Qt-interest Archive, February 2007
A lot of rows to display ... heh...
Message 1 in thread
Hello,
I need to build stock-management application, and one of the forms will
contain a QTableView that will have to show more than a hundred thousand
rows with ability to edit (rows count will be less if the filters will
be used). I need to mark some of the rows with different background
color (not an alternate color), and also ability to keep an empty row at
the bottom if the user will need to add a new row (fields in the new row
has to be in the format column in, for instance if the column is float
the field in the empty bottom row has to be float too).
How is it possible to achieve? Should I use QTableWidget instead to
display the data?
Best regards,
Oleg Romanenko.
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Message 2 in thread
On Wednesday 21 February 2007 19:49, Oleg Romanenko wrote:
> Hello,
>
> I need to build stock-management application, and one of the forms will
> contain a QTableView that will have to show more than a hundred thousand
> rows with ability to edit (rows count will be less if the filters will
> be used). I need to mark some of the rows with different background
> color (not an alternate color), and also ability to keep an empty row at
> the bottom if the user will need to add a new row (fields in the new row
> has to be in the format column in, for instance if the column is float
> the field in the empty bottom row has to be float too).
>
> How is it possible to achieve? Should I use QTableWidget instead to
> display the data?
>
> Best regards,
> Oleg Romanenko.
>
> --
Read the part in the documentation about the MVC-pattern and how to use a
delegate. This will give you some pointers..
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Message 3 in thread
Hello Peter,
Thanks for a reply! I have read about delegates and it seems that they
completely change the way how data is being edited, and to change just
the background of some of the rows, I believe it will consume quite a
lot of resources. Just to be sure that the way I'm doing is right.
Best regards,
Oleg Romanenko.
Peter M. Groen wrote:
> On Wednesday 21 February 2007 19:49, Oleg Romanenko wrote:
>> Hello,
>>
>> I need to build stock-management application, and one of the forms will
>> contain a QTableView that will have to show more than a hundred thousand
>> rows with ability to edit (rows count will be less if the filters will
>> be used). I need to mark some of the rows with different background
>> color (not an alternate color), and also ability to keep an empty row at
>> the bottom if the user will need to add a new row (fields in the new row
>> has to be in the format column in, for instance if the column is float
>> the field in the empty bottom row has to be float too).
>>
>> How is it possible to achieve? Should I use QTableWidget instead to
>> display the data?
>>
>> Best regards,
>> Oleg Romanenko.
>>
>> --
>
> Read the part in the documentation about the MVC-pattern and how to use a
> delegate. This will give you some pointers..
--
[ signature omitted ]
Message 4 in thread
Oleg Romanenko wrote:
> Hello,
>
> I need to build stock-management application, and one of the forms will
> contain a QTableView that will have to show more than a hundred thousand
> rows with ability to edit (rows count will be less if the filters will
> be used). I need to mark some of the rows with different background
> color (not an alternate color), and also ability to keep an empty row at
> the bottom if the user will need to add a new row (fields in the new row
> has to be in the format column in, for instance if the column is float
> the field in the empty bottom row has to be float too).
>
> How is it possible to achieve? Should I use QTableWidget instead to
> display the data?
For the background color, you can use the data role Qt::BackgroundRole
in your implementation of QAbstractItemModel::data.
hth
M
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Message 5 in thread
Thanks Martin,
I have tried it, but it did not work for me. :(
Best regards,
Oleg
Martin wrote:
> Oleg Romanenko wrote:
>> Hello,
>>
>> I need to build stock-management application, and one of the forms will
>> contain a QTableView that will have to show more than a hundred thousand
>> rows with ability to edit (rows count will be less if the filters will
>> be used). I need to mark some of the rows with different background
>> color (not an alternate color), and also ability to keep an empty row at
>> the bottom if the user will need to add a new row (fields in the new row
>> has to be in the format column in, for instance if the column is float
>> the field in the empty bottom row has to be float too).
>>
>> How is it possible to achieve? Should I use QTableWidget instead to
>> display the data?
>
> For the background color, you can use the data role Qt::BackgroundRole
> in your implementation of QAbstractItemModel::data.
>
> hth
> M
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Message 6 in thread
On Wednesday 21 February 2007 19:49, Oleg Romanenko wrote:
> Hello,
>
> I need to build stock-management application, and one of the forms will
> contain a QTableView that will have to show more than a hundred thousand
> rows with ability to edit (rows count will be less if the filters will
> be used). I need to mark some of the rows with different background
> color (not an alternate color), and also ability to keep an empty row at
> the bottom if the user will need to add a new row (fields in the new row
> has to be in the format column in, for instance if the column is float
> the field in the empty bottom row has to be float too).
>
> How is it possible to achieve? Should I use QTableWidget instead to
> display the data?
>
> Best regards,
> Oleg Romanenko.
For that many rows I would recommend using the QTableView and a custom model.
That way you can make the backend implementation and storage most efficient
for your use case. Then giving certain rows colors/fonts/etc is as easy as
modifying the data() function. Rather then each row having a bool for if it
should be italic you can have a list of the 10 rows that have italic for
example.
Here is an example model I wrote that displays one hundred one million rows of
real data (although not editable in this use case).
http://www.icefox.net/programs/?program=NetflixRecommenderFramework
And of course the required eye candy.
http://www.icefox.net/blogs/explorer.png
-Benjamin Meyer
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Message 7 in thread
Thanks a lot Benjamin! I am looking into your code right away!
Best regards,
Oleg Romanenko.
Benjamin Meyer wrote:
> On Wednesday 21 February 2007 19:49, Oleg Romanenko wrote:
>> Hello,
>>
>> I need to build stock-management application, and one of the forms will
>> contain a QTableView that will have to show more than a hundred thousand
>> rows with ability to edit (rows count will be less if the filters will
>> be used). I need to mark some of the rows with different background
>> color (not an alternate color), and also ability to keep an empty row at
>> the bottom if the user will need to add a new row (fields in the new row
>> has to be in the format column in, for instance if the column is float
>> the field in the empty bottom row has to be float too).
>>
>> How is it possible to achieve? Should I use QTableWidget instead to
>> display the data?
>>
>> Best regards,
>> Oleg Romanenko.
>
> For that many rows I would recommend using the QTableView and a custom model.
> That way you can make the backend implementation and storage most efficient
> for your use case. Then giving certain rows colors/fonts/etc is as easy as
> modifying the data() function. Rather then each row having a bool for if it
> should be italic you can have a list of the 10 rows that have italic for
> example.
>
> Here is an example model I wrote that displays one hundred one million rows of
> real data (although not editable in this use case).
>
> http://www.icefox.net/programs/?program=NetflixRecommenderFramework
>
> And of course the required eye candy.
> http://www.icefox.net/blogs/explorer.png
>
> -Benjamin Meyer
>
> --
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