Show labels on layers

// [WriteFile Name=ShowLabelsOnLayers, Category=DisplayInformation]
// [Legal]
// Copyright 2018 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 "ShowLabelsOnLayers.h"

// ArcGIS Maps SDK headers
#include "ArcadeLabelExpression.h"
#include "Envelope.h"
#include "Error.h"
#include "FeatureLayer.h"
#include "LabelDefinition.h"
#include "LabelDefinitionListModel.h"
#include "LayerListModel.h"
#include "Map.h"
#include "MapQuickView.h"
#include "MapTypes.h"
#include "Point.h"
#include "ServiceFeatureTable.h"
#include "SpatialReference.h"
#include "SymbolTypes.h"
#include "TextSymbol.h"
#include "Viewpoint.h"

// Qt headers
#include <QFuture>

using namespace Esri::ArcGISRuntime;

ShowLabelsOnLayers::ShowLabelsOnLayers(QQuickItem* parent /* = nullptr */):
  QQuickItem(parent)
{
}

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

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

  // find QML MapView component
  m_mapView = findChild<MapQuickView*>("mapView");

  // Create a map using the light gray basemap
  m_map = new Map(BasemapStyle::ArcGISLightGray, this);

  // Create a feature layer
  ServiceFeatureTable* featureTable = new ServiceFeatureTable(QUrl("https://services.arcgis.com/P3ePLMYs2RVChkJx/arcgis/rest/services/USA_116th_Congressional_Districts/FeatureServer/0"), this);
  FeatureLayer* featureLayer = new FeatureLayer(featureTable, this);
  connect(featureLayer, &FeatureLayer::doneLoading, this, [this, featureLayer](const Error& e)
  {
    if (!e.isEmpty())
      return;

    m_mapView->setViewpointAsync(Viewpoint(featureLayer->fullExtent().center(), 56759600));
  });
  m_map->operationalLayers()->append(featureLayer);

  // Apply labels to the feature layer
  LabelDefinition* republicanLabelDef = createRepublicanLabelDefinition();
  LabelDefinition* democratLabelDef = createDemocratLabelDefinition();
  featureLayer->labelDefinitions()->append(republicanLabelDef);
  featureLayer->labelDefinitions()->append(democratLabelDef);
  featureLayer->setLabelsEnabled(true);

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

LabelDefinition* ShowLabelsOnLayers::createRepublicanLabelDefinition()
{
  // This particular LabelDefinition will have the following characteristics:
  // (1) The 'ArcadeLabelExpression' defines that the label text displayed comes from the fields 'NAME',
  //     the first letter of PARTY' (R or D), and 'CDFIPS' in the feature service in the format:
  //         Firstname Lastname (R)
  //         District #
  // (2) The 'TextSymbol' for the labeled text will be red with a white halo centered in the target polygon.
  // (3) The 'where' clause of the 'LabelDefinition' restricts the labels to data from Republican districts.

  ArcadeLabelExpression* republicanArcadeLabelExpression = new ArcadeLabelExpression("$feature.NAME + ' (' + left($feature.PARTY,1) + ')\\nDistrict ' + $feature.CDFIPS", this);

  TextSymbol* republicanTextSymbol = new TextSymbol(this);
  republicanTextSymbol->setSize(11);
  republicanTextSymbol->setColor(Qt::red);
  republicanTextSymbol->setHaloColor(Qt::white);
  republicanTextSymbol->setHaloWidth(2);
  republicanTextSymbol->setHorizontalAlignment(HorizontalAlignment::Center);
  republicanTextSymbol->setVerticalAlignment(VerticalAlignment::Middle);

  LabelDefinition* republicanLabelDefinition = new LabelDefinition(republicanArcadeLabelExpression, republicanTextSymbol, this);
  republicanLabelDefinition->setWhereClause("PARTY = 'Republican'");

  return republicanLabelDefinition;
}

LabelDefinition* ShowLabelsOnLayers::createDemocratLabelDefinition()
{
  // This particular LabelDefinition will have the following characteristics:
  // (1) The 'ArcadeLabelExpression' defines that the label text displayed comes from the fields 'NAME',
  //     the first letter of PARTY' (R or D), and 'CDFIPS' in the feature service in the format:
  //         Firstname Lastname (D)
  //         District #
  // (2) The 'TextSymbol' for the labeled text will be blue with a white halo centered in the target polygon.
  // (3) The 'where' clause of the 'LabelDefinition' restricts the labels to data from Democrat districts.

  ArcadeLabelExpression* democratArcadeLabelExpression = new ArcadeLabelExpression("$feature.NAME + ' (' + left($feature.PARTY,1) + ')\\nDistrict ' + $feature.CDFIPS", this);

  TextSymbol* democratTextSymbol = new TextSymbol(this);
  democratTextSymbol->setSize(11);
  democratTextSymbol->setColor(Qt::blue);
  democratTextSymbol->setHaloColor(Qt::white);
  democratTextSymbol->setHaloWidth(2);
  democratTextSymbol->setHorizontalAlignment(HorizontalAlignment::Center);
  democratTextSymbol->setVerticalAlignment(VerticalAlignment::Middle);

  LabelDefinition* democratLabelDefinition = new LabelDefinition(democratArcadeLabelExpression, democratTextSymbol, this);
  democratLabelDefinition->setWhereClause("PARTY = 'Democrat'");

  return democratLabelDefinition;
}

// [WriteFile Name=ShowLabelsOnLayers, Category=DisplayInformation]
// [Legal]
// Copyright 2018 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]

#ifndef SHOWLABELSONLAYERS_H
#define SHOWLABELSONLAYERS_H

// Qt headers
#include <QQuickItem>

namespace Esri::ArcGISRuntime
{
class Map;
class MapQuickView;
class LabelDefinition;
}

class ShowLabelsOnLayers : public QQuickItem
{
  Q_OBJECT

public:
  explicit ShowLabelsOnLayers(QQuickItem* parent = nullptr);
  ~ShowLabelsOnLayers() override = default;

  void componentComplete() override;
  static void init();

private:
  Esri::ArcGISRuntime::LabelDefinition* createRepublicanLabelDefinition();
  Esri::ArcGISRuntime::LabelDefinition* createDemocratLabelDefinition();

  Esri::ArcGISRuntime::Map* m_map = nullptr;
  Esri::ArcGISRuntime::MapQuickView* m_mapView = nullptr;
};

#endif // SHOWLABELSONLAYERS_H

// [WriteFile Name=ShowLabelsOnLayers, Category=DisplayInformation]
// [Legal]
// Copyright 2018 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]

import QtQuick
import QtQuick.Controls
import Esri.Samples

ShowLabelsOnLayersSample {
    id: rootRectangle
    clip: true
    width: 800
    height: 600

    // add a mapView component
    MapView {
        anchors.fill: parent
        objectName: "mapView"

        Component.onCompleted: {
            // Set the focus on MapView to initially enable keyboard navigation
            forceActiveFocus();
        }
    }
}

// [Legal]
// Copyright 2018 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]

// sample headers
#include "ShowLabelsOnLayers.h"

// ArcGIS Maps SDK headers
#include "ArcGISRuntimeEnvironment.h"

// Qt headers
#include <QCommandLineParser>
#include <QDir>
#include <QGuiApplication>
#include <QQmlEngine>
#include <QQuickView>

// Platform specific headers
#ifdef Q_OS_WIN
#include <Windows.h>
#endif

#define STRINGIZE(x) #x
#define QUOTE(x) STRINGIZE(x)

int main(int argc, char *argv[])
{
  Esri::ArcGISRuntime::ArcGISRuntimeEnvironment::setUseLegacyAuthentication(false);
  QGuiApplication app(argc, argv);
  app.setApplicationName(QString("Show Labels on Layers"));

  // Use of ArcGIS location services, such as basemap styles, geocoding, and routing services,
  // requires an access token. For more information see
  // https://links.esri.com/arcgis-runtime-security-auth.

  // The following methods grant an access token:

  // 1. User authentication: Grants a temporary access token associated with a user's ArcGIS account.
  // To generate a token, a user logs in to the app with an ArcGIS account that is part of an
  // organization in ArcGIS Online or ArcGIS Enterprise.

  // 2. API key authentication: Get a long-lived access token that gives your application access to
  // ArcGIS location services. Go to the tutorial at https://links.esri.com/create-an-api-key.
  // Copy the API Key access token.

  const QString accessToken = QString("");

  if (accessToken.isEmpty())
  {
      qWarning() << "Use of ArcGIS location services, such as the basemap styles service, requires" <<
                    "you to authenticate with an ArcGIS account or set the API Key property.";
  }
  else
  {
      Esri::ArcGISRuntime::ArcGISRuntimeEnvironment::setApiKey(accessToken);
  }

  // Initialize the sample
  ShowLabelsOnLayers::init();

  // Initialize application view
  QQuickView view;
  view.setResizeMode(QQuickView::SizeRootObjectToView);

  QString arcGISRuntimeImportPath = QUOTE(ARCGIS_RUNTIME_IMPORT_PATH);

#if defined(LINUX_PLATFORM_REPLACEMENT)
  // on some linux platforms the string 'linux' is replaced with 1
  // fix the replacement paths which were created
  QString replaceString = QUOTE(LINUX_PLATFORM_REPLACEMENT);
  arcGISRuntimeImportPath = arcGISRuntimeImportPath.replace(replaceString, "linux", Qt::CaseSensitive);
#endif

  // Add the import Path
  view.engine()->addImportPath(QDir(QCoreApplication::applicationDirPath()).filePath("qml"));
  // Add the Runtime and Extras path
  view.engine()->addImportPath(arcGISRuntimeImportPath);

  // Set the source
  view.setSource(QUrl("qrc:/Samples/DisplayInformation/ShowLabelsOnLayers/ShowLabelsOnLayers.qml"));

  view.show();

  return app.exec();
}