title: QFileDialog: how to set default filename in "Save as..." dialog
body: <p>I try to create &quot;Save as...&quot; dialog in Mac OS X. But I don't want to use <code>QFileDialog::getSaveFileName()</code> function, because dialog that created by this function is <strong>NOT</strong> truly-native in Mac OS X Lion. So I decide to create dialog as <code>QFileDialog</code> object:</p>
  <pre><code>auto export_dialog( new QFileDialog( main_window ) );
  export_dialog-&gt;setWindowModality( Qt::WindowModal );
  export_dialog-&gt;setFileMode( QFileDialog::AnyFile );
  export_dialog-&gt;setAcceptMode( QFileDialog::AcceptSave );
  </code></pre>
  <p>All works fine, except one problem. I cannot set default name for saved file, so user must type this name manually every time. I know that function <code>QFileDialog::getSaveFileName()</code> allows to set default filename via third argument, <em>dir</em> (<a href="http://qt-project.org/doc/qt-4.8/qfiledialog.html#getSaveFileName" rel="nofollow noreferrer">http://qt-project.org/doc/qt-4.8/qfiledialog.html#getSaveFileName</a>). But how to set this default name without this function?</p>
  <p>I can set default suffix for saved file via <code>QFileDialog::setDefaultSuffix()</code> function, but I need to set whole default name, not only default suffix.</p>
  <p>I've tried to use <code>QFileDialog::setDirectory()</code> function, but it sets only directory where to save, without name of saved file.</p>
  <p>I use Qt 4.8.1 on Mac OS X Lion.</p>