Allow change of preload without restart

imageringlist.cpp

@@ -348,6 +348,35 @@ QVariant ImageRingList::headerData(int section, Qt::Orientation orientation, int
     return QVariant();
 }
 
+void ImageRingList::setPreload(int width)
+{
+    DEFAULT_WIDTH = width;
+    if(m_images.size() == 0)return;
+
+    int newWidth = DEFAULT_WIDTH<m_images.size()/2 ? DEFAULT_WIDTH : m_images.size()/2;
+    if(newWidth > m_width)
+    {
+        for(int i = newWidth - m_width; i>0; i--)
+        {
+            m_firstImage = decrement(m_firstImage);
+            (*m_firstImage)->load();
+            m_lastImage = increment(m_lastImage);
+            (*m_lastImage)->load();
+        }
+    }
+    if(newWidth < m_width)
+    {
+        for(int i = m_width - newWidth; i>0; i--)
+        {
+            (*m_firstImage)->release();
+            m_firstImage = increment(m_firstImage);
+            (*m_lastImage)->release();
+            m_lastImage = decrement(m_lastImage);
+        }
+    }
+    m_width = newWidth;
+}
+
 void ImageRingList::setFiles(const QStringList files, const QString &currentFile)
 {
     QThreadPool::globalInstance()->clear();

imageringlist.h

@@ -89,6 +89,8 @@ public:
     int columnCount(const QModelIndex &parent = QModelIndex()) const override;
     QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
     QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const override;
+public slots:
+    void setPreload(int width);
 protected:
     void setFiles(const QStringList files, const QString &currentFile = QString());
     QList<ImagePtr>::iterator increment(QList<ImagePtr>::iterator iter);

mainwindow.cpp

@@ -627,6 +627,7 @@ void MainWindow::showMarkFilesDialog()
 void MainWindow::showSettingsDialog()
 {
     SettingsDialog settingsDialog(this);
+    connect(&settingsDialog, &SettingsDialog::preloadChanged, m_ringList, &ImageRingList::setPreload);
     settingsDialog.exec();
 }
 

settingsdialog.cpp

@@ -92,4 +92,6 @@ void SettingsDialog::saveSettings()
     settings.setValue("settings/preloadimagecount", m_preloadImages->value());
     settings.setValue("settings/dontusenativedialogs", m_useNativeDialog->isChecked());
     QApplication::setAttribute(Qt::AA_DontUseNativeDialogs, m_useNativeDialog->isChecked());
+    if(DEFAULT_WIDTH != m_preloadImages->value())
+        emit preloadChanged(m_preloadImages->value());
 }

settingsdialog.h

@@ -12,6 +12,8 @@ public:
     explicit SettingsDialog(QWidget *parent = nullptr);
     static void loadSettings();
     static bool loadThumbsizes();
+signals:
+    void preloadChanged(int witdth);
 private:
     void saveSettings();