QTableView not displaying Icon for column zero

[Perdrix]

In my data() mf I have:

        if (role == Qt::DecorationRole)
        {
            if (0 == index.column())
                return rowIcon(file);
            else return QVariant();
        }

rowIcon() looks like:

    //
    // Work out which Icon to display based on the frame type
    //
    QVariant ImageListModel::rowIcon(const ListBitMap& file) const
    {
        QVariant result;
        PICTURETYPE type{ file.m_PictureType };
        int16_t index{ 0 };

        switch (type)
        {
        case PICTURETYPE_LIGHTFRAME:
        case PICTURETYPE_REFLIGHTFRAME:
            index = 0;
            break;
        case PICTURETYPE_DARKFRAME:
        case PICTURETYPE_DARKFLATFRAME:
            index = 1;
            break;
        case PICTURETYPE_FLATFRAME:
            index = 2;
            break;
        case PICTURETYPE_OFFSETFRAME:
            index = 3;
            break;
        default:
            return QVariant();      // we're outta here
        }

        // if (file.m_lNrChannels == 3)
        // index +=0;               // Use xxxxColour Icons
        if (IsCYMGType(file.GetCFAType()))
            index += 4;             // Use xxxxCMYG Icons
        else if (file.GetCFAType() != CFATYPE_NONE)
            index += 8;             // Use xxxxRGB Icons
        else
            index += 12;            // Use xxxxGreyscale Icons

        return ImageListModel::icons[index];
    }

       static inline const std::vector<QIcon> icons{
            QIcon("qrc:///stacking/LightColour.png"),
            QIcon("qrc:///stacking/DarkColour.png"),
            QIcon("qrc:///stacking/FlatColour.png"),
            QIcon("qrc:///stacking/BiasColour.png"),
            QIcon("qrc:///stacking/LightCMYG.png"),
            QIcon("qrc:///stacking/DarkCMYG.png"),
            QIcon("qrc:///stacking/FlatCMYG.png"),
            QIcon("qrc:///stacking/BiasCMYG.png"),
            QIcon("qrc:///stacking/LightRGB.png"),
            QIcon("qrc:///stacking/DarkRGB.png"),
            QIcon("qrc:///stacking/FlatRGB.png"),
            QIcon("qrc:///stacking/BiasRGB.png"),
            QIcon("qrc:///stacking/LightGreyscale.png"),
            QIcon("qrc:///stacking/DarkGreyscale.png"),
            QIcon("qrc:///stacking/FlatGreyscale.png"),
            QIcon("qrc:///stacking/BiasGreyscale.png")
        };

which all seems to make sense to me - expect that I see no Icon displayed for column zero, even though I chased through rowIcon() in the debugger and could see a valid index being calculated, and the icons vector looks fine in the debugger too.

[mpergand]

@Perdrix
Check QIcon::isNull()

[SGaist]

Hi,

In addition to @mpergand checks, shouldn't your path start with ":/" since it's a file path and not a URL ?

[Perdrix]

@mpergand said in QTableView not displaying Icon for column zero:

@Perdrix
Check QIcon::isNull()

Roger- wilco

[Perdrix]

@SGaist said in QTableView not displaying Icon for column zero:

Hi,

In addition to @mpergand checks, shouldn't your path start with ":/" since it's a file path and not a URL ?

I don't know: The docs I am looking at say:

By default, resources are accessible in the application under the same file name as they have in the source tree, with a :/ prefix, or by a URL with a qrc scheme.
For example, the file path :/images/cut.png or the URL qrc:///images/cut.png would give access to the cut.png file, whose location in the application's source tree is images/cut.png. This can be changed using the file tag's alias attribute:
<file alias="cut-img.png">images/cut.png</file>

so I used the qrc::/// format - I will try the :/ format

[SGaist]

QIcon takes a file path, not a QUrl.

[Perdrix]

Gotcha

I changed the code to use :/ instead of qrc:/// and added code to the end of rowIcon() so the end of it now reads:

        if (ImageListModel::icons[index].isNull())
        {
            qDebug("null icon");
        }
        return ImageListModel::icons[index];
    }

and the qDebug line isn't triggered, so I guess the code is returning a valid QIcon.

Sadly no Icon is displayed :(

[SGaist]

What if you test with the full path to the file system ?

[ChrisW67]

Also check that your code is not exiting via the return in the switch default.

[Perdrix]

@ChrisW67 said in QTableView not displaying Icon for column zero:

Also check that your code is not exiting via the return in the switch default.

Yes, I checked that under the debugger - never hit that path.

[Perdrix]

@SGaist Aha! That was much more interesting:

So it looks like I can't use that form of static initialisation for the array of Icons. I'm somewhat surprised I didn't get that error when using the ":/" format!

I'll see what other solution I can come up with to initialise that array.

Thank you

[Perdrix]

I added this to the ctor:

    //
    // Populate the Icon array if it's not already been done
    //
    if (0 == ImageListModel::icons.size())
    {
        std::lock_guard lock(ImageListModel::mutex);
        if (0 == ImageListModel::icons.size())          // check for race condtion
        {
            ImageListModel::icons.emplace_back(":/stacking/LightColour.png");
            // etc
        }
    }

That worked just fine - thank you again for the push to try with filepaths which exposed the real issue.