title: QListView wrapping very slow
body: <p>I want to have a list view just like the one in Windows' file explorer: The data is shown into columns. So I set up a <code>QListView</code> with the code below.
  It looks totally the same (see picture).</p>
  
  <p>But one major drawback: When resizing the window, the wrapping is very slow. On the contrary, the Window's file browser is very fast.</p>
  
  <p>How can I speed up the wrapping in the QListView?</p>
  
  <p><a href="https://i.stack.imgur.com/FexU2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FexU2.png" alt="enter image description here"></a></p>
  
  <p>h:</p>
  
  <pre><code>class MainWindow : public QMainWindow
  {
      Q_OBJECT
  
  public:
      explicit MainWindow(QWidget *parent = 0);
      ~MainWindow();
  protected:
      void resizeEvent(QResizeEvent *);
  private:
      Ui::MainWindow *ui;
  };
  </code></pre>
  
  <p>cpp:</p>
  
  <pre><code>MainWindow::MainWindow(QWidget *parent) :
      QMainWindow(parent),
      ui(new Ui::MainWindow)
  {
      ui-&gt;setupUi(this);
      QStandardItemModel* m=new QStandardItemModel;
      for (int i=100;i&lt;1000;++i){
          m-&gt;insertRow(i-100,new QStandardItem(QString::number(i).repeated(5)+"   "));
      }
      ui-&gt;listView-&gt;setModel(m);
      ui-&gt;listView-&gt;setWrapping(true);
  }
  
  MainWindow::~MainWindow()
  {
      delete ui;
  }
  
  void MainWindow::resizeEvent(QResizeEvent *e)
  {
      QMainWindow::resizeEvent(e);
      ui-&gt;listView-&gt;setWrapping(ui-&gt;listView-&gt;isWrapping());
  }
  </code></pre>