to disable sorting while inserting items because this
>>>> may lead to stringe behaviour. Also if you want to display checkboxes
>>>> these should be set by
>>>> QTableWidgetItem.setFlags(QTablewidgetItem.flags() |
>>>> Qt.ItemIsUSerCheckable)) and setCheckState()  rather than doing a
>>>> QTableWidget.setCellWidget(), because this is way faster. The combooxes
>>>> can be inserted with setCellWidget, but be aware that you may run into
>>>> performance issues if you add a lot of them.
>>>>
>>>> Alternatively you could subclass the QTableWidgetItem and override the<
>>>> operator to provide your own sorting, which will be - of course -
>>>> solower because implemented in python.
>>>>
>>>> Finally when dealing with large datasets I would recommend going for the
>>>> true model/view approach with QTableView, QTableModel and
>>>> QStyledItemDelegate, but those are more hard to use.
>>>>
>>>> Cheers
>>>>
>>>> Sebastian
>>>>
>>>>
>>>>     Am 06.04.2012 02:50, schrieb Frank Rueter | OHUfx:
>>>>> Hi guys,
>>>>>
>>>>> I'm working on a table that has ItemWidgets (comboBoxes, checkBoxes etc)
>>>>> in some cells and I'm trying to figure out how to write a custom sort
>>>>> behaviour that will enable me to sort the table by columns containing
>>>>> widgets using the respective widgets' current value (e.g. show all rows
>>>>> with a checked checkBox first, followed by all rows with an unchecked
>>>>> checkBox).
>>>>>
>>>>> Has anyone done this before?
>>>>> Any pointers would be fabulous!
>>>>>
>>>>> Cheers,
>>>>> frank
>>>>>
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