Added zooming to 100%, i.e one raster pixel will occupy one screen pixel. Only supported for raster layers. Right-click on the layer in the legend, and select from pop-up menu

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@6735 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: homann

src/app/legend/qgslegend.cpp

@@ -1696,6 +1696,34 @@ void QgsLegend::legendLayerZoom()
   QgsProject::instance()->dirty(true);
 }
 
+void QgsLegend::legendLayerZoomNative()
+{
+  QgsLegendItem* citem=dynamic_cast<QgsLegendItem*>(currentItem());
+  if(!citem)
+  {
+      return;
+  }
+  QgsLegendLayer* ll = dynamic_cast<QgsLegendLayer*>(citem);
+  if(!ll)
+  {
+    return;
+  }
+  QgsRasterLayer *layer =  dynamic_cast<QgsRasterLayer*>(ll->firstMapLayer()); 
+  if(layer)
+  {
+    QgsDebugMsg("Raster units per pixel  : " + QString::number(layer->rasterUnitsPerPixel()));
+    QgsDebugMsg("Mupp before             : " + QString::number(mMapCanvas->mupp()));
+
+    mMapCanvas->zoom(fabs( layer->rasterUnitsPerPixel() / mMapCanvas->mupp()));
+    mMapCanvas->refresh();
+
+    QgsDebugMsg("Mupp after              : " + QString::number(mMapCanvas->mupp()));
+
+    // notify the project we've made a change
+    QgsProject::instance()->dirty(true);
+  }
+}
+
 void QgsLegend::legendLayerAttributeTable()
 {
 

src/app/legend/qgslegend.h

@@ -216,6 +216,10 @@ public slots:
   /**Zooms to extent of the current legend layer (considers there may be several
   legend layer files*/
   void legendLayerZoom();
+
+ /***Zooms so that the pixels of the raster layer occupies exactly one screen pixel.
+     Only works on raster layers*/
+  void legendLayerZoomNative();
 
   /**Show attribute table*/
   void legendLayerAttributeTable();

src/app/legend/qgslegendlayer.cpp

@@ -24,6 +24,7 @@
 #include "qgslegendlayerfile.h"
 #include "qgslegendlayerfilegroup.h"
 #include "qgslegendsymbologyitem.h"
+#include "qgslogger.h"
 
 #include "qgsapplication.h"
 #include "qgsfield.h"
@@ -469,7 +470,11 @@ void QgsLegendLayer::addToPopupMenu(QMenu& theMenu)
   // zoom to layer extent
   theMenu.addAction(QIcon(iconsPath+QString("/mActionZoomToLayer.png")),
                     tr("&Zoom to layer extent"), legend(), SLOT(legendLayerZoom()));
-  
+  if (firstLayer && firstLayer->type() == QgsMapLayer::RASTER)
+  {
+    theMenu.addAction(tr("&Zoom to best scale (100%)"), legend(), SLOT(legendLayerZoomNative()));
+  }
+
   // show in overview
   QAction* showInOverviewAction = theMenu.addAction(tr("&Show in overview"), this, SLOT(showInOverview()));
   showInOverviewAction->setCheckable(true); // doesn't support tristate

src/core/raster/qgsrasterlayer.cpp

@@ -1057,10 +1057,10 @@ bool QgsRasterLayer::draw(QPainter * theQPainter,
   myRasterViewPort->topLeftPoint = theQgsMapToPixel->transform(myRasterExtent.xMin(), myRasterExtent.yMax());
   myRasterViewPort->bottomRightPoint = theQgsMapToPixel->transform(myRasterExtent.xMax(), myRasterExtent.yMin());
 
-  myRasterViewPort->drawableAreaXDimInt =
-    abs(static_cast<int> (myRasterViewPort->clippedWidthInt  / theQgsMapToPixel->mapUnitsPerPixel() * adfGeoTransform[1]));
-  myRasterViewPort->drawableAreaYDimInt =
-    abs(static_cast<int> (myRasterViewPort->clippedHeightInt / theQgsMapToPixel->mapUnitsPerPixel() * adfGeoTransform[5]));
+  myRasterViewPort->drawableAreaXDimInt = static_cast<int>
+    (fabs( (myRasterViewPort->clippedWidthInt  / theQgsMapToPixel->mapUnitsPerPixel() * adfGeoTransform[1])) + 0.5);
+  myRasterViewPort->drawableAreaYDimInt = static_cast<int>
+    (fabs( (myRasterViewPort->clippedHeightInt / theQgsMapToPixel->mapUnitsPerPixel() * adfGeoTransform[5])) + 0.5);
 
 #ifdef QGISDEBUG
   QgsLogger::debug("QgsRasterLayer::draw: mapUnitsPerPixel", theQgsMapToPixel->mapUnitsPerPixel(), 1, __FILE__,\
@@ -5262,5 +5262,17 @@ const unsigned int QgsRasterLayer::getBandCount()
   return rasterStatsVector.size();
 };
 
+double QgsRasterLayer::rasterUnitsPerPixel()
+{
+ 
+  // We return one raster pixel per map unit pixel
+  // One raster pixel can have several raster units...
+
+  // We can only use one of the adfGeoTransform[], so go with the
+   // horisontal one.
+  
+  return fabs(adfGeoTransform[1]);
+}
+ 
 
 // ENDS

src/core/raster/qgsrasterlayer.h

@@ -294,6 +294,10 @@ class CORE_EXPORT QgsRasterLayer : public QgsMapLayer
     /** \brief Query gdal to find out the WKT projection string for this layer. This implements the virtual method of the same name defined in QgsMapLayer*/
     QString getProjectionWKT();
 
+    /** \brief Returns the number of raster units per each raster pixel. For rasters with world file, this is
+     normally the first row (without the sign) in that file */
+    double rasterUnitsPerPixel();
+
     /** \brief Draws a thumbnail of the rasterlayer into the supplied pixmap pointer */
      void drawThumbnail(QPixmap * theQPixmap);
 

src/gui/qgsmapcanvas.cpp

@@ -1073,3 +1073,13 @@ void QgsMapCanvas::writeProject(QDomDocument & doc)
 
 
 }
+
+void QgsMapCanvas::zoom(double scaleFactor)
+{
+  
+  QgsRect r = mMapRender->extent();
+  r.scale(scaleFactor);
+  setExtent(r);
+  refresh();
+}
+

src/gui/qgsmapcanvas.h

@@ -230,6 +230,10 @@ class GUI_EXPORT QgsMapCanvas : public QGraphicsView
     //! returns last position of mouse cursor
     QPoint mouseLastXY();
 
+    //! zooms with the factor supplied. Factor > 1 zooms in
+    void zoom(double scaleFactor);
+
+
   public slots:
 
     /**Sets dirty=true and calls render()*/