Show composer maps on demand after project loading

python/core/qgscomposeritem.sip

@@ -253,6 +253,9 @@ class QgsComposerItem: QObject, QGraphicsRectItem
 
     double rotation() const;
 
+    /**Updates item, with the possibility to do custom update for subclasses*/
+    virtual void updateItem();
+
   public slots:
     virtual void setRotation( double r);
 

python/core/qgscomposermap.sip

@@ -94,7 +94,7 @@ class QgsComposerMap : QgsComposerItem
     /**Sets new Extent and changes width, height (and implicitely also scale)*/
     void setNewExtent( const QgsRectangle& extent );
 
-    PreviewMode previewMode();
+    PreviewMode previewMode() const;
     void setPreviewMode( PreviewMode m );
 
     /**Getter for flag that determines if the stored layer set should be used or the current layer set of the qgis mapcanvas
@@ -222,6 +222,10 @@ class QgsComposerMap : QgsComposerItem
     void setCrossLength(double l);
     double crossLength();
 
+    void setMapRotation( double r );
+
+    void updateItem();
+
   public slots:
 
     /**Called if map canvas has changed*/

src/app/composer/qgscomposer.cpp

@@ -1123,6 +1123,22 @@ void QgsComposer::resizeEvent( QResizeEvent *e )
   saveWindowState();
 }
 
+void QgsComposer::showEvent( QShowEvent* event )
+{
+  if ( event->spontaneous() ) //event from the window system
+  {
+    //go through maps and restore original preview modes (show on demand after loading from project file)
+    QMap< QgsComposerMap*, QgsComposerMap::PreviewMode >::iterator mapIt = mMapsToRestore.begin();
+    for ( ; mapIt != mMapsToRestore.end(); ++mapIt )
+    {
+      mapIt.key()->setPreviewMode( mapIt.value() );
+      mapIt.key()->cache();
+      mapIt.key()->update();
+    }
+    mMapsToRestore.clear();
+  }
+}
+
 void QgsComposer::saveWindowState()
 {
   QSettings settings;
@@ -1169,6 +1185,14 @@ void QgsComposer::writeXML( QDomNode& parentNode, QDomDocument& doc )
   QDomElement composerElem = doc.createElement( "Composer" );
   composerElem.setAttribute( "title", mTitle );
 
+  //change preview mode of minimised / hidden maps (show contents only on demand)
+  QMap< QgsComposerMap*, QgsComposerMap::PreviewMode >::iterator mapIt = mMapsToRestore.begin();
+  for ( ; mapIt != mMapsToRestore.end(); ++mapIt )
+  {
+    mapIt.key()->setPreviewMode( mapIt.value() );
+  }
+  mMapsToRestore.clear();
+
   //store if composer is open or closed
   if ( isVisible() )
   {
@@ -1283,6 +1307,20 @@ void QgsComposer::readXML( const QDomElement& composerElem, const QDomDocument&
     QDomElement currentComposerMapElem = composerMapList.at( i ).toElement();
     QgsComposerMap* newMap = new QgsComposerMap( mComposition );
     newMap->readXML( currentComposerMapElem, doc );
+
+    if ( fromTemplate ) //show map directly if loaded from template
+    {
+      newMap->updateItem();
+    }
+    else //show map only on demand if loaded from project
+    {
+      if ( newMap->previewMode() != QgsComposerMap::Rectangle )
+      {
+        mMapsToRestore.insert( newMap, newMap->previewMode() );
+        newMap->setPreviewMode( QgsComposerMap::Rectangle );
+      }
+    }
+
     addComposerMap( newMap );
     mComposition->addItem( newMap );
     mComposition->update();
@@ -1518,6 +1556,12 @@ void QgsComposer::deleteItem( QgsComposerItem* item )
   //the item itself is not deleted here (usually, this is done in the destructor of QgsAddRemoveItemCommand)
   delete( it.value() );
   mItemWidgetMap.remove( it.key() );
+
+  QgsComposerMap* map = dynamic_cast<QgsComposerMap*>( item );
+  if ( map )
+  {
+    mMapsToRestore.remove( map );
+  }
 }
 
 void QgsComposer::setSelectionTool()

src/app/composer/qgscomposer.h

@@ -18,7 +18,7 @@
 #ifndef QGSCOMPOSER_H
 #define QGSCOMPOSER_H
 #include "ui_qgscomposerbase.h"
-#include "qgscomposeritem.h"
+#include "qgscomposermap.h"
 #include "qgscontexthelp.h"
 #include <QPrinter>
 
@@ -26,7 +26,6 @@ class QgisApp;
 class QgsComposerArrow;
 class QgsComposerLabel;
 class QgsComposerLegend;
-class QgsComposerMap;
 class QgsComposerPicture;
 class QgsComposerScaleBar;
 class QgsComposerShape;
@@ -93,6 +92,8 @@ class QgsComposer: public QMainWindow, private Ui::QgsComposerBase
     //! Resize event
     virtual void resizeEvent( QResizeEvent * );
 
+    virtual void showEvent( QShowEvent* event );
+
 #ifdef Q_WS_MAC
     //! Change event (update window menu on ActivationChange)
     virtual void changeEvent( QEvent * );
@@ -321,6 +322,9 @@ class QgsComposer: public QMainWindow, private Ui::QgsComposerBase
     QPrinter mPrinter;
 
     QUndoView* mUndoView;
+
+    //! We load composer map content from project xml only on demand. Therefore we need to store the real preview mode type
+    QMap< QgsComposerMap*, QgsComposerMap::PreviewMode > mMapsToRestore;
 };
 
 #endif

src/core/composer/qgscomposeritem.cpp

@@ -568,6 +568,7 @@ void QgsComposerItem::changeItemRectangle( const QPointF& currentPosition, const
         changeComposerItem->setSceneRect( QRectF( originalItem->transform().dx() + moveRectX,
                                           originalItem->transform().dy() + moveRectY,
                                           originalItem->rect().width(), originalItem->rect().height() ) );
+        changeComposerItem->updateItem();
       }
     }
     return;
@@ -587,6 +588,7 @@ void QgsComposerItem::changeItemRectangle( const QPointF& currentPosition, const
   {
     changeComposerItem->setSceneRect( QRectF( originalItem->transform().dx() + mx, originalItem->transform().dy() + my,
                                       originalItem->rect().width() + rx, originalItem->rect().height() + ry ) );
+    changeComposerItem->updateItem();
   }
 }
 

src/core/composer/qgscomposeritem.h

@@ -217,6 +217,9 @@ class CORE_EXPORT QgsComposerItem: public QObject, public QGraphicsRectItem
 
     double rotation() const {return mRotation;}
 
+    /**Updates item, with the possibility to do custom update for subclasses*/
+    virtual void updateItem() { QGraphicsRectItem::update(); }
+
   public slots:
     virtual void setRotation( double r );
     void repaint();

src/core/composer/qgscomposermap.cpp

@@ -390,6 +390,10 @@ void QgsComposerMap::resize( double dx, double dy )
   QRectF currentRect = rect();
   QRectF newSceneRect = QRectF( transform().dx(), transform().dy(), currentRect.width() + dx, currentRect.height() + dy );
   setSceneRect( newSceneRect );
+  if ( mPreviewMode != QgsComposerMap::Rectangle )
+  {
+    cache();
+  }
 }
 
 void QgsComposerMap::moveContent( double dx, double dy )
@@ -489,10 +493,6 @@ void QgsComposerMap::setSceneRect( const QRectF& rectangle )
   mExtent = QgsRectangle( mExtent.xMinimum(), mExtent.yMinimum(), mExtent.xMaximum(), mExtent.yMinimum() + newHeight );
   mCacheUpdated = false;
 
-  if ( mPreviewMode != Rectangle )
-  {
-    cache();
-  }
   updateBoundingRect();
   update();
   emit itemChanged();
@@ -513,6 +513,10 @@ void QgsComposerMap::setNewExtent( const QgsRectangle& extent )
   double newHeight = currentRect.width() * extent.height() / extent.width();
 
   setSceneRect( QRectF( transform().dx(), transform().dy(), currentRect.width(), newHeight ) );
+  if ( mPreviewMode != QgsComposerMap::Rectangle )
+  {
+    cache();
+  }
 }
 
 void QgsComposerMap::setNewScale( double scaleDenominator )
@@ -545,6 +549,15 @@ void QgsComposerMap::setMapRotation( double r )
   emit rotationChanged( r );
 }
 
+void QgsComposerMap::updateItem()
+{
+  if ( mPreviewMode != QgsComposerMap::Rectangle &&  !mCacheUpdated )
+  {
+    cache();
+  }
+  QgsComposerItem::updateItem();
+}
+
 bool QgsComposerMap::containsWMSLayer() const
 {
   if ( !mMapRenderer )

src/core/composer/qgscomposermap.h

@@ -125,7 +125,7 @@ class CORE_EXPORT QgsComposerMap : public QgsComposerItem
     /**Sets new Extent and changes width, height (and implicitely also scale)*/
     void setNewExtent( const QgsRectangle& extent );
 
-    PreviewMode previewMode() {return mPreviewMode;}
+    PreviewMode previewMode() const {return mPreviewMode;}
     void setPreviewMode( PreviewMode m ) {mPreviewMode = m;}
 
     /**Getter for flag that determines if the stored layer set should be used or the current layer set of the qgis mapcanvas
@@ -254,6 +254,8 @@ class CORE_EXPORT QgsComposerMap : public QgsComposerItem
 
     void setMapRotation( double r );
 
+    void updateItem();
+
     /**Sets canvas pointer (necessary to query and draw map canvas items)*/
     void setMapCanvas( QGraphicsView* canvas ) { mMapCanvas = canvas; }