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flutter Google Maps Flutter - Map just blank, but sign of Google was appear

I am very confused about this. No anyone got a same problem like me after I checked on Github Issues.

I just follow the instructions of used the google_maps_flutter, but I'm not get same result like the instructions.

This is the result of the instructions that I have followed: Screen Shot 2019-04-08 at 03 40 05

Google sign is appear! But, no for map.

This is what happened in Terminal:

Using hardware rendering with device Android SDK built for x86. If you get
graphics artifacts, consider enabling software rendering with
"--enable-software-rendering".
Launching lib/main.dart on Android SDK built for x86 in debug mode...
Initializing gradle...                                              1.3s
Resolving dependencies...                                           1.7s
Running Gradle task 'assembleDebug'...
Running Gradle task 'assembleDebug'... Done                         1.8s
Built build/app/outputs/apk/debug/app-debug.apk.
I/zzbz    ( 8116): Making Creator dynamically
D/        ( 8116): HostConnection::get() New Host Connection established 0xa0be4f40, tid 8129
D/        ( 8116): HostConnection::get() New Host Connection established 0xa0bfa940, tid 8128
W/zygote  ( 8116): Skipping duplicate class check due to unrecognized classloader
I/DynamiteModule( 8116): Considering local module com.google.android.gms.maps_dynamite:0 and remote module com.google.android.gms.maps_dynamite:221
I/DynamiteModule( 8116): Selected remote version of com.google.android.gms.maps_dynamite, version >= 221
V/DynamiteModule( 8116): Dynamite loader version >= 2, using loadModule2NoCrashUtils
W/zygote  ( 8116): Skipping duplicate class check due to unrecognized classloader
I/Google Maps Android API( 8116): Google Play services client version: 12451000
I/Google Maps Android API( 8116): Google Play services package version: 16089022
D/        ( 8116): HostConnection::get() New Host Connection established 0xa0be4a80, tid 8135
D/EGL_emulation( 8116): eglMakeCurrent: 0x9e3c3cc0: ver 3 0 (tinfo 0x9c60d4c0)
I/zygote  ( 8116): Do partial code cache collection, code=27KB, data=23KB
I/zygote  ( 8116): After code cache collection, code=27KB, data=23KB
I/zygote  ( 8116): Increasing code cache capacity to 128KB
E/GoogleMapController( 8116): Cannot enable MyLocation layer as location permissions are not granted
D/        ( 8116): HostConnection::get() New Host Connection established 0x8847f940, tid 8174
D/EGL_emulation( 8116): eglCreateContext: 0xa0e87400: maj 1 min 0 rcv 1
D/EGL_emulation( 8116): eglMakeCurrent: 0xa0e87400: ver 1 0 (tinfo 0x8847e410)
D/EGL_emulation( 8116): eglMakeCurrent: 0x9e3c3960: ver 3 0 (tinfo 0x9c60d760)
D/EGL_emulation( 8116): eglMakeCurrent: 0x9e3c3960: ver 3 0 (tinfo 0x9c60d760)
 2,270ms (!)                                                                                                                                                    🔥  To hot reload changes while running, press "r". To hot restart (and rebuild state), press "R".                                                              An Observatory debugger and profiler on Android SDK built for x86 is available
at: http://127.0.0.1:52938/
For a more detailed help message, press "h". To detach, press "d"; to quit,
press "q".
W/DynamiteModule( 8116): Local module descriptor class for com.google.android.gms.googlecertificates not found.
I/DynamiteModule( 8116): Considering local module com.google.android.gms.googlecertificates:0 and remote module com.google.android.gms.googlecertificates:4
I/DynamiteModule( 8116): Selected remote version of com.google.android.gms.googlecertificates, version >= 4
W/zygote  ( 8116): Skipping duplicate class check due to unrecognized classloader

If I run flutter doctor:

[✓] Flutter (Channel stable, v1.2.1, on Mac OS X 10.14.4 18E226, locale en-ID)
    • Flutter version 1.2.1 at /Users/fuaditrockz/development/flutter
    • Framework revision 8661d8aecd (7 weeks ago), 2019-02-14 19:19:53 -0800
    • Engine revision 3757390fa4
    • Dart version 2.1.2 (build 2.1.2-dev.0.0 0a7dcf17eb)

[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
    • Android SDK at /Users/fuaditrockz/Library/Android/sdk
    • Android NDK location not configured (optional; useful for native profiling
      support)
    • Platform android-28, build-tools 28.0.3
    • ANDROID_HOME = /Users/fuaditrockz/Library/Android/sdk
    • Java binary at: /Applications/Android
      Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_152-release-1248-b01)
    • All Android licenses accepted.

[!] iOS toolchain - develop for iOS devices
    ✗ Xcode installation is incomplete; a full installation is necessary for iOS
      development.
      Download at: https://developer.apple.com/xcode/download/
      Or install Xcode via the App Store.
      Once installed, run:
        sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
    • ios-deploy 1.9.4
    ✗ CocoaPods not installed.
        CocoaPods is used to retrieve the iOS platform side's plugin code that
        responds to your plugin usage on the Dart side.
        Without resolving iOS dependencies with CocoaPods, plugins will not work
        on iOS.
        For more info, see https://flutter.io/platform-plugins
      To install:
        brew install cocoapods
        pod setup

[✓] Android Studio (version 3.3)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 34.0.1
    • Dart plugin version 182.5215
    • Java version OpenJDK Runtime Environment (build
      1.8.0_152-release-1248-b01)

[✓] VS Code (version 1.33.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 2.25.0

[✓] Connected device (1 available)
    • Android SDK built for x86 • emulator-5554 • android-x86 • Android 8.0.0
      (API 26) (emulator)

! Doctor found issues in 1 category.

Btw, I deliberately did not install for IOS. So it doesn't need to be discussed.

this my AndroidManifest.xml:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.cafemates">
    <application
        android:name="io.flutter.app.FlutterApplication"
        android:label="cafemates"
        android:icon="@mipmap/ic_launcher">
        <meta-data android:name="com.google.android.geo.API_KEY"
               android:value="AIzaSyCy7Uaene9DzIU8eIxxxxxxxxxxxxxx"/>
        <activity
            android:name=".MainActivity"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">
            <meta-data
                android:name="io.flutter.app.android.SplashScreenUntilFirstFrame"
                android:value="true" />
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
    </application>
</manifest>

And this is my Widget code;

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';

import '../../helpers/color_setup.dart';

class Nearby extends StatefulWidget {
  @override
  _NearbyState createState() => _NearbyState();
}

class _NearbyState extends State<Nearby> {
  final String title = "Hello, Fuadit";

  Completer<GoogleMapController> _controller = Completer();

  static const LatLng _center = const LatLng(37.42796133580664, -122.085749655962);

  void _onMapCreated(GoogleMapController controller) {
    _controller.complete(controller);
  }

  @override
  Widget build (BuildContext context) {
    return Scaffold(
      appBar: new AppBar(
        leading: new Padding(
          padding: EdgeInsets.all(8.0),
          child: new Container(
            width: 10.0,
            height: 10.0,
            decoration: new BoxDecoration(
              shape: BoxShape.circle,
              image: new DecorationImage(
                fit: BoxFit.fill,
                image: new AssetImage('images/adit.png')
              )
            ),
          ),
        ),
        title: Text(
          "$title",
          style: TextStyle(
            color: MaterialColor(0xFF2d3436, color),
            fontWeight: FontWeight.w700
          ),
        ),
        actions: <Widget>[
          IconButton(
            icon: Icon(Icons.notifications),
            tooltip: 'Open shopping cart',
            onPressed: () {
              // ...
            },
          ),
        ],
      ),
      body: GoogleMap(
        onMapCreated: _onMapCreated,
        initialCameraPosition: CameraPosition(
          target: _center,
          zoom: 14.4746,
        ),
      ),
    );
  }
}

Btw, I've follow instructions from this article => https://medium.com/flutter-io/google-maps-and-flutter-cfb330f9a245

That's a useful answer
Without any help

tried everything before @MartinErskine's method make it work! Thanks