<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- treemodelcompleter.qdoc --> <title>Tree Model Completer Example | Qt Widgets 5.12.6</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <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> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"> <div class="toc"> <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> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <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"> <!DOCTYPE RCC><RCC version="1.0"> <qresource prefix="/"> <file>resources/treemodel.txt</file> </qresource> </RCC> </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">&</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">&</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">&</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">&</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">&</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">></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">&</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">&</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">&</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 "File" menu and "Help" 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">></span>setModel(modelFromFile(<span class="string">":/resources/treemodel.txt"</span>)); completer<span class="operator">-</span><span class="operator">></span>setSeparator(QLatin1String(<span class="string">"."</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">></span>setText(tr(<span class="string">"Tree Model<br>(Double click items to edit)"</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">></span>setText(tr(<span class="string">"Completion Mode"</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">></span>addItem(tr(<span class="string">"Inline"</span>)); modeCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Filtered Popup"</span>)); modeCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Unfiltered Popup"</span>)); modeCombo<span class="operator">-</span><span class="operator">></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">></span>setText(tr(<span class="string">"Case Sensitivity"</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">></span>addItem(tr(<span class="string">"Case Insensitive"</span>)); caseCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Case Sensitive"</span>)); caseCombo<span class="operator">-</span><span class="operator">></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 "Filtered Popup" 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">></span>setText(tr(<span class="string">"Tree Separator"</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">></span>setText(completer<span class="operator">-</span><span class="operator">></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">></span>setText(tr(<span class="string">"Wrap around completions"</span>)); wrapCheckBox<span class="operator">-</span><span class="operator">></span>setChecked(completer<span class="operator">-</span><span class="operator">></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">></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">></span>setModel(completer<span class="operator">-</span><span class="operator">></span>model()); treeView<span class="operator">-</span><span class="operator">></span>header()<span class="operator">-</span><span class="operator">></span>hide(); treeView<span class="operator">-</span><span class="operator">></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">></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">></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">></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">></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">></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">></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">></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">></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">></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">></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">></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">></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">></span>setLayout(layout); setCentralWidget(centralWidget); changeCase(caseCombo<span class="operator">-</span><span class="operator">></span>currentIndex()); changeMode(modeCombo<span class="operator">-</span><span class="operator">></span>currentIndex()); setWindowTitle(tr(<span class="string">"Tree Model Completer"</span>)); lineEdit<span class="operator">-</span><span class="operator">></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 "File" menu and "Help" 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">"Exit"</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">"About"</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">"About Qt"</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">></span>addMenu(tr(<span class="string">"File"</span>)); fileMenu<span class="operator">-</span><span class="operator">></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">></span>addMenu(tr(<span class="string">"About"</span>)); helpMenu<span class="operator">-</span><span class="operator">></span>addAction(aboutAct); helpMenu<span class="operator">-</span><span class="operator">></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">></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">"About"</span>)<span class="operator">,</span> tr(<span class="string">"This example demonstrates how "</span> <span class="string">"to use a QCompleter with a custom tree model."</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">></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 --> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2019 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br/> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br/> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>