1+ // Copyright 2020 Google LLC
2+ //
3+ // Licensed under the Apache License, Version 2.0 (the "License");
4+ // you may not use this file except in compliance with the License.
5+ // You may obtain a copy of the License at
6+ //
7+ // http://www.apache.org/licenses/LICENSE-2.0
8+ //
9+ // Unless required by applicable law or agreed to in writing, software
10+ // distributed under the License is distributed on an "AS IS" BASIS,
11+ // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12+ // See the License for the specific language governing permissions and
13+ // limitations under the License.
14+ package com.example.kotlindemos
15+
16+ import android.Manifest
17+ import android.content.pm.PackageManager
18+ import android.location.Location
19+ import android.os.Bundle
20+ import android.widget.Toast
21+ import androidx.appcompat.app.AppCompatActivity
22+ import androidx.core.app.ActivityCompat.OnRequestPermissionsResultCallback
23+ import androidx.core.content.ContextCompat
24+ import com.example.kotlindemos.PermissionUtils.PermissionDeniedDialog.Companion.newInstance
25+ import com.example.kotlindemos.PermissionUtils.isPermissionGranted
26+ import com.example.kotlindemos.PermissionUtils.requestPermission
27+ import com.google.android.gms.maps.GoogleMap
28+ import com.google.android.gms.maps.GoogleMap.OnMyLocationButtonClickListener
29+ import com.google.android.gms.maps.GoogleMap.OnMyLocationClickListener
30+ import com.google.android.gms.maps.OnMapReadyCallback
31+ import com.google.android.gms.maps.SupportMapFragment
32+
33+ /* *
34+ * This demo shows how GMS Location can be used to check for changes to the users location. The
35+ * "My Location" button uses GMS Location to set the blue dot representing the users location.
36+ * Permission for [Manifest.permission.ACCESS_FINE_LOCATION] is requested at run
37+ * time. If the permission has not been granted, the Activity is finished with an error message.
38+ */
39+ class MyLocationDemoActivity : AppCompatActivity (), OnMyLocationButtonClickListener,
40+ OnMyLocationClickListener , OnMapReadyCallback , OnRequestPermissionsResultCallback {
41+ /* *
42+ * Flag indicating whether a requested permission has been denied after returning in
43+ * [.onRequestPermissionsResult].
44+ */
45+ private var permissionDenied = false
46+ private lateinit var map: GoogleMap
47+ override fun onCreate (savedInstanceState : Bundle ? ) {
48+ super .onCreate(savedInstanceState)
49+ setContentView(R .layout.my_location_demo)
50+ val mapFragment = supportFragmentManager.findFragmentById(R .id.map) as SupportMapFragment ?
51+ mapFragment?.getMapAsync(this )
52+ }
53+
54+ override fun onMapReady (googleMap : GoogleMap ? ) {
55+ map = googleMap ? : return
56+ googleMap.setOnMyLocationButtonClickListener(this )
57+ googleMap.setOnMyLocationClickListener(this )
58+ enableMyLocation()
59+ }
60+
61+ /* *
62+ * Enables the My Location layer if the fine location permission has been granted.
63+ */
64+ private fun enableMyLocation () {
65+ if (! ::map.isInitialized) return
66+ // [START maps_check_location_permission]
67+ if (ContextCompat .checkSelfPermission(this , Manifest .permission.ACCESS_FINE_LOCATION )
68+ == PackageManager .PERMISSION_GRANTED ) {
69+ map.isMyLocationEnabled = true
70+ } else {
71+ // Permission to access the location is missing. Show rationale and request permission
72+ requestPermission(this , LOCATION_PERMISSION_REQUEST_CODE ,
73+ Manifest .permission.ACCESS_FINE_LOCATION , true
74+ )
75+ }
76+ // [END maps_check_location_permission]
77+ }
78+
79+ override fun onMyLocationButtonClick (): Boolean {
80+ Toast .makeText(this , " MyLocation button clicked" Toast .LENGTH_SHORT ).show()
81+ // Return false so that we don't consume the event and the default behavior still occurs
82+ // (the camera animates to the user's current position).
83+ return false
84+ }
85+
86+ override fun onMyLocationClick (location : Location ) {
87+ Toast .makeText(this , " Current location:\n $location " Toast .LENGTH_LONG ).show()
88+ }
89+
90+ // [START maps_check_location_permission_result]
91+ override fun onRequestPermissionsResult (requestCode : Int , permissions : Array <String >, grantResults : IntArray ) {
92+ if (requestCode != LOCATION_PERMISSION_REQUEST_CODE ) {
93+ return
94+ }
95+ if (isPermissionGranted(permissions, grantResults, Manifest .permission.ACCESS_FINE_LOCATION )) {
96+ // Enable the my location layer if the permission has been granted.
97+ enableMyLocation()
98+ } else {
99+ // Permission was denied. Display an error message
100+ // [START_EXCLUDE]
101+ // Display the missing permission error dialog when the fragments resume.
102+ permissionDenied = true
103+ // [END_EXCLUDE]
104+ }
105+ }
106+
107+ // [END maps_check_location_permission_result]
108+ override fun onResumeFragments () {
109+ super .onResumeFragments()
110+ if (permissionDenied) {
111+ // Permission was not granted, display error dialog.
112+ showMissingPermissionError()
113+ permissionDenied = false
114+ }
115+ }
116+
117+ /* *
118+ * Displays a dialog with error message explaining that the location permission is missing.
119+ */
120+ private fun showMissingPermissionError () {
121+ newInstance(true ).show(supportFragmentManager, " dialog"
122+ }
123+
124+ companion object {
125+ /* *
126+ * Request code for location permission request.
127+ *
128+ * @see .onRequestPermissionsResult
129+ */
130+ private const val LOCATION_PERMISSION_REQUEST_CODE = 1
131+ }
132+ }
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