diff --git a/src/plugins/imageviewer/imageview.cpp b/src/plugins/imageviewer/imageview.cpp index c435666d15f..c5ef478e595 100644 --- a/src/plugins/imageviewer/imageview.cpp +++ b/src/plugins/imageviewer/imageview.cpp @@ -57,10 +57,31 @@ namespace ImageViewer { namespace Constants { const qreal DEFAULT_SCALE_FACTOR = 1.2; + const qreal zoomLevels[] = { 0.25, 0.5, 0.75, 1.0, 1.5, 2.0, 4.0, 8.0 }; } namespace Internal { +static qreal nextLevel(qreal currentLevel) +{ + auto iter = std::find_if(std::begin(Constants::zoomLevels), std::end(Constants::zoomLevels), [&](qreal val) { + return val > currentLevel; + }); + if (iter != std::end(Constants::zoomLevels)) + return *iter; + return currentLevel; +} + +static qreal previousLevel(qreal currentLevel) +{ + auto iter = std::find_if(std::rbegin(Constants::zoomLevels), std::rend(Constants::zoomLevels), [&](qreal val) { + return val < currentLevel; + }); + if (iter != std::rend(Constants::zoomLevels)) + return *iter; + return currentLevel; +} + ImageView::ImageView(ImageViewerFile *file) : m_file(file) { @@ -245,16 +266,7 @@ void ImageView::setViewOutline(bool enable) void ImageView::doScale(qreal factor) { - qreal currentScale = transform().m11(); - qreal newScale = currentScale * factor; - qreal actualFactor = factor; - // cap to 0.001 - 1000 - if (newScale > 1000) - actualFactor = 1000./currentScale; - else if (newScale < 0.001) - actualFactor = 0.001/currentScale; - - scale(actualFactor, actualFactor); + scale(factor, factor); emitScaleFactor(); if (auto pixmapItem = dynamic_cast(m_imageItem)) pixmapItem->setTransformationMode( @@ -264,18 +276,26 @@ void ImageView::doScale(qreal factor) void ImageView::wheelEvent(QWheelEvent *event) { qreal factor = qPow(Constants::DEFAULT_SCALE_FACTOR, event->angleDelta().y() / 240.0); - doScale(factor); + qreal currentScale = transform().m11(); + qreal newScale = currentScale * factor; + // cap to 0.001 - 1000 + qreal actualFactor = qBound(0.001, factor, 1000.0); + doScale(actualFactor); event->accept(); } void ImageView::zoomIn() { - doScale(Constants::DEFAULT_SCALE_FACTOR); + qreal nextZoomLevel = nextLevel(transform().m11()); + resetTransform(); + doScale(nextZoomLevel); } void ImageView::zoomOut() { - doScale(1. / Constants::DEFAULT_SCALE_FACTOR); + qreal previousZoomLevel = previousLevel(transform().m11()); + resetTransform(); + doScale(previousZoomLevel); } void ImageView::resetToOriginalSize()