<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>imageviewer.cpp Example File | 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 ><a href="qtwidgets-widgets-imageviewer-example.html">Image Viewer Example</a></td><td >imageviewer.cpp Example File</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="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">imageviewer.cpp Example File</h1> <span class="subtitle">widgets/imageviewer/imageviewer.cpp</span> <!-- $$$widgets/imageviewer/imageviewer.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** BSD License Usage ** Alternatively, you may use this file under the terms of the BSD license ** as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/</span> <span class="preprocessor">#include <QtWidgets></span> <span class="preprocessor">#if defined(QT_PRINTSUPPORT_LIB)</span> <span class="preprocessor">#include <QtPrintSupport/qtprintsupportglobal.h></span> <span class="preprocessor">#if QT_CONFIG(printdialog)</span> <span class="preprocessor">#include <QPrintDialog></span> <span class="preprocessor">#endif</span> <span class="preprocessor">#endif</span> <span class="preprocessor">#include "imageviewer.h"</span> ImageViewer<span class="operator">::</span>ImageViewer() : imageLabel(<span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>) <span class="operator">,</span> scrollArea(<span class="keyword">new</span> <span class="type"><a href="qscrollarea.html">QScrollArea</a></span>) <span class="operator">,</span> scaleFactor(<span class="number">1</span>) { imageLabel<span class="operator">-</span><span class="operator">></span>setBackgroundRole(<span class="type"><a href="../qtgui/qpalette.html">QPalette</a></span><span class="operator">::</span>Base); imageLabel<span class="operator">-</span><span class="operator">></span>setSizePolicy(<span class="type"><a href="qsizepolicy.html">QSizePolicy</a></span><span class="operator">::</span>Ignored<span class="operator">,</span> <span class="type"><a href="qsizepolicy.html">QSizePolicy</a></span><span class="operator">::</span>Ignored); imageLabel<span class="operator">-</span><span class="operator">></span>setScaledContents(<span class="keyword">true</span>); scrollArea<span class="operator">-</span><span class="operator">></span>setBackgroundRole(<span class="type"><a href="../qtgui/qpalette.html">QPalette</a></span><span class="operator">::</span>Dark); scrollArea<span class="operator">-</span><span class="operator">></span>setWidget(imageLabel); scrollArea<span class="operator">-</span><span class="operator">></span>setVisible(<span class="keyword">false</span>); setCentralWidget(scrollArea); createActions(); resize(<span class="type"><a href="../qtgui/qguiapplication.html">QGuiApplication</a></span><span class="operator">::</span>primaryScreen()<span class="operator">-</span><span class="operator">></span>availableSize() <span class="operator">*</span> <span class="number">3</span> <span class="operator">/</span> <span class="number">5</span>); } bool ImageViewer<span class="operator">::</span>loadFile(<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="../qtgui/qimagereader.html">QImageReader</a></span> reader(fileName); reader<span class="operator">.</span>setAutoTransform(<span class="keyword">true</span>); <span class="keyword">const</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span> newImage <span class="operator">=</span> reader<span class="operator">.</span>read(); <span class="keyword">if</span> (newImage<span class="operator">.</span>isNull()) { <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>information(<span class="keyword">this</span><span class="operator">,</span> <span class="type"><a href="../qtgui/qguiapplication.html">QGuiApplication</a></span><span class="operator">::</span>applicationDisplayName()<span class="operator">,</span> tr(<span class="string">"Cannot load %1: %2"</span>) <span class="operator">.</span>arg(<span class="type"><a href="../qtcore/qdir.html">QDir</a></span><span class="operator">::</span>toNativeSeparators(fileName)<span class="operator">,</span> reader<span class="operator">.</span>errorString())); <span class="keyword">return</span> <span class="keyword">false</span>; } setImage(newImage); setWindowFilePath(fileName); <span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> message <span class="operator">=</span> tr(<span class="string">"Opened \"%1\", %2x%3, Depth: %4"</span>) <span class="operator">.</span>arg(<span class="type"><a href="../qtcore/qdir.html">QDir</a></span><span class="operator">::</span>toNativeSeparators(fileName))<span class="operator">.</span>arg(image<span class="operator">.</span>width())<span class="operator">.</span>arg(image<span class="operator">.</span>height())<span class="operator">.</span>arg(image<span class="operator">.</span>depth()); statusBar()<span class="operator">-</span><span class="operator">></span>showMessage(message); <span class="keyword">return</span> <span class="keyword">true</span>; } <span class="type">void</span> ImageViewer<span class="operator">::</span>setImage(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span> <span class="operator">&</span>newImage) { image <span class="operator">=</span> newImage; imageLabel<span class="operator">-</span><span class="operator">></span>setPixmap(<span class="type"><a href="../qtgui/qpixmap.html">QPixmap</a></span><span class="operator">::</span>fromImage(image)); scaleFactor <span class="operator">=</span> <span class="number">1.0</span>; scrollArea<span class="operator">-</span><span class="operator">></span>setVisible(<span class="keyword">true</span>); printAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">true</span>); fitToWindowAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">true</span>); updateActions(); <span class="keyword">if</span> (<span class="operator">!</span>fitToWindowAct<span class="operator">-</span><span class="operator">></span>isChecked()) imageLabel<span class="operator">-</span><span class="operator">></span>adjustSize(); } bool ImageViewer<span class="operator">::</span>saveFile(<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="../qtgui/qimagewriter.html">QImageWriter</a></span> writer(fileName); <span class="keyword">if</span> (<span class="operator">!</span>writer<span class="operator">.</span>write(image)) { <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>information(<span class="keyword">this</span><span class="operator">,</span> <span class="type"><a href="../qtgui/qguiapplication.html">QGuiApplication</a></span><span class="operator">::</span>applicationDisplayName()<span class="operator">,</span> tr(<span class="string">"Cannot write %1: %2"</span>) <span class="operator">.</span>arg(<span class="type"><a href="../qtcore/qdir.html">QDir</a></span><span class="operator">::</span>toNativeSeparators(fileName))<span class="operator">,</span> writer<span class="operator">.</span>errorString()); <span class="keyword">return</span> <span class="keyword">false</span>; } <span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> message <span class="operator">=</span> tr(<span class="string">"Wrote \"%1\""</span>)<span class="operator">.</span>arg(<span class="type"><a href="../qtcore/qdir.html">QDir</a></span><span class="operator">::</span>toNativeSeparators(fileName)); statusBar()<span class="operator">-</span><span class="operator">></span>showMessage(message); <span class="keyword">return</span> <span class="keyword">true</span>; } <span class="keyword">static</span> <span class="type">void</span> initializeImageFileDialog(<span class="type"><a href="qfiledialog.html">QFileDialog</a></span> <span class="operator">&</span>dialog<span class="operator">,</span> <span class="type"><a href="qfiledialog.html">QFileDialog</a></span><span class="operator">::</span>AcceptMode acceptMode) { <span class="keyword">static</span> bool firstDialog <span class="operator">=</span> <span class="keyword">true</span>; <span class="keyword">if</span> (firstDialog) { firstDialog <span class="operator">=</span> <span class="keyword">false</span>; <span class="keyword">const</span> <span class="type"><a href="../qtcore/qstringlist.html">QStringList</a></span> picturesLocations <span class="operator">=</span> <span class="type"><a href="../qtcore/qstandardpaths.html">QStandardPaths</a></span><span class="operator">::</span>standardLocations(<span class="type"><a href="../qtcore/qstandardpaths.html">QStandardPaths</a></span><span class="operator">::</span>PicturesLocation); dialog<span class="operator">.</span>setDirectory(picturesLocations<span class="operator">.</span>isEmpty() <span class="operator">?</span> <span class="type"><a href="../qtcore/qdir.html">QDir</a></span><span class="operator">::</span>currentPath() : picturesLocations<span class="operator">.</span>last()); } <span class="type"><a href="../qtcore/qstringlist.html">QStringList</a></span> mimeTypeFilters; <span class="keyword">const</span> <span class="type"><a href="../qtcore/qbytearraylist.html">QByteArrayList</a></span> supportedMimeTypes <span class="operator">=</span> acceptMode <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qfiledialog.html">QFileDialog</a></span><span class="operator">::</span>AcceptOpen <span class="operator">?</span> <span class="type"><a href="../qtgui/qimagereader.html">QImageReader</a></span><span class="operator">::</span>supportedMimeTypes() : <span class="type"><a href="../qtgui/qimagewriter.html">QImageWriter</a></span><span class="operator">::</span>supportedMimeTypes(); foreach (<span class="keyword">const</span> <span class="type"><a href="../qtcore/qbytearray.html">QByteArray</a></span> <span class="operator">&</span>mimeTypeName<span class="operator">,</span> supportedMimeTypes) mimeTypeFilters<span class="operator">.</span>append(mimeTypeName); mimeTypeFilters<span class="operator">.</span>sort(); dialog<span class="operator">.</span>setMimeTypeFilters(mimeTypeFilters); dialog<span class="operator">.</span>selectMimeTypeFilter(<span class="string">"image/jpeg"</span>); <span class="keyword">if</span> (acceptMode <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qfiledialog.html">QFileDialog</a></span><span class="operator">::</span>AcceptSave) dialog<span class="operator">.</span>setDefaultSuffix(<span class="string">"jpg"</span>); } <span class="type">void</span> ImageViewer<span class="operator">::</span>open() { <span class="type"><a href="qfiledialog.html">QFileDialog</a></span> dialog(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">"Open File"</span>)); initializeImageFileDialog(dialog<span class="operator">,</span> <span class="type"><a href="qfiledialog.html">QFileDialog</a></span><span class="operator">::</span>AcceptOpen); <span class="keyword">while</span> (dialog<span class="operator">.</span>exec() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qdialog.html">QDialog</a></span><span class="operator">::</span>Accepted <span class="operator">&</span><span class="operator">&</span> <span class="operator">!</span>loadFile(dialog<span class="operator">.</span>selectedFiles()<span class="operator">.</span>first())) {} } <span class="type">void</span> ImageViewer<span class="operator">::</span>saveAs() { <span class="type"><a href="qfiledialog.html">QFileDialog</a></span> dialog(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">"Save File As"</span>)); initializeImageFileDialog(dialog<span class="operator">,</span> <span class="type"><a href="qfiledialog.html">QFileDialog</a></span><span class="operator">::</span>AcceptSave); <span class="keyword">while</span> (dialog<span class="operator">.</span>exec() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qdialog.html">QDialog</a></span><span class="operator">::</span>Accepted <span class="operator">&</span><span class="operator">&</span> <span class="operator">!</span>saveFile(dialog<span class="operator">.</span>selectedFiles()<span class="operator">.</span>first())) {} } <span class="type">void</span> ImageViewer<span class="operator">::</span>print() { Q_ASSERT(imageLabel<span class="operator">-</span><span class="operator">></span>pixmap()); <span class="preprocessor">#if QT_CONFIG(printdialog)</span> <span class="type">QPrintDialog</span> dialog(<span class="operator">&</span>printer<span class="operator">,</span> <span class="keyword">this</span>); <span class="keyword">if</span> (dialog<span class="operator">.</span>exec()) { <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&</span>printer); <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> rect <span class="operator">=</span> painter<span class="operator">.</span>viewport(); <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> size <span class="operator">=</span> imageLabel<span class="operator">-</span><span class="operator">></span>pixmap()<span class="operator">-</span><span class="operator">></span>size(); size<span class="operator">.</span>scale(rect<span class="operator">.</span>size()<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>KeepAspectRatio); painter<span class="operator">.</span>setViewport(rect<span class="operator">.</span>x()<span class="operator">,</span> rect<span class="operator">.</span>y()<span class="operator">,</span> size<span class="operator">.</span>width()<span class="operator">,</span> size<span class="operator">.</span>height()); painter<span class="operator">.</span>setWindow(imageLabel<span class="operator">-</span><span class="operator">></span>pixmap()<span class="operator">-</span><span class="operator">></span>rect()); painter<span class="operator">.</span>drawPixmap(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="operator">*</span>imageLabel<span class="operator">-</span><span class="operator">></span>pixmap()); } <span class="preprocessor">#endif</span> } <span class="type">void</span> ImageViewer<span class="operator">::</span>copy() { <span class="preprocessor">#ifndef QT_NO_CLIPBOARD</span> <span class="type"><a href="../qtgui/qguiapplication.html">QGuiApplication</a></span><span class="operator">::</span>clipboard()<span class="operator">-</span><span class="operator">></span>setImage(image); <span class="preprocessor">#endif // !QT_NO_CLIPBOARD</span> } <span class="preprocessor">#ifndef QT_NO_CLIPBOARD</span> <span class="keyword">static</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span> clipboardImage() { <span class="keyword">if</span> (<span class="keyword">const</span> <span class="type"><a href="../qtcore/qmimedata.html">QMimeData</a></span> <span class="operator">*</span>mimeData <span class="operator">=</span> <span class="type"><a href="../qtgui/qguiapplication.html">QGuiApplication</a></span><span class="operator">::</span>clipboard()<span class="operator">-</span><span class="operator">></span>mimeData()) { <span class="keyword">if</span> (mimeData<span class="operator">-</span><span class="operator">></span>hasImage()) { <span class="keyword">const</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span> image <span class="operator">=</span> qvariant_cast<span class="operator"><</span><span class="type"><a href="../qtgui/qimage.html">QImage</a></span><span class="operator">></span>(mimeData<span class="operator">-</span><span class="operator">></span>imageData()); <span class="keyword">if</span> (<span class="operator">!</span>image<span class="operator">.</span>isNull()) <span class="keyword">return</span> image; } } <span class="keyword">return</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span>(); } <span class="preprocessor">#endif // !QT_NO_CLIPBOARD</span> <span class="type">void</span> ImageViewer<span class="operator">::</span>paste() { <span class="preprocessor">#ifndef QT_NO_CLIPBOARD</span> <span class="keyword">const</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span> newImage <span class="operator">=</span> clipboardImage(); <span class="keyword">if</span> (newImage<span class="operator">.</span>isNull()) { statusBar()<span class="operator">-</span><span class="operator">></span>showMessage(tr(<span class="string">"No image in clipboard"</span>)); } <span class="keyword">else</span> { setImage(newImage); setWindowFilePath(<span class="type"><a href="../qtcore/qstring.html">QString</a></span>()); <span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> message <span class="operator">=</span> tr(<span class="string">"Obtained image from clipboard, %1x%2, Depth: %3"</span>) <span class="operator">.</span>arg(newImage<span class="operator">.</span>width())<span class="operator">.</span>arg(newImage<span class="operator">.</span>height())<span class="operator">.</span>arg(newImage<span class="operator">.</span>depth()); statusBar()<span class="operator">-</span><span class="operator">></span>showMessage(message); } <span class="preprocessor">#endif // !QT_NO_CLIPBOARD</span> } <span class="type">void</span> ImageViewer<span class="operator">::</span>zoomIn() { scaleImage(<span class="number">1.25</span>); } <span class="type">void</span> ImageViewer<span class="operator">::</span>zoomOut() { scaleImage(<span class="number">0.8</span>); } <span class="type">void</span> ImageViewer<span class="operator">::</span>normalSize() { imageLabel<span class="operator">-</span><span class="operator">></span>adjustSize(); scaleFactor <span class="operator">=</span> <span class="number">1.0</span>; } <span class="type">void</span> ImageViewer<span class="operator">::</span>fitToWindow() { bool fitToWindow <span class="operator">=</span> fitToWindowAct<span class="operator">-</span><span class="operator">></span>isChecked(); scrollArea<span class="operator">-</span><span class="operator">></span>setWidgetResizable(fitToWindow); <span class="keyword">if</span> (<span class="operator">!</span>fitToWindow) normalSize(); updateActions(); } <span class="type">void</span> ImageViewer<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 Image Viewer"</span>)<span class="operator">,</span> tr(<span class="string">"<p>The <b>Image Viewer</b> example shows how to combine QLabel "</span> <span class="string">"and QScrollArea to display an image. QLabel is typically used "</span> <span class="string">"for displaying a text, but it can also display an image. "</span> <span class="string">"QScrollArea provides a scrolling view around another widget. "</span> <span class="string">"If the child widget exceeds the size of the frame, QScrollArea "</span> <span class="string">"automatically provides scroll bars. </p><p>The example "</span> <span class="string">"demonstrates how QLabel's ability to scale its contents "</span> <span class="string">"(QLabel::scaledContents), and QScrollArea's ability to "</span> <span class="string">"automatically resize its contents "</span> <span class="string">"(QScrollArea::widgetResizable), can be used to implement "</span> <span class="string">"zooming and scaling features. </p><p>In addition the example "</span> <span class="string">"shows how to use QPainter to print an image.</p>"</span>)); } <span class="type">void</span> ImageViewer<span class="operator">::</span>createActions() { <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>)); <span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>openAct <span class="operator">=</span> fileMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"&Open..."</span>)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>ImageViewer<span class="operator">::</span>open); openAct<span class="operator">-</span><span class="operator">></span>setShortcut(<span class="type"><a href="../qtgui/qkeysequence.html">QKeySequence</a></span><span class="operator">::</span>Open); saveAsAct <span class="operator">=</span> fileMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"&Save As..."</span>)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>ImageViewer<span class="operator">::</span>saveAs); saveAsAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); printAct <span class="operator">=</span> fileMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"&Print..."</span>)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>ImageViewer<span class="operator">::</span>print); printAct<span class="operator">-</span><span class="operator">></span>setShortcut(<span class="type"><a href="../qtgui/qkeysequence.html">QKeySequence</a></span><span class="operator">::</span>Print); printAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); fileMenu<span class="operator">-</span><span class="operator">></span>addSeparator(); <span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>exitAct <span class="operator">=</span> fileMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"E&xit"</span>)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qwidget.html">QWidget</a></span><span class="operator">::</span>close); exitAct<span class="operator">-</span><span class="operator">></span>setShortcut(tr(<span class="string">"Ctrl+Q"</span>)); <span class="type"><a href="qmenu.html">QMenu</a></span> <span class="operator">*</span>editMenu <span class="operator">=</span> menuBar()<span class="operator">-</span><span class="operator">></span>addMenu(tr(<span class="string">"&Edit"</span>)); copyAct <span class="operator">=</span> editMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"&Copy"</span>)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>ImageViewer<span class="operator">::</span>copy); copyAct<span class="operator">-</span><span class="operator">></span>setShortcut(<span class="type"><a href="../qtgui/qkeysequence.html">QKeySequence</a></span><span class="operator">::</span>Copy); copyAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); <span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>pasteAct <span class="operator">=</span> editMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"&Paste"</span>)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>ImageViewer<span class="operator">::</span>paste); pasteAct<span class="operator">-</span><span class="operator">></span>setShortcut(<span class="type"><a href="../qtgui/qkeysequence.html">QKeySequence</a></span><span class="operator">::</span>Paste); <span class="type"><a href="qmenu.html">QMenu</a></span> <span class="operator">*</span>viewMenu <span class="operator">=</span> menuBar()<span class="operator">-</span><span class="operator">></span>addMenu(tr(<span class="string">"&View"</span>)); zoomInAct <span class="operator">=</span> viewMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"Zoom &In (25%)"</span>)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>ImageViewer<span class="operator">::</span>zoomIn); zoomInAct<span class="operator">-</span><span class="operator">></span>setShortcut(<span class="type"><a href="../qtgui/qkeysequence.html">QKeySequence</a></span><span class="operator">::</span>ZoomIn); zoomInAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); zoomOutAct <span class="operator">=</span> viewMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"Zoom &Out (25%)"</span>)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>ImageViewer<span class="operator">::</span>zoomOut); zoomOutAct<span class="operator">-</span><span class="operator">></span>setShortcut(<span class="type"><a href="../qtgui/qkeysequence.html">QKeySequence</a></span><span class="operator">::</span>ZoomOut); zoomOutAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); normalSizeAct <span class="operator">=</span> viewMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"&Normal Size"</span>)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>ImageViewer<span class="operator">::</span>normalSize); normalSizeAct<span class="operator">-</span><span class="operator">></span>setShortcut(tr(<span class="string">"Ctrl+S"</span>)); normalSizeAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); viewMenu<span class="operator">-</span><span class="operator">></span>addSeparator(); fitToWindowAct <span class="operator">=</span> viewMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"&Fit to Window"</span>)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>ImageViewer<span class="operator">::</span>fitToWindow); fitToWindowAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); fitToWindowAct<span class="operator">-</span><span class="operator">></span>setCheckable(<span class="keyword">true</span>); fitToWindowAct<span class="operator">-</span><span class="operator">></span>setShortcut(tr(<span class="string">"Ctrl+F"</span>)); <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">"&Help"</span>)); helpMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"&About"</span>)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>ImageViewer<span class="operator">::</span>about); helpMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"About &Qt"</span>)<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qapplication.html">QApplication</a></span><span class="operator">::</span>aboutQt); } <span class="type">void</span> ImageViewer<span class="operator">::</span>updateActions() { saveAsAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="operator">!</span>image<span class="operator">.</span>isNull()); copyAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="operator">!</span>image<span class="operator">.</span>isNull()); zoomInAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="operator">!</span>fitToWindowAct<span class="operator">-</span><span class="operator">></span>isChecked()); zoomOutAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="operator">!</span>fitToWindowAct<span class="operator">-</span><span class="operator">></span>isChecked()); normalSizeAct<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="operator">!</span>fitToWindowAct<span class="operator">-</span><span class="operator">></span>isChecked()); } <span class="type">void</span> ImageViewer<span class="operator">::</span>scaleImage(<span class="type">double</span> factor) { Q_ASSERT(imageLabel<span class="operator">-</span><span class="operator">></span>pixmap()); scaleFactor <span class="operator">*</span><span class="operator">=</span> factor; imageLabel<span class="operator">-</span><span class="operator">></span>resize(scaleFactor <span class="operator">*</span> imageLabel<span class="operator">-</span><span class="operator">></span>pixmap()<span class="operator">-</span><span class="operator">></span>size()); adjustScrollBar(scrollArea<span class="operator">-</span><span class="operator">></span>horizontalScrollBar()<span class="operator">,</span> factor); adjustScrollBar(scrollArea<span class="operator">-</span><span class="operator">></span>verticalScrollBar()<span class="operator">,</span> factor); zoomInAct<span class="operator">-</span><span class="operator">></span>setEnabled(scaleFactor <span class="operator"><</span> <span class="number">3.0</span>); zoomOutAct<span class="operator">-</span><span class="operator">></span>setEnabled(scaleFactor <span class="operator">></span> <span class="number">0.333</span>); } <span class="type">void</span> ImageViewer<span class="operator">::</span>adjustScrollBar(<span class="type"><a href="qscrollbar.html">QScrollBar</a></span> <span class="operator">*</span>scrollBar<span class="operator">,</span> <span class="type">double</span> factor) { scrollBar<span class="operator">-</span><span class="operator">></span>setValue(<span class="type">int</span>(factor <span class="operator">*</span> scrollBar<span class="operator">-</span><span class="operator">></span>value() <span class="operator">+</span> ((factor <span class="operator">-</span> <span class="number">1</span>) <span class="operator">*</span> scrollBar<span class="operator">-</span><span class="operator">></span>pageStep()<span class="operator">/</span><span class="number">2</span>))); } </pre> </div> <!-- @@@widgets/imageviewer/imageviewer.cpp --> </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>