feat: auto long image mode

Author: BLumia

app/graphicsview.cpp

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: 2022 Gary Wang <wzc782970009@gmail.com>
+// SPDX-FileCopyrightText: 2025 Gary Wang <git@blumia.net>
 //
 // SPDX-License-Identifier: MIT
 
@@ -124,6 +124,7 @@ void GraphicsView::resetTransform()
 void GraphicsView::zoomView(qreal scaleFactor)
 {
     m_enableFitInView = false;
+    m_longImageMode = false;
     scale(scaleFactor, scaleFactor);
     applyTransformationModeByScaleFactor();
     emit navigatorViewRequired(!isThingSmallerThanWindowWith(transform()), transform());
@@ -140,6 +141,10 @@ void GraphicsView::rotateView(bool clockwise)
                   0,                  0,                  1);
     tf = transform() * tf;
     setTransform(tf);
+    
+    // Apply transformation mode but don't emit navigator signal here
+    // Let displayScene() handle the navigator visibility correctly
+    applyTransformationModeByScaleFactor();
 }
 
 void GraphicsView::flipView(bool horizontal)
@@ -261,15 +266,93 @@ void GraphicsView::fitByOrientation(Qt::Orientation ori, bool scaleDownOnly)
     emit navigatorViewRequired(!isThingSmallerThanWindowWith(transform()), transform());
 }
 
+bool GraphicsView::isLongImage() const
+{
+    // Get the transformed image size (considering rotation and other transforms)
+    QRectF transformedRect = transform().mapRect(sceneRect());
+    QSizeF imageSize = transformedRect.size();
+    
+    if (imageSize.isEmpty()) return false;
+    
+    qreal aspectRatio = imageSize.width() / imageSize.height();
+    
+    // Check if aspect ratio exceeds 5:2 (wide) or 2:5 (tall)
+    return aspectRatio > 2.5 || aspectRatio < 0.4;
+}
+
+bool GraphicsView::shouldEnterLongImageMode() const
+{
+    // Check if long image mode is enabled in settings
+    if (!Settings::instance()->autoLongImageMode()) return false;
+    
+    // Check if image is a long image
+    if (!isLongImage()) return false;
+    
+    // Check if transformed image size is larger than the size of the view
+    QSizeF imageSize = transform().mapRect(sceneRect()).size();
+    QSizeF viewSize = viewport()->size();
+    
+    return imageSize.width() > viewSize.width() || imageSize.height() > viewSize.height();
+}
+
+void GraphicsView::applyLongImageMode()
+{
+    if (!shouldEnterLongImageMode()) {
+        m_longImageMode = false;
+        return;
+    }
+    
+    m_longImageMode = true;
+    applyLongImageModeDirect();
+}
+
+void GraphicsView::applyLongImageModeDirect()
+{
+    // Determine image orientation based on current transform
+    QRectF transformedRect = transform().mapRect(sceneRect());
+    qreal aspectRatio = transformedRect.width() / transformedRect.height();
+    bool isTallImage = aspectRatio < 0.4;
+    bool isWideImage = aspectRatio > 2.5;
+    
+    // Use fitByOrientation with the migrated logic
+    if (isTallImage) {
+        // Tall image (height >> width): fit by width
+        fitByOrientation(Qt::Horizontal, true);  // scaleDownOnly = true
+    } else if (isWideImage) {
+        // Wide image (width >> height): fit by height
+        fitByOrientation(Qt::Vertical, true);    // scaleDownOnly = true
+    }
+}
+
+bool GraphicsView::isInLongImageMode() const
+{
+    return m_longImageMode;
+}
+
 void GraphicsView::displayScene()
 {
     if (shouldAvoidTransform()) {
         emit navigatorViewRequired(!isThingSmallerThanWindowWith(transform()), transform());
         return;
     }
 
+    // Check if should apply long image mode
+    if (shouldEnterLongImageMode()) {
+        applyLongImageMode();
+        m_firstUserMediaLoaded = true;
+        return;
+    }
+
+    // Not in long image mode
+    m_longImageMode = false;
+
     if (isSceneBiggerThanView()) {
         fitInView(sceneRect(), Qt::KeepAspectRatio);
+        // After fitInView, the image should fit the window, so hide navigator
+        emit navigatorViewRequired(false, transform());
+    } else {
+        // Image is already smaller than window, no navigator needed
+        emit navigatorViewRequired(false, transform());
     }
 
     m_enableFitInView = true;
@@ -291,6 +374,11 @@ void GraphicsView::setEnableAutoFitInView(bool enable)
     m_enableFitInView = enable;
 }
 
+void GraphicsView::setLongImageMode(bool enable)
+{
+    m_longImageMode = enable;
+}
+
 bool GraphicsView::avoidResetTransform() const
 {
     return m_avoidResetTransform;
@@ -363,7 +451,12 @@ void GraphicsView::wheelEvent(QWheelEvent *event)
 
 void GraphicsView::resizeEvent(QResizeEvent *event)
 {
-    if (m_enableFitInView) {
+    if (m_longImageMode) {
+        // In long image mode, reapply long image logic on resize
+        // We directly apply the long image mode logic without rechecking
+        // if we should enter long image mode, as the mode is already active
+        applyLongImageModeDirect();
+    } else if (m_enableFitInView) {
         bool originalSizeSmallerThanWindow = isThingSmallerThanWindowWith(resetScale(transform()));
         if (originalSizeSmallerThanWindow && scaleFactor() >= 1) {
             // no longer need to do fitInView()

app/graphicsview.h

@@ -39,12 +39,20 @@ class GraphicsView : public QGraphicsView
     void displayScene();
     bool isSceneBiggerThanView() const;
     void setEnableAutoFitInView(bool enable = true);
+    void setLongImageMode(bool enable = true);
 
     bool avoidResetTransform() const;
     void setAvoidResetTransform(bool avoidReset);
 
     static QTransform resetScale(const QTransform & orig);
 
+    // Long image mode support
+    bool isLongImage() const;
+    bool shouldEnterLongImageMode() const;
+    void applyLongImageMode();
+    void applyLongImageModeDirect();
+    bool isInLongImageMode() const;
+
 signals:
     void navigatorViewRequired(bool required, QTransform transform);
     void viewportRectChanged();
@@ -70,6 +78,7 @@ public slots:
     // ... or even more? e.g. "fit/snap width" things...
     // Currently it's "no fit" when it's false and "fit when view is smaller" when it's true.
     bool m_enableFitInView = false;
+    bool m_longImageMode = false;
     bool m_avoidResetTransform = false;
     bool m_checkerboardEnabled = false;
     bool m_useLightCheckerboard = false;

app/mainwindow.cpp

@@ -700,6 +700,7 @@ void MainWindow::on_actionActualSize_triggered()
 {
     m_graphicsView->resetScale();
     m_graphicsView->setEnableAutoFitInView(false);
+    m_graphicsView->setLongImageMode(false);
 }
 
 void MainWindow::on_actionToggleMaximize_triggered()
@@ -728,6 +729,7 @@ void MainWindow::on_actionFitInView_triggered()
 {
     m_graphicsView->fitInView(m_gv->sceneRect(), Qt::KeepAspectRatio);
     m_graphicsView->setEnableAutoFitInView(m_graphicsView->scaleFactor() <= 1);
+    m_graphicsView->setLongImageMode(false);
 }
 
 void MainWindow::on_actionFitByWidth_triggered()
@@ -813,14 +815,12 @@ void MainWindow::on_actionRotateClockwise_triggered()
 {
     m_graphicsView->rotateView();
     m_graphicsView->displayScene();
-    m_gv->setVisible(false);
 }
 
 void MainWindow::on_actionRotateCounterClockwise_triggered()
 {
     m_graphicsView->rotateView(false);
     m_graphicsView->displayScene();
-    m_gv->setVisible(false);
 }
 
 void MainWindow::on_actionPrevPicture_triggered()

app/navigatorview.cpp

@@ -9,6 +9,7 @@
 
 #include <QMouseEvent>
 #include <QDebug>
+#include <QTimer>
 
 NavigatorView::NavigatorView(QWidget *parent)
     : QGraphicsView (parent)
@@ -34,10 +35,14 @@ void NavigatorView::setOpacity(qreal opacity, bool animated)
 
 void NavigatorView::updateMainViewportRegion()
 {
-    if (m_mainView != nullptr) {
-        m_viewportRegion = mapFromScene(m_mainView->mapToScene(m_mainView->rect()));
-        update();
-    }
+    // Use QTimer::singleShot with lambda to delay the update
+    // This ensures all geometry updates are complete before calculating viewport region
+    QTimer::singleShot(0, [this]() {
+        if (m_mainView != nullptr) {
+            m_viewportRegion = mapFromScene(m_mainView->mapToScene(m_mainView->rect()));
+            update();
+        }
+    });
 }
 
 void NavigatorView::mousePressEvent(QMouseEvent *event)

app/settings.cpp

@@ -65,6 +65,11 @@ bool Settings::loopGallery() const
     return m_qsettings->value("loop_gallery", true).toBool();
 }
 
+bool Settings::autoLongImageMode() const
+{
+    return m_qsettings->value("auto_long_image_mode", true).toBool();
+}
+
 Settings::DoubleClickBehavior Settings::doubleClickBehavior() const
 {
     QString result = m_qsettings->value("double_click_behavior", "Close").toString();
@@ -117,6 +122,12 @@ void Settings::setLoopGallery(bool on)
     m_qsettings->sync();
 }
 
+void Settings::setAutoLongImageMode(bool on)
+{
+    m_qsettings->setValue("auto_long_image_mode", on);
+    m_qsettings->sync();
+}
+
 void Settings::setDoubleClickBehavior(DoubleClickBehavior dcb)
 {
     m_qsettings->setValue("double_click_behavior", QEnumHelper::toString(dcb));

app/settings.h

@@ -38,6 +38,7 @@ class Settings : public QObject
     bool useBuiltInCloseAnimation() const;
     bool useLightCheckerboard() const;
     bool loopGallery() const;
+    bool autoLongImageMode() const;
     DoubleClickBehavior doubleClickBehavior() const;
     MouseWheelBehavior mouseWheelBehavior() const;
     WindowSizeBehavior initWindowSizeBehavior() const;
@@ -47,6 +48,7 @@ class Settings : public QObject
     void setUseBuiltInCloseAnimation(bool on);
     void setUseLightCheckerboard(bool light);
     void setLoopGallery(bool on);
+    void setAutoLongImageMode(bool on);
     void setDoubleClickBehavior(DoubleClickBehavior dcb);
     void setMouseWheelBehavior(MouseWheelBehavior mwb);
     void setInitWindowSizeBehavior(WindowSizeBehavior wsb);

app/settingsdialog.cpp

@@ -23,6 +23,7 @@ SettingsDialog::SettingsDialog(QWidget *parent)
     , m_useBuiltInCloseAnimation(new QCheckBox)
     , m_useLightCheckerboard(new QCheckBox)
     , m_loopGallery(new QCheckBox)
+    , m_autoLongImageMode(new QCheckBox)
     , m_doubleClickBehavior(new QComboBox)
     , m_mouseWheelBehavior(new QComboBox)
     , m_initWindowSizeBehavior(new QComboBox)
@@ -123,6 +124,7 @@ SettingsDialog::SettingsDialog(QWidget *parent)
     settingsForm->addRow(tr("Use built-in close window animation"), m_useBuiltInCloseAnimation);
     settingsForm->addRow(tr("Use light-color checkerboard"), m_useLightCheckerboard);
     settingsForm->addRow(tr("Loop the loaded gallery"), m_loopGallery);
+    settingsForm->addRow(tr("Auto long image mode"), m_autoLongImageMode);
     settingsForm->addRow(tr("Double-click behavior"), m_doubleClickBehavior);
     settingsForm->addRow(tr("Mouse wheel behavior"), m_mouseWheelBehavior);
     settingsForm->addRow(tr("Default window size"), m_initWindowSizeBehavior);
@@ -132,6 +134,7 @@ SettingsDialog::SettingsDialog(QWidget *parent)
     m_useBuiltInCloseAnimation->setChecked(Settings::instance()->useBuiltInCloseAnimation());
     m_useLightCheckerboard->setChecked(Settings::instance()->useLightCheckerboard());
     m_loopGallery->setChecked(Settings::instance()->loopGallery());
+    m_autoLongImageMode->setChecked(Settings::instance()->autoLongImageMode());
     m_doubleClickBehavior->setModel(new QStringListModel(dcbDropDown));
     Settings::DoubleClickBehavior dcb = Settings::instance()->doubleClickBehavior();
     m_doubleClickBehavior->setCurrentIndex(static_cast<int>(dcb));
@@ -174,6 +177,10 @@ SettingsDialog::SettingsDialog(QWidget *parent)
         Settings::instance()->setLoopGallery(state == Qt::Checked);
     });
 
+    connect(m_autoLongImageMode, &QCHECKBOX_CHECKSTATECHANGED, this, [ = ](QT_CHECKSTATE state){
+        Settings::instance()->setAutoLongImageMode(state == Qt::Checked);
+    });
+
     connect(m_doubleClickBehavior, QOverload<int>::of(&QComboBox::currentIndexChanged), this, [ = ](int index){
         Settings::instance()->setDoubleClickBehavior(_dc_options.at(index).first);
     });

app/settingsdialog.h

@@ -26,6 +26,7 @@ public slots:
     QCheckBox * m_useBuiltInCloseAnimation = nullptr;
     QCheckBox * m_useLightCheckerboard = nullptr;
     QCheckBox * m_loopGallery = nullptr;
+    QCheckBox * m_autoLongImageMode = nullptr;
     QComboBox * m_doubleClickBehavior = nullptr;
     QComboBox * m_mouseWheelBehavior = nullptr;
     QComboBox * m_initWindowSizeBehavior = nullptr;