Merge pull request #1332 from leyan/deletePart

Improve delete part feature for polygon

Author: 3nids

src/app/qgsmaptooldeletepart.cpp

@@ -18,18 +18,20 @@
 #include "qgsmapcanvas.h"
 #include "qgsvertexmarker.h"
 #include "qgsvectorlayer.h"
+#include "qgsgeometry.h"
+#include "qgstolerance.h"
 
 #include <QMouseEvent>
 #include <QMessageBox>
 
 QgsMapToolDeletePart::QgsMapToolDeletePart( QgsMapCanvas* canvas )
-    : QgsMapToolVertexEdit( canvas ), mCross( 0 )
+    : QgsMapToolEdit( canvas ), mRubberBand( 0 )
 {
 }
 
 QgsMapToolDeletePart::~QgsMapToolDeletePart()
 {
-  delete mCross;
+  delete mRubberBand;
 }
 
 void QgsMapToolDeletePart::canvasMoveEvent( QMouseEvent *e )
@@ -40,150 +42,158 @@ void QgsMapToolDeletePart::canvasMoveEvent( QMouseEvent *e )
 
 void QgsMapToolDeletePart::canvasPressEvent( QMouseEvent *e )
 {
-  delete mCross;
-  mCross = 0;
+  mPressedFid = -1;
+  mPressedPartNum = -1;
+  delete mRubberBand;
+  mRubberBand = 0;
 
-  mRecentSnappingResults.clear();
-  //do snap -> new recent snapping results
-  if ( mSnapper.snapToCurrentLayer( e->pos(), mRecentSnappingResults, QgsSnapper::SnapToVertexAndSegment ) != 0 )
+  QgsMapLayer* currentLayer = mCanvas->currentLayer();
+  if ( !currentLayer )
+    return;
+
+  vlayer = qobject_cast<QgsVectorLayer *>( currentLayer );
+  if ( !vlayer )
   {
-    //error
+    notifyNotVectorLayer();
+    return;
   }
 
-  if ( mRecentSnappingResults.size() > 0 )
+  if ( !vlayer->isEditable() )
   {
-    // remove previous warning
-    emit messageDiscarded();
+    notifyNotEditableLayer();
+    return;
+  }
 
-    QgsPoint markerPoint = mRecentSnappingResults.begin()->snappedVertex;
+  QgsGeometry* geomPart;
 
-    //show vertex marker
-    mCross = new QgsVertexMarker( mCanvas );
-    mCross->setIconType( QgsVertexMarker::ICON_X );
-    mCross->setCenter( markerPoint );
-  }
-  else
+  geomPart = partUnderPoint( e->pos(), mPressedFid, mPressedPartNum );
+
+  if ( mPressedFid != -1 )
   {
-    emit messageEmitted( tr( "could not snap to a part on the current layer." ) );
+    mRubberBand = createRubberBand( vlayer->geometryType() );
+
+    mRubberBand->setToGeometry( geomPart, vlayer );
+    mRubberBand->show();
   }
+
 }
 
 void QgsMapToolDeletePart::canvasReleaseEvent( QMouseEvent *e )
 {
   Q_UNUSED( e );
-  delete mCross;
-  mCross = 0;
 
-  QgsMapLayer* currentLayer = mCanvas->currentLayer();
-  if ( !currentLayer )
-    return;
+  delete mRubberBand;
+  mRubberBand = 0;
 
-  QgsVectorLayer* vlayer = qobject_cast<QgsVectorLayer *>( currentLayer );
-  if ( !vlayer )
-    return;
-
-  if ( mRecentSnappingResults.size() > 0 )
+  if ( !vlayer || !vlayer->isEditable() )
   {
-    QList<QgsSnappingResult>::iterator sr_it = mRecentSnappingResults.begin();
-    for ( ; sr_it != mRecentSnappingResults.end(); ++sr_it )
-    {
-      if ( sr_it->snappedVertexNr != -1 )
-        deletePart( sr_it->snappedAtGeometry, sr_it->snappedVertexNr, vlayer );
-      else if ( sr_it->beforeVertexNr != -1 )
-        deletePart( sr_it->snappedAtGeometry, sr_it->beforeVertexNr, vlayer );
-      else if ( sr_it->afterVertexNr != -1 )
-        deletePart( sr_it->snappedAtGeometry, sr_it->afterVertexNr, vlayer );
-    }
+    return;
   }
 
-}
-
+  if ( mPressedFid == -1 )
+    return;
 
-void QgsMapToolDeletePart::deletePart( QgsFeatureId fId, int beforeVertexNr, QgsVectorLayer* vlayer )
-{
   QgsFeature f;
-  vlayer->getFeatures( QgsFeatureRequest().setFilterFid( fId ) ).nextFeature( f );
-
-  // find out the part number
+  vlayer->getFeatures( QgsFeatureRequest().setFilterFid( mPressedFid ) ).nextFeature( f );
   QgsGeometry* g = f.geometry();
-  if ( !g->isMultipart() )
-  {
-    QMessageBox::information( mCanvas, tr( "Delete part" ), tr( "This isn't a multipart geometry." ) );
-    return;
-  }
-
-  int partNum = partNumberOfVertex( g, beforeVertexNr );
 
-  if ( g->deletePart( partNum ) )
+  if ( g->deletePart( mPressedPartNum ) )
   {
     vlayer->beginEditCommand( tr( "Part of multipart feature deleted" ) );
-    vlayer->changeGeometry( fId, g );
+    vlayer->changeGeometry( f.id(), g );
     vlayer->endEditCommand();
     mCanvas->refresh();
   }
   else
   {
-    QMessageBox::information( mCanvas, tr( "Delete part" ), tr( "Couldn't remove the selected part." ) );
+    emit messageEmitted( tr( "Couldn't remove the selected part." ) );
   }
-
+  return;
 }
 
-int QgsMapToolDeletePart::partNumberOfVertex( QgsGeometry* g, int beforeVertexNr )
+QgsGeometry* QgsMapToolDeletePart::partUnderPoint( QPoint point, int& fid, int& partNum )
 {
-  int part;
+  QgsFeature f;
+  QgsGeometry* geomPart = new QgsGeometry();
 
-  switch ( g->wkbType() )
+  switch ( vlayer->geometryType() )
   {
-    case QGis::WKBMultiPoint25D:
-    case QGis::WKBMultiPoint:
-      if ( beforeVertexNr < g->asMultiPoint().count() )
-        return beforeVertexNr;
-      else
-        return -1;
-
-    case QGis::WKBMultiLineString25D:
-    case QGis::WKBMultiLineString:
+    case QGis::Point:
+    case QGis::Line:
     {
-      QgsMultiPolyline mline = g->asMultiPolyline();
-      for ( part = 0; part < mline.count(); part++ )
+      if ( mSnapper.snapToCurrentLayer( point, mRecentSnappingResults, QgsSnapper::SnapToVertexAndSegment ) == 0 )
       {
-        if ( beforeVertexNr < mline[part].count() )
-          return part;
-
-        beforeVertexNr -= mline[part].count();
+        if ( mRecentSnappingResults.length() > 0 )
+        {
+          QgsSnappingResult sr = mRecentSnappingResults.first();
+          int snapVertex = sr.snappedVertexNr;
+          if ( snapVertex == -1 )
+            snapVertex = sr.beforeVertexNr;
+          vlayer->getFeatures( QgsFeatureRequest().setFilterFid( sr.snappedAtGeometry ) ).nextFeature( f );
+          QgsGeometry* g = f.geometry();
+          if ( !g->isMultipart() )
+            return geomPart;
+          if ( g->wkbType() == QGis::WKBMultiPoint || g->wkbType() == QGis::WKBMultiPoint25D )
+          {
+            fid = sr.snappedAtGeometry;
+            partNum = snapVertex;
+            return QgsGeometry::fromPoint( sr.snappedVertex );
+          }
+          if ( g->wkbType() == QGis::WKBMultiLineString || g->wkbType() == QGis::WKBMultiLineString25D )
+          {
+            QgsMultiPolyline mline = g->asMultiPolyline();
+            for ( int part = 0; part < mline.count(); part++ )
+            {
+              if ( snapVertex < mline[part].count() )
+              {
+                fid = sr.snappedAtGeometry;
+                partNum = part;
+                return QgsGeometry::fromPolyline( mline[part] );
+              }
+              snapVertex -= mline[part].count();
+            }
+          }
+        }
       }
-      return -1; // not found
+      break;
     }
-
-    case QGis::WKBMultiPolygon25D:
-    case QGis::WKBMultiPolygon:
+    case QGis::Polygon:
     {
+      QgsPoint layerCoords = toLayerCoordinates( vlayer, point );
+      double searchRadius = QgsTolerance::vertexSearchRadius( mCanvas->currentLayer(), mCanvas->mapSettings() );
+      QgsRectangle selectRect( layerCoords.x() - searchRadius, layerCoords.y() - searchRadius,
+                               layerCoords.x() + searchRadius, layerCoords.y() + searchRadius );
+      QgsFeatureIterator fit = vlayer->getFeatures( QgsFeatureRequest().setFilterRect( selectRect ) );
+      fit.nextFeature( f );
+      QgsGeometry* g = f.geometry();
+      if ( !g )
+        return geomPart;
+      if ( !g->isMultipart() )
+        return geomPart;
       QgsMultiPolygon mpolygon = g->asMultiPolygon();
-      for ( part = 0; part < mpolygon.count(); part++ ) // go through the polygons
+      for ( int part = 0; part < mpolygon.count(); part++ ) // go through the polygons
       {
         const QgsPolygon& polygon = mpolygon[part];
-        for ( int ring = 0; ring < polygon.count(); ring++ ) // go through the rings
+        QgsGeometry* partGeo = QgsGeometry::fromPolygon( polygon );
+        if ( partGeo->contains( &layerCoords ) )
         {
-          if ( beforeVertexNr < polygon[ring].count() )
-            return part;
-
-          beforeVertexNr -= polygon[ring].count();
+          fid = f.id();
+          partNum = part;
+          return partGeo;
         }
       }
-      return -1; // not found
+      break;
     }
-
     default:
-      return -1;
+    {
+      break;
+    }
   }
+  return geomPart;
 }
 
-
 void QgsMapToolDeletePart::deactivate()
 {
-  delete mCross;
-  mCross = 0;
-
   QgsMapTool::deactivate();
 }
 

src/app/qgsmaptooldeletepart.h

@@ -16,12 +16,13 @@
 #ifndef QGSMAPTOOLDELETEPART_H
 #define QGSMAPTOOLDELETEPART_H
 
-#include "qgsmaptoolvertexedit.h"
+#include "qgsmaptooledit.h"
+#include "qgsrubberband.h"
 
 class QgsVertexMarker;
 
 /**Map tool to delete vertices from line/polygon features*/
-class APP_EXPORT QgsMapToolDeletePart: public QgsMapToolVertexEdit
+class APP_EXPORT QgsMapToolDeletePart: public QgsMapToolEdit
 {
     Q_OBJECT
 
@@ -39,14 +40,18 @@ class APP_EXPORT QgsMapToolDeletePart: public QgsMapToolVertexEdit
     void deactivate();
 
   private:
-    QgsVertexMarker* mCross;
+    QgsVectorLayer* vlayer;
+    QList<QgsSnappingResult> mRecentSnappingResults;
 
-    //! delete part of a geometry
-    void deletePart( QgsFeatureId fId, int beforeVertexNr, QgsVectorLayer* vlayer );
+    QgsGeometry* partUnderPoint( QPoint p, int &fid, int &partNum );
 
-    //! find out part number of geometry given the snapped vertex number
-    int partNumberOfVertex( QgsGeometry* g, int beforeVertexNr );
+    /* Rubberband that shows the part being deleted*/
+    QgsRubberBand* mRubberBand;
 
+    //The feature and part where the mouse cursor was pressed
+    //This is used to check whether we are still in the same part at cursor release
+    int mPressedFid;
+    int mPressedPartNum;
 };
 
 #endif