Preload next and previous page if threading is enabled and not on low memory setting

BUGS: 132029

svn path=/branches/KDE/3.5/kdegraphics/kpdf/; revision=609253

core/observer.h

@@ -24,10 +24,11 @@
 
 /** PRIORITIES for requests. Globally defined here. **/
 #define PAGEVIEW_PRIO 1
-#define PAGEVIEW_PRELOAD_PRIO 3
+#define PAGEVIEW_PRELOAD_PRIO 4
 #define THUMBNAILS_PRIO 2
-#define THUMBNAILS_PRELOAD_PRIO 4
+#define THUMBNAILS_PRELOAD_PRIO 5
 #define PRESENTATION_PRIO 0
+#define PRESENTATION_PRELOAD_PRIO 3
 
 class KPDFPage;
 

ui/presentationwidget.cpp

@@ -448,6 +448,27 @@ void PresentationWidget::changePage( int newPage )
         m_document->requestPixmaps( request );
         // restore cursor
         QApplication::restoreOverrideCursor();
+        // ask for next and previous page if not in low memory usage setting
+        if (KpdfSettings::memoryLevel() != KpdfSettings::EnumMemoryLevel::Low && KpdfSettings::enableThreading()) {
+            QValueList< PixmapRequest * > asyncRequests;
+            if (newPage + 1 < (int)m_document->pages())
+            {
+                PresentationFrame *nextFrame = m_frames[ newPage + 1 ];
+                pixW = nextFrame->geometry.width();
+                pixH = nextFrame->geometry.height();
+                if ( !nextFrame->page->hasPixmap( PRESENTATION_ID, pixW, pixH ) )
+                    asyncRequests.push_back( new PixmapRequest( PRESENTATION_ID, newPage + 1, pixW, pixH, PRESENTATION_PRELOAD_PRIO, true ) );
+            }
+            if (newPage - 1 >= 0)
+            {
+                PresentationFrame *prevFrame = m_frames[ newPage - 1 ];
+                pixW = prevFrame->geometry.width();
+                pixH = prevFrame->geometry.height();
+                if ( !prevFrame->page->hasPixmap( PRESENTATION_ID, pixW, pixH ) )
+                    asyncRequests.push_back( new PixmapRequest( PRESENTATION_ID, newPage - 1, pixW, pixH, PRESENTATION_PRELOAD_PRIO, true ) );
+            }
+            if (!asyncRequests.isEmpty()) m_document->requestPixmaps( asyncRequests );
+        }
     }
     else
     {