diff options
Diffstat (limited to 'examples/widgets/gestures/imagegestures/imagewidget.cpp')
| -rw-r--r-- | examples/widgets/gestures/imagegestures/imagewidget.cpp | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/examples/widgets/gestures/imagegestures/imagewidget.cpp b/examples/widgets/gestures/imagegestures/imagewidget.cpp new file mode 100644 index 0000000000..aad40afc26 --- /dev/null +++ b/examples/widgets/gestures/imagegestures/imagewidget.cpp @@ -0,0 +1,267 @@ + +/**************************************************************************** +** +** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/legal +** +** This file is part of the examples of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names +** of its contributors may be used to endorse or promote products derived +** from this software without specific prior written permission. +** +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "imagewidget.h" + +#include <QtWidgets> + +//! [constructor] +ImageWidget::ImageWidget(QWidget *parent) + : QWidget(parent), + position(0), + horizontalOffset(0), + verticalOffset(0), + rotationAngle(0), + scaleFactor(1), + currentStepScaleFactor(1) + +{ + setMinimumSize(QSize(100,100)); + +//! [enable gestures] + grabGesture(Qt::PanGesture); + grabGesture(Qt::PinchGesture); + grabGesture(Qt::SwipeGesture); +//! [enable gestures] +} +//! [constructor] + +//! [event handler] +bool ImageWidget::event(QEvent *event) +{ + if (event->type() == QEvent::Gesture) + return gestureEvent(static_cast<QGestureEvent*>(event)); + return QWidget::event(event); +} +//! [event handler] + +void ImageWidget::paintEvent(QPaintEvent*) +{ + QPainter p(this); + + float iw = currentImage.width(); + float ih = currentImage.height(); + float wh = height(); + float ww = width(); + + p.translate(ww/2, wh/2); + p.translate(horizontalOffset, verticalOffset); + p.rotate(rotationAngle); + p.scale(currentStepScaleFactor * scaleFactor, currentStepScaleFactor * scaleFactor); + p.translate(-iw/2, -ih/2); + p.drawImage(0, 0, currentImage); +} + +void ImageWidget::mouseDoubleClickEvent(QMouseEvent *) +{ + rotationAngle = 0; + scaleFactor = 1; + currentStepScaleFactor = 1; + verticalOffset = 0; + horizontalOffset = 0; + update(); +} + +//! [gesture event handler] +bool ImageWidget::gestureEvent(QGestureEvent *event) +{ + if (QGesture *swipe = event->gesture(Qt::SwipeGesture)) + swipeTriggered(static_cast<QSwipeGesture *>(swipe)); + else if (QGesture *pan = event->gesture(Qt::PanGesture)) + panTriggered(static_cast<QPanGesture *>(pan)); + if (QGesture *pinch = event->gesture(Qt::PinchGesture)) + pinchTriggered(static_cast<QPinchGesture *>(pinch)); + return true; +} +//! [gesture event handler] + +void ImageWidget::panTriggered(QPanGesture *gesture) +{ +#ifndef QT_NO_CURSOR + switch (gesture->state()) { + case Qt::GestureStarted: + case Qt::GestureUpdated: + setCursor(Qt::SizeAllCursor); + break; + default: + setCursor(Qt::ArrowCursor); + } +#endif + QPointF delta = gesture->delta(); + horizontalOffset += delta.x(); + verticalOffset += delta.y(); + update(); +} + +void ImageWidget::pinchTriggered(QPinchGesture *gesture) +{ + QPinchGesture::ChangeFlags changeFlags = gesture->changeFlags(); + if (changeFlags & QPinchGesture::RotationAngleChanged) { + qreal value = gesture->property("rotationAngle").toReal(); + qreal lastValue = gesture->property("lastRotationAngle").toReal(); + rotationAngle += value - lastValue; + } + if (changeFlags & QPinchGesture::ScaleFactorChanged) { + qreal value = gesture->property("scaleFactor").toReal(); + currentStepScaleFactor = value; + } + if (gesture->state() == Qt::GestureFinished) { + scaleFactor *= currentStepScaleFactor; + currentStepScaleFactor = 1; + } + update(); +} + +//! [swipe function] +void ImageWidget::swipeTriggered(QSwipeGesture *gesture) +{ + if (gesture->state() == Qt::GestureFinished) { + if (gesture->horizontalDirection() == QSwipeGesture::Left + || gesture->verticalDirection() == QSwipeGesture::Up) + goPrevImage(); + else + goNextImage(); + update(); + } +} +//! [swipe function] + +void ImageWidget::resizeEvent(QResizeEvent*) +{ + update(); +} + +void ImageWidget::openDirectory(const QString &path) +{ + this->path = path; + QDir dir(path); + QStringList nameFilters; + nameFilters << "*.jpg" << "*.png"; + files = dir.entryList(nameFilters, QDir::Files|QDir::Readable, QDir::Name); + + position = 0; + goToImage(0); + update(); +} + +QImage ImageWidget::loadImage(const QString &fileName) +{ + QImageReader reader(fileName); + if (!reader.canRead()) { + qDebug() << fileName << ": can't load image"; + return QImage(); + } + + QImage image; + if (!reader.read(&image)) { + qDebug() << fileName << ": corrupted image"; + return QImage(); + } + return image; +} + +void ImageWidget::goNextImage() +{ + if (files.isEmpty()) + return; + + if (position < files.size()-1) { + ++position; + prevImage = currentImage; + currentImage = nextImage; + if (position+1 < files.size()) + nextImage = loadImage(path+QLatin1String("/")+files.at(position+1)); + else + nextImage = QImage(); + } + update(); +} + +void ImageWidget::goPrevImage() +{ + if (files.isEmpty()) + return; + + if (position > 0) { + --position; + nextImage = currentImage; + currentImage = prevImage; + if (position > 0) + prevImage = loadImage(path+QLatin1String("/")+files.at(position-1)); + else + prevImage = QImage(); + } + update(); +} + +void ImageWidget::goToImage(int index) +{ + if (files.isEmpty()) + return; + + if (index < 0 || index >= files.size()) { + qDebug() << "goToImage: invalid index: " << index; + return; + } + + if (index == position+1) { + goNextImage(); + return; + } + + if (position > 0 && index == position-1) { + goPrevImage(); + return; + } + + position = index; + + if (index > 0) + prevImage = loadImage(path+QLatin1String("/")+files.at(position-1)); + else + prevImage = QImage(); + currentImage = loadImage(path+QLatin1String("/")+files.at(position)); + if (position+1 < files.size()) + nextImage = loadImage(path+QLatin1String("/")+files.at(position+1)); + else + nextImage = QImage(); + update(); +} |