Show callout

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Sample viewer app

Show a callout with the latitude and longitude of user-tapped points.

Show Callout App

Use case

Callouts are used to display temporary detail content on a map. You can display text and arbitrary UI controls in callouts.

How to use the sample

Tap anywhere on the map. A callout showing the WGS84 coordinates for the tapped point will appear.

How it works

When the user taps, get the tapped location(map point) from the SingleTapConfirmedEvent.
Project the point's geometry to WGS84 using GeometryEngine.projectOrNull(mapPoint, SpatialReference.wgs84()).
To the composable MapView's content, add a composable Callout passing it the location Point and calloutContent string.
Changes to the latLongPoint variable will trigger recomposition of the Callout.

Relevant API

Callout
GeometryEngine
MapView
Point

Additional information

This sample uses the GeoViewCompose Toolkit module to implement a Composable MapView, which supports the use of Callouts.

Sample Code

MainActivity.kt

MapViewModel.kt

MainScreen.kt

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/* Copyright 2023 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.arcgismaps.sample.showcallout

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Surface
import androidx.compose.runtime.Composable
import com.arcgismaps.ApiKey
import com.arcgismaps.ArcGISEnvironment
import com.esri.arcgismaps.sample.sampleslib.theme.SampleAppTheme
import com.esri.arcgismaps.sample.showcallout.screens.MainScreen

class MainActivity : ComponentActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        // authentication with an API key or named user is
        // required to access basemaps and other location services
        ArcGISEnvironment.apiKey = ApiKey.create(BuildConfig.API_KEY)

        setContent {
            SampleAppTheme {
                ShowCalloutApp()
            }
        }
    }

    @Composable
    private fun ShowCalloutApp() {
        Surface(
            color = MaterialTheme.colorScheme.background
        ) {
            MainScreen(
                sampleName = getString(R.string.app_name)
            )
        }
    }
}