src/core/composer/qgsatlascomposition.cpp

@@ -443,38 +443,43 @@ void QgsAtlasComposition::prepareForFeature( int featureI )
     atlasMaps << currentMap;
   }
 
+  //clear the transformed bounds of the previous feature
+  mTransformedFeatureBounds = QgsRectangle();
+
   if ( atlasMaps.isEmpty() )
   {
     //no atlas enabled maps
     return;
   }
 
-  //
-  // compute the new extent
-  // keep the original aspect ratio
-  // and apply a margin
-
-  const QgsCoordinateReferenceSystem& coverage_crs = mCoverageLayer->crs();
-  // transformation needed for feature geometries. This should be set on a per-atlas map basis,
+  // compute extent of current feature in the map CRS. This should be set on a per-atlas map basis,
   // but given that it's not currently possible to have maps with different CRSes we can just
   // calculate it once based on the first atlas maps' CRS.
-  const QgsCoordinateReferenceSystem& destination_crs = atlasMaps[0]->mapRenderer()->destinationCrs();
+  computeExtent( atlasMaps[0] );
+
+  //update atlas bounds of every atlas enabled composer map
+  for ( QList<QgsComposerMap*>::iterator mit = atlasMaps.begin(); mit != atlasMaps.end(); ++mit )
+  {
+    prepareMap( *mit );
+  }
+}
+
+void QgsAtlasComposition::computeExtent( QgsComposerMap* map )
+{
+  // compute the extent of the current feature, in the crs of the specified map
+
+  const QgsCoordinateReferenceSystem& coverage_crs = mCoverageLayer->crs();
+  // transformation needed for feature geometries
+  const QgsCoordinateReferenceSystem& destination_crs = map->mapRenderer()->destinationCrs();
   mTransform.setSourceCrs( coverage_crs );
   mTransform.setDestCRS( destination_crs );
 
   // QgsGeometry::boundingBox is expressed in the geometry"s native CRS
   // We have to transform the grometry to the destination CRS and ask for the bounding box
   // Note: we cannot directly take the transformation of the bounding box, since transformations are not linear
-
   QgsGeometry tgeom( *mCurrentFeature.geometry() );
   tgeom.transform( mTransform );
   mTransformedFeatureBounds = tgeom.boundingBox();
-
-  //update atlas bounds of every atlas enabled composer map
-  for ( QList<QgsComposerMap*>::iterator mit = atlasMaps.begin(); mit != atlasMaps.end(); ++mit )
-  {
-    prepareMap( *mit );
-  }
 }
 
 void QgsAtlasComposition::prepareMap( QgsComposerMap* map )
@@ -484,6 +489,13 @@ void QgsAtlasComposition::prepareMap( QgsComposerMap* map )
     return;
   }
 
+  if ( mTransformedFeatureBounds.isEmpty() )
+  {
+    //transformed extent of current feature hasn't been calculated yet. This can happen if
+    //a map has been set to be atlas controlled after prepare feature was called
+    computeExtent( map );
+  }
+
   double xa1 = mTransformedFeatureBounds.xMinimum();
   double xa2 = mTransformedFeatureBounds.xMaximum();
   double ya1 = mTransformedFeatureBounds.yMinimum();

src/core/composer/qgsatlascomposition.h

@@ -201,6 +201,9 @@ class CORE_EXPORT QgsAtlasComposition : public QObject
 
     //forces all atlas enabled maps to redraw
     void updateAtlasMaps();
+
+    //computes the extent of the current feature, in the crs of the specified map
+    void computeExtent( QgsComposerMap *map );
 };
 
 #endif

src/core/composer/qgscomposerlabel.cpp

@@ -45,6 +45,12 @@ QgsComposerLabel::QgsComposerLabel( QgsComposition *composition ):
   //default to a 10 point font size
   mFont.setPointSizeF( 10 );
 
+  if ( mComposition && mComposition->atlasMode() == QgsComposition::PreviewAtlas )
+  {
+    //a label added while atlas preview is enabled needs to have the expression context set,
+    //otherwise fields in the label aren't correctly evaluated until atlas preview feature changes (#9457)
+    setExpressionContext( mComposition->atlasComposition().currentFeature(), mComposition->atlasComposition().coverageLayer() );
+  }
 }
 
 QgsComposerLabel::~QgsComposerLabel()

src/core/composer/qgscomposermousehandles.cpp

@@ -22,6 +22,7 @@
 #include "qgscomposermousehandles.h"
 #include "qgscomposeritem.h"
 #include "qgscomposition.h"
+#include "qgspaperitem.h"
 #include "qgis.h"
 #include "qgslogger.h"
 
@@ -1185,7 +1186,17 @@ void QgsComposerMouseHandles::collectAlignCoordinates( QMap< double, const QgsCo
       {
         continue;
       }
-      QRectF itemRect = currentItem->sceneBoundingRect();
+      QRectF itemRect;
+      if ( dynamic_cast<const QgsPaperItem *>( *itemIt ) )
+      {
+        //if snapping to paper use the paper item's rect rather then the bounding rect,
+        //since we want to snap to the page edge and not any outlines drawn around the page
+        itemRect = currentItem->rect();
+      }
+      else
+      {
+        itemRect = currentItem->sceneBoundingRect();
+      }
       alignCoordsX.insert( itemRect.left(), currentItem );
       alignCoordsX.insert( itemRect.right(), currentItem );
       alignCoordsX.insert( itemRect.center().x(), currentItem );

tests/src/python/test_qgsblendmodes.py

@@ -30,6 +30,7 @@
 from PyQt4.QtGui import *
 
 from qgis.core import (QgsVectorLayer,
+                       QgsVectorSimplifyMethod,
                        QgsMapLayerRegistry,
                        QgsMapRenderer,
                        QgsCoordinateReferenceSystem,
@@ -63,16 +64,19 @@ def __init__(self, methodName):
         self.mPointLayer = QgsVectorLayer(myShpFile, 'Points', 'ogr')
         self.mMapRegistry.addMapLayer(self.mPointLayer)
 
+        self.mSimplifyMethod = QgsVectorSimplifyMethod() ;
+        self.mSimplifyMethod.setSimplifyHints(QgsVectorLayer.NoSimplification);
+
         # create polygon layer
         myShpFile = os.path.join(TEST_DATA_DIR, 'polys.shp')
         self.mPolygonLayer = QgsVectorLayer(myShpFile, 'Polygons', 'ogr')
-        self.mPolygonLayer.setSimplifyDrawingHints(QgsVectorLayer.NoSimplification)
+        self.mPolygonLayer.setSimplifyMethod(self.mSimplifyMethod)
         self.mMapRegistry.addMapLayer(self.mPolygonLayer)
 
         # create line layer
         myShpFile = os.path.join(TEST_DATA_DIR, 'lines.shp')
         self.mLineLayer = QgsVectorLayer(myShpFile, 'Lines', 'ogr')
-        self.mLineLayer.setSimplifyDrawingHints(QgsVectorLayer.NoSimplification)
+        self.mLineLayer.setSimplifyMethod(self.mSimplifyMethod)
         self.mMapRegistry.addMapLayer(self.mLineLayer)
 
         # create two raster layers