A Flutter Plugin for Accessing The android AlarmManager Service

A Flutter plugin for accessing the Android AlarmManager service, and running Dart code in the background when alarms fire.

Platform Support

| Android | | :-----: | | ✔️ |

Getting Started

After importing this plugin to your project as usual, add the following to your AndroidManifest.xml within the <manifest></manifest> tags:

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
<uses-permission android:name="android.permission.WAKE_LOCK"/>

Next, within the <application></application> tags, add:

<service
    android:name="dev.fluttercommunity.plus.androidalarmmanager.AlarmService"
    android:permission="android.permission.BIND_JOB_SERVICE"
    android:exported="false"/>
<receiver
    android:name="dev.fluttercommunity.plus.androidalarmmanager.AlarmBroadcastReceiver"
    android:exported="false"/>
<receiver
    android:name="dev.fluttercommunity.plus.androidalarmmanager.RebootBroadcastReceiver"
    android:enabled="false">
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED"></action>
    </intent-filter>
</receiver>

Check out our documentation website to learn more. [Plus plugins documentation](https://plus.fluttercommunity.dev/docs/overview)

Then in Dart code add:

import 'package:android_alarm_manager_plus/android_alarm_manager_plus.dart';

static void printHello() {
  final DateTime now = DateTime.now();
  final int isolateId = Isolate.current.hashCode;
  print("[$now] Hello, world! isolate=${isolateId} function='$printHello'");
}

main() async {
  final int helloAlarmID = 0;
  await AndroidAlarmManager.initialize();
  runApp(...);
  await AndroidAlarmManager.periodic(const Duration(minutes: 1), helloAlarmID, printHello);
}

printHello will then run (roughly) every minute, even if the main app ends. However, printHello will not run in the same isolate as the main application. Unlike threads, isolates do not share memory and communication between isolates must be done via message passing (see more documentation on isolates here).

Using other plugins in alarm callbacks

If alarm callbacks will need access to other Flutter plugins, including the alarm manager plugin itself, it may be necessary to inform the background service how to initialize plugins depending on which Flutter Android embedding the application is using.

Flutter Android Embedding V2 (Flutter Version >= 1.12)

For the Flutter Android Embedding V2, plugins are registered with the background isolate via reflection so AlarmService.setPluginRegistrant does not need to be called.

NOTE: this plugin is not completely compatible with the V2 embedding on Flutter versions < 1.12 as the background isolate will not automatically register plugins. This can be resolved by running flutter upgrade to upgrade to the latest Flutter version.

Flutter Android Embedding V1 (DEPRECATED)

For the Flutter Android Embedding V1, the background service must be provided a callback to register plugins with the background isolate. This is done by giving the AlarmService a callback to call the application's onCreate method. See the example's Application overrides.

In particular, its Application class is as follows:

public class Application extends FlutterApplication implements PluginRegistrantCallback {
  @Override
  public void onCreate() {
    super.onCreate();
    AlarmService.setPluginRegistrant(this);
  }

  @Override
  public void registerWith(PluginRegistry registry) {
    GeneratedPluginRegistrant.registerWith(registry);
  }
}

Which must be reflected in the application's AndroidManifest.xml. E.g.:

    <application
        android:name=".Application"
        ...

Note: Not calling AlarmService.setPluginRegistrant will result in an exception being thrown when an alarm eventually fires.

Plugin Development

Running Flutter unit tests

Run normally with flutter test from the root of the project.

Running Espresso tests

The Espresso test runs the same sample code provided in example/lib/main.dart but is run using the Flutter Espresso plugin.

Modifying the main.dart will cause this test to fail.

This test will call into the example/lib/main_espresso.dart file which will enable Flutter Driver and then calls into the main.dart.

See https://pub.dev/packages/espresso for more info on why.

To run the test, run from the example/android folder:

./gradlew app:connectedAndroidTest -Ptarget=`pwd`/../lib/main_espresso.dart

Running End-to-end Flutter Driver tests

To run the Flutter Driver tests, cd into example and run:

flutter driver test_driver/android_alarm_manager_e2e.dart

Important: As of January 2021, the Flutter team is no longer accepting non-critical PRs for the original set of plugins in flutter/plugins, and instead they should be submitted in this project. You can read more about this announcement here. as well as in the Flutter 2 announcement blog post.

Use this package as a library

Depend on it

Run this command:

With Flutter:

 $ flutter pub add android_alarm_manager_plus

This will add a line like this to your package's pubspec.yaml (and run an implicit dart pub get):


dependencies:
  android_alarm_manager_plus: ^1.1.0

Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.

Import it

Now in your Dart code, you can use:

import 'package:android_alarm_manager_plus/android_alarm_manager_plus.dart';

example/lib/main.dart

// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// ignore_for_file: public_member_api_docs

import 'dart:isolate';
import 'dart:math';
import 'dart:ui';

import 'package:android_alarm_manager_plus/android_alarm_manager_plus.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:flutter/material.dart';

/// The [SharedPreferences] key to access the alarm fire count.
const String countKey = 'count';

/// The name associated with the UI isolate's [SendPort].
const String isolateName = 'isolate';

/// A port used to communicate from a background isolate to the UI isolate.
final ReceivePort port = ReceivePort();

/// Global [SharedPreferences] object.
SharedPreferences prefs;

Future<void> main() async {
  // TODO(bkonyi): uncomment
  WidgetsFlutterBinding.ensureInitialized();

  // Register the UI isolate's SendPort to allow for communication from the
  // background isolate.
  IsolateNameServer.registerPortWithName(
    port.sendPort,
    isolateName,
  );
  prefs = await SharedPreferences.getInstance();
  if (!prefs.containsKey(countKey)) {
    await prefs.setInt(countKey, 0);
  }
  runApp(AlarmManagerExampleApp());
}

/// Example app for Espresso plugin.
class AlarmManagerExampleApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      home: _AlarmHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class _AlarmHomePage extends StatefulWidget {
  _AlarmHomePage({Key key, this.title}) : super(key: key);
  final String title;

  @override
  _AlarmHomePageState createState() => _AlarmHomePageState();
}

class _AlarmHomePageState extends State<_AlarmHomePage> {
  int _counter = 0;

  @override
  void initState() {
    super.initState();
    AndroidAlarmManager.initialize();

    // Register for events from the background isolate. These messages will
    // always coincide with an alarm firing.
    port.listen((_) async => await _incrementCounter());
  }

  Future<void> _incrementCounter() async {
    print('Increment counter!');

    // Ensure we've loaded the updated count from the background isolate.
    await prefs.reload();

    setState(() {
      _counter++;
    });
  }

  // The background
  static SendPort uiSendPort;

  // The callback for our alarm
  static Future<void> callback() async {
    print('Alarm fired!');

    // Get the previous cached count and increment it.
    final prefs = await SharedPreferences.getInstance();
    final currentCount = prefs.getInt(countKey);
    await prefs.setInt(countKey, currentCount + 1);

    // This will be null if we're running in the background.
    uiSendPort ??= IsolateNameServer.lookupPortByName(isolateName);
    uiSendPort?.send(null);
  }

  @override
  Widget build(BuildContext context) {
    final textStyle = Theme.of(context).textTheme.headline4;
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'Alarm fired $_counter times',
              style: textStyle,
            ),
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                Text(
                  'Total alarms fired: ',
                  style: textStyle,
                ),
                Text(
                  prefs.getInt(countKey).toString(),
                  key: ValueKey('BackgroundCountText'),
                  style: textStyle,
                ),
              ],
            ),
            ElevatedButton(
              key: ValueKey('RegisterOneShotAlarm'),
              onPressed: () async {
                await AndroidAlarmManager.oneShot(
                  // Setting a random duration just for testing purposes.
                  // This way we can have different alarms for different durations.
                  Duration(milliseconds: 1000 + Random().nextInt(pow(2, 10))),
                  // Ensure we have a unique alarm ID.
                  Random().nextInt(pow(2, 31)),
                  callback,
                  exact: true,
                  wakeup: true,
                );
              },
              child: Text(
                'Schedule OneShot Alarm',
              ),
            ),
            ElevatedButton(
              onPressed: () async {
                setState(() {});
              },
              child: Text(
                'Fetch alarms list',
              ),
            ),
            FutureBuilder(
                future: AndroidAlarmManager.getScheduledAlarms(),
                builder:
                    (BuildContext context, AsyncSnapshot<String> snapshot) {
                  if (snapshot.hasData) {
                    return (snapshot.data == '[]')
                        ? Text('No alarms scheduled')
                        : Text(snapshot.data);
                  } else {
                    return Center(child: CircularProgressIndicator());
                  }
                })
          ],
        ),
      ),
    );
  }
}

#flutter #dart  #mobile #mobile-apps 

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A Flutter Plugin for Accessing The android AlarmManager Service

Build an Android application with Kivy Python framework

If you’re a Python developer thinking about getting started with mobile development, then the Kivy framework is your best bet. With Kivy, you can develop platform-independent applications that compile for iOS, Android, Windows, macOS, and Linux. In this article, we’ll cover Android specifically because it is the most used.

We’ll build a simple random number generator app that you can install on your phone and test when you are done. To follow along with this article, you should be familiar with Python. Let’s get started!

Getting started with Kivy

First, you’ll need a new directory for your app. Make sure you have Python installed on your machine and open a new Python file. You’ll need to install the Kivy module from your terminal using either of the commands below. To avoid any package conflicts, be sure you’re installing Kivy in a virtual environment:

pip install kivy 
//
pip3 install kivy 

Once you have installed Kivy, you should see a success message from your terminal that looks like the screenshots below:

Kivy installation

Successful Kivy installation

 

Next, navigate into your project folder. In the main.py file, we’ll need to import the Kivy module and specify which version we want. You can use Kivy v2.0.0, but if you have a smartphone that is older than Android 8.0, I recommend using Kivy v1.9.0. You can mess around with the different versions during the build to see the differences in features and performance.

Add the version number right after the import kivy line as follows:

kivy.require('1.9.0')

Now, we’ll create a class that will basically define our app; I’ll name mine RandomNumber. This class will inherit the app class from Kivy. Therefore, you need to import the app by adding from kivy.app import App:

class RandomNumber(App): 

In the RandomNumber class, you’ll need to add a function called build, which takes a self parameter. To actually return the UI, we’ll use the build function. For now, I have it returned as a simple label. To do so, you’ll need to import Label using the line from kivy.uix.label import Label:

import kivy
from kivy.app import App
from kivy.uix.label import Label

class RandomNumber(App):
  def build(self):
    return Label(text="Random Number Generator")

Now, our app skeleton is complete! Before moving forward, you should create an instance of the RandomNumber class and run it in your terminal or IDE to see the interface:

import kivy from kivy.app import App from kivy.uix.label import Label class RandomNumber(App):  def build(self):    return Label(text="Random Number Generator") randomApp = RandomNumber() randomApp.run()

When you run the class instance with the text Random Number Generator, you should see a simple interface or window that looks like the screenshot below:

 

Simple interface after running the code

You won’t be able to run the text on Android until you’ve finished building the whole thing.

Outsourcing the interface

Next, we’ll need a way to outsource the interface. First, we’ll create a Kivy file in our directory that will house most of our design work. You’ll want to name this file the same name as your class using lowercase letters and a .kv extension. Kivy will automatically associate the class name and the file name, but it may not work on Android if they are exactly the same.

Inside that .kv file, you need to specify the layout for your app, including elements like the label, buttons, forms, etc. To keep this demonstration simple, I’ll add a label for the title Random Number, a label that will serve as a placeholder for the random number that is generated _, and a Generate button that calls the generate function.

My .kv file looks like the code below, but you can mess around with the different values to fit your requirements:

<boxLayout>:
    orientation: "vertical"
    Label:
        text: "Random Number"
        font_size: 30
        color: 0, 0.62, 0.96

    Label:
        text: "_"
        font_size: 30

    Button:
        text: "Generate"
        font_size: 15 

In the main.py file, you no longer need the Label import statement because the Kivy file takes care of your UI. However, you do need to import boxlayout, which you will use in the Kivy file.

In your main file, you need to add the import statement and edit your main.py file to read return BoxLayout() in the build method:

from kivy.uix.boxlayout import BoxLayout

If you run the command above, you should see a simple interface that has the random number title, the _ place holder, and the clickable generate button:

Random Number app rendered

Notice that you didn’t have to import anything for the Kivy file to work. Basically, when you run the app, it returns boxlayout by looking for a file inside the Kivy file with the same name as your class. Keep in mind, this is a simple interface, and you can make your app as robust as you want. Be sure to check out the Kv language documentation.

Generate the random number function

Now that our app is almost done, we’ll need a simple function to generate random numbers when a user clicks the generate button, then render that random number into the app interface. To do so, we’ll need to change a few things in our files.

First, we’ll import the module that we’ll use to generate a random number with import random. Then, we’ll create a function or method that calls the generated number. For this demonstration, I’ll use a range between 0 and 2000. Generating the random number is simple with the random.randint(0, 2000) command. We’ll add this into our code in a moment.

Next, we’ll create another class that will be our own version of the box layout. Our class will have to inherit the box layout class, which houses the method to generate random numbers and render them on the interface:

class MyRoot(BoxLayout):
    def __init__(self):
        super(MyRoot, self).__init__()

Within that class, we’ll create the generate method, which will not only generate random numbers but also manipulate the label that controls what is displayed as the random number in the Kivy file.

To accommodate this method, we’ll first need to make changes to the .kv file . Since the MyRoot class has inherited the box layout, you can make MyRoot the top level element in your .kv file:

<MyRoot>:
    BoxLayout:
        orientation: "vertical"
        Label:
            text: "Random Number"
            font_size: 30
            color: 0, 0.62, 0.96

        Label:
            text: "_"
            font_size: 30

        Button:
            text: "Generate"
            font_size: 15

Notice that you are still keeping all your UI specifications indented in the Box Layout. After this, you need to add an ID to the label that will hold the generated numbers, making it easy to manipulate when the generate function is called. You need to specify the relationship between the ID in this file and another in the main code at the top, just before the BoxLayout line:

<MyRoot>:
    random_label: random_label
    BoxLayout:
        orientation: "vertical"
        Label:
            text: "Random Number"
            font_size: 30
            color: 0, 0.62, 0.96

        Label:
            id: random_label
            text: "_"
            font_size: 30

        Button:
            text: "Generate"
            font_size: 15

The random_label: random_label line basically means that the label with the ID random_label will be mapped to random_label in the main.py file, meaning that any action that manipulates random_label will be mapped on the label with the specified name.

We can now create the method to generate the random number in the main file:

def generate_number(self):
    self.random_label.text = str(random.randint(0, 2000))

# notice how the class method manipulates the text attributre of the random label by a# ssigning it a new random number generate by the 'random.randint(0, 2000)' funcion. S# ince this the random number generated is an integer, typecasting is required to make # it a string otherwise you will get a typeError in your terminal when you run it.

The MyRoot class should look like the code below:

class MyRoot(BoxLayout):
    def __init__(self):
        super(MyRoot, self).__init__()

    def generate_number(self):
        self.random_label.text = str(random.randint(0, 2000))

Congratulations! You’re now done with the main file of the app. The only thing left to do is make sure that you call this function when the generate button is clicked. You need only add the line on_press: root.generate_number() to the button selection part of your .kv file:

<MyRoot>:
    random_label: random_label
    BoxLayout:
        orientation: "vertical"
        Label:
            text: "Random Number"
            font_size: 30
            color: 0, 0.62, 0.96

        Label:
            id: random_label
            text: "_"
            font_size: 30

        Button:
            text: "Generate"
            font_size: 15
            on_press: root.generate_number()

Now, you can run the app.

Compiling our app on Android

Before compiling our app on Android, I have some bad news for Windows users. You’ll need Linux or macOS to compile your Android application. However, you don’t need to have a separate Linux distribution, instead, you can use a virtual machine.

To compile and generate a full Android .apk application, we’ll use a tool called Buildozer. Let’s install Buildozer through our terminal using one of the commands below:

pip3 install buildozer
//
pip install buildozer

Now, we’ll install some of Buildozer’s required dependencies. I am on Linux Ergo, so I’ll use Linux-specific commands. You should execute these commands one by one:

sudo apt update
sudo apt install -y git zip unzip openjdk-13-jdk python3-pip autoconf libtool pkg-config zlib1g-dev libncurses5-dev libncursesw5-dev libtinfo5 cmake libffi-dev libssl-dev

pip3 install --upgrade Cython==0.29.19 virtualenv 

# add the following line at the end of your ~/.bashrc file
export PATH=$PATH:~/.local/bin/

After executing the specific commands, run buildozer init. You should see an output similar to the screenshot below:

Buildozer successful initialization

The command above creates a Buildozer .spec file, which you can use to make specifications to your app, including the name of the app, the icon, etc. The .spec file should look like the code block below:

[app]

# (str) Title of your application
title = My Application

# (str) Package name
package.name = myapp

# (str) Package domain (needed for android/ios packaging)
package.domain = org.test

# (str) Source code where the main.py live
source.dir = .

# (list) Source files to include (let empty to include all the files)
source.include_exts = py,png,jpg,kv,atlas

# (list) List of inclusions using pattern matching
#source.include_patterns = assets/*,images/*.png

# (list) Source files to exclude (let empty to not exclude anything)
#source.exclude_exts = spec

# (list) List of directory to exclude (let empty to not exclude anything)
#source.exclude_dirs = tests, bin

# (list) List of exclusions using pattern matching
#source.exclude_patterns = license,images/*/*.jpg

# (str) Application versioning (method 1)
version = 0.1

# (str) Application versioning (method 2)
# version.regex = __version__ = \['"\](.*)['"]
# version.filename = %(source.dir)s/main.py

# (list) Application requirements
# comma separated e.g. requirements = sqlite3,kivy
requirements = python3,kivy

# (str) Custom source folders for requirements
# Sets custom source for any requirements with recipes
# requirements.source.kivy = ../../kivy

# (list) Garden requirements
#garden_requirements =

# (str) Presplash of the application
#presplash.filename = %(source.dir)s/data/presplash.png

# (str) Icon of the application
#icon.filename = %(source.dir)s/data/icon.png

# (str) Supported orientation (one of landscape, sensorLandscape, portrait or all)
orientation = portrait

# (list) List of service to declare
#services = NAME:ENTRYPOINT_TO_PY,NAME2:ENTRYPOINT2_TO_PY

#
# OSX Specific
#

#
# author = © Copyright Info

# change the major version of python used by the app
osx.python_version = 3

# Kivy version to use
osx.kivy_version = 1.9.1

#
# Android specific
#

# (bool) Indicate if the application should be fullscreen or not
fullscreen = 0

# (string) Presplash background color (for new android toolchain)
# Supported formats are: #RRGGBB #AARRGGBB or one of the following names:
# red, blue, green, black, white, gray, cyan, magenta, yellow, lightgray,
# darkgray, grey, lightgrey, darkgrey, aqua, fuchsia, lime, maroon, navy,
# olive, purple, silver, teal.
#android.presplash_color = #FFFFFF

# (list) Permissions
#android.permissions = INTERNET

# (int) Target Android API, should be as high as possible.
#android.api = 27

# (int) Minimum API your APK will support.
#android.minapi = 21

# (int) Android SDK version to use
#android.sdk = 20

# (str) Android NDK version to use
#android.ndk = 19b

# (int) Android NDK API to use. This is the minimum API your app will support, it should usually match android.minapi.
#android.ndk_api = 21

# (bool) Use --private data storage (True) or --dir public storage (False)
#android.private_storage = True

# (str) Android NDK directory (if empty, it will be automatically downloaded.)
#android.ndk_path =

# (str) Android SDK directory (if empty, it will be automatically downloaded.)
#android.sdk_path =

# (str) ANT directory (if empty, it will be automatically downloaded.)
#android.ant_path =

# (bool) If True, then skip trying to update the Android sdk
# This can be useful to avoid excess Internet downloads or save time
# when an update is due and you just want to test/build your package
# android.skip_update = False

# (bool) If True, then automatically accept SDK license
# agreements. This is intended for automation only. If set to False,
# the default, you will be shown the license when first running
# buildozer.
# android.accept_sdk_license = False

# (str) Android entry point, default is ok for Kivy-based app
#android.entrypoint = org.renpy.android.PythonActivity

# (str) Android app theme, default is ok for Kivy-based app
# android.apptheme = "@android:style/Theme.NoTitleBar"

# (list) Pattern to whitelist for the whole project
#android.whitelist =

# (str) Path to a custom whitelist file
#android.whitelist_src =

# (str) Path to a custom blacklist file
#android.blacklist_src =

# (list) List of Java .jar files to add to the libs so that pyjnius can access
# their classes. Don't add jars that you do not need, since extra jars can slow
# down the build process. Allows wildcards matching, for example:
# OUYA-ODK/libs/*.jar
#android.add_jars = foo.jar,bar.jar,path/to/more/*.jar

# (list) List of Java files to add to the android project (can be java or a
# directory containing the files)
#android.add_src =

# (list) Android AAR archives to add (currently works only with sdl2_gradle
# bootstrap)
#android.add_aars =

# (list) Gradle dependencies to add (currently works only with sdl2_gradle
# bootstrap)
#android.gradle_dependencies =

# (list) add java compile options
# this can for example be necessary when importing certain java libraries using the 'android.gradle_dependencies' option
# see https://developer.android.com/studio/write/java8-support for further information
# android.add_compile_options = "sourceCompatibility = 1.8", "targetCompatibility = 1.8"

# (list) Gradle repositories to add {can be necessary for some android.gradle_dependencies}
# please enclose in double quotes 
# e.g. android.gradle_repositories = "maven { url 'https://kotlin.bintray.com/ktor' }"
#android.add_gradle_repositories =

# (list) packaging options to add 
# see https://google.github.io/android-gradle-dsl/current/com.android.build.gradle.internal.dsl.PackagingOptions.html
# can be necessary to solve conflicts in gradle_dependencies
# please enclose in double quotes 
# e.g. android.add_packaging_options = "exclude 'META-INF/common.kotlin_module'", "exclude 'META-INF/*.kotlin_module'"
#android.add_gradle_repositories =

# (list) Java classes to add as activities to the manifest.
#android.add_activities = com.example.ExampleActivity

# (str) OUYA Console category. Should be one of GAME or APP
# If you leave this blank, OUYA support will not be enabled
#android.ouya.category = GAME

# (str) Filename of OUYA Console icon. It must be a 732x412 png image.
#android.ouya.icon.filename = %(source.dir)s/data/ouya_icon.png

# (str) XML file to include as an intent filters in <activity> tag
#android.manifest.intent_filters =

# (str) launchMode to set for the main activity
#android.manifest.launch_mode = standard

# (list) Android additional libraries to copy into libs/armeabi
#android.add_libs_armeabi = libs/android/*.so
#android.add_libs_armeabi_v7a = libs/android-v7/*.so
#android.add_libs_arm64_v8a = libs/android-v8/*.so
#android.add_libs_x86 = libs/android-x86/*.so
#android.add_libs_mips = libs/android-mips/*.so

# (bool) Indicate whether the screen should stay on
# Don't forget to add the WAKE_LOCK permission if you set this to True
#android.wakelock = False

# (list) Android application meta-data to set (key=value format)
#android.meta_data =

# (list) Android library project to add (will be added in the
# project.properties automatically.)
#android.library_references =

# (list) Android shared libraries which will be added to AndroidManifest.xml using <uses-library> tag
#android.uses_library =

# (str) Android logcat filters to use
#android.logcat_filters = *:S python:D

# (bool) Copy library instead of making a libpymodules.so
#android.copy_libs = 1

# (str) The Android arch to build for, choices: armeabi-v7a, arm64-v8a, x86, x86_64
android.arch = armeabi-v7a

# (int) overrides automatic versionCode computation (used in build.gradle)
# this is not the same as app version and should only be edited if you know what you're doing
# android.numeric_version = 1

#
# Python for android (p4a) specific
#

# (str) python-for-android fork to use, defaults to upstream (kivy)
#p4a.fork = kivy

# (str) python-for-android branch to use, defaults to master
#p4a.branch = master

# (str) python-for-android git clone directory (if empty, it will be automatically cloned from github)
#p4a.source_dir =

# (str) The directory in which python-for-android should look for your own build recipes (if any)
#p4a.local_recipes =

# (str) Filename to the hook for p4a
#p4a.hook =

# (str) Bootstrap to use for android builds
# p4a.bootstrap = sdl2

# (int) port number to specify an explicit --port= p4a argument (eg for bootstrap flask)
#p4a.port =


#
# iOS specific
#

# (str) Path to a custom kivy-ios folder
#ios.kivy_ios_dir = ../kivy-ios
# Alternately, specify the URL and branch of a git checkout:
ios.kivy_ios_url = https://github.com/kivy/kivy-ios
ios.kivy_ios_branch = master

# Another platform dependency: ios-deploy
# Uncomment to use a custom checkout
#ios.ios_deploy_dir = ../ios_deploy
# Or specify URL and branch
ios.ios_deploy_url = https://github.com/phonegap/ios-deploy
ios.ios_deploy_branch = 1.7.0

# (str) Name of the certificate to use for signing the debug version
# Get a list of available identities: buildozer ios list_identities
#ios.codesign.debug = "iPhone Developer: <lastname> <firstname> (<hexstring>)"

# (str) Name of the certificate to use for signing the release version
#ios.codesign.release = %(ios.codesign.debug)s


[buildozer]

# (int) Log level (0 = error only, 1 = info, 2 = debug (with command output))
log_level = 2

# (int) Display warning if buildozer is run as root (0 = False, 1 = True)
warn_on_root = 1

# (str) Path to build artifact storage, absolute or relative to spec file
# build_dir = ./.buildozer

# (str) Path to build output (i.e. .apk, .ipa) storage
# bin_dir = ./bin

#    -----------------------------------------------------------------------------
#    List as sections
#
#    You can define all the "list" as [section:key].
#    Each line will be considered as a option to the list.
#    Let's take [app] / source.exclude_patterns.
#    Instead of doing:
#
#[app]
#source.exclude_patterns = license,data/audio/*.wav,data/images/original/*
#
#    This can be translated into:
#
#[app:source.exclude_patterns]
#license
#data/audio/*.wav
#data/images/original/*
#


#    -----------------------------------------------------------------------------
#    Profiles
#
#    You can extend section / key with a profile
#    For example, you want to deploy a demo version of your application without
#    HD content. You could first change the title to add "(demo)" in the name
#    and extend the excluded directories to remove the HD content.
#
#[app@demo]
#title = My Application (demo)
#
#[app:source.exclude_patterns@demo]
#images/hd/*
#
#    Then, invoke the command line with the "demo" profile:
#
#buildozer --profile demo android debug

If you want to specify things like the icon, requirements, loading screen, etc., you should edit this file. After making all the desired edits to your application, run buildozer -v android debug from your app directory to build and compile your application. This may take a while, especially if you have a slow machine.

After the process is done, your terminal should have some logs, one confirming that the build was successful:

Android successful build

You should also have an APK version of your app in your bin directory. This is the application executable that you will install and run on your phone:

Android .apk in the bin directory

Conclusion

Congratulations! If you have followed this tutorial step by step, you should have a simple random number generator app on your phone. Play around with it and tweak some values, then rebuild. Running the rebuild will not take as much time as the first build.

As you can see, building a mobile application with Python is fairly straightforward, as long as you are familiar with the framework or module you are working with. Regardless, the logic is executed the same way.

Get familiar with the Kivy module and it’s widgets. You can never know everything all at once. You only need to find a project and get your feet wet as early as possible. Happy coding.

Link: https://blog.logrocket.com/build-android-application-kivy-python-framework/

#python 

Cree Una Aplicación De Android Con El Marco Kivy Python

Si es un desarrollador de Python que está pensando en comenzar con el desarrollo móvil, entonces el marco Kivy es su mejor opción. Con Kivy, puede desarrollar aplicaciones independientes de la plataforma que compilan para iOS, Android, Windows, macOS y Linux. En este artículo, cubriremos Android específicamente porque es el más utilizado.

Construiremos una aplicación generadora de números aleatorios simple que puede instalar en su teléfono y probar cuando haya terminado. Para continuar con este artículo, debe estar familiarizado con Python. ¡Empecemos!

Primeros pasos con Kivy

Primero, necesitará un nuevo directorio para su aplicación. Asegúrese de tener Python instalado en su máquina y abra un nuevo archivo de Python. Deberá instalar el módulo Kivy desde su terminal usando cualquiera de los comandos a continuación. Para evitar conflictos de paquetes, asegúrese de instalar Kivy en un entorno virtual:

pip install kivy 
//
pip3 install kivy 

Una vez que haya instalado Kivy, debería ver un mensaje de éxito de su terminal que se parece a las capturas de pantalla a continuación:

Instalación decepcionada

Instalación exitosa de Kivy

 

A continuación, navegue a la carpeta de su proyecto. En el main.pyarchivo, necesitaremos importar el módulo Kivy y especificar qué versión queremos. Puede usar Kivy v2.0.0, pero si tiene un teléfono inteligente anterior a Android 8.0, le recomiendo usar Kivy v1.9.0. Puede jugar con las diferentes versiones durante la compilación para ver las diferencias en las características y el rendimiento.

Agregue el número de versión justo después de la import kivylínea de la siguiente manera:

kivy.require('1.9.0')

Ahora, crearemos una clase que básicamente definirá nuestra aplicación; Voy a nombrar el mío RandomNumber. Esta clase heredará la appclase de Kivy. Por lo tanto, debe importar appagregando from kivy.app import App:

class RandomNumber(App): 

En la RandomNumberclase, deberá agregar una función llamada build, que toma un selfparámetro. Para devolver la interfaz de usuario, usaremos la buildfunción. Por ahora, lo tengo devuelto como una simple etiqueta. Para hacerlo, deberá importar Labelusando la línea from kivy.uix.label import Label:

import kivy
from kivy.app import App
from kivy.uix.label import Label

class RandomNumber(App):
  def build(self):
    return Label(text="Random Number Generator")

¡Ahora, el esqueleto de nuestra aplicación está completo! Antes de continuar, debe crear una instancia de la RandomNumberclase y ejecutarla en su terminal o IDE para ver la interfaz:

importar kivy de kivy.app importar aplicación de kivy.uix.label clase de etiqueta de importación RandomNumber(App): def build(self): return Label(text="Generador de números aleatorios") randomApp = RandomNumber() randomApp.run()

Cuando ejecuta la instancia de clase con el texto Random Number Generator, debería ver una interfaz o ventana simple que se parece a la siguiente captura de pantalla:

 

Interfaz simple después de ejecutar el código.

No podrá ejecutar el texto en Android hasta que haya terminado de construir todo.

Externalización de la interfaz

A continuación, necesitaremos una forma de subcontratar la interfaz. Primero, crearemos un archivo Kivy en nuestro directorio que albergará la mayor parte de nuestro trabajo de diseño. Querrá nombrar este archivo con el mismo nombre que su clase usando letras minúsculas y una .kvextensión. Kivy asociará automáticamente el nombre de la clase y el nombre del archivo, pero es posible que no funcione en Android si son exactamente iguales.

Dentro de ese .kvarchivo, debe especificar el diseño de su aplicación, incluidos elementos como la etiqueta, los botones, los formularios, etc. Para simplificar esta demostración, agregaré una etiqueta para el título Random Number, una etiqueta que servirá como marcador de posición. para el número aleatorio que se genera _, y un Generatebotón que llama a la generatefunción.

Mi .kvarchivo se parece al siguiente código, pero puede jugar con los diferentes valores para que se ajusten a sus requisitos:

<boxLayout>:
    orientation: "vertical"
    Label:
        text: "Random Number"
        font_size: 30
        color: 0, 0.62, 0.96

    Label:
        text: "_"
        font_size: 30

    Button:
        text: "Generate"
        font_size: 15 

En el main.pyarchivo, ya no necesita la Labeldeclaración de importación porque el archivo Kivy se encarga de su interfaz de usuario. Sin embargo, necesita importar boxlayout, que utilizará en el archivo Kivy.

En su archivo principal, debe agregar la declaración de importación y editar su main.pyarchivo para leer return BoxLayout()el buildmétodo:

from kivy.uix.boxlayout import BoxLayout

Si ejecuta el comando anterior, debería ver una interfaz simple que tiene el título del número aleatorio, el _marcador de posición y el generatebotón en el que se puede hacer clic:

Aplicación de números aleatorios renderizada

Tenga en cuenta que no tuvo que importar nada para que funcione el archivo Kivy. Básicamente, cuando ejecuta la aplicación, regresa boxlayoutbuscando un archivo dentro del archivo Kivy con el mismo nombre que su clase. Tenga en cuenta que esta es una interfaz simple y puede hacer que su aplicación sea tan robusta como desee. Asegúrese de consultar la documentación del idioma Kv .

Generar la función de números aleatorios

Ahora que nuestra aplicación está casi terminada, necesitaremos una función simple para generar números aleatorios cuando un usuario haga clic en el generatebotón y luego mostrar ese número aleatorio en la interfaz de la aplicación. Para hacerlo, necesitaremos cambiar algunas cosas en nuestros archivos.

Primero, importaremos el módulo que usaremos para generar un número aleatorio con import random. Luego, crearemos una función o método que llame al número generado. Para esta demostración, usaré un rango entre 0y 2000. Generar el número aleatorio es simple con el random.randint(0, 2000)comando. Agregaremos esto a nuestro código en un momento.

A continuación, crearemos otra clase que será nuestra propia versión del box layout. Nuestra clase tendrá que heredar la box layoutclase, que alberga el método para generar números aleatorios y representarlos en la interfaz:

class MyRoot(BoxLayout):
    def __init__(self):
        super(MyRoot, self).__init__()

Dentro de esa clase, crearemos el generatemétodo, que no solo generará números aleatorios, sino que también manipulará la etiqueta que controla lo que se muestra como número aleatorio en el archivo Kivy.

Para acomodar este método, primero necesitaremos hacer cambios en el .kvarchivo. Dado que la MyRootclase ha heredado el box layout, puede crear MyRootel elemento de nivel superior en su .kvarchivo:

<MyRoot>:
    BoxLayout:
        orientation: "vertical"
        Label:
            text: "Random Number"
            font_size: 30
            color: 0, 0.62, 0.96

        Label:
            text: "_"
            font_size: 30

        Button:
            text: "Generate"
            font_size: 15

Tenga en cuenta que todavía mantiene todas las especificaciones de la interfaz de usuario con sangría en el archivo Box Layout. Después de esto, debe agregar una identificación a la etiqueta que contendrá los números generados, lo que facilita la manipulación cuando generatese llama a la función. Debe especificar la relación entre la ID en este archivo y otra en el código principal en la parte superior, justo antes de la BoxLayoutlínea:

<MyRoot>:
    random_label: random_label
    BoxLayout:
        orientation: "vertical"
        Label:
            text: "Random Number"
            font_size: 30
            color: 0, 0.62, 0.96

        Label:
            id: random_label
            text: "_"
            font_size: 30

        Button:
            text: "Generate"
            font_size: 15

La random_label: random_labellínea básicamente significa que la etiqueta con el ID random_labelse asignará a random_labelen el main.pyarchivo, lo que significa que cualquier acción que manipula random_labelserán mapeados en la etiqueta con el nombre especificado.

Ahora podemos crear el método para generar el número aleatorio en el archivo principal:

def generate_number(self):
    self.random_label.text = str(random.randint(0, 2000))

# notice how the class method manipulates the text attributre of the random label by a# ssigning it a new random number generate by the 'random.randint(0, 2000)' funcion. S# ince this the random number generated is an integer, typecasting is required to make # it a string otherwise you will get a typeError in your terminal when you run it.

La MyRootclase debería parecerse al siguiente código:

class MyRoot(BoxLayout):
    def __init__(self):
        super(MyRoot, self).__init__()

    def generate_number(self):
        self.random_label.text = str(random.randint(0, 2000))

¡Felicidades! Ya ha terminado con el archivo principal de la aplicación. Lo único que queda por hacer es asegurarse de llamar a esta función cuando se haga generateclic en el botón. Solo necesita agregar la línea on_press: root.generate_number()a la parte de selección de botones de su .kvarchivo:

<MyRoot>:
    random_label: random_label
    BoxLayout:
        orientation: "vertical"
        Label:
            text: "Random Number"
            font_size: 30
            color: 0, 0.62, 0.96

        Label:
            id: random_label
            text: "_"
            font_size: 30

        Button:
            text: "Generate"
            font_size: 15
            on_press: root.generate_number()

Ahora, puede ejecutar la aplicación.

Compilando nuestra aplicación en Android

Antes de compilar nuestra aplicación en Android, tengo malas noticias para los usuarios de Windows. Necesitará Linux o macOS para compilar su aplicación de Android. Sin embargo, no necesita tener una distribución de Linux separada, en su lugar, puede usar una máquina virtual.

Para compilar y generar una .apkaplicación Android completa , usaremos una herramienta llamada Buildozer . Instalemos Buildozer a través de nuestra terminal usando uno de los siguientes comandos:

pip3 install buildozer
//
pip install buildozer

Ahora, instalaremos algunas de las dependencias requeridas de Buildozer. Estoy en Linux Ergo, así que usaré comandos específicos de Linux. Debe ejecutar estos comandos uno por uno:

sudo apt update
sudo apt install -y git zip unzip openjdk-13-jdk python3-pip autoconf libtool pkg-config zlib1g-dev libncurses5-dev libncursesw5-dev libtinfo5 cmake libffi-dev libssl-dev

pip3 install --upgrade Cython==0.29.19 virtualenv 

# add the following line at the end of your ~/.bashrc file
export PATH=$PATH:~/.local/bin/

Después de ejecutar los comandos específicos, ejecute buildozer init. Debería ver un resultado similar a la captura de pantalla a continuación:

Inicialización exitosa de Buildozer

El comando anterior crea un .specarchivo Buildozer , que puede usar para hacer especificaciones para su aplicación, incluido el nombre de la aplicación, el ícono, etc. El .specarchivo debe verse como el bloque de código a continuación:

[app]

# (str) Title of your application
title = My Application

# (str) Package name
package.name = myapp

# (str) Package domain (needed for android/ios packaging)
package.domain = org.test

# (str) Source code where the main.py live
source.dir = .

# (list) Source files to include (let empty to include all the files)
source.include_exts = py,png,jpg,kv,atlas

# (list) List of inclusions using pattern matching
#source.include_patterns = assets/*,images/*.png

# (list) Source files to exclude (let empty to not exclude anything)
#source.exclude_exts = spec

# (list) List of directory to exclude (let empty to not exclude anything)
#source.exclude_dirs = tests, bin

# (list) List of exclusions using pattern matching
#source.exclude_patterns = license,images/*/*.jpg

# (str) Application versioning (method 1)
version = 0.1

# (str) Application versioning (method 2)
# version.regex = __version__ = \['"\](.*)['"]
# version.filename = %(source.dir)s/main.py

# (list) Application requirements
# comma separated e.g. requirements = sqlite3,kivy
requirements = python3,kivy

# (str) Custom source folders for requirements
# Sets custom source for any requirements with recipes
# requirements.source.kivy = ../../kivy

# (list) Garden requirements
#garden_requirements =

# (str) Presplash of the application
#presplash.filename = %(source.dir)s/data/presplash.png

# (str) Icon of the application
#icon.filename = %(source.dir)s/data/icon.png

# (str) Supported orientation (one of landscape, sensorLandscape, portrait or all)
orientation = portrait

# (list) List of service to declare
#services = NAME:ENTRYPOINT_TO_PY,NAME2:ENTRYPOINT2_TO_PY

#
# OSX Specific
#

#
# author = © Copyright Info

# change the major version of python used by the app
osx.python_version = 3

# Kivy version to use
osx.kivy_version = 1.9.1

#
# Android specific
#

# (bool) Indicate if the application should be fullscreen or not
fullscreen = 0

# (string) Presplash background color (for new android toolchain)
# Supported formats are: #RRGGBB #AARRGGBB or one of the following names:
# red, blue, green, black, white, gray, cyan, magenta, yellow, lightgray,
# darkgray, grey, lightgrey, darkgrey, aqua, fuchsia, lime, maroon, navy,
# olive, purple, silver, teal.
#android.presplash_color = #FFFFFF

# (list) Permissions
#android.permissions = INTERNET

# (int) Target Android API, should be as high as possible.
#android.api = 27

# (int) Minimum API your APK will support.
#android.minapi = 21

# (int) Android SDK version to use
#android.sdk = 20

# (str) Android NDK version to use
#android.ndk = 19b

# (int) Android NDK API to use. This is the minimum API your app will support, it should usually match android.minapi.
#android.ndk_api = 21

# (bool) Use --private data storage (True) or --dir public storage (False)
#android.private_storage = True

# (str) Android NDK directory (if empty, it will be automatically downloaded.)
#android.ndk_path =

# (str) Android SDK directory (if empty, it will be automatically downloaded.)
#android.sdk_path =

# (str) ANT directory (if empty, it will be automatically downloaded.)
#android.ant_path =

# (bool) If True, then skip trying to update the Android sdk
# This can be useful to avoid excess Internet downloads or save time
# when an update is due and you just want to test/build your package
# android.skip_update = False

# (bool) If True, then automatically accept SDK license
# agreements. This is intended for automation only. If set to False,
# the default, you will be shown the license when first running
# buildozer.
# android.accept_sdk_license = False

# (str) Android entry point, default is ok for Kivy-based app
#android.entrypoint = org.renpy.android.PythonActivity

# (str) Android app theme, default is ok for Kivy-based app
# android.apptheme = "@android:style/Theme.NoTitleBar"

# (list) Pattern to whitelist for the whole project
#android.whitelist =

# (str) Path to a custom whitelist file
#android.whitelist_src =

# (str) Path to a custom blacklist file
#android.blacklist_src =

# (list) List of Java .jar files to add to the libs so that pyjnius can access
# their classes. Don't add jars that you do not need, since extra jars can slow
# down the build process. Allows wildcards matching, for example:
# OUYA-ODK/libs/*.jar
#android.add_jars = foo.jar,bar.jar,path/to/more/*.jar

# (list) List of Java files to add to the android project (can be java or a
# directory containing the files)
#android.add_src =

# (list) Android AAR archives to add (currently works only with sdl2_gradle
# bootstrap)
#android.add_aars =

# (list) Gradle dependencies to add (currently works only with sdl2_gradle
# bootstrap)
#android.gradle_dependencies =

# (list) add java compile options
# this can for example be necessary when importing certain java libraries using the 'android.gradle_dependencies' option
# see https://developer.android.com/studio/write/java8-support for further information
# android.add_compile_options = "sourceCompatibility = 1.8", "targetCompatibility = 1.8"

# (list) Gradle repositories to add {can be necessary for some android.gradle_dependencies}
# please enclose in double quotes 
# e.g. android.gradle_repositories = "maven { url 'https://kotlin.bintray.com/ktor' }"
#android.add_gradle_repositories =

# (list) packaging options to add 
# see https://google.github.io/android-gradle-dsl/current/com.android.build.gradle.internal.dsl.PackagingOptions.html
# can be necessary to solve conflicts in gradle_dependencies
# please enclose in double quotes 
# e.g. android.add_packaging_options = "exclude 'META-INF/common.kotlin_module'", "exclude 'META-INF/*.kotlin_module'"
#android.add_gradle_repositories =

# (list) Java classes to add as activities to the manifest.
#android.add_activities = com.example.ExampleActivity

# (str) OUYA Console category. Should be one of GAME or APP
# If you leave this blank, OUYA support will not be enabled
#android.ouya.category = GAME

# (str) Filename of OUYA Console icon. It must be a 732x412 png image.
#android.ouya.icon.filename = %(source.dir)s/data/ouya_icon.png

# (str) XML file to include as an intent filters in <activity> tag
#android.manifest.intent_filters =

# (str) launchMode to set for the main activity
#android.manifest.launch_mode = standard

# (list) Android additional libraries to copy into libs/armeabi
#android.add_libs_armeabi = libs/android/*.so
#android.add_libs_armeabi_v7a = libs/android-v7/*.so
#android.add_libs_arm64_v8a = libs/android-v8/*.so
#android.add_libs_x86 = libs/android-x86/*.so
#android.add_libs_mips = libs/android-mips/*.so

# (bool) Indicate whether the screen should stay on
# Don't forget to add the WAKE_LOCK permission if you set this to True
#android.wakelock = False

# (list) Android application meta-data to set (key=value format)
#android.meta_data =

# (list) Android library project to add (will be added in the
# project.properties automatically.)
#android.library_references =

# (list) Android shared libraries which will be added to AndroidManifest.xml using <uses-library> tag
#android.uses_library =

# (str) Android logcat filters to use
#android.logcat_filters = *:S python:D

# (bool) Copy library instead of making a libpymodules.so
#android.copy_libs = 1

# (str) The Android arch to build for, choices: armeabi-v7a, arm64-v8a, x86, x86_64
android.arch = armeabi-v7a

# (int) overrides automatic versionCode computation (used in build.gradle)
# this is not the same as app version and should only be edited if you know what you're doing
# android.numeric_version = 1

#
# Python for android (p4a) specific
#

# (str) python-for-android fork to use, defaults to upstream (kivy)
#p4a.fork = kivy

# (str) python-for-android branch to use, defaults to master
#p4a.branch = master

# (str) python-for-android git clone directory (if empty, it will be automatically cloned from github)
#p4a.source_dir =

# (str) The directory in which python-for-android should look for your own build recipes (if any)
#p4a.local_recipes =

# (str) Filename to the hook for p4a
#p4a.hook =

# (str) Bootstrap to use for android builds
# p4a.bootstrap = sdl2

# (int) port number to specify an explicit --port= p4a argument (eg for bootstrap flask)
#p4a.port =


#
# iOS specific
#

# (str) Path to a custom kivy-ios folder
#ios.kivy_ios_dir = ../kivy-ios
# Alternately, specify the URL and branch of a git checkout:
ios.kivy_ios_url = https://github.com/kivy/kivy-ios
ios.kivy_ios_branch = master

# Another platform dependency: ios-deploy
# Uncomment to use a custom checkout
#ios.ios_deploy_dir = ../ios_deploy
# Or specify URL and branch
ios.ios_deploy_url = https://github.com/phonegap/ios-deploy
ios.ios_deploy_branch = 1.7.0

# (str) Name of the certificate to use for signing the debug version
# Get a list of available identities: buildozer ios list_identities
#ios.codesign.debug = "iPhone Developer: <lastname> <firstname> (<hexstring>)"

# (str) Name of the certificate to use for signing the release version
#ios.codesign.release = %(ios.codesign.debug)s


[buildozer]

# (int) Log level (0 = error only, 1 = info, 2 = debug (with command output))
log_level = 2

# (int) Display warning if buildozer is run as root (0 = False, 1 = True)
warn_on_root = 1

# (str) Path to build artifact storage, absolute or relative to spec file
# build_dir = ./.buildozer

# (str) Path to build output (i.e. .apk, .ipa) storage
# bin_dir = ./bin

#    -----------------------------------------------------------------------------
#    List as sections
#
#    You can define all the "list" as [section:key].
#    Each line will be considered as a option to the list.
#    Let's take [app] / source.exclude_patterns.
#    Instead of doing:
#
#[app]
#source.exclude_patterns = license,data/audio/*.wav,data/images/original/*
#
#    This can be translated into:
#
#[app:source.exclude_patterns]
#license
#data/audio/*.wav
#data/images/original/*
#


#    -----------------------------------------------------------------------------
#    Profiles
#
#    You can extend section / key with a profile
#    For example, you want to deploy a demo version of your application without
#    HD content. You could first change the title to add "(demo)" in the name
#    and extend the excluded directories to remove the HD content.
#
#[app@demo]
#title = My Application (demo)
#
#[app:source.exclude_patterns@demo]
#images/hd/*
#
#    Then, invoke the command line with the "demo" profile:
#
#buildozer --profile demo android debug

Si desea especificar cosas como el ícono, los requisitos, la pantalla de carga, etc., debe editar este archivo. Después de realizar todas las ediciones deseadas en su aplicación, ejecute buildozer -v android debugdesde el directorio de su aplicación para construir y compilar su aplicación. Esto puede llevar un tiempo, especialmente si tiene una máquina lenta.

Una vez finalizado el proceso, su terminal debería tener algunos registros, uno que confirme que la compilación fue exitosa:

Construcción exitosa de Android

También debe tener una versión APK de su aplicación en su directorio bin. Este es el ejecutable de la aplicación que instalará y ejecutará en su teléfono:

Android .apk en el directorio bin

Conclusión

¡Felicidades! Si ha seguido este tutorial paso a paso, debería tener una aplicación simple de generador de números aleatorios en su teléfono. Juega con él y ajusta algunos valores, luego reconstruye. Ejecutar la reconstrucción no llevará tanto tiempo como la primera compilación.

Como puede ver, crear una aplicación móvil con Python es bastante sencillo , siempre que esté familiarizado con el marco o módulo con el que está trabajando. Independientemente, la lógica se ejecuta de la misma manera.

Familiarícese con el módulo Kivy y sus widgets. Nunca se puede saber todo a la vez. Solo necesita encontrar un proyecto y mojarse los pies lo antes posible. Codificación feliz.

Enlace: https://blog.logrocket.com/build-android-application-kivy-python-framework/

#python 

坂本  篤司

坂本 篤司

1641693600

KivyPythonフレームワークを使用してAndroidアプリケーションを構築する

あなたがモバイル開発を始めることを考えているPython開発者なら、Kivyフレームワークが最善の策です。Kivyを使用すると、iOS、Android、Windows、macOS、およびLinux用にコンパイルされるプラットフォームに依存しないアプリケーションを開発できます。この記事では、Androidが最も使用されているため、特にAndroidについて説明します。

簡単な乱数ジェネレーターアプリを作成します。このアプリを携帯電話にインストールして、完了したらテストできます。この記事を続けるには、Pythonに精通している必要があります。始めましょう!

Kivyを使い始める

まず、アプリ用の新しいディレクトリが必要になります。マシンにPythonがインストールされていることを確認し、新しいPythonファイルを開きます。以下のコマンドのいずれかを使用して、ターミナルからKivyモジュールをインストールする必要があります。パッケージの競合を避けるために、Kivyを仮想環境にインストールしていることを確認してください。

pip install kivy 
//
pip3 install kivy 

Kivyをインストールすると、以下のスクリーンショットのような成功メッセージがターミナルから表示されます。

がっかりしたインストール

Kivyのインストールに成功

 

次に、プロジェクトフォルダに移動します。このmain.pyファイルで、Kivyモジュールをインポートし、必要なバージョンを指定する必要があります。Kivy v2.0.0を使用できますが、Android 8.0より古いスマートフォンを使用している場合は、Kivyv1.9.0を使用することをお勧めします。ビルド中にさまざまなバージョンをいじって、機能とパフォーマンスの違いを確認できます。

import kivy次のように、行の直後にバージョン番号を追加します。

kivy.require('1.9.0')

次に、基本的にアプリを定義するクラスを作成します。私の名前を付けますRandomNumber。このクラスはappKivyからクラスを継承します。したがって、次appを追加してインポートする必要がありますfrom kivy.app import App

class RandomNumber(App): 

ではRandomNumberクラスは、呼び出された関数を追加する必要がありますbuildとり、selfパラメータを。実際にUIを返すには、このbuild関数を使用します。今のところ、単純なラベルとして返送しています。そのためには、次Labelの行を使用してインポートする必要がありますfrom kivy.uix.label import Label

import kivy
from kivy.app import App
from kivy.uix.label import Label

class RandomNumber(App):
  def build(self):
    return Label(text="Random Number Generator")

これで、アプリのスケルトンが完成しました。先に進む前に、RandomNumberクラスのインスタンスを作成し、ターミナルまたはIDEで実行して、インターフェイスを確認する必要があります。

import kivy from kivy.app import App from kivy.uix.label import Label class RandomNumber(App):def build(self):return Label(text = "Random Number Generator")randomApp = RandomNumber()randomApp.run()

テキストを使用してクラスインスタンスを実行すると、Random Number Generator次のスクリーンショットのような単純なインターフェイスまたはウィンドウが表示されます。

 

コードを実行した後のシンプルなインターフェイス

すべての構築が完了するまで、Androidでテキストを実行することはできません。

インターフェースのアウトソーシング

次に、インターフェースをアウトソーシングする方法が必要になります。まず、ディレクトリにKivyファイルを作成します。このファイルには、ほとんどの設計作業が含まれています。このファイルには、小文字と.kv拡張子を使用して、クラスと同じ名前を付けることができます。Kivyはクラス名とファイル名を自動的に関連付けますが、それらがまったく同じである場合、Androidでは機能しない可能性があります。

その.kvファイル内で、ラベル、ボタン、フォームなどの要素を含むアプリのレイアウトを指定する必要があります。このデモを簡単にするために、タイトルRandom Numberのラベル、プレースホルダーとして機能するラベルを追加します。生成される乱数_、および関数Generateを呼び出すボタンgenerate

私の.kvファイルは以下のコードのように見えますが、要件に合わせてさまざまな値をいじることができます。

<boxLayout>:
    orientation: "vertical"
    Label:
        text: "Random Number"
        font_size: 30
        color: 0, 0.62, 0.96

    Label:
        text: "_"
        font_size: 30

    Button:
        text: "Generate"
        font_size: 15 

このmain.pyファイルではLabel、KivyファイルがUIを処理するため、importステートメントは不要になりました。ただし、boxlayoutKivyファイルで使用するをインポートする必要があります。

メインファイルで、importステートメントを追加し、main.pyファイルを編集return BoxLayout()してbuildメソッドで読み取る必要があります。

from kivy.uix.boxlayout import BoxLayout

上記のコマンドを実行すると、乱数のタイトル、_プレースホルダー、およびクリック可能なgenerateボタンを備えたシンプルなインターフェイスが表示されます。

レンダリングされた乱数アプリ

Kivyファイルを機能させるために何もインポートする必要がなかったことに注意してください。基本的に、アプリを実行するboxlayoutと、クラスと同じ名前のKivyファイル内のファイルを検索して戻ります。これはシンプルなインターフェースであり、アプリを必要に応じて堅牢にすることができます。Kv言語のドキュメントを必ず確認してください。

乱数関数を生成する

アプリがほぼ完成したので、ユーザーがgenerateボタンをクリックしたときに乱数を生成し、その乱数をアプリのインターフェイスにレンダリングする簡単な関数が必要になります。そのためには、ファイル内のいくつかの変更を行う必要があります。

まず、で乱数を生成するために使用するモジュールをインポートしますimport random。次に、生成された番号を呼び出す関数またはメソッドを作成します。このデモでは、私は間の範囲を使用します02000。このrandom.randint(0, 2000)コマンドを使用すると、乱数を簡単に生成できます。これをすぐにコードに追加します。

次に、独自のバージョンとなる別のクラスを作成しますbox layout。このbox layoutクラスは、乱数を生成してインターフェイス上でレンダリングするメソッドを含むクラスを継承する必要があります。

class MyRoot(BoxLayout):
    def __init__(self):
        super(MyRoot, self).__init__()

そのクラス内で、generate乱数を生成するだけでなく、Kivyファイルに乱数として表示されるものを制御するラベルを操作するメソッドを作成します。

この方法に対応するには、最初に.kvファイルに変更を加える必要があります。以来MyRootクラスが継承しているbox layout、あなたが作ることができるMyRootあなたのトップレベルの要素.kvファイルを:

<MyRoot>:
    BoxLayout:
        orientation: "vertical"
        Label:
            text: "Random Number"
            font_size: 30
            color: 0, 0.62, 0.96

        Label:
            text: "_"
            font_size: 30

        Button:
            text: "Generate"
            font_size: 15

でインデントされたすべてのUI仕様を保持していることに注意してくださいBox Layout。この後、生成された番号を保持するIDをラベルに追加して、generate関数が呼び出されたときに簡単に操作できるようにする必要があります。このファイルのIDと、上部のメインコードの別のIDとの関係を、次のBoxLayout行の直前に指定する必要があります。

<MyRoot>:
    random_label: random_label
    BoxLayout:
        orientation: "vertical"
        Label:
            text: "Random Number"
            font_size: 30
            color: 0, 0.62, 0.96

        Label:
            id: random_label
            text: "_"
            font_size: 30

        Button:
            text: "Generate"
            font_size: 15

このrandom_label: random_label行は基本的に、IDrandom_labelを持つラベルがファイルrandom_label内にマップされることをmain.py意味します。つまり、操作random_labelするアクションはすべて、指定された名前のラベルにマップされます。

これで、メインファイルに乱数を生成するメソッドを作成できます。

def generate_number(self):
    self.random_label.text = str(random.randint(0, 2000))

# notice how the class method manipulates the text attributre of the random label by a# ssigning it a new random number generate by the 'random.randint(0, 2000)' funcion. S# ince this the random number generated is an integer, typecasting is required to make # it a string otherwise you will get a typeError in your terminal when you run it.

MyRootこのクラスは、以下のコードのようになります。

class MyRoot(BoxLayout):
    def __init__(self):
        super(MyRoot, self).__init__()

    def generate_number(self):
        self.random_label.text = str(random.randint(0, 2000))

おめでとう!これで、アプリのメインファイルが完成しました。あとは、generateボタンがクリックされたときに必ずこの関数を呼び出すようにしてください。ファイルのon_press: root.generate_number()ボタン選択部分に行を追加するだけで済み.kvます。

<MyRoot>:
    random_label: random_label
    BoxLayout:
        orientation: "vertical"
        Label:
            text: "Random Number"
            font_size: 30
            color: 0, 0.62, 0.96

        Label:
            id: random_label
            text: "_"
            font_size: 30

        Button:
            text: "Generate"
            font_size: 15
            on_press: root.generate_number()

これで、アプリを実行できます。

Androidでアプリをコンパイルする

Androidでアプリをコンパイルする前に、Windowsユーザーにとって悪いニュースがあります。Androidアプリケーションをコンパイルするには、LinuxまたはmacOSが必要です。ただし、個別のLinuxディストリビューションを用意する必要はなく、代わりに仮想マシンを使用できます。

完全なAndroid.apkアプリケーションをコンパイルして生成するには、Buildozerというツールを使用します。以下のコマンドのいずれかを使用して、ターミナルからBuildozerをインストールしましょう。

pip3 install buildozer
//
pip install buildozer

次に、Buildozerに必要な依存関係のいくつかをインストールします。私はLinuxErgoを使用しているので、Linux固有のコマンドを使用します。これらのコマンドを1つずつ実行する必要があります。

sudo apt update
sudo apt install -y git zip unzip openjdk-13-jdk python3-pip autoconf libtool pkg-config zlib1g-dev libncurses5-dev libncursesw5-dev libtinfo5 cmake libffi-dev libssl-dev

pip3 install --upgrade Cython==0.29.19 virtualenv 

# add the following line at the end of your ~/.bashrc file
export PATH=$PATH:~/.local/bin/

特定のコマンドを実行した後、を実行しbuildozer initます。以下のスクリーンショットのような出力が表示されます。

Buildozerの初期化が成功しました

上記のコマンドはBuildozer.specファイルを作成します。このファイルを使用して、アプリの名前やアイコンなどをアプリに指定.specできます。ファイルは次のコードブロックのようになります。

[app]

# (str) Title of your application
title = My Application

# (str) Package name
package.name = myapp

# (str) Package domain (needed for android/ios packaging)
package.domain = org.test

# (str) Source code where the main.py live
source.dir = .

# (list) Source files to include (let empty to include all the files)
source.include_exts = py,png,jpg,kv,atlas

# (list) List of inclusions using pattern matching
#source.include_patterns = assets/*,images/*.png

# (list) Source files to exclude (let empty to not exclude anything)
#source.exclude_exts = spec

# (list) List of directory to exclude (let empty to not exclude anything)
#source.exclude_dirs = tests, bin

# (list) List of exclusions using pattern matching
#source.exclude_patterns = license,images/*/*.jpg

# (str) Application versioning (method 1)
version = 0.1

# (str) Application versioning (method 2)
# version.regex = __version__ = \['"\](.*)['"]
# version.filename = %(source.dir)s/main.py

# (list) Application requirements
# comma separated e.g. requirements = sqlite3,kivy
requirements = python3,kivy

# (str) Custom source folders for requirements
# Sets custom source for any requirements with recipes
# requirements.source.kivy = ../../kivy

# (list) Garden requirements
#garden_requirements =

# (str) Presplash of the application
#presplash.filename = %(source.dir)s/data/presplash.png

# (str) Icon of the application
#icon.filename = %(source.dir)s/data/icon.png

# (str) Supported orientation (one of landscape, sensorLandscape, portrait or all)
orientation = portrait

# (list) List of service to declare
#services = NAME:ENTRYPOINT_TO_PY,NAME2:ENTRYPOINT2_TO_PY

#
# OSX Specific
#

#
# author = © Copyright Info

# change the major version of python used by the app
osx.python_version = 3

# Kivy version to use
osx.kivy_version = 1.9.1

#
# Android specific
#

# (bool) Indicate if the application should be fullscreen or not
fullscreen = 0

# (string) Presplash background color (for new android toolchain)
# Supported formats are: #RRGGBB #AARRGGBB or one of the following names:
# red, blue, green, black, white, gray, cyan, magenta, yellow, lightgray,
# darkgray, grey, lightgrey, darkgrey, aqua, fuchsia, lime, maroon, navy,
# olive, purple, silver, teal.
#android.presplash_color = #FFFFFF

# (list) Permissions
#android.permissions = INTERNET

# (int) Target Android API, should be as high as possible.
#android.api = 27

# (int) Minimum API your APK will support.
#android.minapi = 21

# (int) Android SDK version to use
#android.sdk = 20

# (str) Android NDK version to use
#android.ndk = 19b

# (int) Android NDK API to use. This is the minimum API your app will support, it should usually match android.minapi.
#android.ndk_api = 21

# (bool) Use --private data storage (True) or --dir public storage (False)
#android.private_storage = True

# (str) Android NDK directory (if empty, it will be automatically downloaded.)
#android.ndk_path =

# (str) Android SDK directory (if empty, it will be automatically downloaded.)
#android.sdk_path =

# (str) ANT directory (if empty, it will be automatically downloaded.)
#android.ant_path =

# (bool) If True, then skip trying to update the Android sdk
# This can be useful to avoid excess Internet downloads or save time
# when an update is due and you just want to test/build your package
# android.skip_update = False

# (bool) If True, then automatically accept SDK license
# agreements. This is intended for automation only. If set to False,
# the default, you will be shown the license when first running
# buildozer.
# android.accept_sdk_license = False

# (str) Android entry point, default is ok for Kivy-based app
#android.entrypoint = org.renpy.android.PythonActivity

# (str) Android app theme, default is ok for Kivy-based app
# android.apptheme = "@android:style/Theme.NoTitleBar"

# (list) Pattern to whitelist for the whole project
#android.whitelist =

# (str) Path to a custom whitelist file
#android.whitelist_src =

# (str) Path to a custom blacklist file
#android.blacklist_src =

# (list) List of Java .jar files to add to the libs so that pyjnius can access
# their classes. Don't add jars that you do not need, since extra jars can slow
# down the build process. Allows wildcards matching, for example:
# OUYA-ODK/libs/*.jar
#android.add_jars = foo.jar,bar.jar,path/to/more/*.jar

# (list) List of Java files to add to the android project (can be java or a
# directory containing the files)
#android.add_src =

# (list) Android AAR archives to add (currently works only with sdl2_gradle
# bootstrap)
#android.add_aars =

# (list) Gradle dependencies to add (currently works only with sdl2_gradle
# bootstrap)
#android.gradle_dependencies =

# (list) add java compile options
# this can for example be necessary when importing certain java libraries using the 'android.gradle_dependencies' option
# see https://developer.android.com/studio/write/java8-support for further information
# android.add_compile_options = "sourceCompatibility = 1.8", "targetCompatibility = 1.8"

# (list) Gradle repositories to add {can be necessary for some android.gradle_dependencies}
# please enclose in double quotes 
# e.g. android.gradle_repositories = "maven { url 'https://kotlin.bintray.com/ktor' }"
#android.add_gradle_repositories =

# (list) packaging options to add 
# see https://google.github.io/android-gradle-dsl/current/com.android.build.gradle.internal.dsl.PackagingOptions.html
# can be necessary to solve conflicts in gradle_dependencies
# please enclose in double quotes 
# e.g. android.add_packaging_options = "exclude 'META-INF/common.kotlin_module'", "exclude 'META-INF/*.kotlin_module'"
#android.add_gradle_repositories =

# (list) Java classes to add as activities to the manifest.
#android.add_activities = com.example.ExampleActivity

# (str) OUYA Console category. Should be one of GAME or APP
# If you leave this blank, OUYA support will not be enabled
#android.ouya.category = GAME

# (str) Filename of OUYA Console icon. It must be a 732x412 png image.
#android.ouya.icon.filename = %(source.dir)s/data/ouya_icon.png

# (str) XML file to include as an intent filters in <activity> tag
#android.manifest.intent_filters =

# (str) launchMode to set for the main activity
#android.manifest.launch_mode = standard

# (list) Android additional libraries to copy into libs/armeabi
#android.add_libs_armeabi = libs/android/*.so
#android.add_libs_armeabi_v7a = libs/android-v7/*.so
#android.add_libs_arm64_v8a = libs/android-v8/*.so
#android.add_libs_x86 = libs/android-x86/*.so
#android.add_libs_mips = libs/android-mips/*.so

# (bool) Indicate whether the screen should stay on
# Don't forget to add the WAKE_LOCK permission if you set this to True
#android.wakelock = False

# (list) Android application meta-data to set (key=value format)
#android.meta_data =

# (list) Android library project to add (will be added in the
# project.properties automatically.)
#android.library_references =

# (list) Android shared libraries which will be added to AndroidManifest.xml using <uses-library> tag
#android.uses_library =

# (str) Android logcat filters to use
#android.logcat_filters = *:S python:D

# (bool) Copy library instead of making a libpymodules.so
#android.copy_libs = 1

# (str) The Android arch to build for, choices: armeabi-v7a, arm64-v8a, x86, x86_64
android.arch = armeabi-v7a

# (int) overrides automatic versionCode computation (used in build.gradle)
# this is not the same as app version and should only be edited if you know what you're doing
# android.numeric_version = 1

#
# Python for android (p4a) specific
#

# (str) python-for-android fork to use, defaults to upstream (kivy)
#p4a.fork = kivy

# (str) python-for-android branch to use, defaults to master
#p4a.branch = master

# (str) python-for-android git clone directory (if empty, it will be automatically cloned from github)
#p4a.source_dir =

# (str) The directory in which python-for-android should look for your own build recipes (if any)
#p4a.local_recipes =

# (str) Filename to the hook for p4a
#p4a.hook =

# (str) Bootstrap to use for android builds
# p4a.bootstrap = sdl2

# (int) port number to specify an explicit --port= p4a argument (eg for bootstrap flask)
#p4a.port =


#
# iOS specific
#

# (str) Path to a custom kivy-ios folder
#ios.kivy_ios_dir = ../kivy-ios
# Alternately, specify the URL and branch of a git checkout:
ios.kivy_ios_url = https://github.com/kivy/kivy-ios
ios.kivy_ios_branch = master

# Another platform dependency: ios-deploy
# Uncomment to use a custom checkout
#ios.ios_deploy_dir = ../ios_deploy
# Or specify URL and branch
ios.ios_deploy_url = https://github.com/phonegap/ios-deploy
ios.ios_deploy_branch = 1.7.0

# (str) Name of the certificate to use for signing the debug version
# Get a list of available identities: buildozer ios list_identities
#ios.codesign.debug = "iPhone Developer: <lastname> <firstname> (<hexstring>)"

# (str) Name of the certificate to use for signing the release version
#ios.codesign.release = %(ios.codesign.debug)s


[buildozer]

# (int) Log level (0 = error only, 1 = info, 2 = debug (with command output))
log_level = 2

# (int) Display warning if buildozer is run as root (0 = False, 1 = True)
warn_on_root = 1

# (str) Path to build artifact storage, absolute or relative to spec file
# build_dir = ./.buildozer

# (str) Path to build output (i.e. .apk, .ipa) storage
# bin_dir = ./bin

#    -----------------------------------------------------------------------------
#    List as sections
#
#    You can define all the "list" as [section:key].
#    Each line will be considered as a option to the list.
#    Let's take [app] / source.exclude_patterns.
#    Instead of doing:
#
#[app]
#source.exclude_patterns = license,data/audio/*.wav,data/images/original/*
#
#    This can be translated into:
#
#[app:source.exclude_patterns]
#license
#data/audio/*.wav
#data/images/original/*
#


#    -----------------------------------------------------------------------------
#    Profiles
#
#    You can extend section / key with a profile
#    For example, you want to deploy a demo version of your application without
#    HD content. You could first change the title to add "(demo)" in the name
#    and extend the excluded directories to remove the HD content.
#
#[app@demo]
#title = My Application (demo)
#
#[app:source.exclude_patterns@demo]
#images/hd/*
#
#    Then, invoke the command line with the "demo" profile:
#
#buildozer --profile demo android debug

アイコン、要件、ロード画面などを指定する場合は、このファイルを編集する必要があります。アプリケーションに必要なすべての編集を行った後buildozer -v android debug、アプリディレクトリから実行して、アプリケーションをビルドおよびコンパイルします。特に低速のマシンを使用している場合は、これに時間がかかることがあります。

プロセスが完了すると、端末にいくつかのログが表示され、ビルドが成功したことを確認できます。

Androidの成功したビルド

また、binディレクトリにアプリのAPKバージョンが必要です。これは、携帯電話にインストールして実行するアプリケーションの実行可能ファイルです。

binディレクトリのAndroid.apk

結論

おめでとう!このチュートリアルをステップバイステップで実行した場合は、電話に単純な乱数ジェネレーターアプリがインストールされているはずです。それをいじって、いくつかの値を微調整してから、再構築してください。再構築の実行は、最初のビルドほど時間はかかりません。

ご覧のとおり、Pythonを使用したモバイルアプリケーションの構築は、使用しているフレームワークまたはモジュールに精通している限り、かなり簡単です。とにかく、ロジックは同じ方法で実行されます。

Kivyモジュールとそのウィジェットに慣れてください。すべてを一度に知ることはできません。プロジェクトを見つけて、できるだけ早く足を濡らすだけです。ハッピーコーディング。

リンク:https//blog.logrocket.com/build-android-application-kivy-python-framework/

#python 

Google's Flutter 1.20 stable announced with new features - Navoki

Flutter Google cross-platform UI framework has released a new version 1.20 stable.

Flutter is Google’s UI framework to make apps for Android, iOS, Web, Windows, Mac, Linux, and Fuchsia OS. Since the last 2 years, the flutter Framework has already achieved popularity among mobile developers to develop Android and iOS apps. In the last few releases, Flutter also added the support of making web applications and desktop applications.

Last month they introduced the support of the Linux desktop app that can be distributed through Canonical Snap Store(Snapcraft), this enables the developers to publish there Linux desktop app for their users and publish on Snap Store.  If you want to learn how to Publish Flutter Desktop app in Snap Store that here is the tutorial.

Flutter 1.20 Framework is built on Google’s made Dart programming language that is a cross-platform language providing native performance, new UI widgets, and other more features for the developer usage.

Here are the few key points of this release:

Performance improvements for Flutter and Dart

In this release, they have got multiple performance improvements in the Dart language itself. A new improvement is to reduce the app size in the release versions of the app. Another performance improvement is to reduce junk in the display of app animation by using the warm-up phase.

sksl_warm-up

If your app is junk information during the first run then the Skia Shading Language shader provides for pre-compilation as part of your app’s build. This can speed it up by more than 2x.

Added a better support of mouse cursors for web and desktop flutter app,. Now many widgets will show cursor on top of them or you can specify the type of supported cursor you want.

Autofill for mobile text fields

Autofill was already supported in native applications now its been added to the Flutter SDK. Now prefilled information stored by your OS can be used for autofill in the application. This feature will be available soon on the flutter web.

flutter_autofill

A new widget for interaction

InteractiveViewer is a new widget design for common interactions in your app like pan, zoom drag and drop for resizing the widget. Informations on this you can check more on this API documentation where you can try this widget on the DartPad. In this release, drag-drop has more features added like you can know precisely where the drop happened and get the position.

Updated Material Slider, RangeSlider, TimePicker, and DatePicker

In this new release, there are many pre-existing widgets that were updated to match the latest material guidelines, these updates include better interaction with Slider and RangeSliderDatePicker with support for date range and time picker with the new style.

flutter_DatePicker

New pubspec.yaml format

Other than these widget updates there is some update within the project also like in pubspec.yaml file format. If you are a flutter plugin publisher then your old pubspec.yaml  is no longer supported to publish a plugin as the older format does not specify for which platform plugin you are making. All existing plugin will continue to work with flutter apps but you should make a plugin update as soon as possible.

Preview of embedded Dart DevTools in Visual Studio Code

Visual Studio code flutter extension got an update in this release. You get a preview of new features where you can analyze that Dev tools in your coding workspace. Enable this feature in your vs code by _dart.previewEmbeddedDevTools_setting. Dart DevTools menu you can choose your favorite page embed on your code workspace.

Network tracking

The updated the Dev tools comes with the network page that enables network profiling. You can track the timings and other information like status and content type of your** network calls** within your app. You can also monitor gRPC traffic.

Generate type-safe platform channels for platform interop

Pigeon is a command-line tool that will generate types of safe platform channels without adding additional dependencies. With this instead of manually matching method strings on platform channel and serializing arguments, you can invoke native class and pass nonprimitive data objects by directly calling the Dartmethod.

There is still a long list of updates in the new version of Flutter 1.2 that we cannot cover in this blog. You can get more details you can visit the official site to know more. Also, you can subscribe to the Navoki newsletter to get updates on these features and upcoming new updates and lessons. In upcoming new versions, we might see more new features and improvements.

You can get more free Flutter tutorials you can follow these courses:

#dart #developers #flutter #app developed #dart devtools in visual studio code #firebase local emulator suite in flutter #flutter autofill #flutter date picker #flutter desktop linux app build and publish on snapcraft store #flutter pigeon #flutter range slider #flutter slider #flutter time picker #flutter tutorial #flutter widget #google flutter #linux #navoki #pubspec format #setup flutter desktop on windows

Adobe XD plugin for Flutter with CodePen Tutorial

Recently Adobe XD releases a new version of the plugin that you can use to export designs directly into flutter widgets or screens. Yes, you read it right, now you can make and export your favorite design in Adobe XD and export all the design in the widget form or as a full-screen design, this can save you a lot of time required in designing.

What we will do?
I will make a simple design of a dialogue box with a card design with text over it as shown below. After you complete this exercise you can experiment with the UI. You can make your own components or import UI kits available with the Adobe XD.

#developers #flutter #adobe xd design export to flutter #adobe xd flutter code #adobe xd flutter code generator - plugin #adobe xd flutter plugin #adobe xd flutter plugin tutorial #adobe xd plugins #adobe xd to flutter #adobe xd tutorial #codepen for flutter.