--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/widgets/imageviewer/imageviewer.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,278 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtGui>
+
+#include "imageviewer.h"
+
+//! [0]
+ImageViewer::ImageViewer()
+{
+ imageLabel = new QLabel;
+ imageLabel->setBackgroundRole(QPalette::Base);
+ imageLabel->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
+ imageLabel->setScaledContents(true);
+
+ scrollArea = new QScrollArea;
+ scrollArea->setBackgroundRole(QPalette::Dark);
+ scrollArea->setWidget(imageLabel);
+ setCentralWidget(scrollArea);
+
+ createActions();
+ createMenus();
+
+ setWindowTitle(tr("Image Viewer"));
+ resize(500, 400);
+}
+//! [0]
+
+//! [1]
+void ImageViewer::open()
+//! [1] //! [2]
+{
+ QString fileName = QFileDialog::getOpenFileName(this,
+ tr("Open File"), QDir::currentPath());
+ if (!fileName.isEmpty()) {
+ QImage image(fileName);
+ if (image.isNull()) {
+ QMessageBox::information(this, tr("Image Viewer"),
+ tr("Cannot load %1.").arg(fileName));
+ return;
+ }
+//! [2] //! [3]
+ imageLabel->setPixmap(QPixmap::fromImage(image));
+//! [3] //! [4]
+ scaleFactor = 1.0;
+
+ printAct->setEnabled(true);
+ fitToWindowAct->setEnabled(true);
+ updateActions();
+
+ if (!fitToWindowAct->isChecked())
+ imageLabel->adjustSize();
+ }
+}
+//! [4]
+
+//! [5]
+void ImageViewer::print()
+//! [5] //! [6]
+{
+ Q_ASSERT(imageLabel->pixmap());
+#ifndef QT_NO_PRINTER
+//! [6] //! [7]
+ QPrintDialog dialog(&printer, this);
+//! [7] //! [8]
+ if (dialog.exec()) {
+ QPainter painter(&printer);
+ QRect rect = painter.viewport();
+ QSize size = imageLabel->pixmap()->size();
+ size.scale(rect.size(), Qt::KeepAspectRatio);
+ painter.setViewport(rect.x(), rect.y(), size.width(), size.height());
+ painter.setWindow(imageLabel->pixmap()->rect());
+ painter.drawPixmap(0, 0, *imageLabel->pixmap());
+ }
+#endif
+}
+//! [8]
+
+//! [9]
+void ImageViewer::zoomIn()
+//! [9] //! [10]
+{
+ scaleImage(1.25);
+}
+
+void ImageViewer::zoomOut()
+{
+ scaleImage(0.8);
+}
+
+//! [10] //! [11]
+void ImageViewer::normalSize()
+//! [11] //! [12]
+{
+ imageLabel->adjustSize();
+ scaleFactor = 1.0;
+}
+//! [12]
+
+//! [13]
+void ImageViewer::fitToWindow()
+//! [13] //! [14]
+{
+ bool fitToWindow = fitToWindowAct->isChecked();
+ scrollArea->setWidgetResizable(fitToWindow);
+ if (!fitToWindow) {
+ normalSize();
+ }
+ updateActions();
+}
+//! [14]
+
+
+//! [15]
+void ImageViewer::about()
+//! [15] //! [16]
+{
+ QMessageBox::about(this, tr("About Image Viewer"),
+ tr("<p>The <b>Image Viewer</b> example shows how to combine QLabel "
+ "and QScrollArea to display an image. QLabel is typically used "
+ "for displaying a text, but it can also display an image. "
+ "QScrollArea provides a scrolling view around another widget. "
+ "If the child widget exceeds the size of the frame, QScrollArea "
+ "automatically provides scroll bars. </p><p>The example "
+ "demonstrates how QLabel's ability to scale its contents "
+ "(QLabel::scaledContents), and QScrollArea's ability to "
+ "automatically resize its contents "
+ "(QScrollArea::widgetResizable), can be used to implement "
+ "zooming and scaling features. </p><p>In addition the example "
+ "shows how to use QPainter to print an image.</p>"));
+}
+//! [16]
+
+//! [17]
+void ImageViewer::createActions()
+//! [17] //! [18]
+{
+ openAct = new QAction(tr("&Open..."), this);
+ openAct->setShortcut(tr("Ctrl+O"));
+ connect(openAct, SIGNAL(triggered()), this, SLOT(open()));
+
+ printAct = new QAction(tr("&Print..."), this);
+ printAct->setShortcut(tr("Ctrl+P"));
+ printAct->setEnabled(false);
+ connect(printAct, SIGNAL(triggered()), this, SLOT(print()));
+
+ exitAct = new QAction(tr("E&xit"), this);
+ exitAct->setShortcut(tr("Ctrl+Q"));
+ connect(exitAct, SIGNAL(triggered()), this, SLOT(close()));
+
+ zoomInAct = new QAction(tr("Zoom &In (25%)"), this);
+ zoomInAct->setShortcut(tr("Ctrl++"));
+ zoomInAct->setEnabled(false);
+ connect(zoomInAct, SIGNAL(triggered()), this, SLOT(zoomIn()));
+
+ zoomOutAct = new QAction(tr("Zoom &Out (25%)"), this);
+ zoomOutAct->setShortcut(tr("Ctrl+-"));
+ zoomOutAct->setEnabled(false);
+ connect(zoomOutAct, SIGNAL(triggered()), this, SLOT(zoomOut()));
+
+ normalSizeAct = new QAction(tr("&Normal Size"), this);
+ normalSizeAct->setShortcut(tr("Ctrl+S"));
+ normalSizeAct->setEnabled(false);
+ connect(normalSizeAct, SIGNAL(triggered()), this, SLOT(normalSize()));
+
+ fitToWindowAct = new QAction(tr("&Fit to Window"), this);
+ fitToWindowAct->setEnabled(false);
+ fitToWindowAct->setCheckable(true);
+ fitToWindowAct->setShortcut(tr("Ctrl+F"));
+ connect(fitToWindowAct, SIGNAL(triggered()), this, SLOT(fitToWindow()));
+
+ aboutAct = new QAction(tr("&About"), this);
+ connect(aboutAct, SIGNAL(triggered()), this, SLOT(about()));
+
+ aboutQtAct = new QAction(tr("About &Qt"), this);
+ connect(aboutQtAct, SIGNAL(triggered()), qApp, SLOT(aboutQt()));
+}
+//! [18]
+
+//! [19]
+void ImageViewer::createMenus()
+//! [19] //! [20]
+{
+ fileMenu = new QMenu(tr("&File"), this);
+ fileMenu->addAction(openAct);
+ fileMenu->addAction(printAct);
+ fileMenu->addSeparator();
+ fileMenu->addAction(exitAct);
+
+ viewMenu = new QMenu(tr("&View"), this);
+ viewMenu->addAction(zoomInAct);
+ viewMenu->addAction(zoomOutAct);
+ viewMenu->addAction(normalSizeAct);
+ viewMenu->addSeparator();
+ viewMenu->addAction(fitToWindowAct);
+
+ helpMenu = new QMenu(tr("&Help"), this);
+ helpMenu->addAction(aboutAct);
+ helpMenu->addAction(aboutQtAct);
+
+ menuBar()->addMenu(fileMenu);
+ menuBar()->addMenu(viewMenu);
+ menuBar()->addMenu(helpMenu);
+}
+//! [20]
+
+//! [21]
+void ImageViewer::updateActions()
+//! [21] //! [22]
+{
+ zoomInAct->setEnabled(!fitToWindowAct->isChecked());
+ zoomOutAct->setEnabled(!fitToWindowAct->isChecked());
+ normalSizeAct->setEnabled(!fitToWindowAct->isChecked());
+}
+//! [22]
+
+//! [23]
+void ImageViewer::scaleImage(double factor)
+//! [23] //! [24]
+{
+ Q_ASSERT(imageLabel->pixmap());
+ scaleFactor *= factor;
+ imageLabel->resize(scaleFactor * imageLabel->pixmap()->size());
+
+ adjustScrollBar(scrollArea->horizontalScrollBar(), factor);
+ adjustScrollBar(scrollArea->verticalScrollBar(), factor);
+
+ zoomInAct->setEnabled(scaleFactor < 3.0);
+ zoomOutAct->setEnabled(scaleFactor > 0.333);
+}
+//! [24]
+
+//! [25]
+void ImageViewer::adjustScrollBar(QScrollBar *scrollBar, double factor)
+//! [25] //! [26]
+{
+ scrollBar->setValue(int(factor * scrollBar->value()
+ + ((factor - 1) * scrollBar->pageStep()/2)));
+}
+//! [26]