Change basemap

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C++

QML

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Sample viewer app

Change a map's basemap. A basemap is beneath all layers on a Map and is used to provide visual reference for the operational layers.

screenshot

Use case

Basemaps should be selected contextually, for example, in maritime applications, it would be more appropriate to use a basemap of the world's oceans as opposed to a basemap of the world's streets.

How to use the sample

Press the Change Basemap button to display the Basemap Gallery. When the gallery appears, select a basemap to be displayed.

How it works

A basemap can be changed by setting the basemap property of a map object to a new basemap object (e.g. map->setBasemap(basemap);). However, this sample utilises the BasemapGallery toolkit component to manage this process and provide a common user experience. In this sample, the BasemapGallery creates a visual display of basemap options and automates the changing of the basemap.

Create a Map object.
Set the map to the MapView object.
Create a BasemapGallery from the toolkit.
Use the setGeoModelFromGeoView method to manage changes to the basemap.

Relevant API

BasemapStyle
Map
MapView

Additional information

This sample uses the BasemapGallery toolkit component and requires the toolkit to be cloned and set-up locally. For information about setting up the toolkit, see the repository's root README file.

Sample Code

ChangeBasemap.cpp

ChangeBasemap.h

ChangeBasemap.qml

Use dark colors for code blocksCopy
// [WriteFile Name=ChangeBasemap, Category=Maps]
// [Legal]
// Copyright 2021 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 "ChangeBasemap.h"

#include "Map.h"
#include "MapQuickView.h"

using namespace Esri::ArcGISRuntime;

ChangeBasemap::ChangeBasemap(QObject* parent /* = nullptr */):
  QObject(parent),
  m_map(new Map(BasemapStyle::ArcGISTopographic, this))
{

}

ChangeBasemap::~ChangeBasemap() = default;

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

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

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

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

  emit mapViewChanged();
}