G E T S T R E A M . I O Library & SDK Lifecycles Design process 1. Define a problem 2. Research overall ideas 3. Verify the feasibility of your ideas 4. Investigate dependencies 5. Draw blueprints of application interfaces 6. Design the application interfaces
G E T S T R E A M . I O Development Strategies Minimize API surfaces class ApiResponseCallAdapter constructor( val resultType: Type ) : CallAdapter>> { override fun responseType(): Type { return resultType } override fun adapt(call: Call): Call> { return ApiResponseCallDelegate(call) } } Client
G E T S T R E A M . I O Development Strategies Minimize API surfaces internal class ApiResponseCallAdapter constructor( private val resultType: Type ) : CallAdapter>> { override fun responseType(): Type { return resultType } override fun adapt(call: Call): Call> { return ApiResponseCallDelegate(call) } } Client
G E T S T R E A M . I O Development Strategies Minimize API surfaces fun Context.dp2Px(dp: Int): Int { val scale = resources.displayMetrics.density return (dp * scale).toInt() } fun Context.px2Sp(px: Int): Int { val scale = resources.displayMetrics.scaledDensity return (px / scale).toInt() } val px = context.dp2Px(dp = 22) val sp = context.px2Sp(px = 22)
G E T S T R E A M . I O Development Strategies Minimize API surfaces internal fun Context.dp2Px(dp: Int): Int { val scale = resources.displayMetrics.density return (dp * scale).toInt() } internal fun Context.px2Sp(px: Int): Int { val scale = resources.displayMetrics.scaledDensity return (px / scale).toInt() } val px = context.dp2Px(dp = 22) // Unresolved reference val sp = context.px2Sp(px = 22) // Unresolved reference
G E T S T R E A M . I O Development Strategies Minimize API surfaces internal fun Context.dp2Px(dp: Int): Int { val scale = resources.displayMetrics.density return (dp * scale).toInt() } internal fun Context.px2Sp(px: Int): Int { val scale = resources.displayMetrics.scaledDensity return (px / scale).toInt() } int px = ContextExtensionKt.dp2Px(context, 11); int sp = ContextExtensionKt.px2Sp(context, 11);
G E T S T R E A M . I O Development Strategies Minimize API surfaces @JvmSynthetic internal fun Context.dp2Px(dp: Int): Int { val scale = resources.displayMetrics.density return (dp * scale).toInt() } @JvmSynthetic internal fun Context.px2Sp(px: Int): Int { val scale = resources.displayMetrics.scaledDensity return (px / scale).toInt() } int px = ContextExtensionKt.dp2Px(context, 11); // Unresolved reference int sp = ContextExtensionKt.px2Sp(context, 11); // Unresolved reference
G E T S T R E A M . I O Development Strategies Exposing resources /classes.jar /res/ /R.txt /public.txt /assets/ /libs/name.jar /jni/abi_name/name.so /proguard.txt /lint.jar /api.jar AAR file
G E T S T R E A M . I O Development Strategies Exposing resources /classes.jar /res/ /R.txt /public.txt /assets/ /libs/name.jar /jni/abi_name/name.so /proguard.txt /lint.jar /api.jar AAR file res/drawable res/layout res/menu res/values res/xml res/raw res/anim res/animator res/mipmap res/font string.xml colors.xml styles.xml dimens.xml arrays.xml … /res/ /res/values/
G E T S T R E A M . I O Development Strategies Exposing resources ● Some issues have been reported in Crashlytics. ● But the reports were not helpful at all. ● Occasionally the library behaves very weirdly. ● Also it’s really difficult to reproduce.
G E T S T R E A M . I O Development Strategies Exposing resources android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center" android:clipChildren="false" android:clipToPadding="false" android:padding="10dp"> android:id="@+id/text" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center_vertical" android:textColor="@android:color/white" /> … Library (layout_balloon.xml) Project (layout_balloon.xml) android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center" android:clipChildren="false" android:clipToPadding="false" android:padding="10dp"> android:id="@+id/text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="12dp" android:text="skydoves" android:textSize="16sp" android:textStyle="bold" /> ...
G E T S T R E A M . I O Development Strategies Exposing resources android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center" android:clipChildren="false" android:clipToPadding="false" android:padding="10dp"> android:id="@+id/text" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center_vertical" android:textColor="@android:color/white" /> … Library (layout_balloon.xml) // wrong behaviors Project (layout_balloon.xml) // runtime error! android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center" android:clipChildren="false" android:clipToPadding="false" android:padding="10dp"> android:id="@+id/text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="12dp" android:text="skydoves" android:textSize="16sp" android:textStyle="bold" /> ...
G E T S T R E A M . I O Development Strategies Non transitive R class :app :library :material (MDC) com.google.android.material.R (:material) implementation implementation
G E T S T R E A M . I O Development Strategies Non transitive R class :app :library :material (MDC) com.my.library.R (:material) (:library) com.google.android.material.R (:material) implementation implementation
G E T S T R E A M . I O Development Strategies Non transitive R class :app :library :material (MDC) com.my.library.R (:material) (:library) com.google.android.material.R (:material) com.my.app.R (:material) (:library) (:app) implementation implementation
G E T S T R E A M . I O Development Strategies Non transitive R class :app :library :material (MDC) Transitive dependency com.my.library.R (:material) (:library) com.google.android.material.R (:material) com.my.app.R (:material) (:library) (:app) implementation implementation
G E T S T R E A M . I O Development Strategies Non transitive R class :app :library :material (MDC) implementation implementation com.my.library.R (:material) (:library) com.google.android.material.R (:material) com.my.app.R (:material) (:library) (:app) Wow, a million of LoC in R classes in a minute!
G E T S T R E A M . I O Development Strategies Non transitive R class Dex format has 64K limit for methods and fields references! 64K (65,536 = 64 x 1024 (2^10))
G E T S T R E A M . I O Development Strategies Non transitive R class :app :library implementation implementation com.my.library.R (:library) com.google.android.material.R (:material) com.my.app.R (:app) Refer to its own resources without pulling resources from dependencies. nonTransitiveRclass :material (MDC)
G E T S T R E A M . I O Development Strategies Non transitive R class aar size diff 226054 bytes -> 214538 bytes (11516 bytes reduced) 10,000 end-users 2260540000 bytes -> 2145380000 bytes (≈115 MB reduced) 100,000 end-users 22605400000 bytes -> 21453800000 bytes (≈1.1 GB reduced) 1,000,000 end-users 226054000000 bytes -> 214538000000 bytes (≈10 GB reduced) 100,000,000 end-users 22605400000000 bytes -> 21453800000000 bytes (≈1 TB reduced)
G E T S T R E A M . I O Development Strategies Non transitive R class :app :feature1 :feature2 :feature3 com.my.app.R (:feature1) (:feature2) (:feature3) (:app) Unresolved reference
G E T S T R E A M . I O Development Strategies Non transitive R class :app :feature1 :feature2 :feature3 com.my.app.R (:feature1) (:feature2) (:feature3) (:app) full name package import with namespacing
G E T S T R E A M . I O Release Maven central repository 1. Registering a Sonatype account 2. Generating a GPG key pair 3. Setting up publication in your project a. Maven publishing setup with Gradle b. Signing artifacts with GPG key c. Configure pom files d. Per-module Gradle setup 4. Publish to sonatype repository 5. Evaluate and close the ticket on staging repositories