Partially port some layout utils for render context creation

nyalldawson · nyalldawson · commit c28202474812 · 2017-07-18T12:42:06.000+10:00
diff --git a/python/core/layout/qgslayout.sip b/python/core/layout/qgslayout.sip
@@ -7,6 +7,7 @@
  ************************************************************************/
 
 
+
 class QgsLayout : QGraphicsScene, QgsExpressionContextGenerator
 {
 %Docstring
@@ -175,6 +176,13 @@ class QgsLayout : QGraphicsScene, QgsExpressionContextGenerator
  :rtype: list of str
 %End
 
+    QgsLayoutItemMap *referenceMap() const;
+%Docstring
+ :rtype: QgsLayoutItemMap
+%End
+
+    void setReferenceMap( QgsLayoutItemMap *map );
+
   signals:
 
     void variablesChanged();
diff --git a/python/core/layout/qgslayoututils.sip b/python/core/layout/qgslayoututils.sip
@@ -8,6 +8,7 @@
 
 
 
+
 class QgsLayoutUtils
 {
 %Docstring
@@ -28,6 +29,25 @@ class QgsLayoutUtils
  :rtype: float
 %End
 
+    static QgsRenderContext createRenderContextForMap( QgsLayoutItemMap *map, QPainter *painter, double dpi = -1 );
+%Docstring
+ Creates a render context suitable for the specified layout ``map`` and ``painter`` destination.
+ This method returns a new QgsRenderContext which matches the scale and settings of the
+ target map. If the ``dpi`` argument is not specified then the dpi will be taken from the destinatation
+ painter device.
+.. seealso:: createRenderContextForLayout()
+ :rtype: QgsRenderContext
+%End
+
+    static QgsRenderContext createRenderContextForLayout( QgsLayout *layout, QPainter *painter );
+%Docstring
+ Creates a render context suitable for the specified ``layout`` and ``painter`` destination.
+ This method returns a new QgsRenderContext which matches the scale and settings from the layout's
+ QgsLayout.referenceMap().
+.. seealso:: createRenderContextForMap()
+ :rtype: QgsRenderContext
+%End
+
 };
 
 /************************************************************************
diff --git a/src/core/layout/qgslayout.cpp b/src/core/layout/qgslayout.cpp
@@ -93,3 +93,13 @@ QStringList QgsLayout::customProperties() const
 {
   return mCustomProperties.keys();
 }
+
+QgsLayoutItemMap *QgsLayout::referenceMap() const
+{
+  return nullptr;
+}
+
+void QgsLayout::setReferenceMap( QgsLayoutItemMap *map )
+{
+  Q_UNUSED( map );
+}
diff --git a/src/core/layout/qgslayout.h b/src/core/layout/qgslayout.h
@@ -21,6 +21,8 @@
 #include "qgslayoutcontext.h"
 #include "qgsexpressioncontextgenerator.h"
 
+class QgsLayoutItemMap;
+
 /**
  * \ingroup core
  * \class QgsLayout
@@ -182,6 +184,25 @@ class CORE_EXPORT QgsLayout : public QGraphicsScene, public QgsExpressionContext
      */
     QStringList customProperties() const;
 
+    /**
+     * Returns the map item which will be used to generate corresponding world files when the
+     * layout is exported. If no map was explicitly set via setReferenceMap(), the largest
+     * map in the layout will be returned (or nullptr if there are no maps in the layout).
+     * \see setReferenceMap()
+     * \see generateWorldFile()
+     */
+    //TODO
+    QgsLayoutItemMap *referenceMap() const;
+
+    /**
+     * Sets the \a map item which will be used to generate corresponding world files when the
+     * layout is exported.
+     * \see referenceMap()
+     * \see setGenerateWorldFile()
+     */
+    //TODO
+    void setReferenceMap( QgsLayoutItemMap *map );
+
   signals:
 
     /**
diff --git a/src/core/layout/qgslayoututils.cpp b/src/core/layout/qgslayoututils.cpp
@@ -16,6 +16,10 @@
  ***************************************************************************/
 
 #include "qgslayoututils.h"
+#include "qgslayout.h"
+#include "qgsrendercontext.h"
+#include "qgslayoutitemmap.h"
+#include <QPainter>
 #include <math.h>
 
 double QgsLayoutUtils::normalizedAngle( const double angle, const bool allowNegative )
@@ -31,3 +35,51 @@ double QgsLayoutUtils::normalizedAngle( const double angle, const bool allowNega
   }
   return clippedAngle;
 }
+
+QgsRenderContext QgsLayoutUtils::createRenderContextForMap( QgsLayoutItemMap *map, QPainter *painter, double dpi )
+{
+  if ( !map )
+  {
+    QgsRenderContext context;
+    context.setPainter( painter );
+    if ( dpi < 0 && painter && painter->device() )
+    {
+      context.setScaleFactor( painter->device()->logicalDpiX() / 25.4 );
+    }
+    else if ( dpi > 0 )
+    {
+      context.setScaleFactor( dpi / 25.4 );
+    }
+    else
+    {
+      context.setScaleFactor( 3.465 ); //assume 88 dpi as standard value
+    }
+    return context;
+  }
+  else
+  {
+    // default to 88 dpi if no painter specified
+    if ( dpi < 0 )
+    {
+      dpi = ( painter && painter->device() ) ? painter->device()->logicalDpiX() : 88;
+    }
+#if 0
+    double dotsPerMM = dpi / 25.4;
+// TODO
+    // get map settings from reference map
+    QgsRectangle extent = *( map->currentMapExtent() );
+    QSizeF mapSizeMM = map->rect().size();
+    QgsMapSettings ms = map->mapSettings( extent, mapSizeMM * dotsPerMM, dpi );
+#endif
+    QgsRenderContext context; // = QgsRenderContext::fromMapSettings( ms );
+    if ( painter )
+      context.setPainter( painter );
+    return context;
+  }
+}
+
+QgsRenderContext QgsLayoutUtils::createRenderContextForLayout( QgsLayout *layout, QPainter *painter )
+{
+  QgsLayoutItemMap *referenceMap = layout ? layout->referenceMap() : nullptr;
+  return createRenderContextForMap( referenceMap, painter );
+}
diff --git a/src/core/layout/qgslayoututils.h b/src/core/layout/qgslayoututils.h
@@ -19,6 +19,11 @@
 
 #include "qgis_core.h"
 
+class QgsRenderContext;
+class QgsLayout;
+class QgsLayoutItemMap;
+class QPainter;
+
 /**
  * \ingroup core
  * Utilities for layouts.
@@ -35,6 +40,23 @@ class CORE_EXPORT QgsLayoutUtils
      */
     static double normalizedAngle( const double angle, const bool allowNegative = false );
 
+    /**
+     * Creates a render context suitable for the specified layout \a map and \a painter destination.
+     * This method returns a new QgsRenderContext which matches the scale and settings of the
+     * target map. If the \a dpi argument is not specified then the dpi will be taken from the destinatation
+     * painter device.
+     * \see createRenderContextForLayout()
+     */
+    static QgsRenderContext createRenderContextForMap( QgsLayoutItemMap *map, QPainter *painter, double dpi = -1 );
+
+    /**
+     * Creates a render context suitable for the specified \a layout and \a painter destination.
+     * This method returns a new QgsRenderContext which matches the scale and settings from the layout's
+     * QgsLayout::referenceMap().
+     * \see createRenderContextForMap()
+     */
+    static QgsRenderContext createRenderContextForLayout( QgsLayout *layout, QPainter *painter );
+
 };
 
 #endif //QGSLAYOUTUTILS_H
diff --git a/tests/src/core/testqgslayout.cpp b/tests/src/core/testqgslayout.cpp
@@ -18,6 +18,7 @@
 #include "qgslayout.h"
 #include "qgstest.h"
 #include "qgsproject.h"
+#include "qgslayoutitemmap.h"
 
 class TestQgsLayout: public QObject
 {
@@ -34,6 +35,7 @@ class TestQgsLayout: public QObject
     void customProperties();
     void variablesEdited();
     void scope();
+    void referenceMap();
 
   private:
     QString mReport;
@@ -213,6 +215,37 @@ void TestQgsLayout::scope()
 
 }
 
+void TestQgsLayout::referenceMap()
+{
+  QgsRectangle extent( 2000, 2800, 2500, 2900 );
+  QgsProject p;
+  QgsLayout l( &p );
+
+  // no maps
+  QVERIFY( !l.referenceMap() );
+#if 0
+
+  QgsLayoutItemMap *map = new QgsLayoutItemMap( &l );
+  map->setNewExtent( extent );
+  map->setSceneRect( QRectF( 30, 60, 200, 100 ) );
+  l.addComposerMap( map );
+  QCOMPARE( l.referenceMap(), map );
+#endif
+#if 0 // TODO
+
+  // add a larger map
+  QgsLayoutItemMap *map2 = new QgsLayoutItemMap( &l );
+  map2->setNewExtent( extent );
+  map2->setSceneRect( QRectF( 30, 60, 250, 150 ) );
+  l.addComposerMap( map2 );
+  QCOMPARE( l.referenceMap(), map2 );
+  // explicitly set reference map
+  l.setReferenceMap( map );
+  QCOMPARE( l.referenceMap(), map );
+#endif
+
+}
+
 
 QGSTEST_MAIN( TestQgsLayout )
 #include "testqgslayout.moc"
diff --git a/tests/src/core/testqgslayoututils.cpp b/tests/src/core/testqgslayoututils.cpp
@@ -18,6 +18,9 @@
 #include "qgslayout.h"
 #include "qgstest.h"
 #include "qgslayoututils.h"
+#include "qgstestutils.h"
+#include "qgsproject.h"
+#include "qgslayoutitemmap.h"
 
 class TestQgsLayoutUtils: public QObject
 {
@@ -29,6 +32,8 @@ class TestQgsLayoutUtils: public QObject
     void init();// will be called before each testfunction is executed.
     void cleanup();// will be called after every testfunction.
     void normalizedAngle(); //test normalised angle function
+    void createRenderContextFromLayout();
+    void createRenderContextFromMap();
 
   private:
     QString mReport;
@@ -112,5 +117,116 @@ void TestQgsLayoutUtils::normalizedAngle()
 }
 
 
+void TestQgsLayoutUtils::createRenderContextFromLayout()
+{
+  QImage testImage = QImage( 250, 250, QImage::Format_RGB32 );
+  testImage.setDotsPerMeterX( 150 / 25.4 * 1000 );
+  testImage.setDotsPerMeterY( 150 / 25.4 * 1000 );
+  QPainter p( &testImage );
+
+  // no composition
+  QgsRenderContext rc = QgsLayoutUtils::createRenderContextForLayout( nullptr, &p );
+  QGSCOMPARENEAR( rc.scaleFactor(), 150 / 25.4, 0.001 );
+  QCOMPARE( rc.painter(), &p );
+
+  // no composition, no painter
+  rc = QgsLayoutUtils::createRenderContextForLayout( nullptr, nullptr );
+  QGSCOMPARENEAR( rc.scaleFactor(), 88 / 25.4, 0.001 );
+  QVERIFY( !rc.painter() );
+
+  //create composition with no reference map
+  QgsRectangle extent( 2000, 2800, 2500, 2900 );
+  QgsProject project;
+  QgsLayout l( &project );
+  rc = QgsLayoutUtils::createRenderContextForLayout( &l, &p );
+  QGSCOMPARENEAR( rc.scaleFactor(), 150 / 25.4, 0.001 );
+  QCOMPARE( rc.painter(), &p );
+
+  // layout, no map, no painter
+  rc = QgsLayoutUtils::createRenderContextForLayout( &l, nullptr );
+  QGSCOMPARENEAR( rc.scaleFactor(), 88 / 25.4, 0.001 );
+  QVERIFY( !rc.painter() );
+
+  // add a reference map
+  QgsLayoutItemMap *map = new QgsLayoutItemMap( &l );
+#if 0 // TODO
+  map->setNewExtent( extent );
+  map->setSceneRect( QRectF( 30, 60, 200, 100 ) );
+  composition->addComposerMap( map );
+#endif
+  l.setReferenceMap( map );
+
+  rc = QgsLayoutUtils::createRenderContextForLayout( &l, &p );
+  QGSCOMPARENEAR( rc.scaleFactor(), 150 / 25.4, 0.001 );
+  QGSCOMPARENEAR( rc.rendererScale(), map->scale(), 1000000 );
+  QCOMPARE( rc.painter(), &p );
+
+  // layout, reference map, no painter
+  rc = QgsLayoutUtils::createRenderContextForLayout( &l, nullptr );
+  QGSCOMPARENEAR( rc.scaleFactor(), 88 / 25.4, 0.001 );
+  QGSCOMPARENEAR( rc.rendererScale(), map->scale(), 1000000 );
+  QVERIFY( !rc.painter() );
+
+  p.end();
+}
+
+void TestQgsLayoutUtils::createRenderContextFromMap()
+{
+  QImage testImage = QImage( 250, 250, QImage::Format_RGB32 );
+  testImage.setDotsPerMeterX( 150 / 25.4 * 1000 );
+  testImage.setDotsPerMeterY( 150 / 25.4 * 1000 );
+  QPainter p( &testImage );
+
+  // no map
+  QgsRenderContext rc = QgsLayoutUtils::createRenderContextForMap( nullptr, &p );
+  QGSCOMPARENEAR( rc.scaleFactor(), 150 / 25.4, 0.001 );
+  QCOMPARE( rc.painter(), &p );
+
+  // no map, no painter
+  rc = QgsLayoutUtils::createRenderContextForMap( nullptr, nullptr );
+  QGSCOMPARENEAR( rc.scaleFactor(), 88 / 25.4, 0.001 );
+  QVERIFY( !rc.painter() );
+
+  //create composition with no reference map
+  QgsRectangle extent( 2000, 2800, 2500, 2900 );
+  QgsProject project;
+  QgsLayout l( &project );
+
+#if 0 // TODO
+  // add a map
+  QgsLayoutItemMap *map = new QgsLayoutItemMap( &l );
+
+  map->setNewExtent( extent );
+  map->setSceneRect( QRectF( 30, 60, 200, 100 ) );
+  l.addComposerMap( map );
+#endif
+
+#if 0 //TODO
+  rc = QgsLayoutUtils::createRenderContextForMap( map, &p );
+  QGSCOMPARENEAR( rc.scaleFactor(), 150 / 25.4, 0.001 );
+  QGSCOMPARENEAR( rc.rendererScale(), map->scale(), 1000000 );
+  QCOMPARE( rc.painter(), &p );
+
+  // map, no painter
+  rc = QgsLayoutUtils::createRenderContextForMap( map, nullptr );
+  QGSCOMPARENEAR( rc.scaleFactor(), 88 / 25.4, 0.001 );
+  QGSCOMPARENEAR( rc.rendererScale(), map->scale(), 1000000 );
+  QVERIFY( !rc.painter() );
+
+  // secondary map
+  QgsLayoutItemMap *map2 = new QgsLayoutItemMap( &l );
+
+  map2->setNewExtent( extent );
+  map2->setSceneRect( QRectF( 30, 60, 100, 50 ) );
+  composition->addComposerMap( map2 );
+
+  rc = QgsLayoutUtils::createRenderContextForMap( map2, &p );
+  QGSCOMPARENEAR( rc.scaleFactor(), 150 / 25.4, 0.001 );
+  QGSCOMPARENEAR( rc.rendererScale(), map2->scale(), 1000000 );
+  QVERIFY( rc.painter() );
+#endif
+  p.end();
+}
+
 QGSTEST_MAIN( TestQgsLayoutUtils )
 #include "testqgslayoututils.moc"

Original file line number	Diff line number	Diff line change
`@@ -93,3 +93,13 @@ QStringList QgsLayout::customProperties() const`
`93`	`93`	`{`
`94`	`94`	`return mCustomProperties.keys();`
`95`	`95`	`}`
	`96`	`+`
	`97`	`+QgsLayoutItemMap *QgsLayout::referenceMap() const`
	`98`	`+{`
	`99`	`+ return nullptr;`
	`100`	`+}`
	`101`	`+`
	`102`	`+void QgsLayout::setReferenceMap( QgsLayoutItemMap *map )`
	`103`	`+{`
	`104`	`+ Q_UNUSED( map );`
	`105`	`+}`