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Diffstat (limited to 'tests/manual/examples/widgets/widgets/imageviewer/imageviewer.cpp')
-rw-r--r-- | tests/manual/examples/widgets/widgets/imageviewer/imageviewer.cpp | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/tests/manual/examples/widgets/widgets/imageviewer/imageviewer.cpp b/tests/manual/examples/widgets/widgets/imageviewer/imageviewer.cpp new file mode 100644 index 0000000000..72a93dbf1b --- /dev/null +++ b/tests/manual/examples/widgets/widgets/imageviewer/imageviewer.cpp @@ -0,0 +1,364 @@ +// Copyright (C) 2016 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause + +#include "imageviewer.h" + +#include <QApplication> +#include <QClipboard> +#include <QColorSpace> +#include <QDir> +#include <QFileDialog> +#include <QImageReader> +#include <QImageWriter> +#include <QLabel> +#include <QMenuBar> +#include <QMessageBox> +#include <QMimeData> +#include <QPainter> +#include <QScreen> +#include <QScrollArea> +#include <QScrollBar> +#include <QStandardPaths> +#include <QStatusBar> + +#if defined(QT_PRINTSUPPORT_LIB) +# include <QtPrintSupport/qtprintsupportglobal.h> + +# if QT_CONFIG(printdialog) +# include <QPrintDialog> +# endif +#endif + +//! [0] +ImageViewer::ImageViewer(QWidget *parent) + : QMainWindow(parent), imageLabel(new QLabel) + , scrollArea(new QScrollArea) +{ + imageLabel->setBackgroundRole(QPalette::Base); + imageLabel->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored); + imageLabel->setScaledContents(true); + + scrollArea->setBackgroundRole(QPalette::Dark); + scrollArea->setWidget(imageLabel); + scrollArea->setVisible(false); + setCentralWidget(scrollArea); + + createActions(); + + resize(QGuiApplication::primaryScreen()->availableSize() * 3 / 5); +} + +//! [0] +//! [2] + +bool ImageViewer::loadFile(const QString &fileName) +{ + QImageReader reader(fileName); + reader.setAutoTransform(true); + const QImage newImage = reader.read(); + if (newImage.isNull()) { + QMessageBox::information(this, QGuiApplication::applicationDisplayName(), + tr("Cannot load %1: %2") + .arg(QDir::toNativeSeparators(fileName), reader.errorString())); + return false; + } +//! [2] + + setImage(newImage); + + setWindowFilePath(fileName); + + const QString description = image.colorSpace().isValid() + ? image.colorSpace().description() : tr("unknown"); + const QString message = tr("Opened \"%1\", %2x%3, Depth: %4 (%5)") + .arg(QDir::toNativeSeparators(fileName)).arg(image.width()).arg(image.height()) + .arg(image.depth()).arg(description); + statusBar()->showMessage(message); + return true; +} + +void ImageViewer::setImage(const QImage &newImage) +{ + if (newImage.colorSpace().isValid()) + image = newImage.convertedToColorSpace(QColorSpace::SRgb); + else + image = newImage; + imageLabel->setPixmap(QPixmap::fromImage(image, Qt::NoFormatConversion)); +//! [4] + scaleFactor = 1.0; + + scrollArea->setVisible(true); + printAct->setEnabled(true); + fitToWindowAct->setEnabled(true); + updateActions(); + + if (!fitToWindowAct->isChecked()) + imageLabel->adjustSize(); +} + +//! [4] + +bool ImageViewer::saveFile(const QString &fileName) +{ + QImageWriter writer(fileName); + + if (!writer.write(image)) { + QMessageBox::information(this, QGuiApplication::applicationDisplayName(), + tr("Cannot write %1: %2") + .arg(QDir::toNativeSeparators(fileName), writer.errorString())); + return false; + } + const QString message = tr("Wrote \"%1\"").arg(QDir::toNativeSeparators(fileName)); + statusBar()->showMessage(message); + return true; +} + +//! [1] + +static void initializeImageFileDialog(QFileDialog &dialog, QFileDialog::AcceptMode acceptMode) +{ + static bool firstDialog = true; + + if (firstDialog) { + firstDialog = false; + const QStringList picturesLocations = QStandardPaths::standardLocations(QStandardPaths::PicturesLocation); + dialog.setDirectory(picturesLocations.isEmpty() ? QDir::currentPath() : picturesLocations.last()); + } + + QStringList mimeTypeFilters; + const QByteArrayList supportedMimeTypes = acceptMode == QFileDialog::AcceptOpen + ? QImageReader::supportedMimeTypes() : QImageWriter::supportedMimeTypes(); + for (const QByteArray &mimeTypeName : supportedMimeTypes) + mimeTypeFilters.append(mimeTypeName); + mimeTypeFilters.sort(); + dialog.setMimeTypeFilters(mimeTypeFilters); + dialog.selectMimeTypeFilter("image/jpeg"); + dialog.setAcceptMode(acceptMode); + if (acceptMode == QFileDialog::AcceptSave) + dialog.setDefaultSuffix("jpg"); +} + +void ImageViewer::open() +{ + QFileDialog dialog(this, tr("Open File")); + initializeImageFileDialog(dialog, QFileDialog::AcceptOpen); + + while (dialog.exec() == QDialog::Accepted && !loadFile(dialog.selectedFiles().constFirst())) {} +} +//! [1] + +void ImageViewer::saveAs() +{ + QFileDialog dialog(this, tr("Save File As")); + initializeImageFileDialog(dialog, QFileDialog::AcceptSave); + + while (dialog.exec() == QDialog::Accepted && !saveFile(dialog.selectedFiles().constFirst())) {} +} + +//! [5] +void ImageViewer::print() +//! [5] //! [6] +{ + Q_ASSERT(!imageLabel->pixmap().isNull()); +#if defined(QT_PRINTSUPPORT_LIB) && QT_CONFIG(printdialog) +//! [6] //! [7] + QPrintDialog dialog(&printer, this); +//! [7] //! [8] + if (dialog.exec()) { + QPainter painter(&printer); + QPixmap pixmap = imageLabel->pixmap(); + QRect rect = painter.viewport(); + QSize size = pixmap.size(); + size.scale(rect.size(), Qt::KeepAspectRatio); + painter.setViewport(rect.x(), rect.y(), size.width(), size.height()); + painter.setWindow(pixmap.rect()); + painter.drawPixmap(0, 0, pixmap); + } +#endif +} +//! [8] + +void ImageViewer::copy() +{ +#ifndef QT_NO_CLIPBOARD + QGuiApplication::clipboard()->setImage(image); +#endif // !QT_NO_CLIPBOARD +} + +#ifndef QT_NO_CLIPBOARD +static QImage clipboardImage() +{ + if (const QMimeData *mimeData = QGuiApplication::clipboard()->mimeData()) { + if (mimeData->hasImage()) { + const QImage image = qvariant_cast<QImage>(mimeData->imageData()); + if (!image.isNull()) + return image; + } + } + return QImage(); +} +#endif // !QT_NO_CLIPBOARD + +void ImageViewer::paste() +{ +#ifndef QT_NO_CLIPBOARD + const QImage newImage = clipboardImage(); + if (newImage.isNull()) { + statusBar()->showMessage(tr("No image in clipboard")); + } else { + setImage(newImage); + setWindowFilePath(QString()); + const QString message = tr("Obtained image from clipboard, %1x%2, Depth: %3") + .arg(newImage.width()).arg(newImage.height()).arg(newImage.depth()); + statusBar()->showMessage(message); + } +#endif // !QT_NO_CLIPBOARD +} + +//! [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] +{ + QMenu *fileMenu = menuBar()->addMenu(tr("&File")); + + QAction *openAct = fileMenu->addAction(tr("&Open..."), this, &ImageViewer::open); + openAct->setShortcut(QKeySequence::Open); + + saveAsAct = fileMenu->addAction(tr("&Save As..."), this, &ImageViewer::saveAs); + saveAsAct->setEnabled(false); + + printAct = fileMenu->addAction(tr("&Print..."), this, &ImageViewer::print); + printAct->setShortcut(QKeySequence::Print); + printAct->setEnabled(false); + + fileMenu->addSeparator(); + + QAction *exitAct = fileMenu->addAction(tr("E&xit"), this, &QWidget::close); + exitAct->setShortcut(tr("Ctrl+Q")); + + QMenu *editMenu = menuBar()->addMenu(tr("&Edit")); + + copyAct = editMenu->addAction(tr("&Copy"), this, &ImageViewer::copy); + copyAct->setShortcut(QKeySequence::Copy); + copyAct->setEnabled(false); + + QAction *pasteAct = editMenu->addAction(tr("&Paste"), this, &ImageViewer::paste); + pasteAct->setShortcut(QKeySequence::Paste); + + QMenu *viewMenu = menuBar()->addMenu(tr("&View")); + + zoomInAct = viewMenu->addAction(tr("Zoom &In (25%)"), this, &ImageViewer::zoomIn); + zoomInAct->setShortcut(QKeySequence::ZoomIn); + zoomInAct->setEnabled(false); + + zoomOutAct = viewMenu->addAction(tr("Zoom &Out (25%)"), this, &ImageViewer::zoomOut); + zoomOutAct->setShortcut(QKeySequence::ZoomOut); + zoomOutAct->setEnabled(false); + + normalSizeAct = viewMenu->addAction(tr("&Normal Size"), this, &ImageViewer::normalSize); + normalSizeAct->setShortcut(tr("Ctrl+S")); + normalSizeAct->setEnabled(false); + + viewMenu->addSeparator(); + + fitToWindowAct = viewMenu->addAction(tr("&Fit to Window"), this, &ImageViewer::fitToWindow); + fitToWindowAct->setEnabled(false); + fitToWindowAct->setCheckable(true); + fitToWindowAct->setShortcut(tr("Ctrl+F")); + + QMenu *helpMenu = menuBar()->addMenu(tr("&Help")); + + helpMenu->addAction(tr("&About"), this, &ImageViewer::about); + helpMenu->addAction(tr("About &Qt"), this, &QApplication::aboutQt); +} +//! [18] + +//! [21] +void ImageViewer::updateActions() +//! [21] //! [22] +{ + saveAsAct->setEnabled(!image.isNull()); + copyAct->setEnabled(!image.isNull()); + zoomInAct->setEnabled(!fitToWindowAct->isChecked()); + zoomOutAct->setEnabled(!fitToWindowAct->isChecked()); + normalSizeAct->setEnabled(!fitToWindowAct->isChecked()); +} +//! [22] + +//! [23] +void ImageViewer::scaleImage(double factor) +//! [23] //! [24] +{ + 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] |