Show a warning before printing WMS layers. Some WMS servers have a limit for WIDTH and HEIGHT parameters

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@9357 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

src/app/composer/qgscomposer.cpp

@@ -435,6 +435,11 @@ void QgsComposer::on_mActionPrint_activated( void )
     return;
   }
 
+  if(containsWMSLayer())
+    {
+      showWMSPrintingWarning();
+    }
+
   QPrinter printer;
 
   //try to set most of the print dialog settings based on composer properties
@@ -487,6 +492,11 @@ void QgsComposer::on_mActionPrint_activated( void )
 
 void QgsComposer::on_mActionExportAsImage_activated( void )
 {
+  if(containsWMSLayer())
+    {
+      showWMSPrintingWarning();
+    }
+
   // Image size
   int width = ( int )( mComposition->printoutResolution() * mComposition->paperWidth() / 25.4 );
   int height = ( int )( mComposition-> printoutResolution() * mComposition->paperHeight() / 25.4 );
@@ -608,6 +618,11 @@ void QgsComposer::on_mActionExportAsImage_activated( void )
 
 void QgsComposer::on_mActionExportAsSVG_activated( void )
 {
+  if(containsWMSLayer())
+    {
+      showWMSPrintingWarning();
+    }
+
   QString myQSettingsLabel = "/UI/displaySVGWarning";
   QSettings myQSettings;
 
@@ -1080,3 +1095,43 @@ void QgsComposer::setSelectionTool()
   mActionSelectMoveItem->setChecked( true );
   on_mActionSelectMoveItem_activated();
 }
+
+bool QgsComposer::containsWMSLayer() const
+{
+  QMap<QgsComposerItem*, QWidget*>::const_iterator item_it = mItemWidgetMap.constBegin();
+  QgsComposerItem* currentItem = 0;
+  QgsComposerMap* currentMap = 0;
+
+  for(; item_it != mItemWidgetMap.constEnd(); ++item_it)
+    {
+      currentItem = item_it.key();
+      currentMap = dynamic_cast<QgsComposerMap*>(currentItem);
+      if(currentMap)
+	{
+	  if(currentMap->containsWMSLayer())
+	    {
+	      return true;
+	    }
+	}
+    }
+  return false;
+}
+
+void QgsComposer::showWMSPrintingWarning()
+{
+  QString myQSettingsLabel = "/UI/displayComposerWMSWarning";
+  QSettings myQSettings;
+
+  bool displayWMSWarning = myQSettings.value( myQSettingsLabel, true ).toBool();
+  if(displayWMSWarning)
+    {
+      QgsMessageViewer* m = new QgsMessageViewer( this );
+      m->setWindowTitle( tr( "Project contains WMS layers" ) );
+      m->setMessage(tr("Some WMS servers (e.g. UMN mapserver) have a limit for the WIDTH and HEIGHT parameter. Printing layers from such servers may exceed this limit. If this is the case, the WMS layer will not be printed"), QgsMessageOutput::MessageText);
+      m->setCheckBoxText( tr( "Don't show this message again" ) );
+      m->setCheckBoxState( Qt::Unchecked );
+      m->setCheckBoxVisible( true );
+      m->setCheckBoxQSettingsLabel( myQSettingsLabel );
+      m->exec();
+    }
+}

src/app/composer/qgscomposer.h

@@ -204,6 +204,12 @@ class QgsComposer: public QMainWindow, private Ui::QgsComposerBase
     //! returns new world matrix for canvas view after zoom with factor scaleChange
     QMatrix updateMatrix( double scaleChange );
 
+    //! True if a composer map contains a WMS layer
+    bool containsWMSLayer() const;
+
+    //! Displays a warning because of possible min/max size in WMS
+    void showWMSPrintingWarning();
+
     //! Pointer to composer view
     QgsComposerView *mView;
 

src/core/composer/qgscomposermap.cpp

@@ -25,6 +25,7 @@
 #include "qgsmaptopixel.h"
 #include "qgsproject.h"
 #include "qgsmaprenderer.h"
+#include "qgsrasterlayer.h"
 #include "qgsrendercontext.h"
 #include "qgsscalecalculator.h"
 #include "qgsvectorlayer.h"
@@ -402,6 +403,40 @@ void QgsComposerMap::setOffset( double xOffset, double yOffset )
   mYOffset = yOffset;
 }
 
+bool QgsComposerMap::containsWMSLayer() const
+{
+  if(!mMapRenderer)
+    {
+      return false;
+    }
+
+  QStringList layers = mMapRenderer->layerSet();
+
+  QStringList::const_iterator layer_it = layers.constBegin();
+  QgsMapLayer* currentLayer = 0;
+
+  for(; layer_it != layers.constEnd(); ++layer_it)
+    {
+      currentLayer = QgsMapLayerRegistry::instance()->mapLayer(*layer_it);
+      if(currentLayer)
+	{
+	  QgsRasterLayer* currentRasterLayer = dynamic_cast<QgsRasterLayer*>(currentLayer);
+	  if(currentRasterLayer)
+	    {
+	      const QgsRasterDataProvider* rasterProvider = 0;
+	      if(rasterProvider = currentRasterLayer->dataProvider())
+		{
+		  if(rasterProvider->name() == "wms")
+		    {
+		      return true;
+		    }
+		}
+	    }
+	}
+    }
+  return false;
+}
+
 double QgsComposerMap::horizontalViewScaleFactor() const
 {
   double result = 1;

src/core/composer/qgscomposermap.h

@@ -118,6 +118,9 @@ class CORE_EXPORT QgsComposerMap : /*public QWidget, private Ui::QgsComposerMapB
     /**Sets offset values to shift image (useful for live updates when moving item content)*/
     void setOffset( double xOffset, double yOffset );
 
+    /**True if composer map renders a WMS layer*/
+    bool containsWMSLayer() const;
+
     /** stores state in Dom node
      * @param elem is Dom element corresponding to 'Composer' tag
      * @param temp write template file