[FEATURE] Add snapping results to default value calculation

... as @snapping_results variable
qgis · Jul 7, 2017 · 9581fe0 · 9581fe0
1 parent a8cceff
commit 9581fe0
Show file tree

Hide file tree

Showing 15 changed files with 120 additions and 13 deletions.
diff --git a/python/core/geometry/qgscompoundcurve.sip b/python/core/geometry/qgscompoundcurve.sip
@@ -77,7 +77,7 @@ class QgsCompoundCurve: QgsCurve
 
     void addCurve( QgsCurve *c /Transfer/ );
 %Docstring
- Adds a curve to the geometr (takes ownership)
+ Adds a curve to the geometry (takes ownership)
 %End
 
     void removeCurve( int i );

diff --git a/python/core/qgsexpressioncontext.sip b/python/core/qgsexpressioncontext.sip
@@ -809,6 +809,15 @@ class QgsExpressionContextUtils
  :rtype: QgsExpressionContextScope
 %End
 
+    static QgsExpressionContextScope *mapToolCaptureScope( const QList<QgsPointLocator::Match> &matches ) /Factory/;
+%Docstring
+ Sets the expression context variables which are available for expressions triggered by
+ a map tool capture like add feature.
+
+.. versionadded:: 3.0
+ :rtype: QgsExpressionContextScope
+%End
+
     static QgsExpressionContextScope *updateSymbolScope( const QgsSymbol *symbol, QgsExpressionContextScope *symbolScope = 0 );
 %Docstring
  Updates a symbol scope related to a QgsSymbol to an expression context.

diff --git a/python/gui/qgsmaptoolcapture.sip b/python/gui/qgsmaptoolcapture.sip
@@ -42,6 +42,14 @@ Adds a whole curve (e.g. circularstring) to the captured geometry. Curve must be
  :rtype: QgsCompoundCurve
 %End
 
+    QList<QgsPointLocator::Match> snappingMatches() const;
+%Docstring
+ Return a list of matches for each point on the captureCurve.
+
+.. versionadded:: 3.0
+ :rtype: list of QgsPointLocator.Match
+%End
+
     virtual void cadCanvasMoveEvent( QgsMapMouseEvent *e );
 
     virtual void keyPressEvent( QKeyEvent *e );

diff --git a/src/app/qgsattributetypedialog.cpp b/src/app/qgsattributetypedialog.cpp
@@ -71,6 +71,8 @@ QgsAttributeTypeDialog::QgsAttributeTypeDialog( QgsVectorLayer *vl, int fieldIdx
     isFieldEditableCheckBox->setEnabled( false );
   }
 
+  mExpressionWidget->registerExpressionContextGenerator( this );
+
   connect( mExpressionWidget, &QgsExpressionLineEdit::expressionChanged, this, &QgsAttributeTypeDialog::defaultExpressionChanged );
   connect( mUniqueCheckBox, &QCheckBox::toggled, this, [ = ]( bool checked )
   {
@@ -293,6 +295,18 @@ void QgsAttributeTypeDialog::setDefaultValueExpression( const QString &expressio
   mExpressionWidget->setExpression( expression );
 }
 
+QgsExpressionContext QgsAttributeTypeDialog::createExpressionContext() const
+{
+  QgsExpressionContext context;
+  context
+      << QgsExpressionContextUtils::globalScope()
+      << QgsExpressionContextUtils::projectScope( QgsProject::instance() )
+      << QgsExpressionContextUtils::layerScope( mLayer )
+      << QgsExpressionContextUtils::mapToolCaptureScope( QList<QgsPointLocator::Match>() );
+
+  return context;
+}
+
 QString QgsAttributeTypeDialog::constraintExpression() const
 {
   return constraintExpressionWidget->asExpression();

diff --git a/src/app/qgsattributetypedialog.h b/src/app/qgsattributetypedialog.h
@@ -26,7 +26,7 @@
 
 class QDialog;
 
-class APP_EXPORT QgsAttributeTypeDialog: public QDialog, private Ui::QgsAttributeTypeDialog
+class APP_EXPORT QgsAttributeTypeDialog: public QDialog, private Ui::QgsAttributeTypeDialog, QgsExpressionContextGenerator
 {
     Q_OBJECT
 
@@ -163,6 +163,8 @@ class APP_EXPORT QgsAttributeTypeDialog: public QDialog, private Ui::QgsAttribut
      */
     void setDefaultValueExpression( const QString &expression );
 
+    QgsExpressionContext createExpressionContext() const override;
+
   private slots:
 
     /**

diff --git a/src/app/qgsfeatureaction.cpp b/src/app/qgsfeatureaction.cpp
@@ -161,7 +161,7 @@ bool QgsFeatureAction::editFeature( bool showModal )
   return true;
 }
 
-bool QgsFeatureAction::addFeature( const QgsAttributeMap &defaultAttributes, bool showModal )
+bool QgsFeatureAction::addFeature( const QgsAttributeMap &defaultAttributes, bool showModal, QgsExpressionContextScope *scope SIP_TRANSFER )
 {
   if ( !mLayer || !mLayer->isEditable() )
     return false;
@@ -188,6 +188,9 @@ bool QgsFeatureAction::addFeature( const QgsAttributeMap &defaultAttributes, boo
   // create new feature template - this will initialize the attributes to valid values, handling default
   // values and field constraints
   QgsExpressionContext context = mLayer->createExpressionContext();
+  if ( scope )
+    context.appendScope( scope );
+
   QgsFeature newFeature = QgsVectorLayerUtils::createFeature( mLayer, mFeature->geometry(), initialAttributeValues,
                           &context );
   *mFeature = newFeature;

diff --git a/src/app/qgsfeatureaction.h b/src/app/qgsfeatureaction.h
@@ -29,6 +29,7 @@ class QgsIdentifyResultsDialog;
 class QgsVectorLayer;
 class QgsHighlight;
 class QgsAttributeDialog;
+class QgsExpressionContextScope;
 
 class APP_EXPORT QgsFeatureAction : public QAction
 {
@@ -51,7 +52,7 @@ class APP_EXPORT QgsFeatureAction : public QAction
      *
      * \returns true if feature was added if showModal is true. If showModal is false, returns true in every case
      */
-    bool addFeature( const QgsAttributeMap &defaultAttributes = QgsAttributeMap(), bool showModal = true );
+    bool addFeature( const QgsAttributeMap &defaultAttributes = QgsAttributeMap(), bool showModal = true, QgsExpressionContextScope *scope = nullptr );
 
   private slots:
     void onFeatureSaved( const QgsFeature &feature );

diff --git a/src/app/qgsmaptooladdfeature.cpp b/src/app/qgsmaptooladdfeature.cpp
@@ -48,8 +48,9 @@ QgsMapToolAddFeature::~QgsMapToolAddFeature()
 
 bool QgsMapToolAddFeature::addFeature( QgsVectorLayer *vlayer, QgsFeature *f, bool showModal )
 {
+  QgsExpressionContextScope *scope = QgsExpressionContextUtils::mapToolCaptureScope( snappingMatches() );
   QgsFeatureAction *action = new QgsFeatureAction( tr( "add feature" ), *f, vlayer, QString(), -1, this );
-  bool res = action->addFeature( QgsAttributeMap(), showModal );
+  bool res = action->addFeature( QgsAttributeMap(), showModal, scope );
   if ( showModal )
     delete action;
   return res;
@@ -250,6 +251,7 @@ void QgsMapToolAddFeature::cadCanvasReleaseEvent( QgsMapMouseEvent *e )
       bool hasCurvedSegments = captureCurve()->hasCurvedSegments();
       bool providerSupportsCurvedSegments = vlayer->dataProvider()->capabilities() & QgsVectorDataProvider::CircularGeometries;
 
+      QList<QgsPointLocator::Match> snappingMatchesList;
       QgsCurve *curveToAdd = nullptr;
       if ( hasCurvedSegments && providerSupportsCurvedSegments )
       {
@@ -258,13 +260,13 @@ void QgsMapToolAddFeature::cadCanvasReleaseEvent( QgsMapMouseEvent *e )
       else
       {
         curveToAdd = captureCurve()->curveToLine();
+        snappingMatchesList = snappingMatches();
       }
 
       if ( mode() == CaptureLine )
       {
-        QgsGeometry *g = new QgsGeometry( curveToAdd );
-        f->setGeometry( *g );
-        delete g;
+        QgsGeometry g( curveToAdd );
+        f->setGeometry( g );
       }
       else
       {
@@ -278,9 +280,8 @@ void QgsMapToolAddFeature::cadCanvasReleaseEvent( QgsMapMouseEvent *e )
           poly = new QgsPolygonV2();
         }
         poly->setExteriorRing( curveToAdd );
-        QgsGeometry *g = new QgsGeometry( poly );
-        f->setGeometry( *g );
-        delete g;
+        QgsGeometry g( poly );
+        f->setGeometry( g );
 
         QgsGeometry featGeom = f->geometry();
         int avoidIntersectionsReturn = featGeom.avoidIntersections( QgsProject::instance()->avoidIntersectionsLayers() );

diff --git a/src/app/qgsmaptooladdfeature.h b/src/app/qgsmaptooladdfeature.h
@@ -44,7 +44,6 @@ class APP_EXPORT QgsMapToolAddFeature : public QgsMapToolCapture
     void setCheckGeometryType( bool checkGeometryType );
 
   private:
-    QVariant snappingMatchesAsVariable() const;
 
     /** Check if CaptureMode matches layer type. Default is true.
      * \since QGIS 2.12 */

diff --git a/src/core/expression/qgsexpression.cpp b/src/core/expression/qgsexpression.cpp
@@ -673,6 +673,19 @@ void QgsExpression::initVariableHelp()
   sVariableHelpTexts.insert( QStringLiteral( "grid_number" ), QCoreApplication::translate( "variable_help", "Current grid annotation value." ) );
   sVariableHelpTexts.insert( QStringLiteral( "grid_axis" ), QCoreApplication::translate( "variable_help", "Current grid annotation axis (e.g., 'x' for longitude, 'y' for latitude)." ) );
 
+  // map tool capture variables
+  sVariableHelpTexts.insert( QStringLiteral( "snapping_results" ), QCoreApplication::translate( "variable_help",
+                             "<p>An array with an item for each snapped point.</p>"
+                             "<p>Each item is a map with the following keys:</p>"
+                             "<dl>"
+                             "<dt>valid</dt><dd>Boolean that indicates if the snapping result is valid</dd>"
+                             "<dt>layer</dt><dd>The layer on which the snapped feature is</dd>"
+                             "<dt>feature_id</dt><dd>The feature id of the snapped feature</dd>"
+                             "<dt>vertex_index</dt><dd>The index of the snapped vertex</dd>"
+                             "<dt>distance</dt><dd>The distance between the mouse cursor and the snapped point at the time of snapping</dd>"
+                             "</dl>" ) );
+
+
   //symbol variables
   sVariableHelpTexts.insert( QStringLiteral( "geometry_part_count" ), QCoreApplication::translate( "variable_help", "Number of parts in rendered feature's geometry." ) );
   sVariableHelpTexts.insert( QStringLiteral( "geometry_part_num" ), QCoreApplication::translate( "variable_help", "Current geometry part number for feature being rendered." ) );

diff --git a/src/core/geometry/qgscompoundcurve.h b/src/core/geometry/qgscompoundcurve.h
@@ -74,7 +74,7 @@ class CORE_EXPORT QgsCompoundCurve: public QgsCurve
      */
     const QgsCurve *curveAt( int i ) const;
 
-    /** Adds a curve to the geometr (takes ownership)
+    /** Adds a curve to the geometry (takes ownership)
      */
     void addCurve( QgsCurve *c SIP_TRANSFER );
 

diff --git a/src/core/qgsexpressioncontext.cpp b/src/core/qgsexpressioncontext.cpp
@@ -912,6 +912,30 @@ QgsExpressionContextScope *QgsExpressionContextUtils::mapSettingsScope( const Qg
   return scope;
 }
 
+QgsExpressionContextScope *QgsExpressionContextUtils::mapToolCaptureScope( const QList<QgsPointLocator::Match> &matches )
+{
+  QgsExpressionContextScope *scope = new QgsExpressionContextScope( QObject::tr( "Map Tool Capture" ) );
+
+  QVariantList matchList;
+
+  for ( const QgsPointLocator::Match &match : matches )
+  {
+    QVariantMap matchMap;
+
+    matchMap.insert( QStringLiteral( "valid" ), match.isValid() );
+    matchMap.insert( QStringLiteral( "layer" ), QVariant::fromValue<QgsWeakMapLayerPointer>( QgsWeakMapLayerPointer( match.layer() ) ) );
+    matchMap.insert( QStringLiteral( "feature_id" ), match.featureId() );
+    matchMap.insert( QStringLiteral( "vertex_index" ), match.vertexIndex() );
+    matchMap.insert( QStringLiteral( "distance" ), match.distance() );
+
+    matchList.append( matchMap );
+  }
+
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "snapping_results" ), matchList ) );
+
+  return scope;
+}
+
 QgsExpressionContextScope *QgsExpressionContextUtils::updateSymbolScope( const QgsSymbol *symbol, QgsExpressionContextScope *symbolScope )
 {
   if ( !symbolScope )

diff --git a/src/core/qgsexpressioncontext.h b/src/core/qgsexpressioncontext.h
@@ -26,6 +26,7 @@
 #include "qgsfeature.h"
 #include "qgsexpression.h"
 #include "qgsexpressionfunction.h"
+#include "qgspointlocator.h"
 
 class QgsExpression;
 class QgsExpressionNodeFunction;
@@ -743,6 +744,14 @@ class CORE_EXPORT QgsExpressionContextUtils
      */
     static QgsExpressionContextScope *mapSettingsScope( const QgsMapSettings &mapSettings ) SIP_FACTORY;
 
+    /**
+     * Sets the expression context variables which are available for expressions triggered by
+     * a map tool capture like add feature.
+     *
+     * \since QGIS 3.0
+     */
+    static QgsExpressionContextScope *mapToolCaptureScope( const QList<QgsPointLocator::Match> &matches ) SIP_FACTORY;
+
     /**
      * Updates a symbol scope related to a QgsSymbol to an expression context.
      * \param symbol symbol to extract properties from

diff --git a/src/gui/qgsmaptoolcapture.cpp b/src/gui/qgsmaptoolcapture.cpp
@@ -222,6 +222,7 @@ bool QgsMapToolCapture::tracingAddVertex( const QgsPointXY &point )
 
       mRubberBand->addPoint( point );
       mCaptureCurve.addVertex( layerPoint );
+      mSnappingMatches.append( QgsPointLocator::Match() );
     }
     return res;
   }
@@ -251,6 +252,7 @@ bool QgsMapToolCapture::tracingAddVertex( const QgsPointXY &point )
       continue; // avoid duplicate vertices if there are any
     mRubberBand->addPoint( points[i], i == points.count() - 1 );
     mCaptureCurve.addVertex( layerPoints[i - 1] );
+    mSnappingMatches.append( QgsPointLocator::Match() );
   }
 
   tracer->reportError( QgsTracer::ErrNone, true ); // clear messagebar if there was any error
@@ -433,6 +435,7 @@ int QgsMapToolCapture::addVertex( const QgsPointXY &point, const QgsPointLocator
     // ordinary digitizing
     mRubberBand->addPoint( point );
     mCaptureCurve.addVertex( layerPoint );
+    mSnappingMatches.append( match );
   }
 
   if ( mCaptureMode == CaptureLine )
@@ -493,10 +496,17 @@ int QgsMapToolCapture::addCurve( QgsCurve *c )
     c->transform( ct, QgsCoordinateTransform::ReverseTransform );
   }
   mCaptureCurve.addCurve( c );
+  for ( int i = 0; i < c->length(); ++i )
+    mSnappingMatches.append( QgsPointLocator::Match() );
 
   return 0;
 }
 
+QList<QgsPointLocator::Match> QgsMapToolCapture::snappingMatches() const
+{
+  return mSnappingMatches;
+}
+
 
 void QgsMapToolCapture::undo()
 {
@@ -531,6 +541,7 @@ void QgsMapToolCapture::undo()
     vertexToRemove.ring = 0;
     vertexToRemove.vertex = size() - 1;
     mCaptureCurve.deleteVertex( vertexToRemove );
+    mSnappingMatches.removeAt( vertexToRemove.vertex );
 
     validateGeometry();
   }
@@ -599,6 +610,7 @@ void QgsMapToolCapture::stopCapturing()
 
   mCapturing = false;
   mCaptureCurve.clear();
+  mSnappingMatches.clear();
   if ( currentVectorLayer() )
     currentVectorLayer()->triggerRepaint();
 }
@@ -717,6 +729,9 @@ void QgsMapToolCapture::setPoints( const QList<QgsPointXY> &pointList )
   QgsLineString *line = new QgsLineString( pointList );
   mCaptureCurve.clear();
   mCaptureCurve.addCurve( line );
+  mSnappingMatches.clear();
+  for ( int i = 0; i < line->length(); ++i )
+    mSnappingMatches.append( QgsPointLocator::Match() );
 }
 
 #ifdef Q_OS_WIN

diff --git a/src/gui/qgsmaptoolcapture.h b/src/gui/qgsmaptoolcapture.h
@@ -56,6 +56,13 @@ class GUI_EXPORT QgsMapToolCapture : public QgsMapToolAdvancedDigitizing
      */
     const QgsCompoundCurve *captureCurve() const { return &mCaptureCurve; }
 
+    /**
+     * Return a list of matches for each point on the captureCurve.
+     *
+     * \since QGIS 3.0
+     */
+    QList<QgsPointLocator::Match> snappingMatches() const;
+
     virtual void cadCanvasMoveEvent( QgsMapMouseEvent *e ) override;
 
     /**
@@ -193,6 +200,8 @@ class GUI_EXPORT QgsMapToolCapture : public QgsMapToolAdvancedDigitizing
     //! List to store the points of digitized lines and polygons (in layer coordinates)
     QgsCompoundCurve mCaptureCurve;
 
+    QList<QgsPointLocator::Match> mSnappingMatches;
+
     void validateGeometry();
     QStringList mValidationWarnings;
     QgsGeometryValidator *mValidator = nullptr;