Android-Wiki

• Branch
• GitLab and SSH keys
• Basic commands
• Android Setup
• Git Basic Commit History
• Gradle Project Structure
• How I organize Android project structure
• Package by features, not layers
• Best practices in Android development by Futurice developers
• Code Style for Contributors
• Architecture Guidelines
• Android MVP Architecture: Sample App
• Google Java Style Guide
• A successful XML naming convention
• Refactoring & Design Patterns
• Display and control your Android device
• Android interview questions
• Java Interview questions
• Kotlin Interview Questions

How to import project

• Make sure GitLab account connected

• Go to your computer's shell and type the following command :

git clone {URL_GIT} || {URL_HTTPS}

README file properties

README.md

• should be created in the project root
• should be written in English
• should be written using markdown

Display logcat via terminal

• Open terminal using Ctrl + T
• Find emulator or devices want to logcat

adb devices

• Note the emulator or devices id
• Start logcat using this command

adb -s {DEVICE_ID} logcat

How to create new branch

• Go to your computer's shell and type the following command :

git branch NAME_OF_BRANCH

How to create new branch and switch new branch

• If you want to create new branch after creating new brach, switch to new branch

git checkout -b NAME_OF_BRANCH

How to change current branch

• If you want to change current branch then following command :

git checkout NAME_OF_BRANCH

How to merge one branch to another

• If you merge to another branch then following command :

git merge NAME_OF_BRANCH

Delete all unmerged local branches

git branch --merged | grep -v \* | xargs git branch -D 

How to add a remote repo

• To add new remote

git remote add {REMOTE_NAME} {URL_HTTPS} || {URL_GIT}

• After set new remote, view your remote properties :

git remote -v

How to pull from remote

• Pull from remote repositories to get all changes

git pull origin NAME_OF_BRANCH

How to fetch from remote

• Fetch data from remote

get checkout --track {REMOTE_NAME}/{NAME_OF_BRANCH}

How to display log history

• Commit history

git log

• Which is show the difference introduced in each commit

git log -p

• Description of output

  • %s Subject
  • %ar Author date, relative
  • %h Commit hash
  • %an Author name
  • %ad Author date
  • %cn Comitter name
  • Example code line :

  git log --pretty=format:"%cn %ar"
  

How to commit changes

• To add and commit all local changes in one command :

git add .
git commit -m "COMMENT TO DESCRIBE THE INTENTION OF THE COMMIT"

• Also if you want to push commit changes following command line :

git push {REMOTE_NAME} {NAME_OF_BRANCH}

• Note: Check this and learn how to write a proper commit message

How to rebase one branch to another

• Before rebase make sure feature branch and master is up to date
• This sample rebase master into feature branch

git checkout master
git pull

• After update master branch now get back feature branch

git checkout {FEATURE_BRANCH_NAME}
git rebase -i master

• After this command if two branches has conflict before push resolve the conflicts

git push --f {REMOTE_NAME} {NAME_OF_BRANCH}

• Note: Check this and learn how to rebase

Delete remove and changes file

git clean -d -f

How to reset commit

• Before start make sure unpushed commit have it
• Check your branch status

git status

• After the result you can obtain your commit id or you can show how many commit ahead in current branch

git reset --hard HEAD~[NUMBER]|[COMMIT_ID]

How to delete local or remote branch

• Before start make sure unpushed commit have it
• If you want to delete local branch type the following command

git branch -d {NAME_OF_BRANCH}

• If you want to delete remote branch type the following command

git push origin -delete {NAME_OF_BRANCH}

Create keytool file for signing apk

• Open the terminal and type this command

keytool -genkey -v -keystore {KEYSTORE_FILE_NAME}.keystore -alias {ALIAS_NAME} -keyalg RSA -keysize 2048 -validity 10000

• After this command terminal wants to more information about who create this file and company name
• Answer the questions
• Create uniq key password and store password
• Don't forget the password after created file you will use
• Move the keytool file inside the /project/app folder
• In your app.gradle file you need to replace keytool file and passwords

  signingConfigs {
        debug {
           storeFile file("{KEYSTORE_FILE_NAME}.keystore")
            keyAlias "{ALIAS_NAME}"
            keyPassword "{KEY_PASSWORD}"
            storePassword "{STORE_PASSWORD}"
        }
    }

• Sync gradle file
• Now you can check your build variant on left bottom side bar in Android Studio
• You will see the all variants, select one of them and build your apk

Extract sha key from apk

• Go to your apk file location
• Extract apk file, open terminal in apk location and use this command :

unzip {APK_NAME} -d {UNZIP_FILE_NAME}

• Go to /META-INF/ANDROID_.RSA file (this file may also be CERT.RSA, but there should only be one .RSA file).
• Use command :

keytool -printcert -file ANDROID_.RSA

• After this command you can get fingerprints

Create static web server for the get http request

• First install the http-server

sudo npm install -g http-server

• After installed http server create new folder
• Create new .json file inside the folder
• {FILE_NAME}.json and add json text inside the document
• Start http server using this command

http-server .

• '.' means is read all file inside the folder
• Http server will start on localhost

Deploy apk remotely

• First connect device through usb
• Open terminal and set port, follow this command :

adb tcpip 5555

• Now you can listen 5555 port while same network
• You don't need to connect with usb
• Now connect to device via network

adb connect {DEVICE_INTERNAL_IP:PORT_NUMBER}

GitLab and SSH key for Command Prompt

• Go to your computer's shell and type the following command :
• Mail adresses should be same as GitLab mail address

ssh-keygen -t rsa -C "your.email@example.com" -b 4096

• Locating an existing SSH key
• You can copy sha key to clipboard for Windows

notepad ~/.ssh/id_rsa.pub  

• For OS

pbcopy < ~/.ssh/id_rsa.pub

type %userprofile%\.ssh\id_rsa.pub

• Open GitLab click on your Avatar and go to your Profile Settings

• Navigate to SSH keys

• Paste your SSH key to Box

• Give title description

• Final step is click to Add Key, also you can see fingerprint

GitLab and SSH key for Linux / macOS

• Go to your computer's shell and type the following command :
• Mail adresses should be same as GitLab mail address
• If you have SSH key then locate existing SSH key :

cat ~/.ssh/id_rsa.pub

• If you see string starting with ssh-rsa you already have SSH key, if not you have to generate new SSH key follow the next step
• Generating new SSH Key

ssh-keygen -t rsa -C "your.email@example.com" -b 4096

• Open GitLab click on your Avatar and go to your Profile Settings

• Navigate to SSH keys

• Paste your SSH key to Box

• Give title description

• Final step is click to Add Key, also you can see fingerprint

Install Android Studio on Windows

1. If you haven't install Android Studio follow the steps :

• Go to Android site, dowload latest version Android Studio
• Setup android-studio-ide.exe

Follow Field Naming Conventions

• Non-public, non-static field names start with m.

• Static field names start with s.

• Other fields start with a lower case letter.

• Public static final fields (constants) are ALL_CAPS_WITH_UNDERSCORES.

public class MyClass {
    public static final int SOME_CONSTANT = 42;
    public int              publicField;
    private static MyClass  sSingleton;
    int                     mPackagePrivate;
    private int             mPrivate;
    protected int           mProtected;
}

Install Android Studio on Linux

1. If you haven't install Android Studio follow the steps :

• Go to Android site, dowload latest version Android Studio
• Unpack the .zip file you downloaded
• Open a terminal, navigate to the android-studio/bin/ directory, and execute studio.sh.
• Select whether you want to import previous Android Studio settings or not, then click OK.

Install Android Studio on MacOS

• If you haven't install Android Studio follow the steps :
  • Go to Android site, dowload latest version Android Studio

• Launch the Android Studio DMG file.
• Drag and drop Android Studio into the Applications folder, then launch Android Studio.
• Select whether you want to import previous Android Studio settings, then click OK.
• The Android Studio Setup Wizard guides you though the rest of the setup, which includes downloading Android SDK components that are required for development.

Project Configuration

• After setup Android Studio follow the steps below :
  • Open SDK Manager from Android Studio, click Tools>SDK Manager or click SDK Manager in the toolbar
  • Select API 27 and API 19
  • After select SDK platform click SDK Tools
  • Must be select Google Play services, Android SDK Build Tools, Android Emulator and Android SDK platform Tools
  • After selected items click Apply and Ok close window

Android SVG to Vector Image

• This links will convert your .svg file to vector image

• This page for svg to Vector Drawable
• This page for android application icon