Android: Difference between revisions

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* [https://www.makeuseof.com/tag/stitcher-tips-listening-podcasts/ 7 Key Tips for Listening to Podcasts Using Stitcher]
* [https://www.makeuseof.com/tag/stitcher-tips-listening-podcasts/ 7 Key Tips for Listening to Podcasts Using Stitcher]
* [https://www.makeuseof.com/tag/science-news-sites-blogs/ Science News That Laymen Understand: 5 Jargon-Free Sites and Blogs]
* [https://www.makeuseof.com/tag/science-news-sites-blogs/ Science News That Laymen Understand: 5 Jargon-Free Sites and Blogs]
== Look up anything ==
https://www.makeuseof.com/tag/reference-apps/


== News ==
== News ==

Revision as of 08:11, 30 June 2018

SDK

http://developer.android.com/sdk/index.html#ExistingIDE

Redhat

At the step of Running your app I cannot run app from Eclipse. The command line way does not work.After several tries, it seems the RHEL does not have an updated Ant package (currently it is 1.7 but I need 1.8). Give up.

Ubuntu

Download the bundle version. The file name I got is <adt-bundle-linux-x86_64-20140321.zip>.

On 64-bit Ubuntu, we need to run 

sudo apt-get install libstdc++6:i386 lib32z1 lib32ncurses5 lib32bz2-1.0

For both 32-bit and 64-bit, we need to get openjdk 

sudo apt-get install openjdk-6-jre openjdk-6-jdk icedtea6-plugin

Then uncompress <adt-bundle-linux-xxx.zip> and run the file <eclipse> from either file manager or command line. It just works!

We can furthermore set up the PATH variable by editing ~/.bashrc file. 

export PATH=$PATH:~/binary/adt-bundle-linux-x86_64-20140321/sdk/platform-tools/
export PATH=$PATH:~/binary/adt-bundle-linux-x86_64-20140321/sdk/tools/
export PATH=$PATH:~/binary/android-ndk-r9d/

Then source the file by 

source ~/.bashrc

A good reference is https://help.ubuntu.com/community/AndroidSDK.

To quickly test NDK, go to the samples/hello-jni directory in NDK. Type the command ndk-build. If the build is successful, it proves that the NDK environment is set up correctly.

Android Studio

After downloading & installing Android Studio, we run the following command to launch it (the first time installation will pop up the 1st screenshot). See <android-studio/install-Linux-tar.txt> file. 

$ ~/Downloads/android-studio/bin/studio.sh

The adb utility's location is located uner ~/Android/Sdk/platform-tools (see the 4th screenshot).

AndroidStudioInstall.png AndroidStudioFirstTime.png AndroidStudioInstComp.png AndroidStudioSetting.png

Another way is install is to use 'snap'; see https://snapcraft.io/android-studio

Windows

Emulation on x86

Anbox

How to Run Android Apps and Games on Linux

No emulation layer like QEMU is necessary.

Android-x86

This isn’t an emulator that lets you run Android within Windows or another operating system.

Remix

https://www.reddit.com/r/RemixOS/comments/40ahkc/is_it_possible_to_run_remix_os_on_virtualbox_if/

Slowww.

Phoenix

BlueStacks

Runs on Windows and Mac. Free.

AMIDuOS

$10 to keep. Work on Windows not Linux. Virtual Machine. Read this article from PCWorld.

Genymotion

Genymotion is a complete set of tools that provides a virtual environment for Android. Genymotion is much better than the ADV included in Android SDK. Before we use download/use it, we need to register.

For some reason, on my Ubuntu 12.04, I need to run the following. 

sudo apt-get install ia32-libs

The genymotion can be integrated into Eclipse. The document about genymotion can be found on https://cloud.genymotion.com/page/doc/

Lineage

How to Install LineageOS on Android

Qt + Android

Installation

We can install requirements of Qt 5 by

  • SDK -> No need to download a special copy. Just use adt-bundle-linux-x86-2013xxxx one.
  • Apache Ant -> sudo apt-get install ant
  • NDK -> android-ndk-r9c-linux-x86.tar.bz2. Use tar -xjvf android-ndk-r9c-linux-x86.tar.bz2 to extract.
  • Download qt-linux-opensource-5.2.0-android-x86-offline.run and install it into a new location, eg ~/Qt5.2.0Android (Cannot be the same as Desktop version).
  • On a new machine, we need to install opengl library as instructed here and here.
sudo apt-get install mesa-common-dev
sudo apt-get install libglu1-mesa-dev -y

The Qt needs to change the setting from Tools > Options > Android where we can specify the locations of Android SDK, Android NDK, Ant and JDK. On Tools > Options > Devices, we can change the Device from default (Local PC) to Run on Android. See the instruction on qt.project.org. Basically we go to project's setting to do changes. It does take a little longer to get the app on device.

Test Installation

We use qt-opensource-linux-x64-android-5.2.1.run to install Qt to ~/qt-5.2.1-Android directory. Note that this installer includes Qt Creator which has preset options. So this is preferred than our other separated installed Qt Creator.

We shall also need to follow episode 3 to set up SDK, NDK, JDK and Ant directories in Qt Creator.

After that, we can create a default Qt Quick application. Before we Run Debugging, we shall also

  • Change project's setting to make sure Android for armeabi-v7a Kit is added to the project.
  • Connect a physical Android device to our computer.

If everything goes well, the Qt app will be deployed to the connected Android device.

If we want to specify the API level, we can select Project > Run > Details > Deploy configurations. See http://qt-project.org/doc/qtcreator-3.0/creator-deploying-android.html

More QML examples can be found in http://qt-project.org/doc/qt-4.7/qdeclarativeexamples.html

Two official Android examples (Quick Forecast & Flyingbus)can be found at https://blog.qt.digia.com/blog/2013/12/10/cross-platform-applications-in-ios-and-android-stores-with-qt/

Help, Applications

NDK

Following are steps to create Android App with NDK.

  1. Create a new folder: jni
  2. Create a new file under jni: <hello.c>
  3. Create a new file under jni: <Android.mk>
  4. Open a shell & go to jni folder. Type ndk-build to generate .so files
  5. Edit <MainActivity.java>
  6. Run as Android Application.

The "hello-jni" is the hello world example. Chapter 1 in Android NDK Cookbook is the same example with simpler code.

Books/Tutorials

http://www.cprogramming.com/android/android_getting_started.html

How to connect your android device on Linux

https://www.howtoforge.com/tutorial/how-to-connect-your-android-device-on-linux/

Online resource

Android Programming: The Big Nerd Ranch Guide

It seems the solution files still have bugs. For example in Chapter 1 "01_FirstApp", the <layout/activity_quiz.xml> file should have 

android:text="@string/question_text_view"

instead of 

android:id="@+id/question_text_view"

within <TextView> tag.

<AndroidProgramming.zip>

Beginning Android 4 Application Development

<Source_code_download_for_Beginning_Android_4_AD.zip>

Android Tutorials

Java Books

  • Head First Object-Oriented Analysis and Design
  • Head First Design Patterns

Material Design

Blogs

Useful Apps

Home screens/Launcher

How to Get Started with Android’s Home Screens

Syncthing: sync without cloud services

http://pcworld.com/article/3195024/linux/sync-your-files-for-free-and-maintain-privacy-using-open-source-syncthing.html

https://docs.syncthing.net/intro/getting-started.html

Sign on a pdf

Adobe Fill & Sign DC

Games

Hidden Game

Go to Settings > About phone, then tap the Android version repeatedly until a stylized "N" logo appears. Press the N icon repeatedly and a game of Flappy Android will eventually appear.

http://www.express.co.uk/life-style/science-technology/613539/Google-Flappy-Bird-Android-6-0-Marshmallow-Easter-Egg

http://www.howtogeek.com/269207/how-to-enable-android-nougats-cat-collecting-easter-egg/

Game for your brain

Exercise Your Brain With These 7 Free Mobile Games

Choose Your Puzzle! These Mobile Collections Offer a Wide Variety

http://www.makeuseof.com/tag/puzzle-mobile-collections/

Files Go

Files Go is a new storage manager that helps you free up space on your phone, find files faster, and share them easily offline with others. It is like Apple's AirDrop; share your pictures, videos, documents, or apps with others nearby who also have the app. With speeds up to 125 Mbps

ES File Explorer

  • Send Files or Folders to Other Android Device
  • Browse and Manage Photos from a Remote Album
  • Browse and Transfer Your Files via LAN and SFTP (Network > Remote Manager)
  • Access your Computer from Android over WiFi (Network > LAN > Scan)
  • Browse the Files Stored on Your Android Device From the Computer
  • Save Files Directly to Various Cloud Services
  • SD card analyst - see the total disk capacity, the shared capacity, and the free space
  • Remove Pre-installed System Apps
  • Manage or Uninstall Multiple Apps at Once
  • Extract the content of any Android App

References:

  1. http://www.howtogeek.com/221582/19-things-you-didnt-know-androids-es-file-explorer-can-do/
  2. http://receivetipstricks.com/es-file-explorer-tips-tricks/

Airdroid

SuperBeam

Brave Browser

Brave Browser for Android now plays YouTube videos in the background

How to Transfer Photos from Android to Your Windows PC

https://www.howtogeek.com/346317/how-to-transfer-photos-from-android-to-your-windows-pc/

Transfer files

AirDroid

Portal

How to Quickly Transfer Files from a Computer to Your Phone with Portal PC goes to http://portal.pushbullet.com/. It'll create a QR code for phone to scan and then connect to the PC.

ES File Explorer

vFTP. It lets you to transfer files to PC.

swiftp

How to Transfer Files Between Your PC and Android Phone Wirelessly

SuperBeam

https://superbe.am/. There will be a URL for the android device to download the files.

Pushbullet

https://www.pushbullet.com/

Dropbox

Google Go

Lightweight Google for slow connections.

Google Search Lite becomes Google Go

Google Now/Google Feed

How to Customize the Google Feed (and Make It Actually Useful)

Google Photos

Google lens

6 Uses for Google Lens, Now Integrated Into Google Photos

Take Photo And Selfie On Your Mobile With Voice Control

https://techblogup.com/take-picture-selfie-mobile-voice-control/

Google Art and Culture

https://play.google.com/store/apps/details?id=com.google.android.apps.cultural

Prey

Getting your laptop or your phone stolen sucks, but there is something you can do about it. Prey is a lightweight theft protection software that lets you keep an eye over them whether in town or abroad, and helps you recover them if ever lost or stolen. It is available on Windows, Mac, Linux and Android.

Calcu

Calculator

OpenSignal

With OpenSignal you can map cellular coverage, find Wi-Fi hotspots, test and improve your reception & get faster data.

Podcast

Look up anything

https://www.makeuseof.com/tag/reference-apps/

News

  • Goole News
  • Flipboard
  • Microsoft News
  • Apple News

Backup/restore

Helium and play store. However, Helium's wiki says it does not back up photos or videos.

Another way is to use Ubuntu's Nautilus. On my Ubuntu 12.04, I need to install gvfs. See http://robert.penz.name/658/howto-access-mtp-devices-via-usb-on-ubuntu-12-04/. We need to reboot Ubuntu 12.04 for this to take effect. 

sudo apt-get install gvfs

Google maps

10 Lesser-Known Features in Google Maps for Android

Offline maps

Offline maps & Navigation

My experience:

  • Entering destination is limited. It provides a database and users can only select from it. Users cannot pick any place on the map and navigate to there. It does provide POI, Coordinates, online search options. The on-screen keyboard in online search option does not have space button???
  • Don't know how to change the scale from kilometer to miles.

MAPS.ME

  • 10m downloads
  • openstreetmap.org maps, highly detailed, Up-to-date map data is added daily.
  • routing including walking directions.
  • bookmark, KML/KMZ supported
  • offline search
  • Auto-follow mode. When enabled, the map automatically orients itself to the direction you are moving.
  • One of the fastest offline maps ever.
  • Maps are updated regularly
  • no voice
  • no 3D

Remember to go to settings and turn off sharing data statistic with the author.

My experience:

  • the road name cannot be changed even I zoom in.
  • it is easy to bookmark a location. Just tap a location on the map.
  • the map is well annotated though it is just 2D.
  • the setting options are limited: measurement units, send statistics, zoom buttons and google play services to get the current location.
  • you can search by food, hotel, transport, gas, parking, shop, ....

GPS Navigation & Maps Sygic

  • TomTom Maps
  • voice navigation
  • 3D mode
  • Free map updates & Free POI database updates
  • Spoken Street Names to focus on the road
  • With options for routing (avoid toll road, highways, ...)
  • The interface and feeling is the same as a standalone GPS
  • show house number
  • Road direction (one way or two ways)
  • 10 million downloads
  • 7 days of premium. See the different price at sygic.com.
  • Road name font is too small, no setting to change
  • Not that intuitive in terms of the interface

MapFactor/Navigator

  • OpenStreetMap data, maps are updated every month.
  • Voice guidance (a little bit inaccurate)
  • Routing
  • Can do search offline (by address or POI or browsing POI), or through google (online connection)
  • Night mode color is too brownish (change the setting is possible but too tedious)
  • even higher review than GPS Navigation & Maps Sygic?

The app is called 'Navigator' on Android's screen. When we launch it, it gives two options: Navigator Free (green color font) & Navigator (blue color). The app sometimes pops a message to ask for purchasing the TomTom map. There is no way to access this option from the free version's UI. The USA map costs 15 EUR on the paid version.

The date of each US states OSM can be found on the MapFactor website.

A Windows or Windows mobile version of the app can be found on its download page.

Navigator also works with Linux by using WINE program. See the Navigator Requirements page.

HERE

  • Voice-guided turn-by-turn navigation
  • offline use
  • route planner
  • save places
  • not sure about the source of maps
  • Nokia Apps LLC

My experience:

  • when in navigation, it does not the road names for nearby location?
  • it keeps saying the compass needs adjusted. It takes time to show the my current location when the way I drove is different from its suggested route.
  • it took too many clicks to navigate.
  • the route is strange.

Wifi and security

How to protect your personal information from hackers while on spring break

  • When you want to go to your bank site or purchase something online with your credit card, hop OFF the public Wi-Fi and go onto a 3G or 4G cell carrier — it's much more secure. After you're done, you can go back to the public Wi-Fi.
  • Every hour or two on a public Wi-Fi network, adjust your phone settings to forget the network, then log back in again. Better yet, when you first log onto any public network, shut off your phone's auto-join function.
  • Try purposely logging onto the public Wi-Fi with the wrong password. If you can get on anyway, that's a sign that someone is monitoring you and you're not secure.
  • Install anti-virus software like Norton anti-virus onto your phones and laptops.

VPN

The 5 Best VPNs for Android May 2, 2018

openvpn

Download a configuration file from vpngate.net. With this, we can act as if we are located in a different country.

vpn defender

tunnelBear VPN

mms streaming

Useful like studioclassroom.com where mx player cannot. vplayer ($5) moboplayer (need sd card?), WonderShare (works, similar to ms player interface) Rock Player 2, BSPlayer (supports mms, but not work), VLC player, RealPlayer.

Play youtube multiwindow

If your devices are not running Android 7 (Nougat), we need some way to watch youtube and open other apps at the same time.

  • Float Tube Video

Play youtube in the background

If you devices are not running Android 7 (Nougat), try Firefox. This browser will allow you to continue to listen to the video of your choice with the screen off or while doing something else on your device.

Youtube Music offline mixtape

See Download music to listen to music offline

Click icon -> Downloads -> Offline mixtape.

Network Signal Info

Play store

Hardware information

CPU-Z

AIDA64

Remote desktop/VNC

VNC

  • bBNC: feel slow
  • VNC view (from tightvnc): Port should be part of the IP (eg 192.168.1.xxx:5901). The mouse pt is different from the touch pt. Screen is kind of zoom-in. The desktop won't be moved.
  • Remote Ripple: good response like VNC view. It has a mouse control image on the desktop. If you don't click the visual mouse, you are moving the desktop.

Remote desktop

  • 2X RDP
  • Windows RDP

Github

The source code is hosted on https://github.com/github/android

Bitbucket

Adobe flash player

Video Editor

Adobe Premiere Clip

Booking.com

Hotel reservations

Bluetooth Auto Connect

Bluetooth Volume

Blue light filter

I am using a paid version.

Since iOS 9.3, this is a built-in function (Blue light reduction) in Settings on Apple devices to do that.

nRF Master Control Panel (BLE)

Arduino 101

AutoCAD 360

IFTTT

SwitftKey

Microsoft Office

NFC Tools

How to Automatically Launch Android Auto with NFC

Watchup

Play store & Plex acquires Watchup

Text messages

https://www.howtogeek.com/314963/the-best-texting-apps-for-android/ (7/17/2017)

How to Make Calls and Use Google Hangouts Like a Pro

https://www.makeuseof.com/tag/google-hangouts-tips/

How to Silence Phone Calls (But Not Text Messages and Notifications)

https://www.howtogeek.com/301644/how-to-silence-phone-calls-but-not-text-messages-and-notifications/

Terrarium TV

Is watching videos on Terrarium TV illegal?

CamScanner

Scan Documents on Your Phone with CamScanner for Android

Scanbot

After you scan your documents, you can mark up your scan with annotations and add signatures to documents using your finger.

Virtual Reality

10 Mobile Apps for Discovering Events Happening Around You

https://www.makeuseof.com/tag/mobile-apps-nearby-events/

Tethering

Got a phone number away from Google voice

Pay $3 to port your number away from Google Voice

Android System

Google Mobile Services vs Android Open Source Project/AOSP

http://www.howtogeek.com/232973/amazons-fire-os-vs.-googles-android-whats-the-difference/

File System Hierarchical

6.0 Mashmallow

How to Secure Your Google Account

How to Secure Your Google Account

Developer Options

Go to Settings > About device and tap on Build number seven times to unlock the Developer options.

See How to kill Android apps and tasks running in the background.

Battery

5 vital Android settings that save your apps, data, battery and more

Notifications & sound

4 ways to turn off annoying notifications on your Android phone or iPhone

Auto restart when plugged to a charger

https://stackoverflow.com/questions/26294258/auto-boot-when-wall-charger-is-plugged

How to mount /system rewritable or read-only

https://android.stackexchange.com/questions/110927/how-to-mount-system-rewritable-or-read-only-rw-ro

How to Speed Up an Old Android Device With 3 Essential Tips

https://www.makeuseof.com/tag/speed-up-android-tips/

Android Oreo (8.x)

8 New Android Oreo Features You Should Know About

Basic(s)

A Word

Sometimes I'll get strange error messages when I do 'Run As Android Application'. The solution is to create a new Android app project and copy the code as I need.

A weird thing is Android SDK will automatically create project 'appcompat_v7', 'appcompat_v7_2', .... If we delete any one of them, it will screw up things.

See also https://developer.android.com/tools/support-library/setup.html, http://developer.android.com/tools/support-library/features.html

See message 1

Use "Ok Google" on Android

https://support.google.com/websearch/answer/6031948?co=GENIE.Platform%3DAndroid&hl=en

  • Google App
  • Languages: Default is English. It is OK to have multiple languages. For example, if I add 國語, Android is able to recognize both English and Chinese.
  • In "Ok Google" detection, we can turn on the option of Say "Ok Google" any time. Your device recognizes your voice when you say "Ok Google", even if the screen is off or you're using your favorite apps.

APKMirror- Download Free Android APKs

http://www.apkmirror.com/

Where to find the apk files on devices

See here. It is located under /data/app/.

The Android device needs

  • If connecting for the first time, User is prompted to install the drivers in which case, point to $ANDROID_SDK_PATH/usb_driver, the drivers will get installed.
  • Change your settings to permit apps that don’t come from the Google Market by going to the home screen and choosing MENU > Settings > Applications > Unknown Sources.
  • Turn USB debugging ON on your phone, On your device go to the home screen, press MENU > Settings > Applications > Development, then enable USB debugging.

adb

Check connected devices by adb (under the same network)

Enable USB debugging on your device first. Before this command can be used, we shall enable USB debugging from the 'Developer option' page. The 'Developer option' page is under Setting but is hidden. To make this screen visible, follow the instruction on http://developer.android.com/tools/device.html. That is, go to Settings > About phone and tap Build number seven times. Return to the previous screen to find Developer options at the bottom (tested on both of my Samsung S3, Nexus 9, ...).

If the android devices are connected to your computer using a USB cable, you can check if the connection is successful. 

$ sdk/platform-tools/adb devices
List of devices attached 
2011060116402004	device

If the android devices are connected to the same network but not on your computer, use 

$ adb tcpip 5555
$ adb connect device_ip_address
# At the end
$ adb disconnect <ip>:<port>

Note: on new Android SDK downloaded from http://developer.android.com/sdk/index.html, the adb command is under 

Android/Sdk/platform-tools/

directory.

'Download' folder on Android

# tested on Oreo 8.0 
$ sudo adb shell ls /sdcard/Download
$ sudo adb push ~/Downloads/xxx /sdcard/Download/

$ sudo adb shell  # interactively
bullhead:/ $ ls
bullhead:/ $ cd /sdcard
bullhead:/sdcard $ ls
AirWemo    DCIM     MyCarTracks   Recorders  camera-p.jpg 
Alarms     Download Notifications Ringtones  dianxin      
Android    Movies   Pictures      XuiteMusic recordings   
CamScanner Music    Podcasts      backups

Then turn off usb debugging under developer options.

How to copy an apk file out to PC

Use adb pull. For example, 

adb pull data/app/com.dotgears.flappybird-1.apk .
adb pull sdcard/Download/SomeFile ~/Downloads/

Note that adding "/" to the beginning of "sdcard" or "data" is optional.

How to put an apk file on device

adb push local remote

Or use the adb install command to install an app. For example, 

adb install com.dotgears.flappybird-1.apk

How to uninstall/delete apk files on devices

http://www.botskool.com/geeks/how-uninstall-apk-files-android-windows-sdk-emulator 

cd SDK/tools
adb shell ls data/app
adb shell rm data/app/com.androidcan.asudoku.apk

How to copy a apk out from devices

http://stackoverflow.com/questions/4032960/how-do-i-get-an-apk-file-from-an-android-device. For example, the adobe reader 

adb shell pm list packages
adb shell pm path com.adobe.reader
adb pull /data/app/com.adobe.reader-1.apk

Failed to install HelloWorld.apk on device (null) Error

http://stackoverflow.com/questions/5229906/android-failed-to-install-helloworld-apk-on-device-null-error

Solution: Try changing the ADB connection timeout. I think it defaults that to 5000ms and I changed mine to 10000ms to get rid of that problem. If you are in Eclipse, you can do this by going through Window -> Preferences and then it is in DDMS under Android.

Build without running an application

Building vs running: Building will just generate apk file but running will install the app to the device.

See here. In Eclipse menu, Windows -> Preferences. From this Preferences window: Android -> Build. Now uncheck "Skip packaging and dexing until export or launch. (Speeds up automatic builds on file save.)". From now on, as long as we save any changes in source files, the apk file will be recreated.

Modified the 'name' shown on Eclipse Package Explorer

Modify the name tag in <.project> file (hidden file).

Structure of an App project

Before we create a new project in Eclipse, we have to enter some information.

  • Application Name: the name that appears to users
  • Project Name: the name of project directory and the name visible in Eclipse
  • Package name: com.example.GUIDemo
  • Minimum Required SDK: API 8
  • Target SDK: API 18
  • Compile With: API 19 (By default, this is set to the latest version of Android available in your SDK)
  • Activity Name: MainActivity (will create <MainActivity.java> and MainActivity class)
  • Layout Name: activity_main (will create <activity_main.xml>)
  • Navigation type: None
src +-- com.example.guidemo
           +-- MainActivity.java

res +-- layout +-- activity_main.xml
       +-- values +-- strings.xml
AndroidManitest.xml
proguard-project.txt
project.properties
.project

Command Line

$ android update project -p .
$ ant debug            // create an .apk file
$ adb install bin/your-project-name-debug.apk // only install, will not run

Debug with Eclipse line by line

The Context Object

  • See stackoverflow.
  • Beginning android application book Chapter 2: Activities, fragments and intents -> Understanding Activities -> Displaying a Dialog Window.

Rotate AVD screen

  1. Enable NUMLOCK;
  2. Open your emulator and press the 7 followed by 9 on the NUMPAD on the right side of your keyboard;

Dialog

Intent

Linking activities using Intents.

  • See Chapter 2 of Beginning Android 4 App Development -> Linking Activities using Intents
  • http://www.vogella.com/tutorials/AndroidIntent/article.html
  • startActivity(). To pass data back from an activity, use startActivityForResult() and onActivityResult().
  • Intent-filter is defined in AndroidManifest.xml file. Other activities that wish to call this activity will invoke it via the activity's name in intent-filter.
  • The category for the intent filter is android.intent.category.DEFAULT. You need to add this to the intent filter so that this activity can be started by another activity using the startActivity() method.
  • Activities in Android can be invoked by any applications running on the device through intent-filter.
  • The <intent-filter> element defines how your activity can be invoked by another activity. If another activity has the same filter name, then when you call the startActivity() method with the same android name in intent-filter, the Android OS will display a selection of activities. See Figure 2-12 in 'Beginning Android 4 App Development'.
  • (Continue above) If you check the 'Use by default for this action" item, then to clear the default, we need to go to the Settings application in Android and select Apps > Manage applications, and then selection the app name. Scoll down to the bottom and click the 'Clear defaults' button.

AndroidManifest.xml

  • It names the Java package for the application.
  • It describes the components of the application — the activities, services, broadcast receivers, and content providers that the application is composed of.
  • Android components register intent filters staticially in the AndroidManifest.xml.
  • It determines which processes will host application components.
  • It declares the minimum level of the Android API that the application requires.

Android nerd ranch book

01_FirstApp_GeoQuiz Project

activity_quiz.xml

Note that

  • A layout is a resource, a piece of your application that is not code.
  • To generate a resource ID for a widget, you include android:id attribute in the widget's definition.
  • There is a + sign in the values for android:id but not n the values for android:text. This is because you are creating the IDs and only referencing the strings.
  • Since we want to interact with 2 buttons in code, so only they need resource IDs.
  • All resource IDs can be found in <gen/com.example.geoquiz/R.java>.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:gravity="center"
  android:orientation="vertical" >

  <TextView    
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/question_text_view"
    android:padding="24dp" />
  
  <LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal">

    <Button
      android:id="@+id/true_button"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="@string/true_button" />

    <Button
      android:id="@+id/false_button"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="@string/false_button" />

  </LinearLayout>

</LinearLayout>

strings.xml

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

  <string name="app_name">GeoQuiz</string>
  <string name="question_text_view">The Pacific Ocean is larger than the Atlantic Ocean.</string> 
  <string name="true_button">True</string>
  <string name="false_button">False</string>  
  <string name="correct_toast">Correct!</string>
  <string name="incorrect_toast">Incorrect!</string>
  <string name="menu_settings">Settings</string>

</resources>

QuizActivity.java

  • Add two member variables to access the buttons (through resource IDs)
  • Notice the prefix m on the member variable names.
  • Import the class android.widget.Button for the buttons. It can be added by organizing imports. This can be done by keyboard shortcut Ctrl + Shift + O.
  • To get references to widgets, we use the Activity method: findViewById(int id).
  • To set listeners (review Java!), use setOnClickListener(OnClickListener) method; something like
        mTrueButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                 // Does nothing yet.
            }
        });
  • Making toasts - a pop-up message. To create a toast, you call the method: makeText(Context context, int resId, int duration). The 2nd parameter is the resource ID of the string that the toast should display. After created a toast, you call Toast.show() on it to get it on screen.

So the complete java code looks like 

package com.bignerdranch.android.geoquiz;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class QuizActivity extends Activity {

    Button mTrueButton;
    Button mFalseButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_quiz);

        mTrueButton = (Button)findViewById(R.id.true_button);
        mTrueButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(QuizActivity.this, 
                        R.string.incorrect_toast, Toast.LENGTH_SHORT)
                        .show();
            }
        });

        mFalseButton = (Button)findViewById(R.id.false_button);		
        mFalseButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(QuizActivity.this, 
                        R.string.correct_toast, Toast.LENGTH_SHORT)
                        .show();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_quiz, menu);
        return true;
    }

}

02_MVC_GeoQuiz

Works.

03_ActivityLifecycle_GeoQuiz

Crash AVD for some reason. The whole practice is the same as Chapter 2 in Beginning Android 4 Application Development (the code works there).

05_SecondActivity_GeoQuiz

07_UIFragments_CriminalIntent

  • One critical difference between the fragment lifecycle and the activity lifecycle is the fragment lifecycle methods are called by the hosting activity, not the OS.

Amazon Devices

Fire TV

Fire Tablet

Android + chroot + Ubuntu

Phone bands

Nexus 5x H790 has LTE bands. Spring uses LTE 25, 26. Tmobile uses LTE 12 & 17.

Nexus 5x H791 is international which remove LTE bands 12, 13 and 25. And it is GSM only; no CDMA.

See this for comparison.

Fine for AT&T (does not use band 12).

LTE discovery app.

GSM (open), CDMA (not open)

Sprint and Verizon are the primary CDMA carriers, while T-Mobile and AT&T are the two primary GSM carriers.

GSM is generally open; CDMA is not. Basically, neither Sprint nor Verizon offer options for customers to bring their own phones. GSM carriers—like AT&T, T-Mobile, MetroPCS, and US Cellular, for example—are pretty “open.” You can take most modern GSM smartphones, drop a SIM card from one of the aforementioned carriers in it, and it should just work, no matter where you bought it from.

See Are Cheap Android Phones Worth It?

sim card ID

How can I find my SIM card number (ICCID) on my Android phone?

Android Pay

Everything You Can Do With Google Pay

Google Smart Lock

What is Google Smart Lock, Exactly?

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