Arrow symbol layer: option to repeat or not the arrow on the line

python/core/symbology-ng/qgsarrowsymbollayer.sip

@@ -85,6 +85,11 @@ class QgsArrowSymbolLayer : public QgsLineSymbolLayerV2
     /** Set whether it is a curved arrow or a straight one */
     void setIsCurved( bool isCurved );
 
+    /** Return whether the arrow is repeated along the line or not */
+    bool isRepeated() const;
+    /** Set whether the arrow is repeated along the line */
+    void setIsRepeated( bool isRepeated );
+
     /** Possible head types */
     enum HeadType
     {

src/core/symbology-ng/qgsarrowsymbollayer.cpp

@@ -28,6 +28,7 @@ QgsArrowSymbolLayer::QgsArrowSymbolLayer()
     , mHeadType( HeadSingle )
     , mArrowType( ArrowPlain )
     , mIsCurved( true )
+    , mIsRepeated( true )
     , mScaledArrowWidth( 1.0 )
     , mScaledArrowStartWidth( 1.0 )
     , mScaledHeadWidth( 1.5 )
@@ -78,6 +79,9 @@ QgsSymbolLayerV2* QgsArrowSymbolLayer::create( const QgsStringMap& props )
   if ( props.contains( "is_curved" ) )
     l->setIsCurved( props["is_curved"].toInt() == 1 );
 
+  if ( props.contains( "is_repeated" ) )
+    l->setIsRepeated( props["is_repeated"].toInt() == 1 );
+
   if ( props.contains( "head_width" ) )
     l->setHeadWidth( props["head_width"].toDouble() );
 
@@ -145,6 +149,7 @@ QgsStringMap QgsArrowSymbolLayer::properties() const
   map["arrow_start_width_unit_scale"] = QgsSymbolLayerV2Utils::encodeMapUnitScale( arrowStartWidthUnitScale() );
 
   map["is_curved"] = QString::number( isCurved() ? 1 : 0 );
+  map["is_repeated"] = QString::number( isRepeated() ? 1 : 0 );
 
   map["head_width"] = QString::number( headWidth() );
   map["head_width_unit"] = QgsSymbolLayerV2Utils::encodeOutputUnit( headWidthUnit() );
@@ -689,52 +694,98 @@ void QgsArrowSymbolLayer::renderPolyline( const QPolygonF& points, QgsSymbolV2Re
   mExpressionScope->setVariable( QgsExpressionContext::EXPR_GEOMETRY_POINT_NUM, 1 );
   if ( isCurved() )
   {
-    for ( int pIdx = 0; pIdx < points.size() - 1; pIdx += 2 )
-    {
-      mExpressionScope->setVariable( QgsExpressionContext::EXPR_GEOMETRY_POINT_NUM, pIdx + 1 );
-      _resolveDataDefined( context );
+    _resolveDataDefined( context );
 
-      if ( points.size() - pIdx >= 3 )
+    if ( ! isRepeated() )
+    {
+      if ( points.size() >= 3 )
       {
         // origin point
-        QPointF po( points.at( pIdx ) );
+        QPointF po( points.at( 0 ) );
         // middle point
-        QPointF pm( points.at( pIdx + 1 ) );
+        QPointF pm( points.at( points.size() / 2 ) );
         // destination point
-        QPointF pd( points.at( pIdx + 2 ) );
+        QPointF pd( points.back() );
 
         QPolygonF poly = curvedArrow( po, pm, pd, mScaledArrowStartWidth, mScaledArrowWidth, mScaledHeadWidth, mScaledHeadHeight, mComputedHeadType, mComputedArrowType, mScaledOffset );
         mSymbol->renderPolygon( poly, /* rings */ nullptr, context.feature(), context.renderContext() );
       }
       // straight arrow
-      else if ( points.size() - pIdx == 2 )
+      else if ( points.size() == 2 )
       {
         // origin point
-        QPointF po( points.at( pIdx ) );
+        QPointF po( points.at( 0 ) );
         // destination point
-        QPointF pd( points.at( pIdx + 1 ) );
+        QPointF pd( points.at( 1 ) );
 
         QPolygonF poly = straightArrow( po, pd, mScaledArrowStartWidth, mScaledArrowWidth, mScaledHeadWidth, mScaledHeadHeight, mComputedHeadType, mComputedArrowType, mScaledOffset );
         mSymbol->renderPolygon( poly, /* rings */ nullptr, context.feature(), context.renderContext() );
       }
     }
+    else
+    {
+      for ( int pIdx = 0; pIdx < points.size() - 1; pIdx += 2 )
+      {
+        mExpressionScope->setVariable( QgsExpressionContext::EXPR_GEOMETRY_POINT_NUM, pIdx + 1 );
+        _resolveDataDefined( context );
+
+        if ( points.size() - pIdx >= 3 )
+        {
+          // origin point
+          QPointF po( points.at( pIdx ) );
+          // middle point
+          QPointF pm( points.at( pIdx + 1 ) );
+          // destination point
+          QPointF pd( points.at( pIdx + 2 ) );
+
+          QPolygonF poly = curvedArrow( po, pm, pd, mScaledArrowStartWidth, mScaledArrowWidth, mScaledHeadWidth, mScaledHeadHeight, mComputedHeadType, mComputedArrowType, mScaledOffset );
+          mSymbol->renderPolygon( poly, /* rings */ nullptr, context.feature(), context.renderContext() );
+        }
+        // straight arrow
+        else if ( points.size() - pIdx == 2 )
+        {
+          // origin point
+          QPointF po( points.at( pIdx ) );
+          // destination point
+          QPointF pd( points.at( pIdx + 1 ) );
+
+          QPolygonF poly = straightArrow( po, pd, mScaledArrowStartWidth, mScaledArrowWidth, mScaledHeadWidth, mScaledHeadHeight, mComputedHeadType, mComputedArrowType, mScaledOffset );
+          mSymbol->renderPolygon( poly, /* rings */ nullptr, context.feature(), context.renderContext() );
+        }
+      }
+    }
   }
   else
   {
-    // only straight arrows
-    for ( int pIdx = 0; pIdx < points.size() - 1; pIdx++ )
+    if ( !isRepeated() )
     {
-      mExpressionScope->setVariable( QgsExpressionContext::EXPR_GEOMETRY_POINT_NUM, pIdx + 1 );
       _resolveDataDefined( context );
 
       // origin point
-      QPointF po( points.at( pIdx ) );
+      QPointF po( points.at( 0 ) );
       // destination point
-      QPointF pd( points.at( pIdx + 1 ) );
+      QPointF pd( points.back() );
 
       QPolygonF poly = straightArrow( po, pd, mScaledArrowStartWidth, mScaledArrowWidth, mScaledHeadWidth, mScaledHeadHeight, mComputedHeadType, mComputedArrowType, mScaledOffset );
       mSymbol->renderPolygon( poly, /* rings */ nullptr, context.feature(), context.renderContext() );
     }
+    else
+    {
+      // only straight arrows
+      for ( int pIdx = 0; pIdx < points.size() - 1; pIdx++ )
+      {
+        mExpressionScope->setVariable( QgsExpressionContext::EXPR_GEOMETRY_POINT_NUM, pIdx + 1 );
+        _resolveDataDefined( context );
+
+        // origin point
+        QPointF po( points.at( pIdx ) );
+        // destination point
+        QPointF pd( points.at( pIdx + 1 ) );
+
+        QPolygonF poly = straightArrow( po, pd, mScaledArrowStartWidth, mScaledArrowWidth, mScaledHeadWidth, mScaledHeadHeight, mComputedHeadType, mComputedArrowType, mScaledOffset );
+        mSymbol->renderPolygon( poly, /* rings */ nullptr, context.feature(), context.renderContext() );
+      }
+    }
   }
   context.renderContext().expressionContext().popScope();
 }

src/core/symbology-ng/qgsarrowsymbollayer.h

@@ -105,6 +105,11 @@ class CORE_EXPORT QgsArrowSymbolLayer : public QgsLineSymbolLayerV2
     /** Set whether it is a curved arrow or a straight one */
     void setIsCurved( bool isCurved ) { mIsCurved = isCurved; }
 
+    /** Return whether the arrow is repeated along the line or not */
+    bool isRepeated() const { return mIsRepeated; }
+    /** Set whether the arrow is repeated along the line */
+    void setIsRepeated( bool isRepeated ) { mIsRepeated = isRepeated; }
+
     /** Possible head types */
     enum HeadType
     {
@@ -178,6 +183,7 @@ class CORE_EXPORT QgsArrowSymbolLayer : public QgsLineSymbolLayerV2
     HeadType mHeadType;
     ArrowType mArrowType;
     bool mIsCurved;
+    bool mIsRepeated;
 
     double mScaledArrowWidth;
     double mScaledArrowStartWidth;

src/gui/symbology-ng/qgsarrowsymbollayerwidget.cpp

@@ -64,6 +64,7 @@ void QgsArrowSymbolLayerWidget::setSymbolLayer( QgsSymbolLayerV2* layer )
   mOffsetUnitWidget->setMapUnitScale( mLayer->offsetMapUnitScale() );
 
   mCurvedArrowChck->setChecked( mLayer->isCurved() );
+  mRepeatArrowChck->setChecked( mLayer->isRepeated() );
 
   registerDataDefinedButton( mArrowWidthDDBtn, "arrow_width", QgsDataDefinedButton::Double, QgsDataDefinedButton::doubleDesc() );
   registerDataDefinedButton( mArrowStartWidthDDBtn, "arrow_start_width", QgsDataDefinedButton::Double, QgsDataDefinedButton::doubleDesc() );
@@ -207,3 +208,12 @@ void QgsArrowSymbolLayerWidget::on_mCurvedArrowChck_stateChanged( int state )
   mLayer->setIsCurved( state == Qt::Checked );
   emit changed();
 }
+
+void QgsArrowSymbolLayerWidget::on_mRepeatArrowChck_stateChanged( int state )
+{
+  if ( ! mLayer )
+    return;
+
+  mLayer->setIsRepeated( state == Qt::Checked );
+  emit changed();
+}

src/gui/symbology-ng/qgsarrowsymbollayerwidget.h

@@ -63,6 +63,7 @@ class GUI_EXPORT QgsArrowSymbolLayerWidget: public QgsSymbolLayerV2Widget, priva
     void on_mOffsetUnitWidget_changed();
 
     void on_mCurvedArrowChck_stateChanged( int );
+    void on_mRepeatArrowChck_stateChanged( int );
 };
 
 #endif