Android Native Development and extra features - AMORG

Widgets, Native

Development and

Extras

1

Mobile Software Development

Dr. Péter Ekler [email protected]

Execute OS commands:

Process process =

Runtime.getRuntime().exec(“ls");

It’s a linux…

Some commands require root privilege

Some special tricks

Mobile Software Development2

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

try {

Process process = Runtime.getRuntime().exec("ls");

BufferedReader bufferedReader = new BufferedReader(

new InputStreamReader(process.getInputStream()));

StringBuilder logString = new StringBuilder();

String line;

while ((line = bufferedReader.readLine()) != null) {

logString.append(line+"\n");

}

TextView tv = (TextView) findViewById(R.id.logTextView);

tv.setText(logString.toString());

} catch (IOException e) {

}

}

Some special tricks


SCHEDULED TASKS -

ALARMMANAGER

Android AlarmManager

AlarmManager System Service

Enables to run operations even when none of

the activities is in the background

Executes an Intent

Enables repeated operation as well

Use carefully and always consider how/when to

stop the repeated operations

Requires typically a BroadcastReceiver that

receives the “Alarm” event


Schedule alarm// Create alarm intent.

Intent intent = new Intent(MainActivity.this,

WakeUpAlarmReceiver.class);

intent.putExtra("alarm_message", "mymessage");

PendingIntent sender =

PendingIntent.getBroadcast(MainActivity.this, 0, intent, 0);

// Schedule alarm.

Calendar calendar = Calendar.getInstance();

calendar.setTimeInMillis(System.currentTimeMillis());

calendar.add(Calendar.SECOND, 10);

AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);

am.setRepeating(AlarmManager.RTC_WAKEUP,

calendar.getTimeInMillis(), 10000, sender);


BroadcastReceiver for Alarmspublic class WakeUpAlarmReceiver extends BroadcastReceiver {

@Override

public void onReceive(Context context, Intent intent) {

try {

Bundle bundle = intent.getExtras();

String message =

bundle.getString("alarm_message");

Toast.makeText(context, message,

Toast.LENGTH_SHORT).show();

} catch (Exception e) {

e.printStackTrace();

}

}

}

Manifest:

<receiverandroid:process=":remote“ android:name="WakeUpAlarmReceiver"/>


Cancel alarm

Intent intent =

new Intent(MainActivity.this,

WakeUpAlarmReceiver.class);

PendingIntent sender =

PendingIntent.getBroadcast(

MainActivity.this, 0, intent, 0);

AlarmManager am =

(AlarmManager)getSystemService(

A LARM_SERVICE);

am.cancel(sender);


Let’s practice

Create an AlarmClock application that

plays an mp3 when alarm is on!


WIDGETS AND LIVE

WALLPAPERS

Lecture 13

Extending Android component model

Extend the application functionality:

Widget (mini application)

Live wallpaper

Useful and quick information for the user

New possibilities for development

Quick and easy to develop

Extend existing applications


Live wallpaper

Available from Android 2.1

Animated interactive wallpaper

Reaches the platform API (2D and 3D drawing,

GPS, sensors, network handling, etc.)

Example:

Animated wallpaper that changes the background

based on the current location or time

Google maps


Implementing life wallpapers

A Service that updates the wallpaper UI

onCreateEngine():

Creating WallpaperService.Engine object

The Engine is responsible for life cycle and drawing

It is very important to optimize the drawing because

of the CPU and Battery!

Handle life cycle functions carefully!

It is necessary to mark Live Wallpaper functionality in the

Manifest:

<uses-feature android:name="android.software.live_wallpaper" />


Event handling on live wallpaper

onVisibilityChanged():

When it is in the background we should pause the

drawing and possible threads.

onOffsetsChanged():

Canges between home screens

onTouchEvent():

Screen touch event

onCommand():

It is possible to send commands to the live wallpaper


Let’s practice

Create an application that

displays the current time on

the wallpaper when

touching the screen!


Live wallpaper - Manifest<manifest xmlns:android=http://schemas.android.com/apk/res/android

package="hu.bute.daai.amorg.examples">

<uses-sdk android:minSdkVersion="7" />

<uses-feature android:name="android.software.live_wallpaper" />

<application

android:label="@string/wallpapers"

android:icon="@drawable/ic_launcher_wallpaper">

<service

android:label="@string/my_wallpaper"

android:name=".MyWallpaper”

android:permission="android.permission.BIND_WALLPAPER">

<intent-filter>

<action android:name="android.service.wallpaper.WallpaperService" />

</intent-filter>

<meta-data android:name="android.service.wallpaper“

android:resource="@xml/mywall" />

</service>

</application>

</manifest>


Live wallpaper – source 1/2

public class CubeWallpaper1 extends

WallpaperService {

private final Handler mHandler =

new Handler();

@Override

public void onCreate() {

super.onCreate();

}

@Override

public void onDestroy() {

super.onDestroy();

}

@Override

public Engine onCreateEngine() {

return new CubeEngine();

}

class CubeEngine extends Engine {

private final Paint mPaint = new Paint();

private float mTouchX = 0;

private float mTouchY = 0;

CubeEngine() {

final Paint paint = mPaint;

paint.setColor(0xffffffff);

paint.setTextSize(25);

}


Live wallpaper – source 2/2

@Override

public void onCreate(SurfaceHolder surfaceHolder)

{

super.onCreate(surfaceHolder);

// Érintés eseményre kezelés jelzése

setTouchEventsEnabled(true);

}

@Override

public void onTouchEvent(MotionEvent event) {

super.onTouchEvent(event);

if (event.getAction()==

MotionEvent.ACTION_UP) {

mTouchX=-1; mTouchY=-1;

} else {

mTouchX = event.getX();

mTouchY = event.getY();

}

drawFrame();

}

void drawFrame() {

final SurfaceHolder holder =

getSurfaceHolder();

Canvas c = null;

try {

c = holder.lockCanvas();

if (c != null) {

c.save();

c.drawColor(0xff000000);

c.drawText(

new Date(System.currentTimeMillis()).

toLocaleString(),

mTouchX, mTouchY, mPaint);

c.restore();

}

} finally {

if (c != null)

holder.unlockCanvasAndPost(c);

}

}}} // osztály bezárása


Live wallpaper example - game

Labyrinth game on live wallpaper


Widgets – mini applications

Small applications that are typically

embedded in the home screen

Can contain UI controls

Refresh state periodically

E.g.: music player


Widget components AppWidgetProviderInfo:

XML based

Meta data (layout, refresh interval, AppWidgetProvider class)

AppWidgetProvider:

Programming interface

Broadcast events: updated, enabled, disabled, deleted

View layout:

XML

Configuration Activity:

Optional

Launches at widget first start


Widget Manifest<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="hu.bute.daai.amorg.examples"

android:versionCode="1"

android:versionName="1.0">

<uses-sdk android:minSdkVersion="8" />

<application android:icon="@drawable/icon" android:label="@string/app_name">



<receiver android:name=".HelloWidget" android:label="@string/app_name">

<intent-filter>

<action android:name="android.appwidget.action.APPWIDGET_UPDATE" />

</intent-filter>

<meta-data android:name="android.appwidget.provider„

android:resource="@xml/hello_widget_provider" />

</receiver>

</application>

</manifest>


Widget AppWidgetProviderInfo XML

<?xml version="1.0" encoding="utf-8"?>

<appwidget-provider xmlns:android=

"http://schemas.android.com/apk/res/android"

android:minWidth="146dip"

android:minHeight="72dip"

android:updatePeriodMillis="500"

android:initialLayout="@layout/main"

/>


Widget Layout<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:orientation="vertical"

android:background="@drawable/amorg"

android:layout_gravity="center"

android:layout_height="wrap_content">

<TextView android:id="@+id/widget_textview"

android:text="@string/hello_text"

android:layout_height="wrap_content"

android:layout_width="wrap_content"

android:layout_gravity="center_horizontal|center"

android:layout_marginTop="5dip"

android:padding="10dip"

android:textColor="@android:color/black"/>

</LinearLayout>


Widget AppWidgetProviderpublic class HelloWidget extends AppWidgetProvider {

@Override

public void onUpdate(Context context,

AppWidgetManager appWidgetManager,

int[] appWidgetIds) {

// refresh

}

}


Which statement is false?

A. Widget is basically a BroadcastReceiver

component.

B. Live Wallpaper is basically a Service

component.

C. Widgets can not contain UI controls like

buttons.

D. Live wallpaper can handle touch events.


Mini application on the home screen

Two refresh state:

Periodic refresh (minimum 30 mins)

Refresh via AlarmManager

Part of HomeScreen process

Initialized by a BroadcastReceiver

Continous refresh:

Launch a Service at onUpdate() that contains a

thread

Widget summary


Let’s practice!

Create a widget that

refreshes its content in every

5 seconds!


Widgets for project work

Now you can use widgets for

project work!


NATIVE DEVELOPMENT

Android NDK

NDK: Native Development Kit

NDK enables to create and reach native class libraries

from Java code

How can we do that?

JNI: Java Native Interface

Well known C++ development

Advantages:

Increase in speed

Code reuse (C++)

Download NDK:

http://developer.android.com/tools/sdk/ndk/index.html



What does NDK offer?

Different tools and libraries for C and C++

compiling

Embed native class libraries into standard

Andorid applications (apk)

Natív class headers and libraries (e.g. native

Activity)

Documentation, examples and numerous

tutorials


NDK hardware support

ARMv5TE (Thumb-1 instructions as well)

Supports ARM based devices

ARMv7-A (Thumb-2 and VFPv3-D16 instruction,

with optional NEON/VFPv3-D32 support)

Hardware FPU

x86 instructions

Note: Target can be defined in the

Application.mk file


When does it worth to use NDK? 1/2

In many cases it is not required!

Think about the advantages and

disadvantages!

NDK does not increase speed always, but

it always increase complexity

Use only when it is really needed!


When does it worth to use NDK? 2/2

Worth to use when:

Independent task

CPU intense operation where memory handling is

important

Signal processing

Physics simulation

Graphics (e.g.: 3D)

It is always worth to check whether there is an

existing Android API for it

Re-use working C/C++ libraries


How to use native code?

Reach native library via JNI:

We can use standard Android tools

Call native library via JNI

Works on Android 1.5 and above

Native Activity:

Android 2.3 and above

NativActivity C++ class with life cycle methods

Other components are not implemented in

native code


Supported native libraries 1/2

libc (C library) headers

libm (math library) headers

JNI interface headers

libz (Zlib compression) headers

liblog (Android logging) headers


Supported native libraries 2/2

OpenGL ES 1.1 and OpenGL ES 2.0 (3D

graphics library) headers

libjnigraphics (reach pixel buffers) header

(Android 2.2 and above).

C++ supporting headers (minimal set)

OpenSL ES native audio library

Android native application library


NDK documentation 1/3

INSTALL.HTML: NDK install and configuration

OVERVIEW.HTML: NDK abilities

ANDROID-MK.HTML: The structure of the Android.mk file

APPLICATION-MK.HTML: Application.mk file structure

CPLUSPLUS-SUPPORT.HTML: C++ support description

CPU-ARCH-ABIS.HTML: CPU architectures and keys

CPU-FEATURES.HTML: Introduces the cpufeatures static

library that can be use to detect CPU type and capabilities

during runtime


NDK documentation 2/3

CPU-ARM-NEON.HTML: compilation steps to ARM

NEON and VFPv3-D32

CHANGES.HTML: changes in the current release

DEVELOPMENT.HTML: NDK release package

preparation steps

HOWTO.HTML: General information about NDK usage

IMPORT-MODULE.HTML: share and re-use modules

LICENSES.HTML: connected open source licenses

NATIVE-ACTIVITY.HTML: native Activity introduction


NDK dokumentáció 3/3

NDK-BUILD.HTML: Introducing the ndk-build script

NDK-GDB.HTML: Native code debugger description

PREBUILTS.HTML: static and dynamic shared libraries

STANDALONE-TOOLCHAIN.HTML: how to use the

standalone compiler

SYSTEM-ISSUES.HTML: known bugs and issues

STABLE-APIS.HTML: APIs (headers) introduction

OVERVIEW.HTML: Overview


NDK development environment

NDK download:

http://developer.android.com/tools/sdk/n

dk/index.html

Install Eclipse NDK plugin

NDK configuration: set NDK folder in

Eclipse

Right click on the project: “Add native

support”Mobile Software Development42


NDK project elements 1/4

Android project folder can not contain

spaces!

New library: jni

All native components goes in the jni

folder:

Android.mk

Application.mk

hello.c



Android.mk:

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

# modul name and sources

LOCAL_MODULE := hello

LOCAL_SRC_FILES := hello.c

include $(BUILD_SHARED_LIBRARY)



Application.mk:

APP_PLATFORM := android-8

APP_ABI := armeabi-v7a



hello.c:

#include <string.h>

#include <jni.h>

jstring

Java_hu_bute_daai_amorg_examples_NativeLib_sayHello(JNIEnv* env,

jobject javaThis) {

return (*env)->NewStringUTF(

env, "Hello Android Csoport - nativ!");

}

jint Java_hu_bute_daai_amorg_examples_NativeLib_add(JNIEnv * env,

jobject javaThis, jint value1, jint value2) {

return (value1 + value2);

}


Result of the compilation

libs and obj folders:


First NDK application

NativeLib.java class:

public class NativeLib {

static {

System.loadLibrary("hello");

}

// native functions with same name as in hello.c

public native String sayHello();

public native int add( int v1, int v2 );

}



Usage from an Activity:

public class NativeTestActivity extends Activity {

private NativeLib nativeLib;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

nativeLib = new NativeLib();

// Natív kód hívása

String hello = nativeLib.sayHello();

new AlertDialog.Builder(this).setMessage(hello).show();

}

}




NDK example

Calculate PI value through 1000000

iteration

Define CPU capabilities in Application.mk

file:

APP_PLATFORM := android-8

APP_ABI := armeabi-v7a


Let’s practice!

Create an Android application

that calls native functions:

sayHello()

add(int a, int b)

pi(int iteration)

Calculate PI value via a specific

number of iterations


Let’s practice!

Create an Android application

that reads out the light sensor

values from native code!

Create a button that can be

used to enable and disable

light sensor reading!


EXTERNAL LIBRARIES

Simple XML: XML serialization

http://simple.sourceforge.net/

ORM Lite: Object Relation Mapping

http://ormlite.com/sqlite_java_android_orm.shtml

Android UI patterns / Android patterns

https://play.google.com/store/apps/details?id=com.groidify.uipatterns&h

l=hu

http://www.androidpatterns.com/

kSoap: SOAP Web Service support

http://code.google.com/p/ksoap2-android/

box2D: 2D physics engine

http://code.google.com/p/androidbox2d/

AndEngine (contains box2D): Game engine

http://www.andengine.org/

Libraries 1/3


http://simple.sourceforge.net/

http://ormlite.com/sqlite_java_android_orm.shtml

https://play.google.com/store/apps/details?id=com.groidify.uipatterns&hl=hu

http://www.androidpatterns.com/

http://code.google.com/p/ksoap2-android/

http://code.google.com/p/androidbox2d/

http://www.andengine.org/

libGDX: drawing and contains box2D as well

http://code.google.com/p/libgdx/

Acra / Bugsense: crash log

http://acra.ch/

https://github.com/ACRA/acra

Java Mail

http://code.google.com/p/javamail-android/

OpenCV: computer vision

http://opencv.org/platforms/android.html

Libraries 2/3


http://code.google.com/p/libgdx/

http://acra.ch/

https://github.com/ACRA/acra

http://code.google.com/p/javamail-android/

http://opencv.org/platforms/android.html

ActionBarSherlock: ActionBar for Android 2.X,

already contains the SupportLib!

http://actionbarsherlock.com/

Unity: game engine

http://unity3d.com/unity/multiplatform/mobile

Commons.net: Apache Common Modul

http://commons.apache.org/net/

Zxing: barcode and QR code scanning

http://code.google.com/p/zxing/

Libraries 3/3


http://actionbarsherlock.com/

http://unity3d.com/unity/multiplatform/mobile

http://commons.apache.org/net/

http://code.google.com/p/zxing/

Display advertisement

~5000 advertisement display ~ 3$

http://www.google.com/ads/admob/

Library:

https://developers.google.com/mobile-ads-sdk/

Developer gets an AdMob publisherID that

should be defined in the XML as the unit ID

For testing, the id should be checked in the

LogCat

AdMob


http://www.google.com/ads/admob/

https://developers.google.com/mobile-ads-sdk/

<com.google.ads.AdView

android:id="@+id/adView"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

ads:adSize="BANNER"

ads:adUnitId="MY_AD_UNIT_ID"

ads:loadAdOnCreate="true"

ads:testDevices="TEST_EMULATOR,

TEST_DEVICE_ID" />

AdMob layout


http://coderesearchlabs.com/androidpdfwri

ter/

Supported functions

Page size

Font type

Embedding images

Drawing shapes

Android PDF Writer


http://coderesearchlabs.com/androidpdfwriter/

Let’s practice

Create an application that

generates a PDF!

Library:

http://avalon.aut.bme.hu/~tyrae

l/androidtanfolyam/pdfwriter.jar


http://avalon.aut.bme.hu/~tyrael/androidtanfolyam/pdfwriter.jar

Cross-platform game development

framework

CPU intensive parts on Native libs

Useful pages:

http://libgdx.badlogicgames.com/

http://code.google.com/p/libgdx-users/

http://obviam.net/index.php/getting-started-in-

android-game-development-with-libgdx-

create-a-working-prototype-in-a-day-tutorial-

part-1/

LibGDX


http://libgdx.badlogicgames.com/

http://code.google.com/p/libgdx-users/

http://obviam.net/index.php/getting-started-in-android-game-development-with-libgdx-create-a-working-prototype-in-a-day-tutorial-part-1/

Let’s practice!

Create an AndEngine based demo!


Let’s practice!

Create an application with

LibGDX that displays a ball!


Acra Crashlog

Crash report to Google Docs, BugSense,

E-mail or personal page

Easy to use

Automatic crash report

More details

http://code.google.com/p/acra/wiki/ACRAHow

To


http://code.google.com/p/acra/wiki/ACRAHowTo

Google I/O: always a good source!

Further tips


Android 4.X New Features

App! Android update67

Andriod 4.X versions

4.0 (14), 4.0.3 (15): Ice Cream Sandwich

4.1, 4.2, 4.3 (16, 17, 18): Jelly Bean

4.4 (19): KitKat

Detailed API changes:

http://developer.android.com/sdk/api_diff/18/changes.

html

General description:

http://developer.android.com/about/versions/jelly-

bean.html


http://developer.android.com/sdk/api_diff/18/changes.html

http://developer.android.com/about/versions/jelly-bean.html

4.0 and 4.0.3 new features

New Social API and Contacts Provider

Invite Intent

VoiceMail provider

Camera.FaceDetectionListener

Camera broadcast intent-ek

Camera.ACTION_NEW_PICTURE, Camera.ACTION_NEW_VIDEO

Spell Checker Service

Hover events (stylus and mouse is also supported!)

Text To Speech features

READ_SOCIAL_STREAM and WRITE_SOCIAL_STREAM

permissions

69 App! Android update

4.1 new features

App stack navigation

android:parentActivityName="hu.bme.aut.amorg.callhierarchydemo.app.MainActi

vity„

getParentActivityIntent(): Intent, that can start the logical parent of the Activity

New Media Codec

Andriod Beam

Bluetooth support for large data

Wi-Fi P2P service discovery

RenderScript

Copy paste with Intents

TV support<uses-feature android:name="android.hardware.type.television"

android:required="true" />


4.2 new features

DayDream

When connected to docking station or charger

Passive and active

Secondary screens

LockScreen widget

Multiple user support

Embedded fragments

Renderscript new features

Blend, Blur, Colro matrix, stb.


4.3 new features

Bluetooth Low Energy

<uses-feature android:name="android.hardware.bluetooth_le"

android:required="true" />

Media DRM advanced features

OpenGL ES 3.0

<uses-feature android:glEsVersion="0x00030000" />

ViewOverlay support

Window attach and focus events without direct View reference

ViewTreeObserver.OnWindowAttachListener

ViewTreeObserver.OnWindowFocusChangeListener

NotificationListenerService

Automated UI testing


Android 4.4

"It's our goal with Android KitKat to

make an amazing Android experience

available for everybody„


Android 4.4 Features

On-device profiling

Print support

IR support

SMS provider (advanced)

Total full screen

Chromium WebView

Renderscript features

RTL localization support (advanced)


OBJECTIVES OF AN ANDROID

ARCHITECT

The Objectives of an Android Architect

Choose proper Android version

Design application architecture (components)

Check UI design (mockup vs. specification), tablet support

Design network communication (protocol, security, etc.)

Clarify performance issues (e.g.: do we need native support?)

Check special functions and algorithm requirements

Choose proper external libraries

Design test environment

Code quality, best practices

Java, Java, Java, … (efficiently!)

Joshua Block: Effective Java


Further Objectives of an Architect

Continuous Integration design and

monitoring

Use version control system properly (GIT,

SVN, etc.)

Library dependency check

Clarify license conditions

Clarify the publication mechanism of the

application

To sum up: always find the best solution!Mobile Software Development77

Questions?


Thank you!


E-mail:

[email protected]

Android Native Development and extra features - AMORG

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