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POOverwrite data and setData in Qt's QFileSystemModel
 

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  1. POOverwrite data and setData in Qt's QFileSystemModel
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    <p>What I'am trying to do: Overwrite QFileSystemModel's setData and data to implement Caching of pictures in the shown directory.</p> <p>I use a QListView for testing purpose.</p> <p>Here is the relevant code:</p> <p>My Class with QFileSystemModel as parent: </p> <p>.h-file:</p> <pre><code>#ifndef QPICSINFILESYSTEMMODEL_H #define QPICSINFILESYSTEMMODEL_H #include &lt;QFileSystemModel&gt; #include &lt;QCache&gt; #include &lt;QDebug&gt; /* This Model holds all Picturefiles with a cached QPixmap of * them. */ class PicsInFileSystemModel : public QFileSystemModel { public: PicsInFileSystemModel(); QVariant data (const QModelIndex &amp; index, int role); private: QCache&lt;qint64,QPixmap&gt; *cache; //Cache for the pictures }; #endif // QPICSINFILESYSTEMMODEL_ </code></pre> <p>.cpp-file:</p> <pre><code>#include "PicsInFileSystemModel.h" PicsInFileSystemModel::PicsInFileSystemModel() { QStringList myFilter; this-&gt;setFilter(QDir::Files | QDir::AllDirs); this-&gt;setRootPath(QDir::rootPath());//QDir::homePath()); myFilter &lt;&lt; "jpeg" &lt;&lt; "jpg" &lt;&lt; "png"; //this-&gt;setNameFilters(myFilter); } /* Reimplement data to send the pictures to the cache */ QVariant PicsInFileSystemModel::data ( const QModelIndex &amp; index, int role = Qt::DisplayRole ) { qDebug() &lt;&lt; "index: " &lt;&lt; index &lt;&lt; "role: " &lt;&lt; role; return ((QFileSystemModel)this).data(index,role); } </code></pre> <p>How I call the object:</p> <pre><code>pics = new PicsInFileSystemModel; form-&gt;listViewPictures-&gt;setModel(pics); form-&gt;listViewPictures-&gt;setRootIndex(pics-&gt;index( "mypath")); </code></pre> <p>So here is the question: In my opinion I should see many debug outputs when the View access the Model. But there is nothing. Has anyone an idea what I'am doing wrong?</p> <p>Thanks!</p> <p>EDIT: The answers work. I also had to change this</p> <pre><code>return ((QFileSystemModel)this).data(index,role); </code></pre> <p>into</p> <pre><code>QFileSystemModel::data(index,role)) </code></pre>
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