Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. QFileSystemModel and QSortFilterProxyModel - root index is not preserved

QFileSystemModel and QSortFilterProxyModel - root index is not preserved

Scheduled Pinned Locked Moved Unsolved General and Desktop
c++qfilesystemmodeqsortfilterproxfiltering
25 Posts 8 Posters 6.7k Views
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • S Offline
    S Offline
    SGaist
    Lifetime Qt Champion
    wrote on 2 Jul 2019, 08:51 last edited by
    #15

    Personally, I didn't. Since you found it, the honour is yours :)

    Interested in AI ? www.idiap.ch
    Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

    1 Reply Last reply
    1
    • M Offline
      M Offline
      mrjj
      Lifetime Qt Champion
      wrote on 2 Jul 2019, 09:03 last edited by
      #16

      Hi
      nope, if i had made report, i would have linked url here :)
      So please do.

      1 Reply Last reply
      0
      • V Offline
        V Offline
        VRonin
        wrote on 2 Jul 2019, 09:15 last edited by
        #17

        I don't think it's a bug.
        setRootIndex is a method of the view. The model has no way of knowing (and shouldn't know) what a view is using as root. The filter set on the proxy applies to the whole model. If the index used as root by a view gets filtered out it's only natural for a view to revert to using QModelIndex() as root.

        What you need is a proxy model that implements the setRootIndex functionality at the model level. This is on the list of nice-things-I-would-like-to-add-to-Qt-models and it's a fairly easy one to do but I need to find time for it :(

        "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
        ~Napoleon Bonaparte

        On a crusade to banish setIndexWidget() from the holy land of Qt

        1 Reply Last reply
        5
        • M Offline
          M Offline
          MasterBLB
          wrote on 2 Jul 2019, 18:34 last edited by
          #18

          ...and now I'm confused :/

          J 1 Reply Last reply 2 Jul 2019, 18:41
          0
          • M MasterBLB
            2 Jul 2019, 18:34

            ...and now I'm confused :/

            J Offline
            J Offline
            JonB
            wrote on 2 Jul 2019, 18:41 last edited by
            #19

            @MasterBLB
            Confused in what way? I have just read this thread and what @VRonin has written seems correct to me. Are you not understanding what he is saying, or what?

            1 Reply Last reply
            0
            • M Offline
              M Offline
              MasterBLB
              wrote on 3 Jul 2019, 07:27 last edited by
              #20

              In the way such behavior breaks SOLID substitute rule - I can't use descendant class QFileSystemModel like it was its base class QAbstractItemModel in QSortFilterProxyModel. While not a 100% bug it's definitely a serious design flaw, and worth to be reported. But where?

              J V 2 Replies Last reply 3 Jul 2019, 08:01
              0
              • M MasterBLB
                3 Jul 2019, 07:27

                In the way such behavior breaks SOLID substitute rule - I can't use descendant class QFileSystemModel like it was its base class QAbstractItemModel in QSortFilterProxyModel. While not a 100% bug it's definitely a serious design flaw, and worth to be reported. But where?

                J Offline
                J Offline
                jsulm
                Lifetime Qt Champion
                wrote on 3 Jul 2019, 08:01 last edited by
                #21

                @MasterBLB said in QFileSystemModel and QSortFilterProxyModel - root index is not preserved:

                But where?

                In Qt bug tracker https://bugreports.qt.io/secure/Dashboard.jspa
                Also you can talk to Qt developers on their mailing list.

                https://forum.qt.io/topic/113070/qt-code-of-conduct

                1 Reply Last reply
                0
                • M MasterBLB
                  3 Jul 2019, 07:27

                  In the way such behavior breaks SOLID substitute rule - I can't use descendant class QFileSystemModel like it was its base class QAbstractItemModel in QSortFilterProxyModel. While not a 100% bug it's definitely a serious design flaw, and worth to be reported. But where?

                  V Offline
                  V Offline
                  VRonin
                  wrote on 3 Jul 2019, 08:44 last edited by VRonin 7 Mar 2019, 10:08
                  #22

                  breaks SOLID

                  It doesn't. In fact, if it worked as you expected it would break SOLID

                  it's definitely a serious design flaw

                  Sorry to be brutal: No, it's not a flaw, you just didn't understand the design of model/views.
                  To help you get a better idea of what is going on, try use the same model with 2 different treeviews. In only one of the view call setRootIndex, and then trigger the filtering.

                  "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
                  ~Napoleon Bonaparte

                  On a crusade to banish setIndexWidget() from the holy land of Qt

                  1 Reply Last reply
                  2
                  • B Offline
                    B Offline
                    Brad1111
                    wrote on 12 Feb 2025, 22:50 last edited by
                    #23

                    Im actually encountering the very same issue.
                    Clearly it wont be fixed by Qt since Ive even seen posts about this issue back from 2011.
                    Could someone help me a little bit by telling me what to do please ?

                    @VRonin You were the most precise, suggesting to implements the setRootIndex to the proxymodel, but I would still require a bit more info if I am to do it on my own please :D

                    1 Reply Last reply
                    0
                    • J Offline
                      J Offline
                      jeremy_k
                      wrote on 13 Feb 2025, 02:51 last edited by
                      #24

                      It looks like @VRonin implemented his idea. See https://github.com/VSRonin/QtModelUtilities/blob/master/READMERootIndexProxyModel.md

                      Asking a question about code? http://eel.is/iso-c++/testcase/

                      B 1 Reply Last reply 13 Feb 2025, 04:28
                      1
                      • J jeremy_k
                        13 Feb 2025, 02:51

                        It looks like @VRonin implemented his idea. See https://github.com/VSRonin/QtModelUtilities/blob/master/READMERootIndexProxyModel.md

                        B Offline
                        B Offline
                        Brad1111
                        wrote on 13 Feb 2025, 04:28 last edited by
                        #25

                        @jeremy_k Wow, Awesome ! Thanks for your answer and massive props to @VRonin !

                        1 Reply Last reply
                        0

                        • Login

                        • Login or register to search.
                        • First post
                          Last post
                        0
                        • Categories
                        • Recent
                        • Tags
                        • Popular
                        • Users
                        • Groups
                        • Search
                        • Get Qt Extensions
                        • Unsolved