34e4a8ef6d
Cleanup the Widgets examples - replace foreach with range-based for loop in the remaining directories Change-Id: I321e6c0f414401a1ae4fb65762b97d894b725afa Reviewed-by: Paul Wicking <paul.wicking@qt.io> Reviewed-by: Luca Beldi <v.ronin@yahoo.it>
298 lines
9.1 KiB
C++
298 lines
9.1 KiB
C++
/****************************************************************************
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**
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** Copyright (C) 2016 The Qt Company Ltd.
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** Contact: https://www.qt.io/licensing/
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**
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** This file is part of the examples of the Qt Toolkit.
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**
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** $QT_BEGIN_LICENSE:BSD$
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** Commercial License Usage
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** Licensees holding valid commercial Qt licenses may use this file in
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** accordance with the commercial license agreement provided with the
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** Software or, alternatively, in accordance with the terms contained in
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** a written agreement between you and The Qt Company. For licensing terms
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** and conditions see https://www.qt.io/terms-conditions. For further
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** information use the contact form at https://www.qt.io/contact-us.
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**
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** BSD License Usage
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** Alternatively, you may use this file under the terms of the BSD license
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** as follows:
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**
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** "Redistribution and use in source and binary forms, with or without
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** modification, are permitted provided that the following conditions are
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** met:
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** * Redistributions of source code must retain the above copyright
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** notice, this list of conditions and the following disclaimer.
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** * Redistributions in binary form must reproduce the above copyright
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** notice, this list of conditions and the following disclaimer in
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** the documentation and/or other materials provided with the
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** distribution.
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** * Neither the name of The Qt Company Ltd nor the names of its
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** contributors may be used to endorse or promote products derived
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** from this software without specific prior written permission.
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**
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**
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** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
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**
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** $QT_END_LICENSE$
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**
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****************************************************************************/
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#include "imagewidget.h"
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#include <QtWidgets>
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Q_LOGGING_CATEGORY(lcExample, "qt.examples.imagegestures")
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//! [constructor]
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ImageWidget::ImageWidget(QWidget *parent)
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: QWidget(parent),
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position(0),
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horizontalOffset(0),
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verticalOffset(0),
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rotationAngle(0),
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scaleFactor(1),
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currentStepScaleFactor(1)
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{
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setMinimumSize(QSize(100,100));
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}
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//! [constructor]
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void ImageWidget::grabGestures(const QList<Qt::GestureType> &gestures)
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{
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//! [enable gestures]
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for (Qt::GestureType gesture : gestures)
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grabGesture(gesture);
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//! [enable gestures]
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}
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//! [event handler]
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bool ImageWidget::event(QEvent *event)
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{
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if (event->type() == QEvent::Gesture)
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return gestureEvent(static_cast<QGestureEvent*>(event));
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return QWidget::event(event);
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}
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//! [event handler]
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//! [paint method]
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void ImageWidget::paintEvent(QPaintEvent*)
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{
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QPainter p(this);
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const qreal iw = currentImage.width();
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const qreal ih = currentImage.height();
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const qreal wh = height();
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const qreal ww = width();
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p.translate(ww/2, wh/2);
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p.translate(horizontalOffset, verticalOffset);
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p.rotate(rotationAngle);
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p.scale(currentStepScaleFactor * scaleFactor, currentStepScaleFactor * scaleFactor);
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p.translate(-iw/2, -ih/2);
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p.drawImage(0, 0, currentImage);
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}
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//! [paint method]
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void ImageWidget::mouseDoubleClickEvent(QMouseEvent *)
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{
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rotationAngle = 0;
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scaleFactor = 1;
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currentStepScaleFactor = 1;
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verticalOffset = 0;
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horizontalOffset = 0;
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update();
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qCDebug(lcExample) << "reset on mouse double click";
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}
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//! [gesture event handler]
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bool ImageWidget::gestureEvent(QGestureEvent *event)
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{
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qCDebug(lcExample) << "gestureEvent():" << event;
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if (QGesture *swipe = event->gesture(Qt::SwipeGesture))
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swipeTriggered(static_cast<QSwipeGesture *>(swipe));
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else if (QGesture *pan = event->gesture(Qt::PanGesture))
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panTriggered(static_cast<QPanGesture *>(pan));
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if (QGesture *pinch = event->gesture(Qt::PinchGesture))
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pinchTriggered(static_cast<QPinchGesture *>(pinch));
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return true;
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}
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//! [gesture event handler]
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void ImageWidget::panTriggered(QPanGesture *gesture)
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{
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#ifndef QT_NO_CURSOR
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switch (gesture->state()) {
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case Qt::GestureStarted:
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case Qt::GestureUpdated:
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setCursor(Qt::SizeAllCursor);
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break;
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default:
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setCursor(Qt::ArrowCursor);
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}
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#endif
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QPointF delta = gesture->delta();
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qCDebug(lcExample) << "panTriggered():" << gesture;
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horizontalOffset += delta.x();
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verticalOffset += delta.y();
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update();
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}
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//! [pinch function]
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void ImageWidget::pinchTriggered(QPinchGesture *gesture)
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{
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QPinchGesture::ChangeFlags changeFlags = gesture->changeFlags();
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if (changeFlags & QPinchGesture::RotationAngleChanged) {
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qreal rotationDelta = gesture->rotationAngle() - gesture->lastRotationAngle();
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rotationAngle += rotationDelta;
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qCDebug(lcExample) << "pinchTriggered(): rotate by" <<
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rotationDelta << "->" << rotationAngle;
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}
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if (changeFlags & QPinchGesture::ScaleFactorChanged) {
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currentStepScaleFactor = gesture->totalScaleFactor();
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qCDebug(lcExample) << "pinchTriggered(): zoom by" <<
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gesture->scaleFactor() << "->" << currentStepScaleFactor;
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}
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if (gesture->state() == Qt::GestureFinished) {
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scaleFactor *= currentStepScaleFactor;
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currentStepScaleFactor = 1;
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}
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update();
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}
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//! [pinch function]
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//! [swipe function]
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void ImageWidget::swipeTriggered(QSwipeGesture *gesture)
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{
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if (gesture->state() == Qt::GestureFinished) {
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if (gesture->horizontalDirection() == QSwipeGesture::Left
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|| gesture->verticalDirection() == QSwipeGesture::Up) {
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qCDebug(lcExample) << "swipeTriggered(): swipe to previous";
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goPrevImage();
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} else {
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qCDebug(lcExample) << "swipeTriggered(): swipe to next";
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goNextImage();
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}
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update();
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}
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}
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//! [swipe function]
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void ImageWidget::resizeEvent(QResizeEvent*)
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{
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update();
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}
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void ImageWidget::openDirectory(const QString &path)
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{
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this->path = path;
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QDir dir(path);
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QStringList nameFilters;
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nameFilters << "*.jpg" << "*.png";
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files = dir.entryList(nameFilters, QDir::Files|QDir::Readable, QDir::Name);
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position = 0;
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goToImage(0);
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update();
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}
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QImage ImageWidget::loadImage(const QString &fileName)
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{
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QImageReader reader(fileName);
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reader.setAutoTransform(true);
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qCDebug(lcExample) << "loading" << QDir::toNativeSeparators(fileName) << position << '/' << files.size();
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if (!reader.canRead()) {
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qCWarning(lcExample) << QDir::toNativeSeparators(fileName) << ": can't load image";
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return QImage();
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}
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QImage image;
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if (!reader.read(&image)) {
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qCWarning(lcExample) << QDir::toNativeSeparators(fileName) << ": corrupted image: " << reader.errorString();
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return QImage();
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}
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const QSize maximumSize(2000, 2000); // Reduce in case someone has large photo images.
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if (image.size().width() > maximumSize.width() || image.height() > maximumSize.height())
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image = image.scaled(maximumSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
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return image;
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}
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void ImageWidget::goNextImage()
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{
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if (files.isEmpty())
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return;
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if (position < files.size()-1) {
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++position;
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prevImage = currentImage;
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currentImage = nextImage;
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if (position+1 < files.size())
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nextImage = loadImage(path + QLatin1Char('/') + files.at(position+1));
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else
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nextImage = QImage();
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}
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update();
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}
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void ImageWidget::goPrevImage()
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{
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if (files.isEmpty())
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return;
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if (position > 0) {
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--position;
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nextImage = currentImage;
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currentImage = prevImage;
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if (position > 0)
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prevImage = loadImage(path + QLatin1Char('/') + files.at(position-1));
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else
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prevImage = QImage();
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}
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update();
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}
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void ImageWidget::goToImage(int index)
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{
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if (files.isEmpty())
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return;
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if (index < 0 || index >= files.size()) {
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qCWarning(lcExample) << "goToImage: invalid index: " << index;
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return;
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}
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if (index == position+1) {
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goNextImage();
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return;
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}
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if (position > 0 && index == position-1) {
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goPrevImage();
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return;
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}
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position = index;
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if (index > 0)
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prevImage = loadImage(path + QLatin1Char('/') + files.at(position-1));
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else
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prevImage = QImage();
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currentImage = loadImage(path + QLatin1Char('/') + files.at(position));
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if (position+1 < files.size())
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nextImage = loadImage(path + QLatin1Char('/') + files.at(position+1));
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else
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nextImage = QImage();
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update();
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}
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