comparison view/View.cpp @ 1363:bbeffb29bf09

Fix inconsistency between centre frame actually set and centre frame notified as set, which caused the start frame location to creep out of place gradually as you page through

         sv_frame_t formerCentre = m_centreFrame;
         m_centreFrame = f;
         
         if (m_zoomLevel.zone == ZoomLevel::PixelsPerFrame) {
 
-#ifdef DEBUG_VIEW_WIDGET_PAINT
+#ifdef DEBUG_VIEW
             SVCERR << "View(" << this << ")::setCentreFrame: in PixelsPerFrame zone, so change must be visible" << endl;
 #endif
             update();
             changeVisible = true;
 

             int formerPixel = int(formerCentre / m_zoomLevel.level);
             int newPixel = int(m_centreFrame / m_zoomLevel.level);
         
             if (newPixel != formerPixel) {
 
-#ifdef DEBUG_VIEW_WIDGET_PAINT
+#ifdef DEBUG_VIEW
                 SVCERR << "View(" << this << ")::setCentreFrame: newPixel " << newPixel << ", formerPixel " << formerPixel << endl;
 #endif
                 // ensure the centre frame is a multiple of the zoom level
                 m_centreFrame = sv_frame_t(newPixel) * m_zoomLevel.level;
+
+#ifdef DEBUG_VIEW
+                SVCERR << "View(" << this
+                       << ")::setCentreFrame: centre frame rounded to "
+                       << m_centreFrame << " (zoom level is "
+                       << m_zoomLevel.level << ")" << endl;
+#endif
                 
                 update();
                 changeVisible = true;
             }
         }
 
         if (e) {
-            sv_frame_t rf = alignToReference(f);
+            sv_frame_t rf = alignToReference(m_centreFrame);
 #ifdef DEBUG_VIEW
             cerr << "View[" << this << "]::setCentreFrame(" << f
-                      << "): emitting centreFrameChanged("
-                      << rf << ")" << endl;
+                 << "): m_centreFrame = " << m_centreFrame
+                 << ", emitting centreFrameChanged with aligned frame "
+                 << rf << endl;
 #endif
             emit centreFrameChanged(rf, m_followPan, m_followPlay);
         }
     }
 

             --fdiff; // round to the left
         }
         result = fdiff + m_centreFrame;
     }
 
-#ifdef DEBUG_VIEW
+#ifdef DEBUG_VIEW_WIDGET_PAINT
     if (x == 0) {
         SVCERR << "getFrameForX(" << x << "): diff = " << diff << ", fdiff = "
                << fdiff << ", m_centreFrame = " << m_centreFrame
                << ", level = " << m_zoomLevel.level
                << ", diff % level = " << (diff % m_zoomLevel.level)

     } else {
         delta = (getEndFrame() - getStartFrame()) / 20;
     }
     if (right) delta = -delta;
 
+#ifdef DEBUG_VIEW
+    SVCERR << "View::scroll(" << right << ", " << lots << ", " << e << "): "
+           << "delta = " << delta << ", m_centreFrame = " << m_centreFrame
+           << endl;
+#endif
+    
     if (m_centreFrame < delta) {
         setCentreFrame(0, e);
     } else if (m_centreFrame - delta >= getModelsEndFrame()) {
         setCentreFrame(getModelsEndFrame(), e);
     } else {