43148c8a55
The example keeps around image file names only and append them to the selected dir path, that works fine for file scheme files, but for Android with content scheme files, that doesn't work as good because usually the paths are returned by a provider and managing them manually like appending a file name to a directory (tree) path might not work. This patch retrieves QFileInfo objects and use the absolute file paths to open any image. Fixes: QTBUG-116181 Change-Id: I9911a181d92ba0452500398cbe052b9583bd79a0 Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io> Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io> (cherry picked from commit 381612f7944b202c8b1428f0cc9d1af72f5f7647) Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
302 lines
9.5 KiB
C++
302 lines
9.5 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 <QDir>
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#include <QImageReader>
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#include <QGestureEvent>
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#include <QPainter>
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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), position(0), horizontalOffset(0), verticalOffset(0)
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, rotationAngle(0), scaleFactor(1), 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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const QStringList nameFilters{"*.jpg", "*.png"};
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files = dir.entryInfoList(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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/*
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With Android's content scheme paths, it might not be possible to simply
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append a file name to the chosen directory path to be able to open the image,
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because usually paths are returned by an Android file provider and handling those
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paths manually is not guaranteed to work. For that reason, it's better to keep
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around QFileInfo objects and use absoluteFilePath().
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*/
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QImage ImageWidget::loadImage(const QFileInfo &fileInfo) const
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{
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const QString fileName = fileInfo.absoluteFilePath();
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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(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(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(files.at(position - 1));
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else
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prevImage = QImage();
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currentImage = loadImage(files.at(position));
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if (position+1 < files.size())
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nextImage = loadImage(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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