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<td >Qt 5.12</td><td ><a href="qtwidgets-index.html">Qt Widgets</a></td><td >Tree Model Completer Example</td></tr></table><table class="buildversion"><tr>
<td id="buildversion" width="100%" align="right"><a href="qtwidgets-index.html">Qt 5.12.6 Reference Documentation</a></td>
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<h3><a name="toc">Contents</a></h3>
<ul>
<li class="level1"><a href="#the-resource-file">The Resource File</a></li>
<li class="level1"><a href="#treemodelcompleter-class-definition">TreeModelCompleter Class Definition</a></li>
<li class="level1"><a href="#treemodelcompleter-class-implementation">TreeModelCompleter Class Implementation</a></li>
<li class="level1"><a href="#mainwindow-class-definition">MainWindow Class Definition</a></li>
<li class="level1"><a href="#mainwindow-class-implementation">MainWindow Class Implementation</a></li>
<li class="level1"><a href="#main-function"><code>main()</code> Function</a></li>
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<h1 class="title">Tree Model Completer Example</h1>
<span class="subtitle"></span>
<!-- $$$tools/treemodelcompleter-brief -->
<p>The Tree Model Completer example shows how to provide completion facilities for a hierarchical model, using a period as the separator to access Child, GrandChild and GrandGrandChild level objects.</p>
<!-- @@@tools/treemodelcompleter -->
<!-- $$$tools/treemodelcompleter-description -->
<div class="descr"> <a name="details"></a>
<p class="centerAlign"><img src="images/treemodelcompleter-example.png" alt="" /></p><p>Similar to the <a href="qtwidgets-tools-completer-example.html">Completer Example</a>, we provide <a href="qcombobox.html">QComboBox</a> objects to enable selection for completion mode and case sensitivity, as well as a <a href="qcheckbox.html">QCheckBox</a> for wrap completions.</p>
<a name="the-resource-file"></a>
<h2 id="the-resource-file">The Resource File</h2>
<p>The contents of the TreeModelCompleter is read from <i>treemodel.txt</i>. This file is embedded within the <i>treemodelcompleter.qrc</i> resource file, which contains the following:</p>
<pre class="cpp">

  &lt;!DOCTYPE RCC&gt;&lt;RCC version=&quot;1.0&quot;&gt;
  &lt;qresource prefix=&quot;/&quot;&gt;
     &lt;file&gt;resources/treemodel.txt&lt;/file&gt;
  &lt;/qresource&gt;
  &lt;/RCC&gt;

</pre>
<a name="treemodelcompleter-class-definition"></a>
<h2 id="treemodelcompleter-class-definition">TreeModelCompleter Class Definition</h2>
<p>The <code>TreeModelCompleter</code> is a subclass of <a href="qcompleter.html">QCompleter</a> with two constructors - one with <i>parent</i> as an argument and another with <i>parent</i> and <i>model</i> as arguments.</p>
<pre class="cpp">

  <span class="keyword">class</span> TreeModelCompleter : <span class="keyword">public</span> <span class="type"><a href="qcompleter.html">QCompleter</a></span>
  {
      Q_OBJECT
      Q_PROPERTY(<span class="type"><a href="../qtcore/qstring.html">QString</a></span> separator READ separator WRITE setSeparator)

  <span class="keyword">public</span>:
      <span class="keyword">explicit</span> TreeModelCompleter(<span class="type"><a href="../qtcore/qobject.html">QObject</a></span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span>);
      <span class="keyword">explicit</span> TreeModelCompleter(<span class="type"><a href="../qtcore/qabstractitemmodel.html">QAbstractItemModel</a></span> <span class="operator">*</span>model<span class="operator">,</span> <span class="type"><a href="../qtcore/qobject.html">QObject</a></span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span>);

      <span class="type"><a href="../qtcore/qstring.html">QString</a></span> separator() <span class="keyword">const</span>;
  <span class="keyword">public</span> <span class="keyword">slots</span>:
      <span class="type">void</span> setSeparator(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&amp;</span>separator);

  <span class="keyword">protected</span>:
      <span class="type"><a href="../qtcore/qstringlist.html">QStringList</a></span> splitPath(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&amp;</span>path) <span class="keyword">const</span> override;
      <span class="type"><a href="../qtcore/qstring.html">QString</a></span> pathFromIndex(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span> <span class="operator">&amp;</span>index) <span class="keyword">const</span> override;

  <span class="keyword">private</span>:
      <span class="type"><a href="../qtcore/qstring.html">QString</a></span> sep;
  };

</pre>
<p>The class reimplements the protected functions <a href="qcompleter.html#splitPath">splitPath()</a> and <a href="qcompleter.html#pathFromIndex">pathFromIndex()</a> to suit a tree model. For more information on customizing <a href="qcompleter.html">QCompleter</a> to suit tree models, refer to <a href="qcompleter.html#handling-tree-models">Handling Tree Models</a>.</p>
<p><code>TreeModelCompleter</code> also has a separator property which is declared using the <a href="../qtcore/qobject.html#Q_PROPERTY">Q_PROPERTY</a>() macro. The separator has READ and WRITE attributes and the corresponding functions <code>separator()</code> and <code>setSeparator()</code>. For more information on <a href="../qtcore/qobject.html#Q_PROPERTY">Q_PROPERTY</a>(), refer to <a href="../qtcore/properties.html">Qt's Property System</a>.</p>
<a name="treemodelcompleter-class-implementation"></a>
<h2 id="treemodelcompleter-class-implementation">TreeModelCompleter Class Implementation</h2>
<p>The first constructor constructs a <code>TreeModelCompleter</code> object with a parent while the second constructor constructs an object with a parent and a <a href="../qtcore/qabstractitemmodel.html">QAbstractItemModel</a>, <i>model</i>.</p>
<pre class="cpp">

  TreeModelCompleter<span class="operator">::</span>TreeModelCompleter(<span class="type"><a href="../qtcore/qobject.html">QObject</a></span> <span class="operator">*</span>parent)
      : <span class="type"><a href="qcompleter.html">QCompleter</a></span>(parent)
  {
  }

  TreeModelCompleter<span class="operator">::</span>TreeModelCompleter(<span class="type"><a href="../qtcore/qabstractitemmodel.html">QAbstractItemModel</a></span> <span class="operator">*</span>model<span class="operator">,</span> <span class="type"><a href="../qtcore/qobject.html">QObject</a></span> <span class="operator">*</span>parent)
      : <span class="type"><a href="qcompleter.html">QCompleter</a></span>(model<span class="operator">,</span> parent)
  {
  }

</pre>
<p>The <code>separator()</code> function is a getter function that returns the separator string.</p>
<pre class="cpp">

  <span class="type"><a href="../qtcore/qstring.html">QString</a></span> TreeModelCompleter<span class="operator">::</span>separator() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> sep;
  }

</pre>
<p>As mentioned earlier, the <code>splitPath()</code> function is reimplemented because the default implementation is more suited to <a href="qfilesystemmodel.html">QFileSystemModel</a> or list models. In order for <a href="qcompleter.html">QCompleter</a> to split the path into a list of strings that are matched at each level, we split it using <a href="../qtcore/qstring.html#split-1">QString::split</a>() with <code>sep</code> as its separator.</p>
<pre class="cpp">

  <span class="type"><a href="../qtcore/qstringlist.html">QStringList</a></span> TreeModelCompleter<span class="operator">::</span>splitPath(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&amp;</span>path) <span class="keyword">const</span>
  {
      <span class="keyword">if</span> (sep<span class="operator">.</span>isNull()) {
          <span class="keyword">return</span> <span class="type"><a href="qcompleter.html">QCompleter</a></span><span class="operator">::</span>splitPath(path);
      }

      <span class="keyword">return</span> path<span class="operator">.</span>split(sep);
  }

</pre>
<p>The <code>pathFromIndex()</code> function returns data for the completionRole() for a tree model. This function is reimplemented as its default implementation is more suitable for list models. If there is no separator, we use <a href="qcompleter.html">QCompleter</a>'s default implementation, otherwise we use the <a href="../qtcore/qlist.html#prepend">prepend()</a> function to navigate upwards and accumulate the data. The function then returns a <a href="../qtcore/qstringlist.html">QStringList</a>, <code>dataList</code>, using a separator to join objects of different levels.</p>
<pre class="cpp">

  <span class="type"><a href="../qtcore/qstring.html">QString</a></span> TreeModelCompleter<span class="operator">::</span>pathFromIndex(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span> <span class="operator">&amp;</span>index) <span class="keyword">const</span>
  {
      <span class="keyword">if</span> (sep<span class="operator">.</span>isNull()) {
          <span class="keyword">return</span> <span class="type"><a href="qcompleter.html">QCompleter</a></span><span class="operator">::</span>pathFromIndex(index);
      }

      <span class="comment">// navigate up and accumulate data</span>
      <span class="type"><a href="../qtcore/qstringlist.html">QStringList</a></span> dataList;
      <span class="keyword">for</span> (<span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span> i <span class="operator">=</span> index; i<span class="operator">.</span>isValid(); i <span class="operator">=</span> i<span class="operator">.</span>parent()) {
          dataList<span class="operator">.</span>prepend(model()<span class="operator">-</span><span class="operator">&gt;</span>data(i<span class="operator">,</span> completionRole())<span class="operator">.</span>toString());
      }

      <span class="keyword">return</span> dataList<span class="operator">.</span>join(sep);
  }

</pre>
<a name="mainwindow-class-definition"></a>
<h2 id="mainwindow-class-definition">MainWindow Class Definition</h2>
<p>The <code>MainWindow</code> class is a subclass of <a href="qmainwindow.html">QMainWindow</a> and implements five custom slots: <code>about()</code>, <code>changeCase()</code>, <code>changeMode()</code>, <code>highlight()</code>, and <code>updateContentsLabel()</code>.</p>
<pre class="cpp">

  <span class="keyword">class</span> MainWindow : <span class="keyword">public</span> <span class="type"><a href="qmainwindow.html">QMainWindow</a></span>
  {
      Q_OBJECT

  <span class="keyword">public</span>:
      MainWindow(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span>);

  <span class="keyword">private</span> <span class="keyword">slots</span>:
      <span class="type">void</span> about();
      <span class="type">void</span> changeCase(<span class="type">int</span>);
      <span class="type">void</span> changeMode(<span class="type">int</span>);
      <span class="type">void</span> highlight(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span><span class="operator">&amp;</span>);
      <span class="type">void</span> updateContentsLabel(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span><span class="operator">&amp;</span>);

</pre>
<p>In addition, the class has two private functions, <code>createMenu()</code> and <code>modelFromFile()</code>, as well as private instances of <a href="qtreeview.html">QTreeView</a>, <a href="qcombobox.html">QComboBox</a>, <a href="qlabel.html">QLabel</a>, <code>TreeModelCompleter</code> and <a href="qlineedit.html">QLineEdit</a>.</p>
<pre class="cpp">

  <span class="keyword">private</span>:
      <span class="type">void</span> createMenu();
      <span class="type"><a href="../qtcore/qabstractitemmodel.html">QAbstractItemModel</a></span> <span class="operator">*</span>modelFromFile(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span><span class="operator">&amp;</span> fileName);

      <span class="type"><a href="qtreeview.html">QTreeView</a></span> <span class="operator">*</span>treeView;
      <span class="type"><a href="qcombobox.html">QComboBox</a></span> <span class="operator">*</span>caseCombo;
      <span class="type"><a href="qcombobox.html">QComboBox</a></span> <span class="operator">*</span>modeCombo;
      <span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>contentsLabel;
      TreeModelCompleter <span class="operator">*</span>completer;
      <span class="type"><a href="qlineedit.html">QLineEdit</a></span> <span class="operator">*</span>lineEdit;
  };

</pre>
<a name="mainwindow-class-implementation"></a>
<h2 id="mainwindow-class-implementation">MainWindow Class Implementation</h2>
<p>The <code>MainWindow</code>'s constructor creates a <code>MainWindow</code> object with a parent and initializes the <code>completer</code> and <code>lineEdit</code>. The <code>createMenu()</code> function is invoked to set up the &quot;File&quot; menu and &quot;Help&quot; menu. The <code>completer</code>'s model is set to the <a href="../qtcore/qabstractitemmodel.html">QAbstractItemModel</a> obtained from <code>modelFromFile()</code>, and the <a href="qcompleter.html#highlighted">highlighted()</a> signal is connected to <code>MainWindow</code>'s <code>highlight()</code> slot.</p>
<pre class="cpp">

  MainWindow<span class="operator">::</span>MainWindow(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent)
      : <span class="type"><a href="qmainwindow.html">QMainWindow</a></span>(parent)<span class="operator">,</span> completer(<span class="number">0</span>)<span class="operator">,</span> lineEdit(<span class="number">0</span>)
  {
      createMenu();

      completer <span class="operator">=</span> <span class="keyword">new</span> TreeModelCompleter(<span class="keyword">this</span>);
      completer<span class="operator">-</span><span class="operator">&gt;</span>setModel(modelFromFile(<span class="string">&quot;:/resources/treemodel.txt&quot;</span>));
      completer<span class="operator">-</span><span class="operator">&gt;</span>setSeparator(QLatin1String(<span class="string">&quot;.&quot;</span>));
      <span class="type"><a href="../qtcore/qobject.html">QObject</a></span><span class="operator">::</span>connect(completer<span class="operator">,</span> SIGNAL(highlighted(<span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span>))<span class="operator">,</span>
                       <span class="keyword">this</span><span class="operator">,</span> SLOT(highlight(<span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span>)));

      <span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>centralWidget <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qwidget.html">QWidget</a></span>;

      <span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>modelLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>;
      modelLabel<span class="operator">-</span><span class="operator">&gt;</span>setText(tr(<span class="string">&quot;Tree Model&lt;br&gt;(Double click items to edit)&quot;</span>));

      <span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>modeLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>;
      modeLabel<span class="operator">-</span><span class="operator">&gt;</span>setText(tr(<span class="string">&quot;Completion Mode&quot;</span>));
      modeCombo <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qcombobox.html">QComboBox</a></span>;
      modeCombo<span class="operator">-</span><span class="operator">&gt;</span>addItem(tr(<span class="string">&quot;Inline&quot;</span>));
      modeCombo<span class="operator">-</span><span class="operator">&gt;</span>addItem(tr(<span class="string">&quot;Filtered Popup&quot;</span>));
      modeCombo<span class="operator">-</span><span class="operator">&gt;</span>addItem(tr(<span class="string">&quot;Unfiltered Popup&quot;</span>));
      modeCombo<span class="operator">-</span><span class="operator">&gt;</span>setCurrentIndex(<span class="number">1</span>);

      <span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>caseLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>;
      caseLabel<span class="operator">-</span><span class="operator">&gt;</span>setText(tr(<span class="string">&quot;Case Sensitivity&quot;</span>));
      caseCombo <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qcombobox.html">QComboBox</a></span>;
      caseCombo<span class="operator">-</span><span class="operator">&gt;</span>addItem(tr(<span class="string">&quot;Case Insensitive&quot;</span>));
      caseCombo<span class="operator">-</span><span class="operator">&gt;</span>addItem(tr(<span class="string">&quot;Case Sensitive&quot;</span>));
      caseCombo<span class="operator">-</span><span class="operator">&gt;</span>setCurrentIndex(<span class="number">0</span>);

</pre>
<p>The <a href="qlabel.html">QLabel</a> objects <code>modelLabel</code>, <code>modeLabel</code> and <code>caseLabel</code> are instantiated. Also, the <a href="qcombobox.html">QComboBox</a> objects, <code>modeCombo</code> and <code>caseCombo</code>, are instantiated and populated. By default, the <code>completer</code>'s mode is &quot;Filtered Popup&quot; and the case is insensitive.</p>
<pre class="cpp">

      <span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>separatorLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>;
      separatorLabel<span class="operator">-</span><span class="operator">&gt;</span>setText(tr(<span class="string">&quot;Tree Separator&quot;</span>));

      <span class="type"><a href="qlineedit.html">QLineEdit</a></span> <span class="operator">*</span>separatorLineEdit <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlineedit.html">QLineEdit</a></span>;
      separatorLineEdit<span class="operator">-</span><span class="operator">&gt;</span>setText(completer<span class="operator">-</span><span class="operator">&gt;</span>separator());
      connect(separatorLineEdit<span class="operator">,</span> SIGNAL(textChanged(<span class="type"><a href="../qtcore/qstring.html">QString</a></span>))<span class="operator">,</span>
              completer<span class="operator">,</span> SLOT(setSeparator(<span class="type"><a href="../qtcore/qstring.html">QString</a></span>)));

      <span class="type"><a href="qcheckbox.html">QCheckBox</a></span> <span class="operator">*</span>wrapCheckBox <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qcheckbox.html">QCheckBox</a></span>;
      wrapCheckBox<span class="operator">-</span><span class="operator">&gt;</span>setText(tr(<span class="string">&quot;Wrap around completions&quot;</span>));
      wrapCheckBox<span class="operator">-</span><span class="operator">&gt;</span>setChecked(completer<span class="operator">-</span><span class="operator">&gt;</span>wrapAround());
      connect(wrapCheckBox<span class="operator">,</span> SIGNAL(clicked(bool))<span class="operator">,</span> completer<span class="operator">,</span> SLOT(setWrapAround(bool)));

      contentsLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>;
      contentsLabel<span class="operator">-</span><span class="operator">&gt;</span>setSizePolicy(<span class="type"><a href="qsizepolicy.html">QSizePolicy</a></span><span class="operator">::</span>Fixed<span class="operator">,</span> <span class="type"><a href="qsizepolicy.html">QSizePolicy</a></span><span class="operator">::</span>Fixed);
      connect(separatorLineEdit<span class="operator">,</span> SIGNAL(textChanged(<span class="type"><a href="../qtcore/qstring.html">QString</a></span>))<span class="operator">,</span>
              <span class="keyword">this</span><span class="operator">,</span> SLOT(updateContentsLabel(<span class="type"><a href="../qtcore/qstring.html">QString</a></span>)));

      treeView <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qtreeview.html">QTreeView</a></span>;
      treeView<span class="operator">-</span><span class="operator">&gt;</span>setModel(completer<span class="operator">-</span><span class="operator">&gt;</span>model());
      treeView<span class="operator">-</span><span class="operator">&gt;</span>header()<span class="operator">-</span><span class="operator">&gt;</span>hide();
      treeView<span class="operator">-</span><span class="operator">&gt;</span>expandAll();

      connect(modeCombo<span class="operator">,</span> SIGNAL(activated(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(changeMode(<span class="type">int</span>)));
      connect(caseCombo<span class="operator">,</span> SIGNAL(activated(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(changeCase(<span class="type">int</span>)));

      lineEdit <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlineedit.html">QLineEdit</a></span>;
      lineEdit<span class="operator">-</span><span class="operator">&gt;</span>setCompleter(completer);

</pre>
<p>We use a <a href="qgridlayout.html">QGridLayout</a> to place all the objects in the <code>MainWindow</code>.</p>
<pre class="cpp">

      <span class="type"><a href="qgridlayout.html">QGridLayout</a></span> <span class="operator">*</span>layout <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qgridlayout.html">QGridLayout</a></span>;
      layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(modelLabel<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span>); layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(treeView<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">1</span>);
      layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(modeLabel<span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">0</span>);  layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(modeCombo<span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">1</span>);
      layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(caseLabel<span class="operator">,</span> <span class="number">2</span><span class="operator">,</span> <span class="number">0</span>);  layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(caseCombo<span class="operator">,</span> <span class="number">2</span><span class="operator">,</span> <span class="number">1</span>);
      layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(separatorLabel<span class="operator">,</span> <span class="number">3</span><span class="operator">,</span> <span class="number">0</span>); layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(separatorLineEdit<span class="operator">,</span> <span class="number">3</span><span class="operator">,</span> <span class="number">1</span>);
      layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(wrapCheckBox<span class="operator">,</span> <span class="number">4</span><span class="operator">,</span> <span class="number">0</span>);
      layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(contentsLabel<span class="operator">,</span> <span class="number">5</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">2</span>);
      layout<span class="operator">-</span><span class="operator">&gt;</span>addWidget(lineEdit<span class="operator">,</span> <span class="number">6</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">2</span>);
      centralWidget<span class="operator">-</span><span class="operator">&gt;</span>setLayout(layout);
      setCentralWidget(centralWidget);

      changeCase(caseCombo<span class="operator">-</span><span class="operator">&gt;</span>currentIndex());
      changeMode(modeCombo<span class="operator">-</span><span class="operator">&gt;</span>currentIndex());

      setWindowTitle(tr(<span class="string">&quot;Tree Model Completer&quot;</span>));
      lineEdit<span class="operator">-</span><span class="operator">&gt;</span>setFocus();
  }

</pre>
<p>The <code>createMenu()</code> function sets up the <a href="qaction.html">QAction</a> objects required and adds them to the &quot;File&quot; menu and &quot;Help&quot; menu. The <a href="qaction.html#triggered">triggered()</a> signals from these actions are connected to their respective slots.</p>
<pre class="cpp">

  <span class="type">void</span> MainWindow<span class="operator">::</span>createMenu()
  {
      <span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>exitAction <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaction.html">QAction</a></span>(tr(<span class="string">&quot;Exit&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      <span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>aboutAct <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaction.html">QAction</a></span>(tr(<span class="string">&quot;About&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);
      <span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>aboutQtAct <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaction.html">QAction</a></span>(tr(<span class="string">&quot;About Qt&quot;</span>)<span class="operator">,</span> <span class="keyword">this</span>);

      connect(exitAction<span class="operator">,</span> SIGNAL(triggered())<span class="operator">,</span> <a href="qapplication.html#qApp">qApp</a><span class="operator">,</span> SLOT(quit()));
      connect(aboutAct<span class="operator">,</span> SIGNAL(triggered())<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(about()));
      connect(aboutQtAct<span class="operator">,</span> SIGNAL(triggered())<span class="operator">,</span> <a href="qapplication.html#qApp">qApp</a><span class="operator">,</span> SLOT(aboutQt()));

      <span class="type"><a href="qmenu.html">QMenu</a></span><span class="operator">*</span> fileMenu <span class="operator">=</span> menuBar()<span class="operator">-</span><span class="operator">&gt;</span>addMenu(tr(<span class="string">&quot;File&quot;</span>));
      fileMenu<span class="operator">-</span><span class="operator">&gt;</span>addAction(exitAction);

      <span class="type"><a href="qmenu.html">QMenu</a></span><span class="operator">*</span> helpMenu <span class="operator">=</span> menuBar()<span class="operator">-</span><span class="operator">&gt;</span>addMenu(tr(<span class="string">&quot;About&quot;</span>));
      helpMenu<span class="operator">-</span><span class="operator">&gt;</span>addAction(aboutAct);
      helpMenu<span class="operator">-</span><span class="operator">&gt;</span>addAction(aboutQtAct);
  }

</pre>
<p>The <code>changeMode()</code> function accepts an <i>index</i> corresponding to the user's choice of completion mode and changes the <code>completer</code>'s mode accordingly.</p>
<pre class="cpp">

  <span class="type">void</span> MainWindow<span class="operator">::</span>changeMode(<span class="type">int</span> index)
  {
      <span class="type"><a href="qcompleter.html">QCompleter</a></span><span class="operator">::</span>CompletionMode mode;
      <span class="keyword">if</span> (index <span class="operator">=</span><span class="operator">=</span> <span class="number">0</span>)
          mode <span class="operator">=</span> <span class="type"><a href="qcompleter.html">QCompleter</a></span><span class="operator">::</span>InlineCompletion;
      <span class="keyword">else</span> <span class="keyword">if</span> (index <span class="operator">=</span><span class="operator">=</span> <span class="number">1</span>)
          mode <span class="operator">=</span> <span class="type"><a href="qcompleter.html">QCompleter</a></span><span class="operator">::</span>PopupCompletion;
      <span class="keyword">else</span>
          mode <span class="operator">=</span> <span class="type"><a href="qcompleter.html">QCompleter</a></span><span class="operator">::</span>UnfilteredPopupCompletion;

      completer<span class="operator">-</span><span class="operator">&gt;</span>setCompletionMode(mode);
  }

</pre>
<p>The <code>about()</code> function provides a brief description on the Tree Model Completer example.</p>
<pre class="cpp">

  <span class="type">void</span> MainWindow<span class="operator">::</span>about()
  {
      <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>about(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">&quot;About&quot;</span>)<span class="operator">,</span> tr(<span class="string">&quot;This example demonstrates how &quot;</span>
          <span class="string">&quot;to use a QCompleter with a custom tree model.&quot;</span>));
  }

</pre>
<p>The <code>changeCase()</code> function alternates between <a href="../qtcore/qt.html#CaseSensitivity-enum">Case Sensitive</a> and <a href="../qtcore/qt.html#CaseSensitivity-enum">Case Insensitive</a> modes, depending on the value of <i>cs</i>.</p>
<pre class="cpp">

  <span class="type">void</span> MainWindow<span class="operator">::</span>changeCase(<span class="type">int</span> cs)
  {
      completer<span class="operator">-</span><span class="operator">&gt;</span>setCaseSensitivity(cs <span class="operator">?</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>CaseSensitive : <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>CaseInsensitive);
  }

</pre>
<a name="main-function"></a>
<h2 id="main-function"><code>main()</code> Function</h2>
<p>The <code>main()</code> function instantiates <code>MainWindow</code> and invokes the <a href="qwidget.html#show">show()</a> function to display it.</p>
<pre class="cpp">

  <span class="type">int</span> main(<span class="type">int</span> argc<span class="operator">,</span> <span class="type">char</span> <span class="operator">*</span>argv<span class="operator">[</span><span class="operator">]</span>)
  {
      Q_INIT_RESOURCE(treemodelcompleter);

      <span class="type"><a href="qapplication.html">QApplication</a></span> app(argc<span class="operator">,</span> argv);
      MainWindow window;
      window<span class="operator">.</span>show();
      <span class="keyword">return</span> app<span class="operator">.</span>exec();
  }

</pre>
<p>Files:</p>
<ul>
<li><a href="qtwidgets-tools-treemodelcompleter-main-cpp.html">tools/treemodelcompleter/main.cpp</a></li>
<li><a href="qtwidgets-tools-treemodelcompleter-mainwindow-cpp.html">tools/treemodelcompleter/mainwindow.cpp</a></li>
<li><a href="qtwidgets-tools-treemodelcompleter-mainwindow-h.html">tools/treemodelcompleter/mainwindow.h</a></li>
<li><a href="qtwidgets-tools-treemodelcompleter-treemodelcompleter-cpp.html">tools/treemodelcompleter/treemodelcompleter.cpp</a></li>
<li><a href="qtwidgets-tools-treemodelcompleter-treemodelcompleter-h.html">tools/treemodelcompleter/treemodelcompleter.h</a></li>
<li><a href="qtwidgets-tools-treemodelcompleter-treemodelcompleter-pro.html">tools/treemodelcompleter/treemodelcompleter.pro</a></li>
<li><a href="qtwidgets-tools-treemodelcompleter-treemodelcompleter-qrc.html">tools/treemodelcompleter/treemodelcompleter.qrc</a></li>
</ul>
</div>
<!-- @@@tools/treemodelcompleter -->
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