diff -r 000000000000 -r 1918ee327afb examples/widgets/imageviewer/imageviewer.cpp --- /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 + +#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("

The Image Viewer 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.

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.

In addition the example " + "shows how to use QPainter to print an image.

")); +} +//! [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]