<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- calendarwidget.qdoc --> <title>Calendar Widget 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 >Calendar Widget 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="#window-class-definition">Window Class Definition</a></li> <li class="level1"><a href="#window-class-implementation">Window Class Implementation</a></li> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">Calendar Widget Example</h1> <span class="subtitle"></span> <!-- $$$widgets/calendarwidget-brief --> <p>The Calendar Widget example shows use of <a href="qcalendarwidget.html">QCalendarWidget</a>.</p> <!-- @@@widgets/calendarwidget --> <!-- $$$widgets/calendarwidget-description --> <div class="descr"> <a name="details"></a> <div class="border"><p class="centerAlign"><img src="images/calendarwidgetexample.png" alt="" /></p></div><p><a href="qcalendarwidget.html">QCalendarWidget</a> displays one calendar month at a time and lets the user select a date. The calendar consists of four components: a navigation bar that lets the user change the month that is displayed, a grid where each cell represents one day in the month, and two headers that display weekday names and week numbers.</p> <p>The Calendar Widget example displays a <a href="qcalendarwidget.html">QCalendarWidget</a> and lets the user configure its appearance and behavior using <a href="qcombobox.html">QComboBox</a>es, <a href="qcheckbox.html">QCheckBox</a>es, and <a href="qdateedit.html">QDateEdit</a>s. In addition, the user can influence the formatting of individual dates and headers.</p> <p>The properties of the <a href="qcalendarwidget.html">QCalendarWidget</a> are summarized in the table below.</p> <div class="table"><table class="generic"> <thead><tr class="qt-style"><th >Property</th><th >Description</th></tr></thead> <tr valign="top" class="odd"><td ><a href="qcalendarwidget.html#selectedDate-prop">selectedDate</a></td><td >The currently selected date.</td></tr> <tr valign="top" class="even"><td ><a href="qcalendarwidget.html#minimumDate-prop">minimumDate</a></td><td >The earliest date that can be selected.</td></tr> <tr valign="top" class="odd"><td ><a href="qcalendarwidget.html#maximumDate-prop">maximumDate</a></td><td >The latest date that can be selected.</td></tr> <tr valign="top" class="even"><td ><a href="qcalendarwidget.html#firstDayOfWeek-prop">firstDayOfWeek</a></td><td >The day that is displayed as the first day of the week (usually Sunday or Monday).</td></tr> <tr valign="top" class="odd"><td ><a href="qcalendarwidget.html#gridVisible-prop">gridVisible</a></td><td >Whether the grid should be shown.</td></tr> <tr valign="top" class="even"><td ><a href="qcalendarwidget.html#selectionMode-prop">selectionMode</a></td><td >Whether the user can select a date or not.</td></tr> <tr valign="top" class="odd"><td ><a href="qcalendarwidget.html#horizontalHeaderFormat-prop">horizontalHeaderFormat</a></td><td >The format of the day names in the horizontal header (e.g., "M", "Mon", or "Monday").</td></tr> <tr valign="top" class="even"><td ><a href="qcalendarwidget.html#verticalHeaderFormat-prop">verticalHeaderFormat</a></td><td >The format of the vertical header.</td></tr> <tr valign="top" class="odd"><td ><a href="qcalendarwidget.html#navigationBarVisible-prop">navigationBarVisible</a></td><td >Whether the navigation bar at the top of the calendar widget is shown.</td></tr> </table></div> <p>The example consists of one class, <code>Window</code>, which creates and lays out the <a href="qcalendarwidget.html">QCalendarWidget</a> and the other widgets that let the user configure the <a href="qcalendarwidget.html">QCalendarWidget</a>.</p> <a name="window-class-definition"></a> <h2 id="window-class-definition">Window Class Definition</h2> <p>Here is the definition of the <code>Window</code> class:</p> <pre class="cpp"> <span class="keyword">class</span> Window : <span class="keyword">public</span> <span class="type"><a href="qwidget.html">QWidget</a></span> { Q_OBJECT <span class="keyword">public</span>: Window(); <span class="keyword">private</span> <span class="keyword">slots</span>: <span class="type">void</span> localeChanged(<span class="type">int</span> index); <span class="type">void</span> firstDayChanged(<span class="type">int</span> index); <span class="type">void</span> selectionModeChanged(<span class="type">int</span> index); <span class="type">void</span> horizontalHeaderChanged(<span class="type">int</span> index); <span class="type">void</span> verticalHeaderChanged(<span class="type">int</span> index); <span class="type">void</span> selectedDateChanged(); <span class="type">void</span> minimumDateChanged(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qdate.html">QDate</a></span> <span class="operator">&</span>date); <span class="type">void</span> maximumDateChanged(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qdate.html">QDate</a></span> <span class="operator">&</span>date); <span class="type">void</span> weekdayFormatChanged(); <span class="type">void</span> weekendFormatChanged(); <span class="type">void</span> reformatHeaders(); <span class="type">void</span> reformatCalendarPage(); <span class="keyword">private</span>: <span class="type">void</span> createPreviewGroupBox(); <span class="type">void</span> createGeneralOptionsGroupBox(); <span class="type">void</span> createDatesGroupBox(); <span class="type">void</span> createTextFormatsGroupBox(); <span class="type"><a href="qcombobox.html">QComboBox</a></span> <span class="operator">*</span>createColorComboBox(); <span class="type"><a href="qgroupbox.html">QGroupBox</a></span> <span class="operator">*</span>previewGroupBox; <span class="type"><a href="qgridlayout.html">QGridLayout</a></span> <span class="operator">*</span>previewLayout; <span class="type"><a href="qcalendarwidget.html">QCalendarWidget</a></span> <span class="operator">*</span>calendar; <span class="type"><a href="qgroupbox.html">QGroupBox</a></span> <span class="operator">*</span>generalOptionsGroupBox; <span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>localeLabel; <span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>firstDayLabel; ... <span class="type"><a href="qcheckbox.html">QCheckBox</a></span> <span class="operator">*</span>mayFirstCheckBox; }; </pre> <p>As is often the case with classes that represent self-contained windows, most of the API is private. We will review the private members as we stumble upon them in the implementation.</p> <a name="window-class-implementation"></a> <h2 id="window-class-implementation">Window Class Implementation</h2> <p>Let's now review the class implementation, starting with the constructor:</p> <pre class="cpp"> Window<span class="operator">::</span>Window() { createPreviewGroupBox(); createGeneralOptionsGroupBox(); createDatesGroupBox(); createTextFormatsGroupBox(); <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(previewGroupBox<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(generalOptionsGroupBox<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(datesGroupBox<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(textFormatsGroupBox<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>setSizeConstraint(<span class="type"><a href="qlayout.html">QLayout</a></span><span class="operator">::</span>SetFixedSize); setLayout(layout); previewLayout<span class="operator">-</span><span class="operator">></span>setRowMinimumHeight(<span class="number">0</span><span class="operator">,</span> calendar<span class="operator">-</span><span class="operator">></span>sizeHint()<span class="operator">.</span>height()); previewLayout<span class="operator">-</span><span class="operator">></span>setColumnMinimumWidth(<span class="number">0</span><span class="operator">,</span> calendar<span class="operator">-</span><span class="operator">></span>sizeHint()<span class="operator">.</span>width()); setWindowTitle(tr(<span class="string">"Calendar Widget"</span>)); } </pre> <p>We start by creating the four <a href="qgroupbox.html">QGroupBox</a>es and their child widgets (including the <a href="qcalendarwidget.html">QCalendarWidget</a>) using four private <code>create...GroupBox()</code> functions, described below. Then we arrange the group boxes in a <a href="qgridlayout.html">QGridLayout</a>.</p> <p>We set the grid layout's resize policy to <a href="qlayout.html#SizeConstraint-enum">QLayout::SetFixedSize</a> to prevent the user from resizing the window. In that mode, the window's size is set automatically by <a href="qgridlayout.html">QGridLayout</a> based on the size hints of its contents widgets.</p> <p>To ensure that the window isn't automatically resized every time we change a property of the <a href="qcalendarwidget.html">QCalendarWidget</a> (for example, hiding the navigation bar, the vertical header, or the grid), we set the minimum height of row 0 and the minimum width of column 0 to the initial size of the <a href="qcalendarwidget.html">QCalendarWidget</a>.</p> <p>Let's move on to the <code>createPreviewGroupBox()</code> function:</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>createPreviewGroupBox() { previewGroupBox <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qgroupbox.html">QGroupBox</a></span>(tr(<span class="string">"Preview"</span>)); calendar <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qcalendarwidget.html">QCalendarWidget</a></span>; calendar<span class="operator">-</span><span class="operator">></span>setMinimumDate(<span class="type"><a href="../qtcore/qdate.html">QDate</a></span>(<span class="number">1900</span><span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">1</span>)); calendar<span class="operator">-</span><span class="operator">></span>setMaximumDate(<span class="type"><a href="../qtcore/qdate.html">QDate</a></span>(<span class="number">3000</span><span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">1</span>)); calendar<span class="operator">-</span><span class="operator">></span>setGridVisible(<span class="keyword">true</span>); connect(calendar<span class="operator">,</span> SIGNAL(currentPageChanged(<span class="type">int</span><span class="operator">,</span><span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(reformatCalendarPage())); previewLayout <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qgridlayout.html">QGridLayout</a></span>; previewLayout<span class="operator">-</span><span class="operator">></span>addWidget(calendar<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>AlignCenter); previewGroupBox<span class="operator">-</span><span class="operator">></span>setLayout(previewLayout); } </pre> <p>The <b>Preview</b> group box contains only one widget: the <a href="qcalendarwidget.html">QCalendarWidget</a>. We set it up, connect its <a href="qcalendarwidget.html#currentPageChanged">currentPageChanged()</a> signal to our <code>reformatCalendarPage()</code> slot to make sure that every new page gets the formatting specified by the user.</p> <p>The <code>createGeneralOptionsGroupBox()</code> function is somewhat large and several widgets are set up in the same way. We will look at parts of its implementation here and skip the rest:</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>createGeneralOptionsGroupBox() { generalOptionsGroupBox <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qgroupbox.html">QGroupBox</a></span>(tr(<span class="string">"General Options"</span>)); localeCombo <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qcombobox.html">QComboBox</a></span>; <span class="type">int</span> curLocaleIndex <span class="operator">=</span> <span class="operator">-</span><span class="number">1</span>; <span class="type">int</span> index <span class="operator">=</span> <span class="number">0</span>; <span class="keyword">for</span> (<span class="type">int</span> _lang <span class="operator">=</span> <span class="type"><a href="../qtcore/qlocale.html">QLocale</a></span><span class="operator">::</span>C; _lang <span class="operator"><</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qlocale.html">QLocale</a></span><span class="operator">::</span>LastLanguage; <span class="operator">+</span><span class="operator">+</span>_lang) { <span class="type"><a href="../qtcore/qlocale.html">QLocale</a></span><span class="operator">::</span>Language lang <span class="operator">=</span> <span class="keyword">static_cast</span><span class="operator"><</span><span class="type"><a href="../qtcore/qlocale.html">QLocale</a></span><span class="operator">::</span>Language<span class="operator">></span>(_lang); <span class="type"><a href="../qtcore/qlist.html">QList</a></span><span class="operator"><</span><span class="type"><a href="../qtcore/qlocale.html">QLocale</a></span><span class="operator">::</span>Country<span class="operator">></span> countries <span class="operator">=</span> <span class="type"><a href="../qtcore/qlocale.html">QLocale</a></span><span class="operator">::</span>countriesForLanguage(lang); <span class="keyword">for</span> (<span class="type">int</span> i <span class="operator">=</span> <span class="number">0</span>; i <span class="operator"><</span> countries<span class="operator">.</span>count(); <span class="operator">+</span><span class="operator">+</span>i) { <span class="type"><a href="../qtcore/qlocale.html">QLocale</a></span><span class="operator">::</span>Country country <span class="operator">=</span> countries<span class="operator">.</span>at(i); <span class="type"><a href="../qtcore/qstring.html">QString</a></span> label <span class="operator">=</span> <span class="type"><a href="../qtcore/qlocale.html">QLocale</a></span><span class="operator">::</span>languageToString(lang); label <span class="operator">+</span><span class="operator">=</span> QLatin1Char(<span class="char">'/'</span>); label <span class="operator">+</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qlocale.html">QLocale</a></span><span class="operator">::</span>countryToString(country); <span class="type"><a href="../qtcore/qlocale.html">QLocale</a></span> locale(lang<span class="operator">,</span> country); <span class="keyword">if</span> (<span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>locale()<span class="operator">.</span>language() <span class="operator">=</span><span class="operator">=</span> lang <span class="operator">&</span><span class="operator">&</span> <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>locale()<span class="operator">.</span>country() <span class="operator">=</span><span class="operator">=</span> country) curLocaleIndex <span class="operator">=</span> index; localeCombo<span class="operator">-</span><span class="operator">></span>addItem(label<span class="operator">,</span> locale); <span class="operator">+</span><span class="operator">+</span>index; } } <span class="keyword">if</span> (curLocaleIndex <span class="operator">!</span><span class="operator">=</span> <span class="operator">-</span><span class="number">1</span>) localeCombo<span class="operator">-</span><span class="operator">></span>setCurrentIndex(curLocaleIndex); localeLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(tr(<span class="string">"&Locale"</span>)); localeLabel<span class="operator">-</span><span class="operator">></span>setBuddy(localeCombo); firstDayCombo <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qcombobox.html">QComboBox</a></span>; firstDayCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Sunday"</span>)<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Sunday); firstDayCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Monday"</span>)<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Monday); firstDayCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Tuesday"</span>)<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Tuesday); firstDayCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Wednesday"</span>)<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Wednesday); firstDayCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Thursday"</span>)<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Thursday); firstDayCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Friday"</span>)<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Friday); firstDayCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Saturday"</span>)<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Saturday); firstDayLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(tr(<span class="string">"Wee&k starts on:"</span>)); firstDayLabel<span class="operator">-</span><span class="operator">></span>setBuddy(firstDayCombo); ... </pre> <p>We start with the setup of the <b>Week starts on</b> combobox. This combobox controls which day should be displayed as the first day of the week.</p> <p>The <a href="qcombobox.html">QComboBox</a> class lets us attach user data as a <a href="../qtcore/qvariant.html">QVariant</a> to each item. The data can later be retrieved with <a href="qcombobox.html">QComboBox</a>'s <a href="qcombobox.html#itemData">itemData()</a> function. <a href="../qtcore/qvariant.html">QVariant</a> doesn't directly support the <a href="../qtcore/qt.html#DayOfWeek-enum">Qt::DayOfWeek</a> data type, but it supports <code>int</code>, and C++ will happily convert any enum value to <code>int</code>.</p> <pre class="cpp"> ... connect(localeCombo<span class="operator">,</span> SIGNAL(currentIndexChanged(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(localeChanged(<span class="type">int</span>))); connect(firstDayCombo<span class="operator">,</span> SIGNAL(currentIndexChanged(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(firstDayChanged(<span class="type">int</span>))); connect(selectionModeCombo<span class="operator">,</span> SIGNAL(currentIndexChanged(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(selectionModeChanged(<span class="type">int</span>))); connect(gridCheckBox<span class="operator">,</span> SIGNAL(toggled(bool))<span class="operator">,</span> calendar<span class="operator">,</span> SLOT(setGridVisible(bool))); connect(navigationCheckBox<span class="operator">,</span> SIGNAL(toggled(bool))<span class="operator">,</span> calendar<span class="operator">,</span> SLOT(setNavigationBarVisible(bool))); connect(horizontalHeaderCombo<span class="operator">,</span> SIGNAL(currentIndexChanged(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(horizontalHeaderChanged(<span class="type">int</span>))); connect(verticalHeaderCombo<span class="operator">,</span> SIGNAL(currentIndexChanged(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(verticalHeaderChanged(<span class="type">int</span>))); ... </pre> <p>After having created the widgets, we connect the signals and slots. We connect the comboboxes to private slots of <code>Window</code> or to public slots provided by <a href="qcombobox.html">QComboBox</a>.</p> <pre class="cpp"> ... firstDayChanged(firstDayCombo<span class="operator">-</span><span class="operator">></span>currentIndex()); selectionModeChanged(selectionModeCombo<span class="operator">-</span><span class="operator">></span>currentIndex()); horizontalHeaderChanged(horizontalHeaderCombo<span class="operator">-</span><span class="operator">></span>currentIndex()); verticalHeaderChanged(verticalHeaderCombo<span class="operator">-</span><span class="operator">></span>currentIndex()); } </pre> <p>At the end of the function, we call the slots that update the calendar to ensure that the <a href="qcalendarwidget.html">QCalendarWidget</a> is synchronized with the other widgets on startup.</p> <p>Let's now take a look at the <code>createDatesGroupBox()</code> private function:</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>createDatesGroupBox() { datesGroupBox <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qgroupbox.html">QGroupBox</a></span>(tr(<span class="string">"Dates"</span>)); minimumDateEdit <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qdateedit.html">QDateEdit</a></span>; minimumDateEdit<span class="operator">-</span><span class="operator">></span>setDisplayFormat(<span class="string">"MMM d yyyy"</span>); minimumDateEdit<span class="operator">-</span><span class="operator">></span>setDateRange(calendar<span class="operator">-</span><span class="operator">></span>minimumDate()<span class="operator">,</span> calendar<span class="operator">-</span><span class="operator">></span>maximumDate()); minimumDateEdit<span class="operator">-</span><span class="operator">></span>setDate(calendar<span class="operator">-</span><span class="operator">></span>minimumDate()); minimumDateLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(tr(<span class="string">"&Minimum Date:"</span>)); minimumDateLabel<span class="operator">-</span><span class="operator">></span>setBuddy(minimumDateEdit); currentDateEdit <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qdateedit.html">QDateEdit</a></span>; currentDateEdit<span class="operator">-</span><span class="operator">></span>setDisplayFormat(<span class="string">"MMM d yyyy"</span>); currentDateEdit<span class="operator">-</span><span class="operator">></span>setDate(calendar<span class="operator">-</span><span class="operator">></span>selectedDate()); currentDateEdit<span class="operator">-</span><span class="operator">></span>setDateRange(calendar<span class="operator">-</span><span class="operator">></span>minimumDate()<span class="operator">,</span> calendar<span class="operator">-</span><span class="operator">></span>maximumDate()); currentDateLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(tr(<span class="string">"&Current Date:"</span>)); currentDateLabel<span class="operator">-</span><span class="operator">></span>setBuddy(currentDateEdit); maximumDateEdit <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qdateedit.html">QDateEdit</a></span>; maximumDateEdit<span class="operator">-</span><span class="operator">></span>setDisplayFormat(<span class="string">"MMM d yyyy"</span>); maximumDateEdit<span class="operator">-</span><span class="operator">></span>setDateRange(calendar<span class="operator">-</span><span class="operator">></span>minimumDate()<span class="operator">,</span> calendar<span class="operator">-</span><span class="operator">></span>maximumDate()); maximumDateEdit<span class="operator">-</span><span class="operator">></span>setDate(calendar<span class="operator">-</span><span class="operator">></span>maximumDate()); maximumDateLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(tr(<span class="string">"Ma&ximum Date:"</span>)); maximumDateLabel<span class="operator">-</span><span class="operator">></span>setBuddy(maximumDateEdit); </pre> <p>In this function, we create the <b>Minimum Date</b>, <b>Maximum Date</b>, and <b>Current Date</b> editor widgets, which control the calendar's minimum, maximum, and selected dates. The calendar's minimum and maximum dates have already been set in <code>createPrivewGroupBox()</code>; we can then set the widgets default values to the calendars values.</p> <pre class="cpp"> connect(currentDateEdit<span class="operator">,</span> SIGNAL(dateChanged(<span class="type"><a href="../qtcore/qdate.html">QDate</a></span>))<span class="operator">,</span> calendar<span class="operator">,</span> SLOT(setSelectedDate(<span class="type"><a href="../qtcore/qdate.html">QDate</a></span>))); connect(calendar<span class="operator">,</span> SIGNAL(selectionChanged())<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(selectedDateChanged())); connect(minimumDateEdit<span class="operator">,</span> SIGNAL(dateChanged(<span class="type"><a href="../qtcore/qdate.html">QDate</a></span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(minimumDateChanged(<span class="type"><a href="../qtcore/qdate.html">QDate</a></span>))); connect(maximumDateEdit<span class="operator">,</span> SIGNAL(dateChanged(<span class="type"><a href="../qtcore/qdate.html">QDate</a></span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(maximumDateChanged(<span class="type"><a href="../qtcore/qdate.html">QDate</a></span>))); ... } </pre> <p>We connect the <code>currentDateEdit</code>'s <a href="qdatetimeedit.html#dateChanged">dateChanged()</a> signal directly to the calendar's <a href="qcalendarwidget.html#selectedDate-prop">setSelectedDate()</a> slot. When the calendar's selected date changes, either as a result of a user action or programmatically, our <code>selectedDateChanged()</code> slot updates the <b>Current Date</b> editor. We also need to react when the user changes the <b>Minimum Date</b> and <b>Maximum Date</b> editors.</p> <p>Here is the <code>createTextFormatsGroup()</code> function:</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>createTextFormatsGroupBox() { textFormatsGroupBox <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qgroupbox.html">QGroupBox</a></span>(tr(<span class="string">"Text Formats"</span>)); weekdayColorCombo <span class="operator">=</span> createColorComboBox(); weekdayColorCombo<span class="operator">-</span><span class="operator">></span>setCurrentIndex( weekdayColorCombo<span class="operator">-</span><span class="operator">></span>findText(tr(<span class="string">"Black"</span>))); weekdayColorLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(tr(<span class="string">"&Weekday color:"</span>)); weekdayColorLabel<span class="operator">-</span><span class="operator">></span>setBuddy(weekdayColorCombo); weekendColorCombo <span class="operator">=</span> createColorComboBox(); weekendColorCombo<span class="operator">-</span><span class="operator">></span>setCurrentIndex( weekendColorCombo<span class="operator">-</span><span class="operator">></span>findText(tr(<span class="string">"Red"</span>))); weekendColorLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(tr(<span class="string">"Week&end color:"</span>)); weekendColorLabel<span class="operator">-</span><span class="operator">></span>setBuddy(weekendColorCombo); </pre> <p>We set up the <b>Weekday Color</b> and <b>Weekend Color</b> comboboxes using <code>createColorCombo()</code>, which instantiates a <a href="qcombobox.html">QComboBox</a> and populates it with colors ("Red", "Blue", etc.).</p> <pre class="cpp"> headerTextFormatCombo <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qcombobox.html">QComboBox</a></span>; headerTextFormatCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Bold"</span>)); headerTextFormatCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Italic"</span>)); headerTextFormatCombo<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Plain"</span>)); headerTextFormatLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(tr(<span class="string">"&Header text:"</span>)); headerTextFormatLabel<span class="operator">-</span><span class="operator">></span>setBuddy(headerTextFormatCombo); firstFridayCheckBox <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qcheckbox.html">QCheckBox</a></span>(tr(<span class="string">"&First Friday in blue"</span>)); mayFirstCheckBox <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qcheckbox.html">QCheckBox</a></span>(tr(<span class="string">"May &1 in red"</span>)); </pre> <p>The <b>Header Text Format</b> combobox lets the user change the text format (bold, italic, or plain) used for horizontal and vertical headers. The <b>First Friday in blue</b> and <b>May 1 in red</b> check box affect the rendering of specific dates.</p> <pre class="cpp"> connect(weekdayColorCombo<span class="operator">,</span> SIGNAL(currentIndexChanged(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(weekdayFormatChanged())); connect(weekdayColorCombo<span class="operator">,</span> SIGNAL(currentIndexChanged(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(reformatCalendarPage())); connect(weekendColorCombo<span class="operator">,</span> SIGNAL(currentIndexChanged(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(weekendFormatChanged())); connect(weekendColorCombo<span class="operator">,</span> SIGNAL(currentIndexChanged(<span class="type">int</span>))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(reformatCalendarPage())); connect(headerTextFormatCombo<span class="operator">,</span> SIGNAL(currentIndexChanged(<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(reformatHeaders())); connect(firstFridayCheckBox<span class="operator">,</span> SIGNAL(toggled(bool))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(reformatCalendarPage())); connect(mayFirstCheckBox<span class="operator">,</span> SIGNAL(toggled(bool))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(reformatCalendarPage())); </pre> <p>We connect the check boxes and comboboxes to various private slots. The <b>First Friday in blue</b> and <b>May 1 in red</b> check boxes are both connected to <code>reformatCalendarPage()</code>, which is also called when the calendar switches month.</p> <pre class="cpp"> ... reformatHeaders(); reformatCalendarPage(); } </pre> <p>At the end of <code>createTextFormatsGroupBox()</code>, we call private slots to synchronize the <a href="qcalendarwidget.html">QCalendarWidget</a> with the other widgets.</p> <p>We're now done reviewing the four <code>create...GroupBox()</code> functions. Let's now take a look at the other private functions and slots.</p> <pre class="cpp"> <span class="type"><a href="qcombobox.html">QComboBox</a></span> <span class="operator">*</span>Window<span class="operator">::</span>createColorComboBox() { <span class="type"><a href="qcombobox.html">QComboBox</a></span> <span class="operator">*</span>comboBox <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qcombobox.html">QComboBox</a></span>; comboBox<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Red"</span>)<span class="operator">,</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>red)); comboBox<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Blue"</span>)<span class="operator">,</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>blue)); comboBox<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Black"</span>)<span class="operator">,</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>black)); comboBox<span class="operator">-</span><span class="operator">></span>addItem(tr(<span class="string">"Magenta"</span>)<span class="operator">,</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>magenta)); <span class="keyword">return</span> comboBox; } </pre> <p>In <code>createColorCombo()</code>, we create a combobox and populate it with standard colors. The second argument to <a href="qcombobox.html#addItem">QComboBox::addItem</a>() is a <a href="../qtcore/qvariant.html">QVariant</a> storing user data (in this case, <a href="../qtgui/qcolor.html">QColor</a> objects).</p> <p>This function was used to set up the <b>Weekday Color</b> and <b>Weekend Color</b> comboboxes.</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>firstDayChanged(<span class="type">int</span> index) { calendar<span class="operator">-</span><span class="operator">></span>setFirstDayOfWeek(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>DayOfWeek( firstDayCombo<span class="operator">-</span><span class="operator">></span>itemData(index)<span class="operator">.</span>toInt())); } </pre> <p>When the user changes the <b>Week starts on</b> combobox's value, <code>firstDayChanged()</code> is invoked with the index of the combobox's new value. We retrieve the custom data item associated with the new current item using <a href="qcombobox.html#itemData">itemData()</a> and cast it to a <a href="../qtcore/qt.html#DayOfWeek-enum">Qt::DayOfWeek</a>.</p> <p><code>selectionModeChanged()</code>, <code>horizontalHeaderChanged()</code>, and <code>verticalHeaderChanged()</code> are very similar to <code>firstDayChanged()</code>, so they are omitted.</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>selectedDateChanged() { currentDateEdit<span class="operator">-</span><span class="operator">></span>setDate(calendar<span class="operator">-</span><span class="operator">></span>selectedDate()); } </pre> <p>The <code>selectedDateChanged()</code> updates the <b>Current Date</b> editor to reflect the current state of the <a href="qcalendarwidget.html">QCalendarWidget</a>.</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>minimumDateChanged(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qdate.html">QDate</a></span> <span class="operator">&</span>date) { calendar<span class="operator">-</span><span class="operator">></span>setMinimumDate(date); maximumDateEdit<span class="operator">-</span><span class="operator">></span>setDate(calendar<span class="operator">-</span><span class="operator">></span>maximumDate()); } </pre> <p>When the user changes the minimum date, we tell the QCalenderWidget. We also update the <b>Maximum Date</b> editor, because if the new minimum date is later than the current maximum date, <a href="qcalendarwidget.html">QCalendarWidget</a> will automatically adapt its maximum date to avoid a contradicting state.</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>maximumDateChanged(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qdate.html">QDate</a></span> <span class="operator">&</span>date) { calendar<span class="operator">-</span><span class="operator">></span>setMaximumDate(date); minimumDateEdit<span class="operator">-</span><span class="operator">></span>setDate(calendar<span class="operator">-</span><span class="operator">></span>minimumDate()); } </pre> <p><code>maximumDateChanged()</code> is implemented similarly to <code>minimumDateChanged()</code>.</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>weekdayFormatChanged() { <span class="type"><a href="../qtgui/qtextcharformat.html">QTextCharFormat</a></span> format; format<span class="operator">.</span>setForeground(qvariant_cast<span class="operator"><</span><span class="type"><a href="../qtgui/qcolor.html">QColor</a></span><span class="operator">></span>( weekdayColorCombo<span class="operator">-</span><span class="operator">></span>itemData(weekdayColorCombo<span class="operator">-</span><span class="operator">></span>currentIndex()))); calendar<span class="operator">-</span><span class="operator">></span>setWeekdayTextFormat(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Monday<span class="operator">,</span> format); calendar<span class="operator">-</span><span class="operator">></span>setWeekdayTextFormat(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Tuesday<span class="operator">,</span> format); calendar<span class="operator">-</span><span class="operator">></span>setWeekdayTextFormat(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Wednesday<span class="operator">,</span> format); calendar<span class="operator">-</span><span class="operator">></span>setWeekdayTextFormat(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Thursday<span class="operator">,</span> format); calendar<span class="operator">-</span><span class="operator">></span>setWeekdayTextFormat(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Friday<span class="operator">,</span> format); } </pre> <p>Each combobox item has a <a href="../qtgui/qcolor.html">QColor</a> object as user data corresponding to the item's text. After fetching the colors from the comboboxes, we set the text format of each day of the week.</p> <p>The text format of a column in the calendar is given as a <a href="../qtgui/qtextcharformat.html">QTextCharFormat</a>, which besides the foreground color lets us specify various character formatting information. In this example, we only show a subset of the possibilities.</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>weekendFormatChanged() { <span class="type"><a href="../qtgui/qtextcharformat.html">QTextCharFormat</a></span> format; format<span class="operator">.</span>setForeground(qvariant_cast<span class="operator"><</span><span class="type"><a href="../qtgui/qcolor.html">QColor</a></span><span class="operator">></span>( weekendColorCombo<span class="operator">-</span><span class="operator">></span>itemData(weekendColorCombo<span class="operator">-</span><span class="operator">></span>currentIndex()))); calendar<span class="operator">-</span><span class="operator">></span>setWeekdayTextFormat(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Saturday<span class="operator">,</span> format); calendar<span class="operator">-</span><span class="operator">></span>setWeekdayTextFormat(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Sunday<span class="operator">,</span> format); } </pre> <p><code>weekendFormatChanged()</code> is the same as <code>weekdayFormatChanged()</code>, except that it affects Saturday and Sunday instead of Monday to Friday.</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>reformatHeaders() { <span class="type"><a href="../qtcore/qstring.html">QString</a></span> text <span class="operator">=</span> headerTextFormatCombo<span class="operator">-</span><span class="operator">></span>currentText(); <span class="type"><a href="../qtgui/qtextcharformat.html">QTextCharFormat</a></span> format; <span class="keyword">if</span> (text <span class="operator">=</span><span class="operator">=</span> tr(<span class="string">"Bold"</span>)) { format<span class="operator">.</span>setFontWeight(<span class="type"><a href="../qtgui/qfont.html">QFont</a></span><span class="operator">::</span>Bold); } <span class="keyword">else</span> <span class="keyword">if</span> (text <span class="operator">=</span><span class="operator">=</span> tr(<span class="string">"Italic"</span>)) { format<span class="operator">.</span>setFontItalic(<span class="keyword">true</span>); } <span class="keyword">else</span> <span class="keyword">if</span> (text <span class="operator">=</span><span class="operator">=</span> tr(<span class="string">"Green"</span>)) { format<span class="operator">.</span>setForeground(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>green); } calendar<span class="operator">-</span><span class="operator">></span>setHeaderTextFormat(format); } </pre> <p>The <code>reformatHeaders()</code> slot is called when the user changes the text format of the headers. We compare the current text of the <b>Header Text Format</b> combobox to determine which format to apply. (An alternative would have been to store <a href="../qtgui/qtextcharformat.html">QTextCharFormat</a> values alongside the combobox items.)</p> <pre class="cpp"> <span class="type">void</span> Window<span class="operator">::</span>reformatCalendarPage() { <span class="type"><a href="../qtgui/qtextcharformat.html">QTextCharFormat</a></span> mayFirstFormat; <span class="keyword">const</span> <span class="type"><a href="../qtcore/qdate.html">QDate</a></span> mayFirst(calendar<span class="operator">-</span><span class="operator">></span>yearShown()<span class="operator">,</span> <span class="number">5</span><span class="operator">,</span> <span class="number">1</span>); <span class="type"><a href="../qtgui/qtextcharformat.html">QTextCharFormat</a></span> firstFridayFormat; <span class="type"><a href="../qtcore/qdate.html">QDate</a></span> firstFriday(calendar<span class="operator">-</span><span class="operator">></span>yearShown()<span class="operator">,</span> calendar<span class="operator">-</span><span class="operator">></span>monthShown()<span class="operator">,</span> <span class="number">1</span>); <span class="keyword">while</span> (firstFriday<span class="operator">.</span>dayOfWeek() <span class="operator">!</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Friday) firstFriday <span class="operator">=</span> firstFriday<span class="operator">.</span>addDays(<span class="number">1</span>); <span class="keyword">if</span> (firstFridayCheckBox<span class="operator">-</span><span class="operator">></span>isChecked()) { firstFridayFormat<span class="operator">.</span>setForeground(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>blue); } <span class="keyword">else</span> { <span class="comment">// Revert to regular colour for this day of the week.</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>DayOfWeek dayOfWeek(<span class="keyword">static_cast</span><span class="operator"><</span><span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>DayOfWeek<span class="operator">></span>(firstFriday<span class="operator">.</span>dayOfWeek())); firstFridayFormat<span class="operator">.</span>setForeground(calendar<span class="operator">-</span><span class="operator">></span>weekdayTextFormat(dayOfWeek)<span class="operator">.</span>foreground()); } calendar<span class="operator">-</span><span class="operator">></span>setDateTextFormat(firstFriday<span class="operator">,</span> firstFridayFormat); <span class="comment">// When it is checked, "May First in Red" always takes precedence over "First Friday in Blue".</span> <span class="keyword">if</span> (mayFirstCheckBox<span class="operator">-</span><span class="operator">></span>isChecked()) { mayFirstFormat<span class="operator">.</span>setForeground(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>red); } <span class="keyword">else</span> <span class="keyword">if</span> (<span class="operator">!</span>firstFridayCheckBox<span class="operator">-</span><span class="operator">></span>isChecked() <span class="operator">|</span><span class="operator">|</span> firstFriday <span class="operator">!</span><span class="operator">=</span> mayFirst) { <span class="comment">// We can now be certain we won't be resetting "May First in Red" when we restore</span> <span class="comment">// may 1st's regular colour for this day of the week.</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>DayOfWeek dayOfWeek(<span class="keyword">static_cast</span><span class="operator"><</span><span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>DayOfWeek<span class="operator">></span>(mayFirst<span class="operator">.</span>dayOfWeek())); calendar<span class="operator">-</span><span class="operator">></span>setDateTextFormat(mayFirst<span class="operator">,</span> calendar<span class="operator">-</span><span class="operator">></span>weekdayTextFormat(dayOfWeek)); } calendar<span class="operator">-</span><span class="operator">></span>setDateTextFormat(mayFirst<span class="operator">,</span> mayFirstFormat); } </pre> <p>In <code>reformatCalendarPage()</code>, we set the text format of the first Friday in the month and May 1 in the current year. The text formats that are actually used depend on which check boxes are checked and what the weekday/weekend formats are.</p> <p><a href="qcalendarwidget.html">QCalendarWidget</a> lets us set the text format of individual dates with the <a href="qcalendarwidget.html#setDateTextFormat">setDateTextFormat()</a>. We chose to set the date formats when the calendar page changes - i.e. a new month is displayed - and when the weekday/weekend format is changed. We check which of the <code>mayFirstCheckBox</code> and <code>firstDayCheckBox</code>, if any, are checked and set the text formats accordingly.</p> <p>Files:</p> <ul> <li><a href="qtwidgets-widgets-calendarwidget-calendarwidget-pro.html">widgets/calendarwidget/calendarwidget.pro</a></li> <li><a href="qtwidgets-widgets-calendarwidget-main-cpp.html">widgets/calendarwidget/main.cpp</a></li> <li><a href="qtwidgets-widgets-calendarwidget-window-cpp.html">widgets/calendarwidget/window.cpp</a></li> <li><a href="qtwidgets-widgets-calendarwidget-window-h.html">widgets/calendarwidget/window.h</a></li> </ul> </div> <!-- @@@widgets/calendarwidget --> </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>