Offline geocode

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C++

QML

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Sample viewer app

Geocode addresses to locations and reverse geocode locations to addresses offline.

screenshot

Use case

You can use an address locator file to geocode addresses and locations. For example, you could provide offline geocoding capabilities to field workers repairing critical infrastructure in a disaster when network availability is limited.

How to use the sample

Type the address in the Search menu option or select from the list to Geocode the address and view the result on the map. Tap the location you want to reverse geocode. Select the pin to highlight the PictureMarkerSymbol (i.e. single tap on the pin) and then tap-hold and drag on the map to get real-time geocoding.

How it works

Use the path of a .loc file to create a LocatorTask object.
Set up GeocodeParameters and call geocode to get geocode results.

Relevant API

GeocodeParameters
GeocodeResult
LocatorTask
ReverseGeocodeParameters

Offline Data

Read more about how to set up the sample's offline data here.

Link	Local Location
SanDiego tpkx File	`<userhome>`/ArcGIS/Runtime/Data/tpkx/streetmap_SD.tpkx
SanDiego loc Files	`<userhome>`/ArcGIS/Runtime/Data/Locators/SanDiegoStreetAddressLocator/SanDiego_StreetAddress.loc

Sample Code

OfflineGeocode.cpp

OfflineGeocode.h

OfflineGeocode.qml

Use dark colors for code blocksCopy
// [WriteFile Name=OfflineGeocode, Category=Search]
// [Legal]
// Copyright 2016 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

#include "OfflineGeocode.h"

#include "Map.h"
#include "Point.h"
#include "Graphic.h"
#include "CalloutData.h"
#include "LocatorTask.h"
#include "MapQuickView.h"
#include "GeocodeResult.h"
#include "GraphicsOverlay.h"
#include "SuggestListModel.h"
#include "ArcGISTiledLayer.h"
#include "GeocodeParameters.h"
#include "PictureMarkerSymbol.h"
#include "IdentifyGraphicsOverlayResult.h"

#include <QScopedPointer>
#include <QDir>
#include <QtCore/qglobal.h>
#include <memory>

#ifdef Q_OS_IOS
#include <QStandardPaths>
#endif // Q_OS_IOS

using namespace Esri::ArcGISRuntime;

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

  #ifdef Q_OS_ANDROID
    dataPath = "/sdcard";
  #elif defined Q_OS_IOS
    dataPath = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation);
  #else
    dataPath = QDir::homePath();
  #endif

    return dataPath;
  }
} // namespace

using namespace Esri::ArcGISRuntime;

OfflineGeocode::OfflineGeocode(QQuickItem* parent):
  QQuickItem(parent),
  m_dataPath(defaultDataPath() + "/ArcGIS/Runtime/Data/")
{
}

OfflineGeocode::~OfflineGeocode() = default;

void OfflineGeocode::init()
{
  qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView");
  qmlRegisterType<OfflineGeocode>("Esri.Samples", 1, 0, "OfflineGeocodeSample");
  qmlRegisterUncreatableType<CalloutData>("Esri.Samples", 1, 0, "CalloutData", "CalloutData is an uncreatable type");
  qmlRegisterUncreatableType<SuggestListModel>("Esri.Samples", 1, 0, "SuggestListModel", "SuggestionListModel is an uncreatable type");
}

void OfflineGeocode::componentComplete()
{
  QQuickItem::componentComplete();

  // find QML MapView component
  m_mapView = findChild<MapQuickView*>("mapView");
  m_mapView->setWrapAroundMode(WrapAroundMode::Disabled);

  // create a tiled layer using a local .tpkx file
  TileCache* tileCache = new TileCache(m_dataPath + "tpkx/streetmap_SD.tpkx", this);
  connect(tileCache, &TileCache::errorOccurred, this, &OfflineGeocode::logError);

  m_tiledLayer = new ArcGISTiledLayer(tileCache, this);

  // create basemap and add tiled layer
  Basemap* basemap = new Basemap(this);
  basemap->baseLayers()->append(m_tiledLayer);

  // create map using basemap
  m_map = new Map(basemap, this);
  m_map->setInitialViewpoint(Viewpoint(Point(-13042254.715252, 3857970.236806, SpatialReference(3857)), 2e4));

  // Set map to map view
  m_mapView->setMap(m_map);

  // create locator task
  //! [OfflineGeocode create LocatorTask]
  m_locatorTask = new LocatorTask(m_dataPath + "Locators/SanDiegoStreetAddressLocator/SanDiego_StreetAddress.loc", this);
  //! [OfflineGeocode create LocatorTask]

  // set the suggestions Q_PROPERTY
  m_suggestListModel = m_locatorTask->suggestions();
  emit suggestionsChanged();

  // set geocode parameters
  m_geocodeParameters.setMinScore(75);
  m_geocodeParameters.setMaxResults(1);
  m_reverseGeocodeParameters.setMaxResults(1);

  // create graphics overlay and add pin graphic
  m_graphicsOverlay = new GraphicsOverlay(this);
  PictureMarkerSymbol* pinSymbol = new PictureMarkerSymbol(QUrl("qrc:/Samples/Search/OfflineGeocode/red_pin.png"), this);
  pinSymbol->setHeight(36);
  pinSymbol->setWidth(19);
  pinSymbol->setOffsetY(pinSymbol->height() / 2);
  m_pinGraphic = new Graphic(Point(-13042254.715252, 3857970.236806, SpatialReference(3857)), pinSymbol, this);
  m_pinGraphic->setVisible(false);
  m_graphicsOverlay->graphics()->append(m_pinGraphic);
  m_mapView->graphicsOverlays()->append(m_graphicsOverlay);

  // initialize callout
  m_mapView->calloutData()->setVisible(false);
  m_mapView->calloutData()->setTitle("Address");
  m_calloutData = m_mapView->calloutData();

  connectSignals();
}

void OfflineGeocode::geocodeWithText(const QString& address)
{
  m_locatorTask->geocodeWithParameters(address, m_geocodeParameters);
}

void OfflineGeocode::geocodeWithSuggestion(int index)
{
  m_locatorTask->geocodeWithSuggestResultAndParameters(m_suggestListModel->suggestResults().at(index), m_geocodeParameters);
}

void OfflineGeocode::setSuggestionsText(const QString& searchText)
{
  m_suggestListModel->setSearchText(searchText);
}

void OfflineGeocode::logError(const Error error)
{
  setErrorMessage( QString("%1: %2").arg(error.message(), error.additionalMessage()));
}

SuggestListModel* OfflineGeocode::suggestions() const
{
  return m_suggestListModel;
}

bool OfflineGeocode::geocodeInProgress() const
{
  return m_geocodeInProgress;
}

bool OfflineGeocode::noResults() const
{
  return m_noResults;
}

bool OfflineGeocode::suggestInProgress() const
{
  return m_suggestInProgress;
}

void OfflineGeocode::connectSignals()
{
  connect(m_map, &Map::errorOccurred, this, &OfflineGeocode::logError);
  connect(m_mapView, &MapQuickView::errorOccurred, this, &OfflineGeocode::logError);
  connect(m_mapView, &MapQuickView::mouseClicked, this, [this](QMouseEvent& mouseEvent)
  {
    m_clickedPoint = m_mapView->screenToLocation(mouseEvent.x(), mouseEvent.y());
    m_mapView->identifyGraphicsOverlay(m_graphicsOverlay, mouseEvent.x(), mouseEvent.y(), 5, false, 1);
  });

  connect(m_mapView, &MapQuickView::mousePressedAndHeld, this, [this](QMouseEvent& mouseEvent)
  {
    m_isPressAndHold = true;
    m_isReverseGeocode = true;

    // reverse geocode
    m_locatorTask->reverseGeocodeWithParameters(Point(m_mapView->screenToLocation(mouseEvent.x(), mouseEvent.y())), m_reverseGeocodeParameters);

    // make busy indicator visible
    m_geocodeInProgress = true;
    emit geocodeInProgressChanged();
  });

  connect(m_mapView, &MapQuickView::mouseMoved, this, [this](QMouseEvent& mouseEvent)
  {
    // if user is dragging mouse hold, realtime reverse geocode
    if (m_isPressAndHold)
    {
      m_locatorTask->reverseGeocodeWithParameters(Point(m_mapView->screenToLocation(mouseEvent.x(), mouseEvent.y())), m_reverseGeocodeParameters);

      m_geocodeInProgress = true;
      emit geocodeInProgressChanged();
    }
  });

  // reset after user stops holding down mouse
  connect(m_mapView, &MapQuickView::mouseReleased, this, [this]()
  {
    m_isPressAndHold = false;
    m_isReverseGeocode = false;
  });

  // dismiss no results notification and suggestions on mouse press
  connect(m_mapView, &MapQuickView::mousePressed, this, [this]()
  {
    m_noResults = false;
    emit noResultsChanged();
    emit dismissSuggestions();
  });

  connect(m_suggestListModel, &SuggestListModel::errorOccurred, this, &OfflineGeocode::logError);
  connect(m_suggestListModel, &SuggestListModel::suggestInProgressChanged, this, [this]()
  {
    m_suggestInProgress = m_suggestListModel->suggestInProgress();
    emit suggestInProgressChanged();
  });

  // if clicked pin graphic, show callout. otherwise, reverse geocode
  connect(m_mapView, &MapQuickView::identifyGraphicsOverlayCompleted, this, [this](QUuid, IdentifyGraphicsOverlayResult* rawIdentifyResult)
  {
    // Delete rawIdentifyResult when we leave scope.
    auto identifyResult = std::unique_ptr<IdentifyGraphicsOverlayResult>(rawIdentifyResult);

    if (!identifyResult)
      return;

    // if user clicked on pin, display callout
    const QList<Graphic*> graphics = identifyResult->graphics();
    if (graphics.count() > 0)
      m_calloutData->setVisible(true);

    // otherwise, reverse geocode at that point
    else
    {
      m_isReverseGeocode = true;
      m_locatorTask->reverseGeocodeWithParameters(m_clickedPoint, m_reverseGeocodeParameters);

      m_geocodeInProgress = true;
      emit geocodeInProgressChanged();
    }
  });

  connect(m_locatorTask, &LocatorTask::errorOccurred, this, &OfflineGeocode::logError);
  connect(m_locatorTask, &LocatorTask::geocodeCompleted, this, [this](QUuid, const QList<GeocodeResult>& geocodeResults)
  {
    // dismiss busy indicator
    m_geocodeInProgress = false;
    emit geocodeInProgressChanged();

    if (geocodeResults.length() > 0)
    {
      // dismiss no results notification
      m_noResults = false;
      emit noResultsChanged();

      // dismiss callouts
      m_calloutData->setVisible(false);

      // zoom to result's extent
      m_mapView->setViewpointCenter(geocodeResults.at(0).displayLocation());

      // set pin graphic's location
      m_pinGraphic->setGeometry(geocodeResults.at(0).displayLocation());
      m_pinGraphic->setVisible(true);

      // set callout location and detail
      m_calloutData->setDetail(geocodeResults.at(0).label());
      m_calloutData->setGeoElement(m_pinGraphic);

      if (m_isReverseGeocode)
        m_calloutData->setVisible(true);

      // continue reverse geocoding if user is pressing and holding
      if (!m_isPressAndHold)
        m_isReverseGeocode = false;
    }

    // if there are no matching results, notify user
    else
    {
      m_noResults = true;
      emit noResultsChanged();
    }
  });
}

QString OfflineGeocode::errorMessage() const
{
  return m_errorMsg;
}

void OfflineGeocode::setErrorMessage(const QString& msg)
{
  m_errorMsg = msg;
  qDebug() << m_errorMsg;
  emit errorMessageChanged();
}