[tracer] improved reporting of warnings

qgis · Jan 11, 2016 · e7d277f · e7d277f
1 parent 2c414ce
commit e7d277f
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Showing 7 changed files with 100 additions and 41 deletions.
diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
@@ -1974,10 +1974,8 @@ void QgisApp::createToolBars()
   // Cad toolbar
   mAdvancedDigitizeToolBar->insertAction( mActionUndo, mAdvancedDigitizingDockWidget->enableAction() );
 
-  mTracer = new QgsMapCanvasTracer( mMapCanvas );
+  mTracer = new QgsMapCanvasTracer( mMapCanvas, messageBar() );
   mAdvancedDigitizeToolBar->insertAction( mActionUndo, mTracer->actionEnableTracing() );
-  connect( mTracer, SIGNAL( messageEmitted( QString, QgsMessageBar::MessageLevel ) ),
-           this, SLOT( displayMapToolMessage( QString, QgsMessageBar::MessageLevel ) ) );
 }
 
 void QgisApp::createStatusBar()

diff --git a/src/core/qgstracer.cpp b/src/core/qgstracer.cpp
@@ -486,14 +486,14 @@ bool QgsTracer::initGraph()
       }
 
       extract_linework( f.geometry(), mpl );
+
       ++featuresCounted;
+      if ( mMaxFeatureCount != 0 && featuresCounted >= mMaxFeatureCount )
+        return false;
     }
   }
   int timeExtract = t1.elapsed();
 
-  if ( mMaxFeatureCount != 0 && featuresCounted >= mMaxFeatureCount )
-    return false;
-
   // resolve intersections
 
   t2.start();
@@ -611,18 +611,32 @@ void QgsTracer::onGeometryChanged( QgsFeatureId fid, QgsGeometry& geom )
   invalidateGraph();
 }
 
-QVector<QgsPoint> QgsTracer::findShortestPath( const QgsPoint& p1, const QgsPoint& p2 )
+QVector<QgsPoint> QgsTracer::findShortestPath(const QgsPoint& p1, const QgsPoint& p2, PathError* error )
 {
   init();  // does nothing if the graph exists already
   if ( !mGraph )
+  {
+    if ( error ) *error = ErrTooManyFeatures;
     return QVector<QgsPoint>();
+  }
 
   QTime t;
   t.start();
   int v1 = point_in_graph( *mGraph, p1 );
   int v2 = point_in_graph( *mGraph, p2 );
   int tPrep = t.elapsed();
 
+  if ( v1 == -1 )
+  {
+    if ( error ) *error = ErrPoint1;
+    return QVector<QgsPoint>();
+  }
+  if ( v2 == -1 )
+  {
+    if ( error ) *error = ErrPoint2;
+    return QVector<QgsPoint>();
+  }
+
   QTime t2;
   t2.start();
   QgsPolyline points = shortest_path( *mGraph, v1, v2 );
@@ -632,6 +646,9 @@ QVector<QgsPoint> QgsTracer::findShortestPath( const QgsPoint& p1, const QgsPoin
 
   reset_graph( *mGraph );
 
+  if ( error )
+    *error = points.isEmpty() ? ErrNoPath : ErrNone;
+
   return points;
 }
 

diff --git a/src/core/qgstracer.h b/src/core/qgstracer.h
@@ -68,11 +68,20 @@ class CORE_EXPORT QgsTracer : public QObject
     //! if necessary.
     virtual bool init();
 
+    enum PathError
+    {
+      ErrNone,
+      ErrTooManyFeatures,
+      ErrPoint1,
+      ErrPoint2,
+      ErrNoPath,
+    };
+
     //! Given two points, find the shortest path and return points on the way.
     //! If the points are not located on existing vertices or edges,
     //! search will fail and return empty array. The search will also fail
     //! if the two points are not connected.
-    QVector<QgsPoint> findShortestPath( const QgsPoint& p1, const QgsPoint& p2 );
+    QVector<QgsPoint> findShortestPath( const QgsPoint& p1, const QgsPoint& p2, PathError* error = 0 );
 
     //! Find out whether the point is snapped to a vertex or edge (i.e. it can be used for tracing start/stop)
     bool isPointSnapped( const QgsPoint& pt );

diff --git a/src/gui/qgsmapcanvastracer.cpp b/src/gui/qgsmapcanvastracer.cpp
@@ -4,6 +4,7 @@
 #include "qgsmapcanvas.h"
 #include "qgsmaplayerregistry.h"
 #include "qgsmessagebar.h"
+#include "qgsmessagebaritem.h"
 #include "qgssnappingutils.h"
 #include "qgsvectorlayer.h"
 
@@ -12,8 +13,10 @@
 QHash<QgsMapCanvas*, QgsMapCanvasTracer*> QgsMapCanvasTracer::sTracers;
 
 
-QgsMapCanvasTracer::QgsMapCanvasTracer( QgsMapCanvas* canvas )
+QgsMapCanvasTracer::QgsMapCanvasTracer( QgsMapCanvas* canvas, QgsMessageBar* messageBar )
     : mCanvas( canvas )
+    , mMessageBar( messageBar )
+    , mLastMessage( nullptr )
 {
   sTracers.insert( canvas, this );
 
@@ -29,7 +32,7 @@ QgsMapCanvasTracer::QgsMapCanvasTracer( QgsMapCanvas* canvas )
 
   // arbitrarily chosen limit that should allow for fairly fast initialization
   // of the underlying graph structure
-  setMaxFeatureCount( 10000 );
+  setMaxFeatureCount( QSettings().value( "/qgis/digitizing/tracing_max_feature_count", 10000 ).toInt() );
 
   updateSettings(); // initialize
   updateLayerSettings();
@@ -43,10 +46,6 @@ QgsMapCanvasTracer::~QgsMapCanvasTracer()
 bool QgsMapCanvasTracer::init()
 {
   bool res = QgsTracer::init();
-
-  if ( !res )
-    emit messageEmitted( tr( "Tracing disabled because there are too many features displayed. Try zooming in or disable some layers." ) );
-
   return res;
 }
 
@@ -55,6 +54,45 @@ QgsMapCanvasTracer* QgsMapCanvasTracer::tracerForCanvas( QgsMapCanvas* canvas )
   return sTracers.value( canvas, 0 );
 }
 
+void QgsMapCanvasTracer::reportError( QgsTracer::PathError err, bool addingVertex )
+{
+  if ( !mMessageBar )
+    return;
+
+  // remove previous message (if any)
+  mMessageBar->popWidget( mLastMessage );
+  mLastMessage = nullptr;
+
+  QString message;
+  switch ( err )
+  {
+  case ErrTooManyFeatures:
+    message = tr( "Disabled - there are too many features displayed. Try zooming in or disable some layers." );
+    break;
+  case ErrPoint1:
+    message = tr( "The start point needs to be snapped and in the visible map view" );
+    break;
+  case ErrPoint2:
+    if ( addingVertex )
+      message = tr( "The end point needs to be snapped" );
+    break;
+  case ErrNoPath:
+    if ( addingVertex )
+      message = tr( "Endpoints are not connected" );
+    break;
+  case ErrNone:
+  default:
+    break;
+  }
+
+  if ( message.isEmpty() )
+    return;
+
+  mLastMessage = new QgsMessageBarItem( tr( "Tracing" ), message, QgsMessageBar::WARNING,
+                                        QSettings().value( "/qgis/messageTimeout", 5 ).toInt() );
+  mMessageBar->pushItem( mLastMessage );
+}
+
 void QgsMapCanvasTracer::updateSettings()
 {
   setDestinationCrs( mCanvas->mapSettings().destinationCrs() );

diff --git a/src/gui/qgsmapcanvastracer.h b/src/gui/qgsmapcanvastracer.h
@@ -1,18 +1,19 @@
 #ifndef QGSMAPCANVASTRACER_H
 #define QGSMAPCANVASTRACER_H
 
-#include "qgsmessagebar.h"
 #include "qgstracer.h"
 
 class QAction;
 class QgsMapCanvas;
+class QgsMessageBar;
+class QgsMessageBarItem;
 
 class GUI_EXPORT QgsMapCanvasTracer : public QgsTracer
 {
     Q_OBJECT
 
   public:
-    explicit QgsMapCanvasTracer( QgsMapCanvas* canvas );
+    explicit QgsMapCanvasTracer( QgsMapCanvas* canvas, QgsMessageBar* messageBar = 0 );
     ~QgsMapCanvasTracer();
 
     QAction* actionEnableTracing() { return mActionEnableTracing; }
@@ -24,12 +25,8 @@ class GUI_EXPORT QgsMapCanvasTracer : public QgsTracer
     //! instances for easier access to the common tracer by various map tools
     static QgsMapCanvasTracer* tracerForCanvas( QgsMapCanvas* canvas );
 
-  signals:
-    //! emit a message
-    void messageEmitted( const QString& message, QgsMessageBar::MessageLevel = QgsMessageBar::INFO );
-
-    //! emit signal to clear previous message
-    //void messageDiscarded();
+    //! Report a path finding error to the user
+    void reportError( PathError err, bool addingVertex );
 
   private slots:
     void updateSettings();
@@ -38,6 +35,8 @@ class GUI_EXPORT QgsMapCanvasTracer : public QgsTracer
 
   private:
     QgsMapCanvas* mCanvas;
+    QgsMessageBar* mMessageBar;
+    QgsMessageBarItem* mLastMessage;
 
     QAction* mActionEnableTracing;
 

diff --git a/src/gui/qgsmaptoolcapture.cpp b/src/gui/qgsmaptoolcapture.cpp
@@ -174,14 +174,15 @@ void QgsMapToolCapture::tracingMouseMove( QgsMapMouseEvent* e )
   if ( !tracer )
     return;  // this should not happen!
 
-  if ( !tracer->init() )  // normally no-op if the graph is built already
-    return;  // graph would be too big
-
   mTempRubberBand->reset( mCaptureMode == CapturePolygon ? QGis::Polygon : QGis::Line );
 
-  QVector<QgsPoint> points = tracer->findShortestPath( pt0, e->mapPoint() );
+  QgsTracer::PathError err;
+  QVector<QgsPoint> points = tracer->findShortestPath( pt0, e->mapPoint(), &err );
   if ( points.isEmpty() )
+  {
+    tracer->reportError( err, false );
     return;
+  }
 
   if ( mCaptureMode == CapturePolygon )
     mTempRubberBand->addPoint( *mRubberBand->getPoint( 0, 0 ), false );
@@ -192,19 +193,20 @@ void QgsMapToolCapture::tracingMouseMove( QgsMapMouseEvent* e )
 }
 
 
-bool QgsMapToolCapture::tracingAddVertex( const QgsPoint& point, bool& pathNotFound )
+bool QgsMapToolCapture::tracingAddVertex( const QgsPoint& point )
 {
-  pathNotFound = false;
-
   QgsMapCanvasTracer* tracer = QgsMapCanvasTracer::tracerForCanvas( mCanvas );
   if ( !tracer )
     return false;  // this should not happen!
 
-  if ( !tracer->init() )  // normally no-op if the graph is built already
-    return false;  // graph would be too big
-
   if ( mCaptureCurve.numPoints() == 0 )
   {
+    if ( !tracer->init() )
+    {
+      tracer->reportError( QgsTracer::ErrTooManyFeatures, true );
+      return false;
+    }
+
     // only accept first point if it is snapped to the graph (to vertex or edge)
     bool res = tracer->isPointSnapped( point );
     if ( res )
@@ -222,10 +224,11 @@ bool QgsMapToolCapture::tracingAddVertex( const QgsPoint& point, bool& pathNotFo
   if ( pt0 == QgsPoint() )
     return false;
 
-  QVector<QgsPoint> points = tracer->findShortestPath( pt0, point );
+  QgsTracer::PathError err;
+  QVector<QgsPoint> points = tracer->findShortestPath( pt0, point, &err );
   if ( points.isEmpty() )
   {
-    pathNotFound = true;
+    tracer->reportError( err, true );
     return false; // ignore the vertex - can't find path to the end point!
   }
 
@@ -369,14 +372,9 @@ int QgsMapToolCapture::addVertex( const QgsPoint& point )
 
   if ( tracingEnabled() )
   {
-    bool pathNotFound;
-    bool res = tracingAddVertex( point, pathNotFound );
+    bool res = tracingAddVertex( point );
     if ( !res )
-    {
-      if ( pathNotFound )
-        emit messageEmitted( tr( "Tracing: The point needs to be snapped to a geometry" ), QgsMessageBar::WARNING );
       return 1;  // early exit if the point cannot be accepted
-    }
   }
   else
   {

diff --git a/src/gui/qgsmaptoolcapture.h b/src/gui/qgsmaptoolcapture.h
@@ -148,7 +148,7 @@ class GUI_EXPORT QgsMapToolCapture : public QgsMapToolAdvancedDigitizing
     //! handle of mouse movement when tracing enabled and capturing has started
     void tracingMouseMove( QgsMapMouseEvent* e );
     //! handle of addition of clicked point (with the rest of the trace) when tracing enabled
-    bool tracingAddVertex( const QgsPoint& point, bool& pathNotFound );
+    bool tracingAddVertex( const QgsPoint& point );
 
   private:
     /** Flag to indicate a map canvas capture operation is taking place */