From e3d30af7358887616c2bc6616ae2e29facee7c79 Mon Sep 17 00:00:00 2001
From: Larry Shaffer <larrys@dakotacarto.com>
Date: Wed, 14 Nov 2012 18:31:27 -0700
Subject: [PATCH] Update to limit of number of features sent to PAL
- Distributes max number across total number of features registered in PAL
- Caveat: PAL may not show label for every registered feature
---
python/core/qgsmaprenderer.sip | 3 +++
python/core/qgspallabeling.sip | 2 --
src/core/qgsmaprenderer.h | 4 ++++
src/core/qgspallabeling.cpp | 44 +++++++++++++++++++++++++++-------
src/core/qgspallabeling.h | 7 +++---
src/core/qgsvectorlayer.cpp | 15 ++++++++++++
src/ui/qgslabelingguibase.ui | 7 ++++--
7 files changed, 67 insertions(+), 15 deletions(-)
diff --git a/python/core/qgsmaprenderer.sip b/python/core/qgsmaprenderer.sip
index 578c4198c8f..2cd7e31c470 100644
--- a/python/core/qgsmaprenderer.sip
+++ b/python/core/qgsmaprenderer.sip
@@ -40,6 +40,9 @@ class QgsLabelingEngineInterface
//! called when starting rendering of a layer
//! @note: this method was added in version 1.6
virtual int prepareLayer( QgsVectorLayer* layer, QSet<int>& attrIndices, QgsRenderContext& ctx ) = 0;
+ //! returns PAL layer settings for a registered layer
+ //! @note: this method was added in version 1.9
+ virtual QgsPalLayerSettings& layer( const QString& layerName ) = 0;
//! adds a diagram layer to the labeling engine
virtual int addDiagramLayer( QgsVectorLayer* layer, QgsDiagramLayerSettings* s );
//! called for every feature
diff --git a/python/core/qgspallabeling.sip b/python/core/qgspallabeling.sip
index bb785b729a1..9a6130e9d64 100644
--- a/python/core/qgspallabeling.sip
+++ b/python/core/qgspallabeling.sip
@@ -126,8 +126,6 @@ class QgsPalLayerSettings
double minFeatureSize; // minimum feature size to be labelled (in mm)
bool limitNumLabels; // whether to limit the number of labels to be drawn
int maxNumLabels; // maximum number of labels to be drawn
- //bool rndMaxNumLabels; // whether to take a randomized maxNumLabels subset of features to be labeled
-
// Adds '<' or '>', or user-defined symbol to the label string pointing to the
// direction of the line / polygon ring
// Works only if Placement == Line
diff --git a/src/core/qgsmaprenderer.h b/src/core/qgsmaprenderer.h
index df75b919392..792b0c2b7fd 100644
--- a/src/core/qgsmaprenderer.h
+++ b/src/core/qgsmaprenderer.h
@@ -39,6 +39,7 @@ class QgsDistanceArea;
class QgsOverlayObjectPositionManager;
class QgsVectorLayer;
+class QgsPalLayerSettings;
class QgsDiagramLayerSettings;
class CORE_EXPORT QgsLabelPosition
@@ -75,6 +76,9 @@ class CORE_EXPORT QgsLabelingEngineInterface
//! called when starting rendering of a layer
//! @note: this method was added in version 1.6
virtual int prepareLayer( QgsVectorLayer* layer, QSet<int>& attrIndices, QgsRenderContext& ctx ) = 0;
+ //! returns PAL layer settings for a registered layer
+ //! @note: this method was added in version 1.9
+ virtual QgsPalLayerSettings& layer( const QString& layerName ) = 0;
//! adds a diagram layer to the labeling engine
virtual int addDiagramLayer( QgsVectorLayer* layer, QgsDiagramLayerSettings* s )
{ Q_UNUSED( layer ); Q_UNUSED( s ); return 0; }
diff --git a/src/core/qgspallabeling.cpp b/src/core/qgspallabeling.cpp
index 76194f19884..e2e2e685d17 100644
--- a/src/core/qgspallabeling.cpp
+++ b/src/core/qgspallabeling.cpp
@@ -177,7 +177,7 @@ class QgsPalGeometry : public PalGeometry
// -------------
QgsPalLayerSettings::QgsPalLayerSettings()
- : palLayer( NULL ), ct( NULL ), extentGeom( NULL ), expression( NULL )
+ : palLayer( NULL ), ct( NULL ), extentGeom( NULL ), mFeaturesToLabel( 0 ), mFeatsSendingToPal( 0 ), mFeatsRegPal( 0 ), expression( NULL )
{
placement = AroundPoint;
placementFlags = 0;
@@ -658,13 +658,6 @@ void QgsPalLayerSettings::calculateLabelSize( const QFontMetricsF* fm, QString t
void QgsPalLayerSettings::registerFeature( QgsVectorLayer* layer, QgsFeature& f, const QgsRenderContext& context )
{
-
- // check if max number of labels to draw (already registered features) has been reached
- if ( limitNumLabels && ( maxNumLabels == 0 || palLayer->getNbFeatures() >= maxNumLabels ) )
- {
- return;
- }
-
// data defined show label? defaults to show label if not 0
QMap< DataDefinedProperties, int >::const_iterator showIt = dataDefinedProperties.find( QgsPalLayerSettings::Show );
if ( showIt != dataDefinedProperties.constEnd() )
@@ -822,6 +815,32 @@ void QgsPalLayerSettings::registerFeature( QgsVectorLayer* layer, QgsFeature& f
if ( geos_geom == NULL )
return; // invalid geometry
+ // likelihood exists label will be registered with PAL and may be drawn
+ // check if max number of features to label (already registered with PAL) has been reached
+ // Debug output at end of QgsPalLabeling::drawLabeling(), when deleting temp geometries
+ if ( limitNumLabels )
+ {
+ if ( !maxNumLabels )
+ {
+ return;
+ }
+ mFeatsRegPal = palLayer->getNbFeatures();
+ if ( mFeatsRegPal >= maxNumLabels )
+ {
+ return;
+ }
+
+ int divNum = ( int )(( mFeaturesToLabel / maxNumLabels ) + 0.5 );
+ if ( divNum && ( mFeatsRegPal == ( int )( mFeatsSendingToPal / divNum ) ) )
+ {
+ mFeatsSendingToPal += 1;
+ if ( divNum && mFeatsSendingToPal % divNum )
+ {
+ return;
+ }
+ }
+ }
+
GEOSGeometry* geos_geom_clone = GEOSGeom_clone( geos_geom );
//data defined position / alignment / rotation?
@@ -1259,6 +1278,8 @@ int QgsPalLabeling::prepareLayer( QgsVectorLayer* layer, QSet<int>& attrIndices,
// rect for clipping
lyr.extentGeom = QgsGeometry::fromRect( mMapRenderer->extent() );
+ lyr.mFeatsSendingToPal = 0;
+
return 1; // init successful
}
@@ -1656,6 +1677,13 @@ void QgsPalLabeling::drawLabeling( QgsRenderContext& context )
QgsPalLayerSettings& lyr = lit.value();
for ( QList<QgsPalGeometry*>::iterator git = lyr.geometries.begin(); git != lyr.geometries.end(); ++git )
delete *git;
+ if ( lyr.limitNumLabels )
+ {
+ QgsDebugMsg( QString( "mFeaturesToLabel: %1" ).arg( lyr.mFeaturesToLabel ) );
+ QgsDebugMsg( QString( "maxNumLabels: %1" ).arg( lyr.maxNumLabels ) );
+ QgsDebugMsg( QString( "mFeatsSendingToPal: %1" ).arg( lyr.mFeatsSendingToPal ) );
+ QgsDebugMsg( QString( "mFeatsRegPal: %1" ).arg( lyr.geometries.count() ) );
+ }
lyr.geometries.clear();
}
diff --git a/src/core/qgspallabeling.h b/src/core/qgspallabeling.h
index 02e973f79fd..4081a1d9568 100644
--- a/src/core/qgspallabeling.h
+++ b/src/core/qgspallabeling.h
@@ -180,8 +180,6 @@ class CORE_EXPORT QgsPalLayerSettings
double minFeatureSize; // minimum feature size to be labelled (in mm)
bool limitNumLabels; // whether to limit the number of labels to be drawn
int maxNumLabels; // maximum number of labels to be drawn
- //bool rndMaxNumLabels; // whether to take a randomized maxNumLabels subset of features to be labeled
-
// Adds '<' or '>', or user-defined symbol to the label string pointing to the
// direction of the line / polygon ring
// Works only if Placement == Line
@@ -228,7 +226,7 @@ class CORE_EXPORT QgsPalLayerSettings
@return font pixel size*/
int sizeToPixel( double size, const QgsRenderContext& c , bool buffer = false ) const;
- // temporary stuff: set when layer gets prepared
+ // temporary stuff: set when layer gets prepared or labeled
pal::Layer* palLayer;
int fieldIndex;
const QgsMapToPixel* xform;
@@ -236,6 +234,9 @@ class CORE_EXPORT QgsPalLayerSettings
QgsPoint ptZero, ptOne;
QList<QgsPalGeometry*> geometries;
QgsGeometry* extentGeom;
+ int mFeaturesToLabel; // total features that will probably be labeled, may be less (figured before PAL)
+ int mFeatsSendingToPal; // total features tested for sending into PAL (relative to maxNumLabels)
+ int mFeatsRegPal; // number of features registered in PAL, when using limitNumLabels
private:
/**Checks if a feature is larger than a minimum size (in mm)
diff --git a/src/core/qgsvectorlayer.cpp b/src/core/qgsvectorlayer.cpp
index 886e1f6b8a0..9d7e8c5c226 100644
--- a/src/core/qgsvectorlayer.cpp
+++ b/src/core/qgsvectorlayer.cpp
@@ -5699,6 +5699,21 @@ void QgsVectorLayer::prepareLabelingAndDiagrams( QgsRenderContext& rendererConte
labeling = true;
}
+ if ( labeling )
+ {
+ // see if feature count limit is set for labeling
+ QgsPalLayerSettings& palyr = rendererContext.labelingEngine()->layer( this->id() );
+ if ( palyr.limitNumLabels && palyr.maxNumLabels > 0 )
+ {
+ select( QgsAttributeList(), rendererContext.extent() );
+ // total number of features that may be labeled
+ QgsFeature ftr;
+ int nFeatsToLabel = 0;
+ while ( nextFeature( ftr ) ) { nFeatsToLabel += 1; }
+ palyr.mFeaturesToLabel = nFeatsToLabel;
+ }
+ }
+
//register diagram layers
if ( mDiagramRenderer && mDiagramLayerSettings )
{
diff --git a/src/ui/qgslabelingguibase.ui b/src/ui/qgslabelingguibase.ui
index 545936a61a5..bae1aa65b3a 100644
--- a/src/ui/qgslabelingguibase.ui
+++ b/src/ui/qgslabelingguibase.ui
@@ -2780,7 +2780,7 @@
</sizepolicy>
</property>
<property name="text">
- <string>Limit number of labels drawn to</string>
+ <string>Limit number of features to be labeled to</string>
</property>
</widget>
</item>
@@ -2795,6 +2795,9 @@
<height>0</height>
</size>
</property>
+ <property name="toolTip">
+ <string>Number of features sent to labeling engine, though not all may be labeled</string>
+ </property>
<property name="alignment">
<set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
</property>
@@ -2855,7 +2858,7 @@
<rect>
<x>0</x>
<y>0</y>
- <width>686</width>
+ <width>488</width>
<height>981</height>
</rect>
</property>