[composer] Refresh main map canvas when atlas preview feature changes, allows for easier customisation of maps styled using $atlasfeatureid expressions

Author: nyalldawson

src/app/composer/qgscomposer.cpp

@@ -507,6 +507,8 @@ QgsComposer::QgsComposer( QgisApp *qgis, const QString& title )
   mActionExportAtlasAsImage->setEnabled( false );
   mActionExportAtlasAsSVG->setEnabled( false );
   mActionExportAtlasAsPDF->setEnabled( false );
+  QgsAtlasComposition* atlasMap = &mComposition->atlasComposition();
+  connect( atlasMap, SIGNAL( toggled( bool ) ), this, SLOT( toggleAtlasControls( bool ) ) );
 
   // Create size grip (needed by Mac OS X for QMainWindow if QStatusBar is not visible)
   //should not be needed now that composer has a status bar?
@@ -857,6 +859,7 @@ void QgsComposer::on_mActionAtlasPreview_triggered( bool checked )
   if ( checked )
   {
     atlasMap->firstFeature();
+    emit( atlasPreviewFeatureChanged() );
   }
   else
   {
@@ -875,7 +878,7 @@ void QgsComposer::on_mActionAtlasNext_triggered()
   }
 
   atlasMap->nextFeature();
-
+  emit( atlasPreviewFeatureChanged() );
 }
 
 void QgsComposer::on_mActionAtlasPrev_triggered()
@@ -887,7 +890,7 @@ void QgsComposer::on_mActionAtlasPrev_triggered()
   }
 
   atlasMap->prevFeature();
-
+  emit( atlasPreviewFeatureChanged() );
 }
 
 void QgsComposer::on_mActionAtlasFirst_triggered()
@@ -899,6 +902,7 @@ void QgsComposer::on_mActionAtlasFirst_triggered()
   }
 
   atlasMap->firstFeature();
+  emit( atlasPreviewFeatureChanged() );
 }
 
 void QgsComposer::on_mActionAtlasLast_triggered()
@@ -910,6 +914,7 @@ void QgsComposer::on_mActionAtlasLast_triggered()
   }
 
   atlasMap->lastFeature();
+  emit( atlasPreviewFeatureChanged() );
 }
 
 QgsMapCanvas *QgsComposer::mapCanvas( void )

src/app/composer/qgscomposer.h

@@ -123,6 +123,9 @@ class QgsComposer: public QMainWindow, private Ui::QgsComposerBase
     //!Composer deletes the old composerview when loading a template
     void composerWillBeRemoved( QgsComposerView* v );
 
+    //! Is emitted when the atlas preview feature changes
+    void atlasPreviewFeatureChanged();
+
   public slots:
     //! Zoom to full extent of the paper
     void on_mActionZoomAll_triggered();

src/app/qgisapp.cpp

@@ -5048,6 +5048,7 @@ QgsComposer* QgisApp::createNewComposer( QString title )
   emit composerAdded( newComposerObject->view() );
   connect( newComposerObject, SIGNAL( composerAdded( QgsComposerView* ) ), this, SIGNAL( composerAdded( QgsComposerView* ) ) );
   connect( newComposerObject, SIGNAL( composerWillBeRemoved( QgsComposerView* ) ), this, SIGNAL( composerWillBeRemoved( QgsComposerView* ) ) );
+  connect( newComposerObject, SIGNAL( atlasPreviewFeatureChanged() ), this, SLOT( refreshMapCanvas() ) );
   markDirty();
   return newComposerObject;
 }
@@ -5137,6 +5138,7 @@ bool QgisApp::loadComposersFromProject( const QDomDocument& doc )
     emit composerAdded( composer->view() );
     connect( composer, SIGNAL( composerAdded( QgsComposerView* ) ), this, SIGNAL( composerAdded( QgsComposerView* ) ) );
     connect( composer, SIGNAL( composerWillBeRemoved( QgsComposerView* ) ), this, SIGNAL( composerWillBeRemoved( QgsComposerView* ) ) );
+    connect( composer, SIGNAL( atlasPreviewFeatureChanged() ), this, SLOT( refreshMapCanvas() ) );
   }
   return true;
 }