Results 1 to 5 of 5

Thread: [model/view] slow refresh on big table

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date
    May 2006
    Posts
    55
    Thanks
    7
    Thanked 1 Time in 1 Post
    Qt products
    Qt4
    Platforms
    MacOS X Unix/X11 Windows

    Default [model/view] slow refresh on big table

    Hi,
    I am using QTableView with a rather big model under (1500x30 cells).
    When I try to scroll it is horribly slow. I tried to see what's going on by
    placing a breakpoint in ::data(QModelIndex, int) and the debugger
    and the window with the table side by side hoping not to interfere too much
    on the refresh mecanism : dream on !
    The backingstore mecanism seems to want to erase the background everytime
    the window gets the focus (and when the debugger stops at a breakpoint,
    the window loses focus and regain it when you hit the run button).
    Anyone has a tip for measuring refresh time in another way, counting the
    number of times the model/view framework call ::data on the same cell for
    a same refresh occasion ?
    Thx in advance.
    Last edited by lauranger; 17th May 2006 at 12:11.

  2. #2
    Join Date
    Jan 2006
    Location
    Warsaw, Poland
    Posts
    33,363
    Thanks
    3
    Thanked 5,012 Times in 4,791 Posts
    Qt products
    Qt3 Qt4 Qt5 Qt/Embedded
    Platforms
    Unix/X11 Windows Android Maemo/MeeGo
    Wiki edits
    10

    Default Re: [model/view] slow refresh on big table

    What kind of model do you use?

  3. #3
    Join Date
    May 2006
    Posts
    55
    Thanks
    7
    Thanked 1 Time in 1 Post
    Qt products
    Qt4
    Platforms
    MacOS X Unix/X11 Windows

    Default Re: [model/view] slow refresh on big table

    I use an implementation of QAbstractTableModel with
    a QSortFilterProxyModel in between.
    (I was writing a much more dataful version of this message
    when the spirit of the web formulars played me a bad trick).
    I feel that the performance problem is not with the implementation
    I wrote but with the number of rows it presents and the way
    Qt seems to handle refreshes. I'd like to know from where could
    I trace refresh start and refresh end.
    Had anybody faced such slowliness with big model ?
    Last edited by lauranger; 17th May 2006 at 16:07.

  4. #4
    Join Date
    Jun 2007
    Posts
    52
    Thanks
    6

    Default Re: [model/view] slow refresh on big table

    If someone knows how to do this this would be great. I am also having the same issue.

  5. #5
    Join Date
    Jan 2006
    Location
    Warsaw, Poland
    Posts
    33,363
    Thanks
    3
    Thanked 5,012 Times in 4,791 Posts
    Qt products
    Qt3 Qt4 Qt5 Qt/Embedded
    Platforms
    Unix/X11 Windows Android Maemo/MeeGo
    Wiki edits
    10

    Default Re: [model/view] slow refresh on big table

    How do you know it is the same issue?

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Digia, Qt and their respective logos are trademarks of Digia Plc in Finland and/or other countries worldwide.