Service area

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Sample viewer app

Find the service area within a network from a given point.

screenshot

Use case

A service area shows locations that can be reached from a facility based off a certain impedance, such as travel time or distance. Barriers can increase impedance by either adding to the time it takes to pass through the barrier or by altogether preventing passage.

You might calculate the region around a hospital in which ambulances can service in 30 min or less.

How to use sample

In order to find any services areas at least one ServiceAreaFaciltiy needs to be added.

To add a facility, select "Facility" from the combo-box then click anywhere on the MapView.
To add a barrier, select "Barrier" from the combo-box and click multiple locations on the MapView to draw a barrier.
To start a new line in a distinct location, click "new barrier"
To show service areas around facilities that were added, click the "Solve" button.
The "Reset" button, clears all graphics and resets the ServiceAreaTask.

How it works

Create a new ServiceAreaTask from a network service.
Create default ServiceAreaParameters from the service area task.
Set the parameters to return polygons (true) to return all service areas.
Add a ServiceAreaFacility to the parameters.
Get the ServiceAreaResult by solving the service area task using the parameters.
Get any ServiceAreaPolygons that were returned, serviceAreaResult.getResultPolygons(facilityIndex).
Display the service area polygons as graphics in a GraphicsOverlay on the MapView.

Relevant API

PolylineBarrier
ServiceAreaFacility
ServiceAreaParameters
ServiceAreaPolygon
ServiceAreaResult
ServiceAreaTask

Sample Code

ServiceArea.cpp

ServiceArea.h

ServiceArea.qml

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// [WriteFile Name=ServiceArea, Category=Routing]
// [Legal]
// Copyright 2017 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 "ServiceArea.h"

// ArcGIS Maps SDK headers
#include "Error.h"
#include "Graphic.h"
#include "GraphicListModel.h"
#include "GraphicsOverlay.h"
#include "GraphicsOverlayListModel.h"
#include "Map.h"
#include "MapQuickView.h"
#include "MapTypes.h"
#include "MapViewTypes.h"
#include "NetworkAnalystTypes.h"
#include "PictureMarkerSymbol.h"
#include "Point.h"
#include "Polygon.h"
#include "Polyline.h"
#include "PolylineBarrier.h"
#include "PolylineBuilder.h"
#include "ServiceAreaFacility.h"
#include "ServiceAreaPolygon.h"
#include "ServiceAreaResult.h"
#include "ServiceAreaTask.h"
#include "SimpleFillSymbol.h"
#include "SimpleLineSymbol.h"
#include "SimpleRenderer.h"
#include "SpatialReference.h"
#include "SymbolTypes.h"
#include "Viewpoint.h"

// Qt headers
#include <QFuture>
#include <QUuid>

using namespace Esri::ArcGISRuntime;

ServiceArea::ServiceArea(QQuickItem* parent /* = nullptr */):
  QQuickItem(parent),
  m_task(new ServiceAreaTask(
           QUrl("https://sampleserver6.arcgisonline.com/arcgis/rest/services/NetworkAnalysis/SanDiego/NAServer/ServiceArea"), this))
{
}

ServiceArea::~ServiceArea() = default;

void ServiceArea::init()
{
  qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView");
  qmlRegisterType<ServiceArea>("Esri.Samples", 1, 0, "ServiceAreaSample");
}

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

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

  // set view to be over San Diego
  m_map = new Map(BasemapStyle::ArcGISStreets, this);
  m_map->setInitialViewpoint(Viewpoint(Point(-13041154, 3858170, SpatialReference(3857)), 1e5));

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

  connect(m_task, &ServiceAreaTask::doneLoading, this, [this](const Error& loadError)
  {
    if (!loadError.isEmpty())
      return;

    if (m_task->loadStatus() != LoadStatus::Loaded)
      return;

    setupRouting();
  });
  m_task->load();

  setupGraphics();
}

void ServiceArea::setFacilityMode()
{
  m_mode = SampleMode::Facility;
}

void ServiceArea::setBarrierMode()
{
  m_mode = SampleMode::Barrier;

  if (m_barrierBuilder)
    return;

  m_barrierBuilder = new PolylineBuilder(SpatialReference::webMercator(), this);
}

void ServiceArea::solveServiceArea()
{
  setBusy(true);

  m_parameters.clearFacilities();
  m_parameters.clearPolylineBarriers();

  GraphicListModel* facilitiesGraphics = m_facilitiesOverlay->graphics();
  if (!facilitiesGraphics || facilitiesGraphics->rowCount() == 0)
  {
    setBusy(false);
    m_message = "At least 1 Facility is required.";
    emit messageChanged();
    return;
  }

  QList<ServiceAreaFacility> facilities;
  facilities.reserve(facilitiesGraphics->rowCount());
  for (int f = 0; f < facilitiesGraphics->rowCount(); ++f)
  {
    Graphic* g = facilitiesGraphics->at(f);
    if (!g)
      continue;

    facilities.append(ServiceAreaFacility(geometry_cast<Point>(g->geometry())));
  }
  m_parameters.setFacilities(facilities);

  GraphicListModel* barrierGraphics = m_barrierOverlay->graphics();
  QList<PolylineBarrier> barriers;
  barriers.reserve(barrierGraphics->rowCount());
  for (int b = 0; b < barrierGraphics->rowCount(); ++b)
  {
    Graphic* g = barrierGraphics->at(b);
    if (!g)
      continue;

    barriers.append(PolylineBarrier(geometry_cast<Polyline>(g->geometry())));
  }

  if (!barriers.isEmpty())
    m_parameters.setPolylineBarriers(barriers);

  m_task->solveServiceAreaAsync(m_parameters).then(this, [this](const ServiceAreaResult& serviceAreaResult)
  {
    setBusy(false);
    if (serviceAreaResult.isEmpty())
    {
      m_message = "No Serice Areas calculated!";
      emit messageChanged();
      return;
    }

    int numFacilities = m_facilitiesOverlay->graphics()->size();
    for (int i = 0; i < numFacilities; ++i)
    {
      const QList<ServiceAreaPolygon> results = serviceAreaResult.resultPolygons(i);
      if (!m_graphicParent)
        m_graphicParent = new QObject(this);
      for (const ServiceAreaPolygon& poly : results)
        m_areasOverlay->graphics()->append(new Graphic(poly.geometry(), m_graphicParent));
    }
  });
}

void ServiceArea::reset()
{
  m_facilitiesOverlay->graphics()->clear();
  m_barrierOverlay->graphics()->clear();
  if (m_barrierBuilder)
  {
    delete m_barrierBuilder;
    m_barrierBuilder = new PolylineBuilder(SpatialReference::webMercator(), this);
  }
  m_areasOverlay->graphics()->clear();
  if (m_graphicParent)
  {
    delete m_graphicParent;
    m_graphicParent = nullptr;
  }
}

void ServiceArea::newBarrier()
{
  if (m_barrierBuilder)
  {
    delete m_barrierBuilder;
    m_barrierBuilder = nullptr;
  }

  setBarrierMode();
  if (!m_graphicParent)
    m_graphicParent = new QObject(this);
  m_barrierOverlay->graphics()->append(new Graphic(m_barrierBuilder->toPolyline(), m_graphicParent));
}

bool ServiceArea::busy() const
{
  return m_busy;
}

QString ServiceArea::message() const
{
  return m_message;
}

void ServiceArea::setBusy(bool val)
{
  if (m_busy == val)
    return;

  m_message.clear();
  m_busy = val;
  emit busyChanged();
  emit messageChanged();
}

void ServiceArea::setupGraphics()
{
  // create a symbol for the incidents
  PictureMarkerSymbol* facilitySymbol = new PictureMarkerSymbol(
        QUrl(QStringLiteral("https://static.arcgis.com/images/Symbols/SafetyHealth/Hospital.png")), this);
  facilitySymbol->setHeight(30);
  facilitySymbol->setWidth(30);

  // create a graphics overlay for the facilities and add a renderer for the symbol
  m_facilitiesOverlay = new GraphicsOverlay(this);
  SimpleRenderer* renderer = new SimpleRenderer(facilitySymbol, this);
  m_facilitiesOverlay->setRenderer(renderer);

  m_mapView->graphicsOverlays()->append(m_facilitiesOverlay);

  // create a symbol for the barriers
  float lineWidth = 3.0f;
  SimpleLineSymbol* lineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle::Solid, Qt::black, lineWidth, this);
  m_barrierOverlay = new GraphicsOverlay(this);
  SimpleRenderer* lineRenderer = new SimpleRenderer(lineSymbol, this);
  m_barrierOverlay->setRenderer(lineRenderer);

  m_mapView->graphicsOverlays()->append(m_barrierOverlay);

  //create a symbol for the service areas
  SimpleFillSymbol* fillSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle::Solid, Qt::green, lineSymbol, this);
  m_areasOverlay = new GraphicsOverlay(this);
  SimpleRenderer* areaRenderer = new SimpleRenderer(fillSymbol, this);
  m_areasOverlay->setRenderer(areaRenderer);
  m_areasOverlay->setOpacity(0.5f);

  m_mapView->graphicsOverlays()->append(m_areasOverlay);
}

void ServiceArea::setupRouting()
{
  connect(m_mapView, &MapQuickView::mouseClicked, this, [this](QMouseEvent& mouseEvent)
  {
    if (busy())
      return;

    switch (m_mode) {
    case SampleMode::Barrier:
    case SampleMode::Facility:
      break;
    default:
      return;
    }

    setBusy(true);

    Point mapPoint = m_mapView->screenToLocation(mouseEvent.position().x(), mouseEvent.position().y());
    Point projectedPoint(mapPoint.x(), mapPoint.y(), SpatialReference::webMercator());

    if (m_mode == SampleMode::Barrier)
      handleBarrierPoint(projectedPoint);
    else if(m_mode == SampleMode::Facility)
      handleFacilityPoint(projectedPoint);

    setBusy(false);
  });

  m_task->createDefaultParametersAsync().then(this, [this](const ServiceAreaParameters& defaultParameters)
  {
    m_parameters = defaultParameters;
    m_parameters.setOutputSpatialReference(SpatialReference::webMercator());
    m_parameters.setReturnPolygons(true);
    m_parameters.setPolygonDetail(ServiceAreaPolygonDetail::High);
    setBusy(false);
  });
}

void ServiceArea::handleFacilityPoint(const Point &p)
{
  if (!m_graphicParent)
    m_graphicParent = new QObject(this);
  m_facilitiesOverlay->graphics()->append(new Graphic(p, m_graphicParent));
}

void ServiceArea::handleBarrierPoint(const Point &p)
{
  if (!m_graphicParent)
    m_graphicParent = new QObject(this);
  m_barrierBuilder->addPoint(p);
  // update the geometry for the current barrier - or create 1 if it does not exist
  Graphic* barrier = m_barrierOverlay->graphics()->isEmpty() ?
                       nullptr :
                       m_barrierOverlay->graphics()->last();

  if (barrier)
    barrier->setGeometry(m_barrierBuilder->toPolyline());
  else
    m_barrierOverlay->graphics()->append(new Graphic(m_barrierBuilder->toPolyline(), m_graphicParent));
}