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();