feat: auto focusing when scrolling with mouse (which should have a second scroll wheel like mine:) or keyboard

config.example.json

@@ -23,7 +23,7 @@
     "window_height": 500
   },
   "sort": {
-    "type": "size",
+    "type": "name",
     "reverse": false
   }
 }

src/designer/main_window.ui

@@ -47,7 +47,7 @@
       <property name="sizeHint" stdset="0">
        <size>
         <width>20</width>
-        <height>20</height>
+        <height>10</height>
        </size>
       </property>
      </spacer>

src/images_carousel.cpp

@@ -1,13 +1,15 @@
 /*
  * @Author: Uyanide pywang0608@foxmail.com
  * @Date: 2025-08-05 01:22:53
- * @LastEditTime: 2025-08-06 00:47:21
+ * @LastEditTime: 2025-08-06 01:27:49
  * @Description: Animated carousel widget for displaying and selecting images.
  */
 #include "images_carousel.h"
 
 #include <pthread.h>
 #include <qboxlayout.h>
+#include <qdebug.h>
+#include <qobject.h>
 
 #include <QLabel>
 #include <QMetaObject>
@@ -30,7 +32,6 @@ ImagesCarousel::ImagesCarousel(const double itemAspectRatio,
     : QWidget(parent),
       ui(new Ui::ImagesCarousel),
       m_updateTimer(new QTimer(this)),
-      m_scrollAnimation(nullptr),
       m_itemWidth(itemWidth),
       m_itemHeight(static_cast<int>(itemWidth / itemAspectRatio)),
       m_itemFocusWidth(itemFocusWidth),
@@ -40,11 +41,40 @@ ImagesCarousel::ImagesCarousel(const double itemAspectRatio,
     ui->setupUi(this);
 
     m_imagesLayout = dynamic_cast<QHBoxLayout*>(ui->scrollAreaWidgetContents->layout());
-    connect(m_updateTimer, &QTimer::timeout, this, &ImagesCarousel::_updateImages);
+
+    // Load initial images
+    connect(m_updateTimer,
+            &QTimer::timeout,
+            this,
+            &ImagesCarousel::_updateImages);
+    connect(this,
+            &ImagesCarousel::imagesLoaded,
+            this,
+            [this]() {
+                _focusCurrImage();
+                disconnect(this, &ImagesCarousel::imagesLoaded, this, nullptr);
+            });
     m_updateTimer->start(100);
 
-    connect(this, &ImagesCarousel::imagesLoaded, this, [this]() {
+    // Auto focus when scrolling
-        _focusCurrImage();
+    m_scrollDebounceTimer = new QTimer(this);
+    m_scrollDebounceTimer->setSingleShot(true);
+    m_scrollDebounceTimer->setInterval(200);
+    connect(m_scrollDebounceTimer,
+            &QTimer::timeout,
+            this,
+            [this]() {
+                _onScrollBarValueChanged(m_pendingScrollValue);
+            });
+    connect(ui->scrollArea->horizontalScrollBar(),
+            &QScrollBar::valueChanged,
+            this,
+            [this](int value) {
+                m_pendingScrollValue = value;
+                if (m_suppressAutoFocus) {
+                    return;
+                }
+                m_scrollDebounceTimer->start();
             });
 }
 
@@ -57,7 +87,7 @@ ImagesCarousel::~ImagesCarousel() {
     // ...
     if (m_scrollAnimation) {
         m_scrollAnimation->stop();
-        delete m_scrollAnimation;
+        m_scrollAnimation->deleteLater();
     }
 }
 
@@ -199,7 +229,7 @@ void ImagesCarousel::_focusCurrImage() {
 
     if (m_scrollAnimation) {
         m_scrollAnimation->stop();
-        delete m_scrollAnimation;
+        m_scrollAnimation->deleteLater();
         m_scrollAnimation = nullptr;
     }
 
@@ -208,9 +238,39 @@ void ImagesCarousel::_focusCurrImage() {
     m_scrollAnimation->setStartValue(hScrollBar->value());
     m_scrollAnimation->setEndValue(leftOffset);
     m_scrollAnimation->setEasingCurve(QEasingCurve::OutCubic);
+
+    // Suppress auto focus during animation
+    connect(m_scrollAnimation,
+            &QPropertyAnimation::finished,
+            this,
+            [this]() {
+                m_suppressAutoFocus = false;
+            });
+    m_suppressAutoFocus = true;
     m_scrollAnimation->start();
 }
 
+void ImagesCarousel::_onScrollBarValueChanged(int value) {
+    // Stop the animation if it is running
+    if (m_scrollAnimation && m_scrollAnimation->state() == QPropertyAnimation::Running) {
+        m_scrollAnimation->stop();
+        m_scrollAnimation->deleteLater();
+        m_scrollAnimation = nullptr;
+    }
+    int centerOffset = (value + m_itemFocusWidth / 2);
+    int itemOffset   = m_itemWidth + ui->scrollAreaWidgetContents->layout()->spacing();
+    int index        = centerOffset / itemOffset;
+    if (index < 0 || index >= m_loadedImages.size()) {
+        return;  // Out of bounds
+    }
+    if (index == m_currentIndex) {
+        return;  // Already focused
+    }
+    _unfocusCurrImage();
+    m_currentIndex = index;
+    _focusCurrImage();
+}
+
 ImageItem::ImageItem(const ImageData* data,
                      const int itemWidth,
                      const int itemHeight,

src/images_carousel.h

@@ -1,7 +1,7 @@
 /*
  * @Author: Uyanide pywang0608@foxmail.com
  * @Date: 2025-08-05 01:22:53
- * @LastEditTime: 2025-08-06 00:47:12
+ * @LastEditTime: 2025-08-06 01:32:56
  * @Description: Animated carousel widget for displaying and selecting images.
  */
 #ifndef IMAGES_CAROUSEL_H
@@ -125,9 +125,11 @@ class ImagesCarousel : public QWidget {
 
   private slots:
     void _unfocusCurrImage();
+    void _onScrollBarValueChanged(int value);
 
   public:
-    void appendImages(const QStringList& paths);
+    void
+    appendImages(const QStringList& paths);
 
   private:
     Q_INVOKABLE void _addImageToQueue(const ImageData* data);
@@ -141,10 +143,13 @@ class ImagesCarousel : public QWidget {
     QList<ImageItem*> m_loadedImages;
     QTimer* m_updateTimer;
     int m_currentIndex                    = 0;
-    QPropertyAnimation* m_scrollAnimation;
+    QPropertyAnimation* m_scrollAnimation = nullptr;
     QHBoxLayout* m_imagesLayout           = nullptr;
     QMutex m_imageCountMutex;
     int m_imageCount              = 0;
+    bool m_suppressAutoFocus      = false;
+    int m_pendingScrollValue      = 0;
+    QTimer* m_scrollDebounceTimer = nullptr;
 
   signals:
     void imageFocused(const QString& path, const int index, const int count);
@@ -157,13 +162,17 @@ class ImagesCarouselScrollArea : public QScrollArea {
   public:
     explicit ImagesCarouselScrollArea(QWidget* parent = nullptr)
         : QScrollArea(parent) {
-        setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+        // setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
-        setWidgetResizable(true);
+        // setWidgetResizable(true);
     }
 
   protected:
     void keyPressEvent(QKeyEvent* event) override {
+        if (event->key() == Qt::Key_Left || event->key() == Qt::Key_Right) {
             event->ignore();
+        } else {
+            QScrollArea::keyPressEvent(event);
+        }
     }
 };