List of Android Tips

A curated list of awesome Android Tips. Feel free to contrubute.

Other Awesome List

awesome-android
awesome-android-ui
awesome-android-libraries

Index

Android Studio
Tools
Gradle
UI/UX
About Me

Android Studio

Keyboard shortcuts

Description	Mac	Linux/Win
Open recently edited file	`Cmd` `Shift` `E`	`Ctrl` `Shift` `E`
Last Edited Location	`Cmd` `Shift` `Backspace`	`Ctrl` `Shift` `Backspace`
Refactor This	`Ctrl` `T`	`Ctrl` `Alt` `Shift` `T`
Multicursor Selection	`Ctrl` `G`	`Alt` `J`
Lookup IDE commands / Actions	`Cmd` `Shift` `A`	`Ctrl` `Shift` `A`
Open Symbol	`Cmd` `Opt` `O`	`Alt` `Shift` `N`

Complete Keymap Guide : MacOSX | Linux/Win

Plugins

Name	Description
android-xml-sorter	Android Studio & IntelliJ Plugin for sort xml by name="xxx"
android-material-design-icon-generator-plugin	This plugin help you to set material design icon to your project
android-selector-chapek	Android Studio plugin which automatically generates drawable selectors from appropriately named resources
android-selector-intellij-plugin	Generate selectors for background drawable
android-parcelable-intellij-plugin	IntelliJ Plugin for Android Parcelable boilerplate code generation
adb-idea	Plugin for Android Studio and Intellij IDEA that speeds up your day to day android development
android-butterknife-zelezny	Android Studio plug-in for generating ButterKnife injections from selected layout XML
GsonFormat	This is a plugin you can generate Json model from Json String
CodeGlance	Intelij IDEA plugin for displaying a code mini-map similar to the one found in Sublime
ADBWIFI	ADBWIFI Android Studio plugin for debug android app over Wi-Fi
android-styler	Android Studio / IDEA plugin that helps to create styles
android-drawable-importer-intellij-plugin	Adds an option to IntelliJ to import drawables in different resolutions from AndroidIcons, own "drawable repos" and scale a certain image down/up to the defined resolutions
genymotion	This plugin allows you to create and start Genymotion virtual devices from Android Studio
dagger-intellij-plugin	An IntelliJ IDEA plugin for Dagger which provides insight into how injections and providers are used
gradle-dependencies-helper	library is searched in Smart Code Completion by Maven repository
AndroidProguardPlugin	Android Studio generate proguard codes
idea-markdown	Markdown language support for IntelliJ IDEA
idea-multimarkdown	Markdown language support for IntelliJ IDEA
folding-plugin	Android File Grouping Plugin
gradle-retrolambda	A gradle plugin for getting java lambda support in java 6, 7 and android
idea-gitignore	.ignore support plugin for IntelliJ IDEA
checkstyle-idea	CheckStyle plug-in for IntelliJ IDEA
permissions-dispatcher-plugin	IntelliJ plugin for supporting PermissionsDispatcher
jetbrains-wakatime	IntelliJ IDEA, PyCharm, RubyMine, PhpStorm, AppCode, AndroidStudio, Gogland, Rider, & WebStorm plugin for quantifying your coding
AndroidWiFiADB	ntelliJ/AndroidStudio plugin which provides a button to connect your Android device over WiFi to install, run and debug your applications without a USB connected
AndroidLocalizationer	This is a Android Studio/ IntelliJ IDEA plugin to localize your Android app, translate your string resources automactically
KeyPromoter	The plugin basically will annoy the hell out of you by showing you a big screen overlay with the key combination you should have used, if you used your mouse to execute some command to a level when you basically would start using the key combination just to avoid KeyPromoter annoying you all the time. It also has some useful features, like it will prompt you to create a key binding for a command whenever an action does not have a key binding and you have used it 3 times using your cursor
String Manipulation	Provides actions for text manipulation such as Toggle case, encode/decode, sorting
Sonar Lint	The plugin that provides on-the-fly feedback to developers on new bugs and quality issues injected into Java, JavaScript and PHP code
Exynap	The plugin which helps you find and implement the code you require in an instant

Gradle Plugin

Name	Description
gradle-play-publisher	Gradle Plugin to upload your APK and metadata to the Google Play Store
dexcount-gradle-plugin	A Gradle plugin to report the number of method references in your APK on every build
maven-android-sdk-deployer	A tool to install components of the Android SDK into a Maven repository or repository manager to use with the Android Maven Plugin, Gradle and other tools
gradle-versions-plugin	Gradle plugin to discover dependency updates
bintray-release	A helper for releasing from gradle up to bintray
ViewInspector	View Inspection Toolbar for Android Development

Live Templates

newInstance - Generates the static newInstance function inside a Fragment
const - Define a android style int constant
psf - public static final
visible - Set view visibility to VISIBLE
gone - Set view visibility to GONE
noInstance - private empty constructor to prohibit instance creation

Comprehensive list of all Live Templates: https://github.com/keyboardsurfer/idea-live-templates

Postfix code completion

Android Studio/IntelliJ havea special kind of code completion which allows you to write code specific to a field

<expr>.null will auto complete to if(<expr> == null)
<expr>.nootnull will auto complete to if(<expr> != null)
<expr>.var will auto complete to T name = <expr>
<expr>.field will auto complete to create a global field variable field = <expr>
<ArrayExpr>.for will auto complete to for(T item : <Arrayexpr>)
<ArrayExpr>.fori will auto complete to for(int i = 0; i < <Arrayexpr>.length; i++)
<ArrayExpr>.forr will auto complete to for(int i = <Arrayexpr>.length - 1; i > 0 ; i--)

Complete list of available postfix code completion can be found at: Settings → Editor → Postfix Templates

Tools

Name	Repository
Vysor	This one needs special mention due to how useful it is. It basically is a window to your device i.e it streams and allows you to interact with your physical device on your laptop. Very useful when you are demoing your app during a presentation. You can interact with your physical device and it will be shown right in your laptop screen. It has a paid/free version, paid version is totally worth buying
DeskDock	It enables you to control your Android device as if it was part of your desktop computer
simplify	Generic Android Deobfuscator
jadx	Dex to Java decompiler
apk2gold	CLI tool for decompiling Android apps to Java. It does resources! It does Java! Its real easy!
procyon	Procyon is a suite of Java metaprogramming tools focused on code generation and analysis
classyshark.com	handy Android and Java executables viewer
backdoor-apk	backdoor-apk is a shell script that simplifies the process of adding a backdoor to any Android APK file. Users of this shell script should have working knowledge of Linux, Bash, Metasploit, Apktool, the Android SDK, smali, etc. This shell script is provided as-is without warranty of any kind and is intended for educational purposes only
enjarify	Enjarify is a tool for translating Dalvik bytecode to equivalent Java bytecode. This allows Java analysis tools to analyze Android applications
dexterity	Dex manipulation library
android-classyshark	Executables (apk, multi-dex, jar) browser for Android, Java and Kotlin
Battery Historian	A tool to analyze battery consumers using Android "bugreport" files
TinyPNG	Optimize your images with a perfect balance in quality and file size

Mock

Mockey - A tool for testing application interactions over http, with a focus on testing web services, specifically web applications that consume XML, JSON, and HTML.
JSON Placeholder - Fake Online REST API for Testing and Prototyping
API Studio - a playground for API developers
Mocky - Mock your HTTP responses to test your REST API
Mockbin - Mockbin allows you to generate custom endpoints to test, mock, and track HTTP requests & responses between libraries, sockets and APIs.

Gradle

Use shrinkResources

android {
  ...
  buildTypes {
      release {
          shrinkResources true
          minifyEnabled true
          ...
      }
  }
}

Split your apk using gradle when using Native code, do not bundle all of em together and ship!.. coz that will make you evil

defaultConfig {
    ...

    ndk {
      abiFilters "armeabi", "armeabi-v7a", "mips", "x86"
    }
  }

//Split into platform dependent APK
splits {
  abi {
    enable true
    reset()
    include 'armeabi', 'armeabi-v7a', 'mips', 'x86' //select ABIs to build APKs for
    universalApk false //generate an additional APK that contains all the ABIs
  }
}

// map for the version code
project.ext.versionCodes = ['armeabi': 1, 'armeabi-v7a': 2, 'mips': 5, 'x86': 8]

// Rename with proper versioning
android.applicationVariants.all { variant ->
  // assign different version code for each output
  variant.outputs.each { output ->
    output.versionCodeOverride =
        project.ext.versionCodes.get(output.getFilter(com.android.build.OutputFile.ABI), 0) *
            1000000 +
            android.defaultConfig.versionCode
  }
}

To force re-download of dependencies
```
./gradlew --refresh-dependencies
```
To exclude a certain task from being run by gradle

Suppose you want to exclude the task javaDoc then use -x option followed by the task name, i.e javaDoc in this case.
```
./gradlew clean build -x javaDoc
```
To have the each subproject script name match that of the project name

Then add this line in settings.gradle
```
rootProject.children.each{
  it.buildFileName = it.name + '.gradle'
}
```
Checkout more gradle tips here

Use different package name for non-release builds

  android {
      buildTypes {
          debug {
              applicationIdSuffix '.debug'
              versionNameSuffix '-DEBUG'
          }

          release {
              // ...
          }
      }
  }

If you’re creating a gradient in xml with a part being completely transparent, be really careful when using @android:color/transparent
Follow a standard naming convention for your resources
Make use of custom gradle tasks in your build.gradle files

Android uses Gradle as its build system, which actually allows one to make a lot of things easy by creating tasks to automate things. This reddit post enlists a lot of such useful gradle scripts
Stop a running gradle build process
```
./gradlew -stop
```
Donot include both jcenter() & mavenCentral() in your build.gradle file

JCenter is a superset of MavenCentral. [Ref tweet]
Clear your gradle cache if you think that bundled support and google play services lib in android sdk are inconsistent
- Goto ~/.gradle/caches/ and delete everything inside the cache folder.
- Open SDK Manager and resync all support libs and google play services
- Next re-sync your project
- Everything should become consistent and functional.

Setup handy adb aliases for your terminal [Ref Link]

Append the below Aliases to your ~/.bashrc or ~/.zshrc file, save and restart the terminal. Once saved, use them as show in Usage column

Alias	Usage
`alias screenshot="adb exec-out screencap -p > screen-$(date -j "+%s").png"`	`screenshot`
`alias startintent="adb devices	tail -n +2
`alias apkinstall="adb devices	tail -n +2
`alias rmapp="adb devices	tail -n +2
`alias clearapp="adb devices	tail -n +2

Setup Android Studio to fail build if code contains //STOPSHIP [Ref Link]

To enable the //STOPSHIP lint check, in your build.gradle
```
android {
...
    lintOptions {
        abortOnError true
        fatal 'StopShip'
    }
}
```
If you have a //STOPSHIP comment in your code, this will cause an error to be thrown when a release apk is generated.

You can turn on //STOPSHIP highlighting in Android Studio (isn't enabled by default) in

Preferences > Editor > Code Style > Inspections.

Search for STOPSHIP to find the correct setting.
Use adb install -g to grant all permissions listed in the manifest [More Info]
Use alfi to find the gradle dependency statement for a library

Its basically the command line version of Gradle, Please which is a web hosted.
- Run
```
alfi name_of_library
```
- Copy the desired library
- Paste in your build.gradle
Use dryrun to test a library directly
- Just Run
```
dryrun REMOTE_GIT_URL
```

Output unit tests directly to the console [Ref Link]

A small neat trick to see Android unit tests logging results as they happen in the terminal.

android {
    ...
    testOptions.unitTests.all {
      testLogging {
        events 'passed', 'skipped', 'failed', 'standardOut', 'standardError'
        outputs.upToDateWhen { false }
        showStandardStreams = true
      }
    }
  }

Reduce installed app size with "android:extractNativeLibs:false" in <application> [Ref Link]

This will essentially prevent the system from creating a second copy of the .so files and fix the System.loadLibrary call so it’s able to find and open native libs straight from the APK, no code changes on your part required.
Selectivily execute a specific method in Android Studio [Ref Link]
Did you get one of these Google Play Developer Policy Violation Emails? Worry not, generate a Privacy Policy for your android app [Ref ink]
- Take a look at App Privacy Policy Generator, a web app to generate a generic privacy policy for your app.

Define a variable at build time In your build.gradle

android{
  defaultConfig {
    ...
    buildConfigField "String", "SERVER_ENDPOINT", '"http://www.myendpoint.com"'
    buildConfigField "int", "FOO", "52"
    buildConfigField "boolean", "LOG", "false"
    ...
  }
}

and then use it in code as BuildConfig.SERVER_ENDPOINT, BuildConfig.FOO,BuildConfig.LOG

Calculate the version code and version name in your build.gradle manually, based of version values* In your app's build.gradle

versionMajor = 0
versionMinor = 0
versionPatch = 0
versionBuild = 1


verCode = versionMajor * 1000000 + versionMinor * 10000 + versionPatch * 100 + versionBuild
verName = "${versionMajor}.${versionMinor}.${versionPatch}"

// Use
android{
  defaultConfig {
    ...
    versionCode verCode
    versionName verName
    ...
  }
}

Calculate the version code and version name in your build.gradle automatically, based on git information*

Note: These functions go specifically inside the app's build.gradle and cannot be used with ext.

In your app's build.gradle

// Version code is calculated as the number of commits from last commit on master
def getVersionCode = { ->
  try {
    def code = new ByteArrayOutputStream()
    exec {
      commandLine 'git', 'rev-list', 'HEAD', '--count'
      standardOutput = code
    }
    return Integer.parseInt(code.toString().trim())
  } catch (exception) {
    return "1";
  }
}

// Version name is Last Tag Name + No. of commits form last Tag +  short git sha
def getVersionName = { ->
  try {
    def stdout = new ByteArrayOutputStream()
    exec {
      commandLine 'git', 'describe', '--tags', '--dirty'
      standardOutput = stdout
    }
    return stdout.toString().trim()
  } catch (exception) {
    return "0.0.0.1";
  }
}

// Use
android{
  defaultConfig {
    ...
    versionCode getVersionCode()
    versionName getVersionName()
    ...
  }
}

Get the date of build as a variable* In your app's build.gradle

// Get the date of build
def getDateOfBuild = { -> // ISO 8601 time format
  return new Date().format("yyyy-MM-dd'T'HH:mm'Z'").toString().trim()
}

// then use it as a variable in BuildConfig
android{
  defaultConfig {
    ...
    buildConfigField "String", "DATE_OF_BUILD", "\"${getDateOfBuild()}\""
  }
}

Get the Git SHA as a variable* In your app's build.gradle

// Get the last Git Short Hash
def getGitHash = { ->
  def stdout = new ByteArrayOutputStream()
  exec {
    commandLine 'git', 'rev-parse', '--short', 'HEAD'
    standardOutput = stdout
  }
  return stdout.toString().trim()
}

// then use it as a variable in BuildConfig
android{
  defaultConfig {
    ...
    buildConfigField "String", "GIT_SHA", "\"${getGitHash()}\""
  }
}

Have a look at the Paperwork Project, which generates build info for your Android project without breaking incremental compilation

Activity LifeCycle [Ref Link]
Tip about onSaveInstanceState()
onSaveInstanceState() is called only when the OS decides to kill the Activity instance. It will not be called when Activity is explicitly killed i.e User pressed back button or finish() is called from code.
Read about whats in an APK here
Learn about various techniques involved when using ADB
Input some text in an editfield in a running emulator from your keyboard
```
adb shell input text "keyboard text"
```
Use areNotificationsEnabled() from NotificationManagerCompat to detect whether your users blocked your Notifications [Ref Link]
Don't hard-code encryption keys, a simple grep for "Ljavax/crypto" reveals them in bytecode [Ref Link]
Intents have a limited payload size (1Mb), don't serialize and attach entire file to it [Ref Link]
Always copy a file before sending it as intent URI. Receiving app could edit it & send a canceled result [Ref Link]
Use http:// as scheme for app deeplinks, they are more universal & when app not installed drive users to a domain you own [Ref Link]

Use below to display your app launch time [Ref Link]

adb shell am start -W <packagename>/. <activityname>

Use Java 8 features by adding sourceCompatibility & targetCompatibility to your build.gradle file

android {
  ...
  compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
  }
}

Setup a gradle task to archive apks and proguard files on build, for backup purposes

task deployApks(type:Copy) {
    description = "Copies APKs and Proguard mappings to the deploy directory"
    def appName = "<app_name>";
    def versionDir = android.defaultConfig.versionName+"_"+android.defaultConfig.versionCode;

    println("Copies APK and Proguard to " + versionDir)

    from 'build/outputs/mapping/release/'
    include '**/mapping.txt'
    into '../.admin/deploy/' + versionDir
    rename ('mapping.txt', "${versionDir}-mapping.txt")

    from ('.') {
        exclude '**/build', '**/src'
    }

    include '*.apk'
    into '../.admin/deploy/' + versionDir
    rename ('app-release.apk', "${appName}-${versionDir}.apk")
}

Use activity-alias or your launcher icons will disappear when renaming/moving your MainActivity

UI/UX

Motion

Material Design uses real-world metaphors as its foundation. Objects in the real world don't move linearly, they move in curved paths and accelerate and decelerate according to the motion's properties.
As such, motion should also use such properties and animate objects so that the motion feels natural rather than forced
For example, a car leaving the screen in a movie starts off slowly, then accelerates till it's out of the frame. Similarly, views should be interpolated using classes like AccelerateInterpolator, FastOutSlowInInterpolator, etc. [More Info]

Typography

While custom typefaces can be used for branding, it is essential to stick to Roboto and Noto if possible, especially for body text, due to their clarity and optimistic nature.
Roboto covers Latin, Greek and Cyrillic extended scripts, with Noto filling in for other language scripts [More Info]
Weight balancing is an important aspect of typography, the fundamental concept of which is that the larger a typeface is, the less its weight should be so that it doesn't appear too thick and balances its weight with smaller typefaces of higher weights
Typography should align to a 4dp baseline grid, and maintain a minimum contrast ratio of 4.5:1 based on luminance values, with a recommended ratio being 7:1.
The ideal reading length for large blocks of text is 40 to 60 characters per line. Anything less is too narrow and anything more is too wide.

Icons

Icons should be designed at 48dp, with 1dp edges, which equates to
- 48px by 48px at mdpi
- 72px by 72px at hdpi
- 96px by 96px at xhdpi
- 144px by 144px at xxhdpi
- 192px by 192px at xxxhdpi
An additional icon of 512px by 512px should be designed for use on Google Play
Material icons, in addition to the base icon, should contain the following important elements
- 1dp tinted edge at the top
- 1dp shaded edge at the bottom
- Contact shadow - a soft shadow around all edges of raised elements
- Finish - a soft tint to provide surface lighting, fading from upper life to lower right [More Info]

Ripples

When implementing Ripple Effect use ?attr/selectableItemBackground instead of ?android:attr (Ref)
When implementing Ripples contained within the view like Button, use (Ref)

android:background="?attr/selectableItemBackground"

When implementing Ripples that extend beyond the view's bounds like ImageView: (Ref)

?attr/selectableItemBackgroundBorderless

Other

Views should be aligned to Material Design's 8dp baseline grid and the keylines when possible. This gives the UI a sense of structure and hierarchy. [More Info]
If you plan on keeping a reference to any ViewGroup (LinearLayout, FrameLayout, RelativeLayout, etc.), and you don’t want to use any methods specific to this particular type of Layout, keep it as a ViewGroup object. [More Info]
While picking an accent color (if the brand already has one), pick a color complementary to the primary color so that the contrast is high enough

About Me

Github: https://github.com/thanhtoan1196
Facebook: https://www.facebook.com/thanhtoan1196
Email: thanhtoan1196@gmail.com

License

Copyright 2017 Toan Tran

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

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Readme.md

Readme.md

List of Android Tips

Other Awesome List

Index

Android Studio

Keyboard shortcuts

Plugins

Gradle Plugin

Live Templates

Postfix code completion

Tools

Mock

Gradle

UI/UX

Motion

Typography

Icons

Ripples

Other

About Me

License

Files

Readme.md

Latest commit

History

Readme.md

File metadata and controls

List of Android Tips

Other Awesome List

Index

Android Studio

Keyboard shortcuts

Plugins

Gradle Plugin

Live Templates

Postfix code completion

Tools

Mock

Gradle

UI/UX

Motion

Typography

Icons

Ripples

Other

About Me

License