Enable snapping on intersection introduced

qgis · Oct 5, 2012 · e0d4784 · e0d4784
1 parent 3c525fd
commit e0d4784
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Showing 4 changed files with 155 additions and 28 deletions.
diff --git a/src/app/qgssnappingdialog.cpp b/src/app/qgssnappingdialog.cpp
@@ -72,6 +72,7 @@ QgsSnappingDialog::QgsSnappingDialog( QWidget* parent, QgsMapCanvas* canvas ): Q
   connect( QgsMapLayerRegistry::instance(), SIGNAL( layersAdded( QList<QgsMapLayer * > ) ), this, SLOT( addLayers( QList<QgsMapLayer * > ) ) );
   connect( QgsMapLayerRegistry::instance(), SIGNAL( layersWillBeRemoved( QStringList ) ), this, SLOT( layersWillBeRemoved( QStringList ) ) );
   connect( cbxEnableTopologicalEditingCheckBox, SIGNAL( stateChanged( int ) ), this, SLOT( on_cbxEnableTopologicalEditingCheckBox_stateChanged( int ) ) );
+  connect( cbxEnableIntersectionSnappingCheckBox, SIGNAL( stateChanged( int ) ), this, SLOT( on_cbxEnableIntersectionSnappingCheckBox_stateChanged( int ) ) );
 
   reload();
 
@@ -113,12 +114,20 @@ void QgsSnappingDialog::reload()
   }
 
   setTopologicalEditingState();
+  setIntersectionSnapppingState();
 }
 
 void QgsSnappingDialog::on_cbxEnableTopologicalEditingCheckBox_stateChanged( int state )
 {
   int topologicalEditingEnabled = ( state == Qt::Checked ) ? 1 : 0;
   QgsProject::instance()->writeEntry( "Digitizing", "/TopologicalEditing", topologicalEditingEnabled );
+  setTopologicalEditingState();
+}
+
+void QgsSnappingDialog::on_cbxEnableIntersectionSnappingCheckBox_stateChanged( int state )
+{
+  int intersectionSnappingEnabled = ( state == Qt::Checked ) ? 1 : 0;
+  QgsProject::instance()->writeEntry( "Digitizing", "/IntersectionSnapping", intersectionSnappingEnabled );
 }
 
 void QgsSnappingDialog::closeEvent( QCloseEvent* event )
@@ -188,6 +197,7 @@ void QgsSnappingDialog::apply()
 void QgsSnappingDialog::show()
 {
   setTopologicalEditingState();
+  setIntersectionSnapppingState();
   if ( mDock )
     mDock->setVisible( true );
   else
@@ -317,6 +327,9 @@ void QgsSnappingDialog::addLayer( QgsMapLayer * theMapLayer )
     {
       connect( cbxAvoidIntersection, SIGNAL( stateChanged( int ) ), this, SLOT( apply() ) );
     }
+
+    setTopologicalEditingState();
+    setIntersectionSnapppingState();
   }
 }
 
@@ -354,3 +367,19 @@ void QgsSnappingDialog::setTopologicalEditingState()
   }
   cbxEnableTopologicalEditingCheckBox->blockSignals( false );
 }
+
+void QgsSnappingDialog::setIntersectionSnapppingState()
+{
+  // read the digitizing settings
+  int intersectionSnapping = QgsProject::instance()->readNumEntry( "Digitizing", "/IntersectionSnapping", 0 );
+  cbxEnableIntersectionSnappingCheckBox->blockSignals( true );
+  if ( intersectionSnapping != 0 )
+  {
+    cbxEnableIntersectionSnappingCheckBox->setCheckState( Qt::Checked );
+  }
+  else
+  {
+    cbxEnableIntersectionSnappingCheckBox->setCheckState( Qt::Unchecked );
+  }
+  cbxEnableIntersectionSnappingCheckBox->blockSignals( false );
+}
diff --git a/src/app/qgssnappingdialog.h b/src/app/qgssnappingdialog.h
@@ -55,6 +55,8 @@ class QgsSnappingDialog: public QDialog, private Ui::QgsSnappingDialogBase
 
     void on_cbxEnableTopologicalEditingCheckBox_stateChanged( int );
 
+    void on_cbxEnableIntersectionSnappingCheckBox_stateChanged( int );
+
   protected:
     /**Constructor
     @param canvas pointer to the map canvas (for detecting which vector layers are loaded
@@ -85,6 +87,9 @@ class QgsSnappingDialog: public QDialog, private Ui::QgsSnappingDialogBase
 
     /**Set checkbox value based on project setting*/
     void setTopologicalEditingState();
+
+    /**Set checkbox value based on project setting*/
+    void setIntersectionSnapppingState();
 };
 
 #endif
diff --git a/src/gui/qgsmapcanvassnapper.cpp b/src/gui/qgsmapcanvassnapper.cpp
@@ -23,7 +23,8 @@
 #include "qgsvectorlayer.h"
 #include "qgstolerance.h"
 #include <QSettings>
-
+#include "qgslogger.h"
+#include "qgsgeometry.h"
 
 QgsMapCanvasSnapper::QgsMapCanvasSnapper( QgsMapCanvas* canvas ): mMapCanvas( canvas ), mSnapper( 0 )
 {
@@ -133,15 +134,34 @@ int QgsMapCanvasSnapper::snapToBackgroundLayers( const QPoint& p, QList<QgsSnapp
   {
     //topological editing on?
     int topologicalEditing = QgsProject::instance()->readNumEntry( "Digitizing", "/TopologicalEditing", 0 );
+
+    //snapping on intersection on?
+    int intersectionSnapping = QgsProject::instance()->readNumEntry(  "Digitizing", "/IntersectionSnapping", 0 );
+
     if ( topologicalEditing == 0 )
     {
-      mSnapper->setSnapMode( QgsSnapper::SnapWithOneResult );
+        if ( intersectionSnapping == 0 )
+        {
+          mSnapper->setSnapMode( QgsSnapper::SnapWithOneResult );
+        }
+        else
+        {
+          mSnapper->setSnapMode( QgsSnapper::SnapWithResultsWithinTolerances );
+        }
     }
     else
     {
-      mSnapper->setSnapMode( QgsSnapper::SnapWithResultsForSamePosition );
+        if ( intersectionSnapping == 0 )
+        {
+          mSnapper->setSnapMode( QgsSnapper::SnapWithResultsForSamePosition );
+        }
+        else
+        {
+          mSnapper->setSnapMode( QgsSnapper::SnapWithResultsWithinTolerances );
+        }
     }
 
+
     //read snapping settings from project
     bool ok; //todo: take the default snapping tolerance for all vector layers if snapping not defined in project
     bool snappingDefinedInProject = true;
@@ -252,13 +272,73 @@ int QgsMapCanvasSnapper::snapToBackgroundLayers( const QPoint& p, QList<QgsSnapp
 
       snapLayers.append( snapLayer );
     }
-
     mSnapper->setSnapLayers( snapLayers );
 
     if ( mSnapper->snapPoint( p, results, excludePoints ) != 0 )
     {
       return 4;
     }
+
+    if( intersectionSnapping == 1 )
+    {
+      QList<QgsSnappingResult>::const_iterator it = results.constBegin();
+      QList<QgsSnappingResult> segments;
+      QList<QgsSnappingResult> points;
+      for ( ; it != results.constEnd(); ++it )
+      {
+        if(it->snappedVertexNr==-1)
+        {
+          QgsDebugMsg("segment");
+          segments.push_back(*it);
+        }
+        else
+        {
+          QgsDebugMsg("no segment");
+          points.push_back(*it);
+        }
+      }
+
+      if(segments.length() >=2 )
+      {
+
+        QgsGeometry* intersectionPoint;
+        QList<QgsSnappingResult> myResults;
+
+        QList<QgsSnappingResult>::const_iterator oSegIt = segments.constBegin();
+        QList<QgsSnappingResult>::iterator iSegIt;
+        for( ; oSegIt != segments.constEnd(); ++oSegIt)
+        {
+            QgsDebugMsg( QString::number(oSegIt->beforeVertexNr) );
+
+            QVector<QgsPoint> vertexPoints;
+            vertexPoints.append( oSegIt->beforeVertex );
+            vertexPoints.append( oSegIt->afterVertex );
+            QgsGeometry* lineA = QgsGeometry::fromPolyline( vertexPoints );
+
+            for( iSegIt = segments.begin(); iSegIt != segments.end(); ++iSegIt)
+            {
+                QVector<QgsPoint> vertexPoints;
+                vertexPoints.append( iSegIt->beforeVertex );
+                vertexPoints.append( iSegIt->afterVertex );
+                QgsGeometry* lineB = QgsGeometry::fromPolyline( vertexPoints );
+
+                intersectionPoint = lineA->intersection(lineB);
+                if( intersectionPoint->type()  == QGis::Point)
+                {
+                    iSegIt->snappedVertex = intersectionPoint->asPoint();
+                    myResults.append(*iSegIt);
+                }
+            }
+
+        }
+
+        if( myResults.length() > 0 )
+        {
+          results.clear();
+          results = myResults;
+        }
+      }
+    }
     return 0;
   }
   else

diff --git a/src/ui/qgssnappingdialogbase.ui b/src/ui/qgssnappingdialogbase.ui
@@ -14,30 +14,7 @@
    <string>Snapping options</string>
   </property>
   <layout class="QGridLayout" name="gridLayout">
-   <item row="1" column="0">
+   <item row="0" column="0" colspan="3">
-    <widget class="QCheckBox" name="cbxEnableTopologicalEditingCheckBox">
-     <property name="text">
-      <string>Enable topological editing</string>
-     </property>
-     <property name="checked">
-      <bool>false</bool>
-     </property>
-     <property name="tristate">
-      <bool>false</bool>
-     </property>
-    </widget>
-   </item>
-   <item row="1" column="1">
-    <widget class="QDialogButtonBox" name="mButtonBox">
-     <property name="orientation">
-      <enum>Qt::Horizontal</enum>
-     </property>
-     <property name="standardButtons">
-      <set>QDialogButtonBox::Apply|QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
-     </property>
-    </widget>
-   </item>
-   <item row="0" column="0" colspan="2">
     <widget class="QTreeWidget" name="mLayerTreeWidget">
      <property name="selectionMode">
       <enum>QAbstractItemView::NoSelection</enum>
@@ -89,6 +66,42 @@
      </column>
     </widget>
    </item>
+   <item row="1" column="0">
+    <widget class="QCheckBox" name="cbxEnableTopologicalEditingCheckBox">
+     <property name="text">
+      <string>Enable topological editing</string>
+     </property>
+     <property name="checked">
+      <bool>false</bool>
+     </property>
+     <property name="tristate">
+      <bool>false</bool>
+     </property>
+    </widget>
+   </item>
+   <item row="1" column="1">
+    <widget class="QCheckBox" name="cbxEnableIntersectionSnappingCheckBox">
+     <property name="text">
+      <string>Enable snapping on intersection</string>
+     </property>
+     <property name="checked">
+      <bool>false</bool>
+     </property>
+     <property name="tristate">
+      <bool>false</bool>
+     </property>
+    </widget>
+   </item>
+   <item row="1" column="2">
+    <widget class="QDialogButtonBox" name="mButtonBox">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Apply|QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+     </property>
+    </widget>
+   </item>
   </layout>
  </widget>
  <resources/>