move magnification in map settings

python/core/qgsmapsettings.sip

@@ -17,7 +17,7 @@ class QgsMapSettings
     //! The actual visible extent used for rendering could be slightly different
     //! since the given extent may be expanded in order to fit the aspect ratio
     //! of output size. Use visibleExtent() to get the resulting extent.
-    void setExtent( const QgsRectangle& rect );
+    void setExtent( const QgsRectangle& rect, bool magnified = true );
 
     //! Return the size of the resulting map image
     QSize outputSize() const;
@@ -39,6 +39,13 @@ class QgsMapSettings
     //! Set DPI used for conversion between real world units (e.g. mm) and pixels
     void setOutputDpi( int dpi );
 
+    //! Set the magnification factor.
+    //! @note added in 2.16
+    void setMagnificationFactor( double factor );
+    //! Return the magnification factor.
+    //! @note added in 2.16
+   double magnificationFactor() const;
+
     //! Get list of layer IDs for map rendering
     //! The layers are stored in the reverse order of how they are rendered (layer with index 0 will be on top)
     QStringList layers() const;

python/gui/qgsmapcanvas.sip

@@ -57,6 +57,7 @@ class QgsMapCanvas : QGraphicsView
     void setMagnificationFactor( double level );
 
     //! Returns the magnification factor
+    //! @note added in 2.16
     double magnificationFactor() const;
 
     void setLayerSet( QList<QgsMapCanvasLayer>& layers );

src/core/qgsmapsettings.cpp

@@ -35,6 +35,7 @@ QgsMapSettings::QgsMapSettings()
     , mSize( QSize( 0, 0 ) )
     , mExtent()
     , mRotation( 0.0 )
+    , mMagnificationFactor( 1.0 )
     , mProjectionsEnabled( false )
     , mDestCRS( GEOCRS_ID, QgsCoordinateReferenceSystem::InternalCrsId )  // WGS 84
     , mDatumTransformStore( mDestCRS )
@@ -53,15 +54,42 @@ QgsMapSettings::QgsMapSettings()
   setMapUnits( QGis::Degrees );
 }
 
+void QgsMapSettings::setMagnificationFactor( double factor )
+{
+  double ratio = mMagnificationFactor / factor;
+  mMagnificationFactor = factor;
+
+  double rot = rotation();
+  setRotation( 0.0 );
+
+  QgsRectangle ext = visibleExtent();
+  ext.scale( ratio );
+
+  mRotation = rot;
+  mExtent = ext;
+  mDpi = outputDpi() / ratio;
+
+  updateDerived();
+}
+
+double QgsMapSettings::magnificationFactor() const
+{
+  return mMagnificationFactor;
+}
 
 QgsRectangle QgsMapSettings::extent() const
 {
   return mExtent;
 }
 
-void QgsMapSettings::setExtent( const QgsRectangle& extent )
+void QgsMapSettings::setExtent( const QgsRectangle& extent, bool magnified )
 {
-  mExtent = extent;
+  QgsRectangle magnifiedExtent = extent;
+
+  if ( !magnified )
+    magnifiedExtent.scale( 1 / mMagnificationFactor );
+
+  mExtent = magnifiedExtent;
 
   updateDerived();
 }

src/core/qgsmapsettings.h

@@ -64,7 +64,7 @@ class CORE_EXPORT QgsMapSettings
     //! The actual visible extent used for rendering could be slightly different
     //! since the given extent may be expanded in order to fit the aspect ratio
     //! of output size. Use visibleExtent() to get the resulting extent.
-    void setExtent( const QgsRectangle& rect );
+    void setExtent( const QgsRectangle& rect, bool magnified = true );
 
     //! Return the size of the resulting map image
     QSize outputSize() const;
@@ -86,6 +86,13 @@ class CORE_EXPORT QgsMapSettings
     //! Set DPI used for conversion between real world units (e.g. mm) and pixels
     void setOutputDpi( int dpi );
 
+    //! Set the magnification factor.
+    //! @note added in 2.16
+    void setMagnificationFactor( double factor );
+    //! Return the magnification factor.
+    //! @note added in 2.16
+    double magnificationFactor() const;
+
     //! Get list of layer IDs for map rendering
     //! The layers are stored in the reverse order of how they are rendered (layer with index 0 will be on top)
     QStringList layers() const;
@@ -261,6 +268,7 @@ class CORE_EXPORT QgsMapSettings
     QgsRectangle mExtent;
 
     double mRotation;
+    double mMagnificationFactor;
 
     QStringList mLayers;
     QMap<QString, QString> mLayerStyleOverrides;

src/gui/qgsmapcanvas.cpp

@@ -313,21 +313,15 @@ QgsMapCanvas::~QgsMapCanvas()
 
 void QgsMapCanvas::setMagnificationFactor( double level )
 {
-  QgsMapSettings settings = mSettings;
-  settings.setRotation( 0.0 );
-
-  double ratio = mMagnificationFactor / level;
-  mMagnificationFactor = level;
-
-  QgsRectangle ext = settings.visibleExtent();
-  ext.scale( ratio );
-
-  mSettings.setOutputDpi( mSettings.outputDpi() / ratio );
-  setExtent( ext, true );
-
+  mSettings.setMagnificationFactor( level );
   refresh();
 }
 
+double QgsMapCanvas::magnificationFactor() const
+{
+  return mSettings.magnificationFactor();
+}
+
 void QgsMapCanvas::enableAntiAliasing( bool theFlag )
 {
   mSettings.setFlag( QgsMapSettings::Antialiasing, theFlag );
@@ -905,11 +899,7 @@ void QgsMapCanvas::setExtent( QgsRectangle const & r, bool magnified )
   }
   else
   {
-    QgsRectangle magnifiedExtent = r;
-    if ( ! magnified )
-      magnifiedExtent.scale( 1 / mMagnificationFactor );
-
-    mSettings.setExtent( magnifiedExtent );
+    mSettings.setExtent( r, magnified );
   }
   emit extentsChanged();
   updateScale();

src/gui/qgsmapcanvas.h

@@ -126,7 +126,8 @@ class GUI_EXPORT QgsMapCanvas : public QGraphicsView
     void setMagnificationFactor( double level );
 
     //! Returns the magnification factor
-    double magnificationFactor() const { return mMagnificationFactor; };
+    //! @note added in 2.16
+    double magnificationFactor() const;
 
     void setLayerSet( QList<QgsMapCanvasLayer>& layers );