fix: use SmoothTransformation when scale factor less than 100%

CMakeLists.txt

@@ -6,7 +6,7 @@ include (GNUInstallDirs)
 
 set (CMAKE_AUTOMOC ON)
 set (CMAKE_AUTORCC ON)
-set (QT_MINIMUM_VERSION "5.7.1")
+set (QT_MINIMUM_VERSION "5.10")
 
 find_package(Qt5 ${QT_MINIMUM_VERSION} CONFIG REQUIRED Widgets Svg LinguistTools)
 

appveyor.yml

@@ -1,11 +1,8 @@
 environment:
   matrix:
-    - build_name: mingw73_32_qt5_12_5
-      QTPATH: C:\Qt\5.12.5\mingw73_32
+    - build_name: mingw73_32_qt5_12_6
+      QTPATH: C:\Qt\5.12.6\mingw73_32
       MINGW32: C:\Qt\Tools\mingw730_32
-#    - build_name: msvc2017_64
-#      QTPATH: C:\Qt\5.11.2\msvc2017_64
-#      MINGW32: C:\Qt\Tools\mingw530_32
 
 install:
   - cd %APPVEYOR_BUILD_FOLDER%

graphicsscene.cpp

@@ -60,6 +60,17 @@ void GraphicsScene::showGif(const QString &filepath)
     this->setSceneRect(m_theThing->boundingRect());
 }
 
+bool GraphicsScene::trySetTransformationMode(Qt::TransformationMode mode)
+{
+    QGraphicsPixmapItem * pixmapItem = qgraphicsitem_cast<QGraphicsPixmapItem *>(m_theThing);
+    if (pixmapItem) {
+        pixmapItem->setTransformationMode(mode);
+        return true;
+    }
+
+    return false;
+}
+
 QPixmap GraphicsScene::renderToPixmap()
 {
     QPixmap pixmap(sceneRect().toRect().size());

graphicsscene.h

@@ -15,6 +15,8 @@ public:
     void showSvg(const QString &filepath);
     void showGif(const QString &filepath);
 
+    bool trySetTransformationMode(Qt::TransformationMode mode);
+
     QPixmap renderToPixmap();
 
 private:

graphicsview.cpp

@@ -117,6 +117,7 @@ void GraphicsView::zoomView(qreal scaleFactor)
 {
     m_enableFitInView = false;
     scale(scaleFactor, scaleFactor);
+    applyTransformationModeByScaleFactor();
     emit navigatorViewRequired(!isThingSmallerThanWindowWith(transform()), m_rotateAngle);
 }
 
@@ -136,6 +137,7 @@ void GraphicsView::rotateView(qreal rotateAngel)
 void GraphicsView::fitInView(const QRectF &rect, Qt::AspectRatioMode aspectRadioMode)
 {
     QGraphicsView::fitInView(rect, aspectRadioMode);
+    applyTransformationModeByScaleFactor();
 }
 
 void GraphicsView::checkAndDoFitInView()
@@ -213,9 +215,9 @@ void GraphicsView::dragEnterEvent(QDragEnterEvent *event)
     } else {
         event->ignore();
     }
-    qDebug() << event->mimeData() << "Drag Enter Event"
-             << event->mimeData()->hasUrls() << event->mimeData()->hasImage()
-             << event->mimeData()->formats() << event->mimeData()->hasFormat("text/uri-list");
+//    qDebug() << event->mimeData() << "Drag Enter Event"
+//             << event->mimeData()->hasUrls() << event->mimeData()->hasImage()
+//             << event->mimeData()->formats() << event->mimeData()->hasFormat("text/uri-list");
 
     return QGraphicsView::dragEnterEvent(event);
 }
@@ -285,9 +287,9 @@ void GraphicsView::setCheckerboardEnabled(bool enabled)
     if (m_checkerboardEnabled) {
         // Prepare background check-board pattern
         QPixmap tilePixmap(0x20, 0x20);
-        tilePixmap.fill(QColor(35, 35, 35, 110));
+        tilePixmap.fill(QColor(35, 35, 35, 170));
         QPainter tilePainter(&tilePixmap);
-        QColor color(40, 40, 40, 110);
+        QColor color(45, 45, 45, 170);
         tilePainter.fillRect(0, 0, 0x10, 0x10, color);
         tilePainter.fillRect(0x10, 0x10, 0x10, 0x10, color);
         tilePainter.end();
@@ -298,6 +300,15 @@ void GraphicsView::setCheckerboardEnabled(bool enabled)
     }
 }
 
+void GraphicsView::applyTransformationModeByScaleFactor()
+{
+    if (this->scaleFactor() < 1) {
+        scene()->trySetTransformationMode(Qt::SmoothTransformation);
+    } else {
+        scene()->trySetTransformationMode(Qt::FastTransformation);
+    }
+}
+
 void GraphicsView::resetWithScaleAndRotate(qreal scaleFactor, qreal rotateAngle)
 {
     QGraphicsView::resetTransform();

graphicsview.h

@@ -54,6 +54,7 @@ private:
     bool isThingSmallerThanWindowWith(const QTransform &transform) const;
     bool shouldIgnoreMousePressMoveEvent(const QMouseEvent *event) const;
     void setCheckerboardEnabled(bool enabled);
+    void applyTransformationModeByScaleFactor();
 
     void resetWithScaleAndRotate(qreal scaleFactor, qreal rotateAngle);
 

mainwindow.cpp

@@ -268,8 +268,8 @@ void MainWindow::mousePressEvent(QMouseEvent *event)
     if (event->buttons() & Qt::LeftButton && !isMaximized()) {
         m_clickedOnWindow = true;
         m_oldMousePos = event->pos();
-        qDebug() << m_oldMousePos << m_graphicsView->transform().m11()
-                 << m_graphicsView->transform().m22() << m_graphicsView->matrix().m12();
+//        qDebug() << m_oldMousePos << m_graphicsView->transform().m11()
+//                 << m_graphicsView->transform().m22() << m_graphicsView->matrix().m12();
         event->accept();
     }