Tap and hold on a map to show a magnifier.

Use case
Due to the limited screen size of some mobile devices, it may be difficult to identify individual features on a map where there is a high density of information, or the scale is very small. This can be the case when a mobile device is used for navigation, and the user wishes to magnify a particular area to better identify a road intersection.
How to use the sample
Tap and hold on the map to show a magnifier, then drag across the map to move the magnifier. You can also pan the map while holding the magnifier, by dragging the magnifier to the edge of the map.
How it works
- Create a new
MapView, and add aMapto it:mapView::setMap(map). - Enable the magnifier using
mapView::setMagnifierEnabled(true). This will set the magnifier to be shown on the map when the user performs a long press gesture. Note: The default value isfalse. MapView::setMagnifierMapPanningEnabled()is set totrueby default to allow you to pan the map when the magnifier get’s near the edge of the map.
Relevant API
- Map
- MapView
- MapView::setMagnifierMapPanningEnabled()
- MapView::setMagnifierEnabled()
Additional information
This sample only works on a device with a touch screen. The magnifier will not appear via a mouse click.
Tags
magnify, map, zoom
Sample Code
// [WriteFile Name=ShowMagnifier, Category=Maps]// [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
// sample headers#include "ShowMagnifier.h"
// ArcGIS Maps SDK headers#include "Basemap.h"#include "Map.h"#include "MapQuickView.h"#include "MapTypes.h"#include "Point.h"#include "SpatialReference.h"#include "Viewpoint.h"
using namespace Esri::ArcGISRuntime;
ShowMagnifier::ShowMagnifier(QQuickItem* parent) : QQuickItem(parent){}
ShowMagnifier::~ShowMagnifier() = default;
void ShowMagnifier::init(){ qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView"); qmlRegisterType<ShowMagnifier>("Esri.Samples", 1, 0, "ShowMagnifierSample");}
void ShowMagnifier::componentComplete(){ QQuickItem::componentComplete();
// find QML MapView component m_mapView = findChild<MapQuickView*>("mapView");
// create a new basemap instance Basemap* basemap = new Basemap(BasemapStyle::ArcGISImageryStandard, this);
// create a new map instance m_map = new Map(basemap, this); m_map->setInitialViewpoint(Viewpoint(Point(-110.8258, 32.1545089, SpatialReference::wgs84()), 2e4));
// set map on the map view m_mapView->setMap(m_map);
// enable magnifier m_mapView->setMagnifierEnabled(true);}// [WriteFile Name=ShowMagnifier, Category=Maps]// [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]
#ifndef SHOW_MAGNIFIER_H#define SHOW_MAGNIFIER_H
// Qt headers#include <QQuickItem>
namespace Esri::ArcGISRuntime{ class Map; class MapQuickView;}
class ShowMagnifier : public QQuickItem{ Q_OBJECT
public: explicit ShowMagnifier(QQuickItem* parent = nullptr); ~ShowMagnifier() override;
void componentComplete() override; static void init();
private: Esri::ArcGISRuntime::Map* m_map = nullptr; Esri::ArcGISRuntime::MapQuickView* m_mapView = nullptr;};
#endif // SHOW_MAGNIFIER_H// [WriteFile Name=ShowMagnifier, Category=Maps]// [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]
import QtQuickimport QtQuick.Controlsimport Esri.Samples
ShowMagnifierSample { 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 2015 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 "ShowMagnifier.h"
// ArcGIS Maps SDK headers#include "ArcGISRuntimeEnvironment.h"
// Qt headers#include <QCommandLineParser>#include <QDir>#include <QGuiApplication>#include <QQmlEngine>#include <QQuickView>#include <QSettings>
// 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("ShowMagnifier"));
// 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 ShowMagnifier::init();
// Initialize application view QQuickView view; view.setResizeMode(QQuickView::SizeRootObjectToView);
// Add the import Path view.engine()->addImportPath(QDir(QCoreApplication::applicationDirPath()).filePath("qml"));
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 Runtime and Extras path view.engine()->addImportPath(arcGISRuntimeImportPath);
// Set the source view.setSource(QUrl("qrc:/Samples/Maps/ShowMagnifier/ShowMagnifier.qml"));
view.show();
return app.exec();}