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QListWidget row size with a custom QListWidgetItem

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  • kshegunovK kshegunov

    @canellas said in QListWidget row size with a custom QListWidgetItem:

    What would be correct values, if I do not know the size or resolution of the display?

    How does the display figure here? You need to provide two numbers - width and height - to the layout engine so it know how big to draw the rows and columns of the list widget. You calculate the width and height based on the contents of the widget and/or the size policy that's set. I don't know what widget you're creating so it's hard to say how exactly this should be calculated, but I hope you understand what I meant.

    canellasC Offline
    canellasC Offline
    canellas
    wrote on last edited by canellas
    #5

    @kshegunov The Item class is like this: alt text.

    The width is set to 278, and height to 138. sizePolicy.HorizontalPolicy and sizePolicy.HorizontalPolicy are set to Prefered.

    And this is how the screen looks like in my cell:

    alt text

    kshegunovK 1 Reply Last reply
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    • canellasC canellas

      @kshegunov The Item class is like this: alt text.

      The width is set to 278, and height to 138. sizePolicy.HorizontalPolicy and sizePolicy.HorizontalPolicy are set to Prefered.

      And this is how the screen looks like in my cell:

      alt text

      kshegunovK Offline
      kshegunovK Offline
      kshegunov
      Moderators
      wrote on last edited by
      #6

      You have to upload the images to an external site (e.g postimage.org).
      However, with that size policy you'd get multiple inquiries about the sizes of your widget by Qt so it can calculate the correct size. If it's a fixed size, you need to set the correct policy.

      Read and abide by the Qt Code of Conduct

      canellasC 1 Reply Last reply
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      • kshegunovK kshegunov

        You have to upload the images to an external site (e.g postimage.org).
        However, with that size policy you'd get multiple inquiries about the sizes of your widget by Qt so it can calculate the correct size. If it's a fixed size, you need to set the correct policy.

        canellasC Offline
        canellasC Offline
        canellas
        wrote on last edited by canellas
        #7

        @kshegunov

        The Item class
        alt text

        The screen on my cel, with sizePolicy set to Fixed in both dimensions:
        alt text

        And with setSizeHint(QSize(0, 150));

        kshegunovK 1 Reply Last reply
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        • canellasC canellas

          @kshegunov

          The Item class
          alt text

          The screen on my cel, with sizePolicy set to Fixed in both dimensions:
          alt text

          And with setSizeHint(QSize(0, 150));

          kshegunovK Offline
          kshegunovK Offline
          kshegunov
          Moderators
          wrote on last edited by
          #8

          Okay, wait a bit. So you have a compound widget, does that widget have a layout? If it does you shouldn't need to do anything (even set the hint).

          Read and abide by the Qt Code of Conduct

          canellasC 1 Reply Last reply
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          • kshegunovK kshegunov

            Okay, wait a bit. So you have a compound widget, does that widget have a layout? If it does you shouldn't need to do anything (even set the hint).

            canellasC Offline
            canellasC Offline
            canellas
            wrote on last edited by canellas
            #9

            @kshegunov Yes, The first TextLabel and the text box by its side are grouped in a horizontal layout, as the Text Label and the text box below, and the whole Item class, sub class of QWidget, has a vertical layout.

            I wonder if the QListWidgetItem, or the list object should, somehow, have a layout defined.

            kshegunovK 1 Reply Last reply
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            • canellasC canellas

              @kshegunov Yes, The first TextLabel and the text box by its side are grouped in a horizontal layout, as the Text Label and the text box below, and the whole Item class, sub class of QWidget, has a vertical layout.

              I wonder if the QListWidgetItem, or the list object should, somehow, have a layout defined.

              kshegunovK Offline
              kshegunovK Offline
              kshegunov
              Moderators
              wrote on last edited by kshegunov
              #10

              Hm that's odd. If you have a vertical layout for the widget, I'd set the policy to expanding both directions. Aside from that it might be some peculiarity of the view ... but I haven't encountered it by now.

              I wonder if the QListWidgetItem, or the list object should, somehow, have a layout defined.

              It has a special way of laying out the items (implemented for the view itself).

              Read and abide by the Qt Code of Conduct

              canellasC 1 Reply Last reply
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              • kshegunovK kshegunov

                Hm that's odd. If you have a vertical layout for the widget, I'd set the policy to expanding both directions. Aside from that it might be some peculiarity of the view ... but I haven't encountered it by now.

                I wonder if the QListWidgetItem, or the list object should, somehow, have a layout defined.

                It has a special way of laying out the items (implemented for the view itself).

                canellasC Offline
                canellasC Offline
                canellas
                wrote on last edited by
                #11

                @kshegunov I set the sizePolicy to Expanding in horizontal and vertical dimensions, but the result was the same. I tried to remove the setSizeHint(QSize(0, 150));,and also the setSizeAdjustPolicy(QListWidget::AdjustToContents);, but with the same result.

                kshegunovK 1 Reply Last reply
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                • canellasC canellas

                  @kshegunov I set the sizePolicy to Expanding in horizontal and vertical dimensions, but the result was the same. I tried to remove the setSizeHint(QSize(0, 150));,and also the setSizeAdjustPolicy(QListWidget::AdjustToContents);, but with the same result.

                  kshegunovK Offline
                  kshegunovK Offline
                  kshegunov
                  Moderators
                  wrote on last edited by
                  #12

                  It's possible it may be a bug too. Can you prepare a minimal example that reproduces the behaviour? Btw, do you experience this only on the mobile device, when the screen is small?

                  Read and abide by the Qt Code of Conduct

                  canellasC 1 Reply Last reply
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                  • kshegunovK kshegunov

                    It's possible it may be a bug too. Can you prepare a minimal example that reproduces the behaviour? Btw, do you experience this only on the mobile device, when the screen is small?

                    canellasC Offline
                    canellasC Offline
                    canellas
                    wrote on last edited by
                    #13

                    @kshegunov Only in the mobile. When I run on a 14" notebook display, it works as expected, i.e., the row height and width expand and reduce according to the size of the window.

                    I have the example ready. Where should I send it to?

                    In time, thanks a lot for your time!

                    kshegunovK 1 Reply Last reply
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                    • canellasC canellas

                      @kshegunov Only in the mobile. When I run on a 14" notebook display, it works as expected, i.e., the row height and width expand and reduce according to the size of the window.

                      I have the example ready. Where should I send it to?

                      In time, thanks a lot for your time!

                      kshegunovK Offline
                      kshegunovK Offline
                      kshegunov
                      Moderators
                      wrote on last edited by
                      #14

                      Upload it where it's convenient. I'd try on my machine but I don't have any device on hand, so it might be a very limited test. For now my advice is to wait a bit so our other users can see and possibly offer insight, but you may need to post it (the example and description) as a bugreport. Don't hold your breath of it being fixed though, the widgets module isn't priority ...

                      Read and abide by the Qt Code of Conduct

                      canellasC 1 Reply Last reply
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                      • kshegunovK kshegunov

                        Upload it where it's convenient. I'd try on my machine but I don't have any device on hand, so it might be a very limited test. For now my advice is to wait a bit so our other users can see and possibly offer insight, but you may need to post it (the example and description) as a bugreport. Don't hold your breath of it being fixed though, the widgets module isn't priority ...

                        canellasC Offline
                        canellasC Offline
                        canellas
                        wrote on last edited by
                        #15

                        @kshegunov I uploaded the project to https://www.dropbox.com/s/tx88huu23d5cfcm/untitled6.tar.gz?dl=0. It is a tar.gz file, if you do not mind.

                        Well, if it is a bug, that means big trouble to me, as I am using something similar in a customer application.

                        Again, thanks for your help and time!

                        kshegunovK 1 Reply Last reply
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                        • canellasC canellas

                          @kshegunov I uploaded the project to https://www.dropbox.com/s/tx88huu23d5cfcm/untitled6.tar.gz?dl=0. It is a tar.gz file, if you do not mind.

                          Well, if it is a bug, that means big trouble to me, as I am using something similar in a customer application.

                          Again, thanks for your help and time!

                          kshegunovK Offline
                          kshegunovK Offline
                          kshegunov
                          Moderators
                          wrote on last edited by kshegunov
                          #16

                          I took a peek at your code and I have artifacts when resizing the widget. But it's my bad. You can't do this the way you're trying to. Here:

                          This function should only be used to display static content in the place of a list widget item. If you want to display custom dynamic content or implement a custom editor widget, use QListView and subclass QItemDelegate instead.

                          So what you need to do is to rework your code to use a list view with a delegate.

                          Read and abide by the Qt Code of Conduct

                          canellasC 1 Reply Last reply
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                          • kshegunovK kshegunov

                            I took a peek at your code and I have artifacts when resizing the widget. But it's my bad. You can't do this the way you're trying to. Here:

                            This function should only be used to display static content in the place of a list widget item. If you want to display custom dynamic content or implement a custom editor widget, use QListView and subclass QItemDelegate instead.

                            So what you need to do is to rework your code to use a list view with a delegate.

                            canellasC Offline
                            canellasC Offline
                            canellas
                            wrote on last edited by
                            #17

                            @kshegunov I understand... well, I'll try, once more, to understand views, models and delegates, and how Qt implement them. 8)

                            The examples that come with QtCreator do not, as far as I could see, show how to insert in a Q*View a custom class object, and searching the web, I could not find an example either.

                            Do you know any link that shows how to implement it? I would not mind to take a few days to do it from scratch on my own, but I do not have a lot of time to fix the app.

                            Anyway, thanks a lot!!!

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