Draw page shadow in layout units

Simplifies code a lot, pixel based size proved to complex for small result
qgis · Jul 25, 2017 · 4cf9827 · 4cf9827
1 parent 5cfc9cc
commit 4cf9827
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Showing 6 changed files with 31 additions and 10 deletions.
diff --git a/python/core/layout/qgslayoutitempage.sip b/python/core/layout/qgslayoutitempage.sip
@@ -79,6 +79,7 @@ class QgsLayoutItemPage : QgsLayoutItem
 
     virtual void draw( QgsRenderContext &context, const QStyleOptionGraphicsItem *itemStyle = 0 );
 
+
 };
 
 /************************************************************************

diff --git a/python/core/layout/qgslayoutpagecollection.sip b/python/core/layout/qgslayoutpagecollection.sip
@@ -21,6 +21,16 @@ class QgsLayoutPageCollection : QObject
 %End
   public:
 
+    static const double SPACE_BETWEEN_PAGES;
+%Docstring
+Space between pages in the layout, in layout coordinates
+%End
+
+    static const double PAGE_SHADOW_WIDTH;
+%Docstring
+Size of page shadow, in layout coordinates
+%End
+
     explicit QgsLayoutPageCollection( QgsLayout *layout /TransferThis/ );
 %Docstring
  Constructor for QgsLayoutItemPage, with the specified parent ``layout``.

diff --git a/src/core/layout/qgslayoutitempage.cpp b/src/core/layout/qgslayoutitempage.cpp
@@ -21,21 +21,21 @@
 #include "qgssymbollayerutils.h"
 #include <QPainter>
 
-#define SHADOW_WIDTH_PIXELS 5
 QgsLayoutItemPage::QgsLayoutItemPage( QgsLayout *layout )
   : QgsLayoutItem( layout )
 {
   setFlag( QGraphicsItem::ItemIsSelectable, false );
   setFlag( QGraphicsItem::ItemIsMovable, false );
   setZValue( QgsLayout::ZPage );
 
-  // bit hacky - we set a big hidden pen to avoid Qt clipping out the cosmetic shadow for the page
-  // Unfortunately it's possible to adapt the item's bounding rect based on the view's transform, so it's
-  // impossible to have a pixel based bounding rect. Instead we just set a big pen to force the page's
-  // bounding rect to be kinda large enough to handle the shadow at most zoom levels...
-  QPen shadowPen( QBrush( Qt::transparent ), 30 );
-  shadowPen.setCosmetic( true );
+  // use a hidden pen to specify the amount the page "bleeds" outside it's scene bounds,
+  // (it's a lot easier than reimplementing boundingRect() just to handle this)
+  QPen shadowPen( QBrush( Qt::transparent ), QgsLayoutPageCollection::PAGE_SHADOW_WIDTH * 2 );
   setPen( shadowPen );
+
+  QFont font;
+  QFontMetrics fm( font );
+  mMaximumShadowWidth = fm.width( "X" );
 }
 
 void QgsLayoutItemPage::setPageSize( const QgsLayoutSize &size )
@@ -134,7 +134,8 @@ void QgsLayoutItemPage::draw( QgsRenderContext &context, const QStyleOptionGraph
     //shadow
     painter->setBrush( QBrush( QColor( 150, 150, 150 ) ) );
     painter->setPen( Qt::NoPen );
-    painter->drawRect( pageRect.translated( SHADOW_WIDTH_PIXELS, SHADOW_WIDTH_PIXELS ) );
+    painter->drawRect( pageRect.translated( qMin( scale * QgsLayoutPageCollection::PAGE_SHADOW_WIDTH, mMaximumShadowWidth ),
+                                            qMin( scale * QgsLayoutPageCollection::PAGE_SHADOW_WIDTH, mMaximumShadowWidth ) ) );
 
     //page area
     painter->setBrush( QColor( 215, 215, 215 ) );

diff --git a/src/core/layout/qgslayoutitempage.h b/src/core/layout/qgslayoutitempage.h
@@ -88,6 +88,11 @@ class CORE_EXPORT QgsLayoutItemPage : public QgsLayoutItem
   protected:
 
     void draw( QgsRenderContext &context, const QStyleOptionGraphicsItem *itemStyle = nullptr ) override;
+
+  private:
+
+    double mMaximumShadowWidth = -1;
+
 };
 
 #endif //QGSLAYOUTITEMPAGE_H
diff --git a/src/core/layout/qgslayoutpagecollection.cpp b/src/core/layout/qgslayoutpagecollection.cpp
@@ -17,8 +17,6 @@
 #include "qgslayoutpagecollection.h"
 #include "qgslayout.h"
 
-#define SPACE_BETWEEN_PAGES 10
-
 QgsLayoutPageCollection::QgsLayoutPageCollection( QgsLayout *layout )
   : QObject( layout )
   , mLayout( layout )

diff --git a/src/core/layout/qgslayoutpagecollection.h b/src/core/layout/qgslayoutpagecollection.h
@@ -39,6 +39,12 @@ class CORE_EXPORT QgsLayoutPageCollection : public QObject
 
   public:
 
+    //! Space between pages in the layout, in layout coordinates
+    static constexpr double SPACE_BETWEEN_PAGES = 10;
+
+    //! Size of page shadow, in layout coordinates
+    static constexpr double PAGE_SHADOW_WIDTH = 5; // Must be less than SPACE_BETWEEN_PAGES
+
     /**
      * Constructor for QgsLayoutItemPage, with the specified parent \a layout.
      */