Edit features with feature-linked annotation

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Sample viewer app

Edit feature attributes which are linked to annotation through an expression.

screenshot

Use case

Annotation is useful for displaying text that you don't want to move or resize when the map is panned or zoomed (unlike labels which will move and resize). Feature-linked annotation will update when a feature attribute referenced by the annotation expression is also updated. Additionally, the position of the annotation will transform to match any transformation to the linked feature's geometry.

How to use the sample

Pan and zoom the map to see that the text on the map is annotation, not labels. Tap one of the address points to update the house number (AD_ADDRESS) and street name (ST_STR_NAM). Tap one of the dashed parcel polylines and tap another location to change its geometry. NOTE: Selection is only enabled for points and straight (single segment) polylines.

The feature-linked annotation will update accordingly.

How it works

Load the geodatabase. NOTE: Read/write geodatabases should normally come from a GeodatabaseSyncTask, but this has been omitted here. That functionality is covered in the sample Generate geodatabase.
Create FeatureLayers from geodatabase feature tables found in the geodatabase with Geodatabase::geodatabaseFeatureTable.
Create AnnotationLayers from geodatabase feature tables found in the geodatabase with Geodatabase::geodatabaseAnnotationTable.
Add the feature layers and annotation layers to the map's operational layers.
Connect to MapQuickView::mouseClicked to capture clicks on the map to either select address points or parcel polyline features. NOTE: Selection is only enabled for points and straight (single segment) polylines.
- For the address points, a dialog will opened to allow editing of the address number (AD_ADDRESS) and street name (ST_STR_NAM) attributes. A second tap will change the location of the point.
- For the parcel lines, a second tap will change one of the polyline's vertices.

Both expressions were defined by the data author in ArcGIS Pro using the Arcade expression language.

Relevant API

AnnotationLayer
Feature
FeatureLayer
Geodatabase

Offline data

Link	Local Location
Loudoun geodatabase	`<userhome>/ArcGIS/Runtime/Data/geodatabase/loudoun_anno.geodatabase`

About the data

This sample uses data derived from the Loudoun GeoHub.

The annotation linked to the point data in this sample is defined by arcade expression $feature.AD_ADDRESS + " " + $feature.ST_STR_NAM. The annotation linked to the parcel polyline data is defined by Round(Length(Geometry($feature), 'feet'), 2).

Sample Code

EditFeaturesWithFeatureLinkedAnnotation.cpp

EditFeaturesWithFeatureLinkedAnnotation.h

EditFeaturesWithFeatureLinkedAnnotation.qml

Use dark colors for code blocksCopy
// [WriteFile Name=EditFeaturesWithFeatureLinkedAnnotation, Category=EditData]
// [Legal]
// Copyright 2020 Esri.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// [Legal]

#ifdef PCH_BUILD
#include "pch.hpp"
#endif // PCH_BUILD

// sample headers
#include "EditFeaturesWithFeatureLinkedAnnotation.h"

// ArcGIS Maps SDK headers
#include "AnnotationLayer.h"
#include "AttributeListModel.h"
#include "Feature.h"
#include "FeatureLayer.h"
#include "GeoElement.h"
#include "Geodatabase.h"
#include "GeodatabaseFeatureTable.h"
#include "GeometryEngine.h"
#include "IdentifyLayerResult.h"
#include "ImmutablePart.h"
#include "ImmutablePartCollection.h"
#include "LayerListModel.h"
#include "Map.h"
#include "MapQuickView.h"
#include "MapTypes.h"
#include "Part.h"
#include "PartCollection.h"
#include "Polyline.h"
#include "PolylineBuilder.h"
#include "ProximityResult.h"
#include "SpatialReference.h"
#include "Viewpoint.h"

// Qt headers
#include <QFile>
#include <QFuture>
#include <QStandardPaths>
#include <QString>
#include <QTimer>
#include <QUuid>
#include <QtCore/qglobal.h>

// STL headers
#include <memory>

using namespace Esri::ArcGISRuntime;

// helper method to get cross platform data path
namespace
{
QString defaultDataPath()
{
  QString dataPath;

#ifdef Q_OS_IOS
  dataPath = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation);
#else
  dataPath = QStandardPaths::writableLocation(QStandardPaths::HomeLocation);
#endif

  return dataPath;
}
} // namespace

using namespace Esri::ArcGISRuntime;

namespace
{
  // Convenience RAII struct that deletes all pointers in given container.
  struct IdentifyLayerResultsScopedCleanup
  {
    IdentifyLayerResultsScopedCleanup(const QList<IdentifyLayerResult*>& list) : results(list) { }
    ~IdentifyLayerResultsScopedCleanup() { qDeleteAll(results); }
    const QList<IdentifyLayerResult*>& results;
  };
}

EditFeaturesWithFeatureLinkedAnnotation::EditFeaturesWithFeatureLinkedAnnotation(QObject* parent /* = nullptr */):
  QObject(parent),
  s_ad_address(QStringLiteral("AD_ADDRESS")),
  s_st_str_nam(QStringLiteral("ST_STR_NAM"))
{
  constexpr double lat = 39.0204;
  constexpr double lon = -77.4159;
  constexpr double scale = 2256.994353;
  m_map = new Map(BasemapStyle::ArcGISLightGray, this);
  m_map->setInitialViewpoint(Viewpoint(lat, lon, scale));

  const QString dataPath = defaultDataPath() + "/ArcGIS/Runtime/Data/geodatabase/loudoun_anno.geodatabase";

  m_geodatabase = new Geodatabase(dataPath, this);
  connect(m_geodatabase, &Geodatabase::doneLoading, this, &EditFeaturesWithFeatureLinkedAnnotation::onGeodatabaseDoneLoading_);

  m_geodatabase->load();
}

EditFeaturesWithFeatureLinkedAnnotation::~EditFeaturesWithFeatureLinkedAnnotation() = default;

void EditFeaturesWithFeatureLinkedAnnotation::init()
{
  // Register the map view for QML
  qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView");
  qmlRegisterType<EditFeaturesWithFeatureLinkedAnnotation>("Esri.Samples", 1, 0, "EditFeaturesWithFeatureLinkedAnnotationSample");
}

MapQuickView* EditFeaturesWithFeatureLinkedAnnotation::mapView() const
{
  return m_mapView;
}

// Set the view (created in QML)
void EditFeaturesWithFeatureLinkedAnnotation::setMapView(MapQuickView* mapView)
{
  if (!mapView || mapView == m_mapView)
    return;

  m_mapView = mapView;
  m_mapView->setMap(m_map);

  connect(m_mapView, &MapQuickView::mouseClicked, this, &EditFeaturesWithFeatureLinkedAnnotation::onMouseClicked_);

  emit mapViewChanged();
}

void EditFeaturesWithFeatureLinkedAnnotation::onGeodatabaseDoneLoading_(const Error& error)
{
  if (!error.isEmpty())
    return;

  GeodatabaseFeatureTable* pointFeatureTable = m_geodatabase->geodatabaseFeatureTable("Loudoun_Address_Points_1");
  GeodatabaseFeatureTable* parcelLinesFeatureTable = m_geodatabase->geodatabaseFeatureTable("ParcelLines_1");

  GeodatabaseFeatureTable* addressPointsAnnotationTable = m_geodatabase->geodatabaseAnnotationTable("Loudoun_Address_PointsAnno_1");
  GeodatabaseFeatureTable* parcelLinesAnnotationTable = m_geodatabase->geodatabaseAnnotationTable("ParcelLinesAnno_1");

  // create feature layers from tables in the geodatabase
  m_pointFeatureLayer = new FeatureLayer(pointFeatureTable, this);
  m_parcelLinesFeatureLayer = new FeatureLayer(parcelLinesFeatureTable, this);

  // create annotation layers from tables in the geodatabase
  m_addressPointsAnnotationLayer = new AnnotationLayer(addressPointsAnnotationTable, this);
  m_parcelLinesAnnotationLayer = new AnnotationLayer(parcelLinesAnnotationTable, this);

  // add feature layers to map
  m_map->operationalLayers()->append(m_pointFeatureLayer);
  m_map->operationalLayers()->append(m_parcelLinesFeatureLayer);

  // add annotation layers to map
  m_map->operationalLayers()->append(m_addressPointsAnnotationLayer);
  m_map->operationalLayers()->append(m_parcelLinesAnnotationLayer);
}

void EditFeaturesWithFeatureLinkedAnnotation::onMouseClicked_(QMouseEvent& mouseEvent)
{
  clearSelection();

  if (m_selectedFeature)
  {
    // move feature to clicked locaiton if already selected
    const Point clickedPoint = m_mapView->screenToLocation(mouseEvent.position().x(), mouseEvent.position().y());
    moveFeature(clickedPoint);
  }
  else
  {
    // identify and select feature
    m_mapView->identifyLayersAsync(mouseEvent.position(), 10, false).then(this, [this](const QList<IdentifyLayerResult*>& identifyResults)
    {
      onIdentifyLayersCompleted_(identifyResults);
    });
  }
}

void EditFeaturesWithFeatureLinkedAnnotation::onIdentifyLayersCompleted_(const QList<IdentifyLayerResult*>& identifyResults)
{
  // A convenience wrapper that deletes the contents of identifyResults when we leave scope.
  IdentifyLayerResultsScopedCleanup identifyResultsScopedCleanup(identifyResults);

  for (IdentifyLayerResult* identifyResult : identifyResults)
  {
    if (!identifyResult->geoElements().isEmpty())
    {
      // only perform selections on Feature Layers
      FeatureLayer* featureLayer = dynamic_cast<FeatureLayer*>(identifyResult->layerContent());

      // if cast was successful select features.
      if (featureLayer)
      {
        m_selectedFeature = static_cast<Feature*>(identifyResult->geoElements().at(0));

        // Prevent the feature from being deleted when identifyResultsLock goes out of scope and cleans up identifyResults
        m_selectedFeature->setParent(this);

        const GeometryType selectedFeatureGeomType = m_selectedFeature->geometry().geometryType();

        if (selectedFeatureGeomType == GeometryType::Polyline)
        {
          const Polyline geom = geometry_cast<Polyline>(m_selectedFeature->geometry());
          const PolylineBuilder polylineBuilder(geom);

          // if the selected feature is a polyline with any part containing more than one segment
          // (i.e. a curve) do not select it
          if (polylineBuilder.toPolyline().parts().part(0).segmentCount() > 1)
          {
            clearSelection();
            delete m_selectedFeature;
            m_selectedFeature = nullptr;
            return;
          }
        }
        else if (selectedFeatureGeomType == GeometryType::Point)
        {
          // clear string list with attribute values.
          m_addressAndStreetText.clear();

          // update QML text fields with the attributes for the selected point feature
          const QString addressText = m_selectedFeature->attributes()->attributeValue(s_ad_address).toString();
          m_addressAndStreetText.append(addressText);
          const QString streetNameText = m_selectedFeature->attributes()->attributeValue(s_st_str_nam).toString();
          m_addressAndStreetText.append(streetNameText);

          emit addressAndStreetTextChanged();
        }
        featureLayer->selectFeature(m_selectedFeature);
        return;
      }
    }
  }
}

void EditFeaturesWithFeatureLinkedAnnotation::clearSelection()
{
  for (Layer* layer : *m_map->operationalLayers())
  {
    FeatureLayer* featureLayer = dynamic_cast<FeatureLayer*>(layer);
    if (featureLayer)
      featureLayer->clearSelection();
  }
}

void EditFeaturesWithFeatureLinkedAnnotation::moveFeature(Point mapPoint)
{
  const Geometry geom = m_selectedFeature->geometry();

  const Point projectedMapPoint = geometry_cast<Point>(GeometryEngine::project(mapPoint, geom.spatialReference()));
  if (geom.geometryType() == GeometryType::Polyline)
  {
    // get nearest vertex to the map point on the selected polyline
    const ProximityResult nearestVertex = GeometryEngine::nearestVertex(geom, projectedMapPoint);
    const PolylineBuilder polylineBuilder(geometry_cast<Polyline>(geom));

    // get part of polyline nearest to map point
    Part* part = polylineBuilder.parts()->part(nearestVertex.partIndex());

    // remove nearest point to map point
    part->removePoint(nearestVertex.pointIndex());

    // add the map point as a new point
    part->addPoint(projectedMapPoint);

    // update the selected feature with the new geometry
    m_selectedFeature->setGeometry(polylineBuilder.toGeometry());
  }
  else if (geom.geometryType() == GeometryType::Point)
  {
    // if the selected feature is a point, change the geometry with the map point
    m_selectedFeature->setGeometry(mapPoint);
  }

  // update the selected feature with the new geometry
  auto future = m_selectedFeature->featureTable()->updateFeatureAsync(m_selectedFeature);
  Q_UNUSED(future)
  clearSelection();
  delete m_selectedFeature;
  m_selectedFeature = nullptr;
}

void EditFeaturesWithFeatureLinkedAnnotation::updateSelectedFeature(const QString& address, const QString& streetName)
{
  if (!m_selectedFeature)
    return;

  // update the two attributes with the inputted text.
  m_selectedFeature->attributes()->replaceAttribute(s_ad_address, address);
  m_selectedFeature->attributes()->replaceAttribute(s_st_str_nam, streetName);
  auto future = m_selectedFeature->featureTable()->updateFeatureAsync(m_selectedFeature);
  Q_UNUSED(future)
}