Show magnifier

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Sample viewer app

Tap and hold on a map to show a magnifier.

Image of show 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 an ArcGISMap to it using 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 is false.
Optionally, use mapView.setCanMagnifierPanMap(true) to allow the map to be panned automatically when the magnifier gets near the edge of the map.

Relevant API

ArcGISMap
MapView
MapView.setCanMagnifierPanMap(...)
MapView.setMagnifierEnabled(...)

Additional information

This sample only works on a device with a touch screen. The magnifier will not appear via a mouse click.

Sample Code

MainActivity.java
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/* 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.
 *
 */

package com.esri.arcgisruntime.sample.showmagnifier;

import android.os.Bundle;

import androidx.appcompat.app.AppCompatActivity;
import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.mapping.ArcGISMap;
import com.esri.arcgisruntime.mapping.BasemapStyle;
import com.esri.arcgisruntime.mapping.Viewpoint;
import com.esri.arcgisruntime.mapping.view.MapView;

public class MainActivity extends AppCompatActivity {

  private MapView mMapView;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // authentication with an API key or named user is required to access basemaps and other
    // location services
    ArcGISRuntimeEnvironment.setApiKey(BuildConfig.API_KEY);

    // inflate MapView from layout
    mMapView = findViewById(R.id.mapView);
    // create a map with the Basemap Style topographic
    ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_TOPOGRAPHIC);
    // set the map to be displayed in this view
    mMapView.setMap(map);
    mMapView.setViewpoint(new Viewpoint(34.056295, -117.195800, 1000000));
    // enable magnifier
    mMapView.getInteractionOptions().setMagnifierEnabled(true);
    // allow magnifier to pan near the edge of the map bounds
    mMapView.getInteractionOptions().setCanMagnifierPanMap(true);
  }

  @Override
  protected void onPause() {
    super.onPause();
    mMapView.pause();
  }

  @Override
  protected void onResume() {
    super.onResume();
    mMapView.resume();
  }

  @Override
  protected void onDestroy() {
    super.onDestroy();
    mMapView.dispose();
  }
}