Support Task Configuration Avoidance

build.gradle

@@ -6,15 +6,14 @@ buildscript {
       'compileSdk': 28,
 
       'androidTools': '26.2.0',
-      'kotlin': '1.2.71',
-
+      'kotlin': '1.3.11',
       'release': '8.8.1',
   ]
 
   ext.deps = [
       android: [
           'runtime': 'com.google.android:android:4.1.1.4',
-          'gradlePlugin': "com.android.tools.build:gradle:3.1.4",
+          'gradlePlugin': "com.android.tools.build:gradle:3.3.0",
       ],
       'androidx': [
           'core': "androidx.core:core:1.0.0",
@@ -57,7 +56,7 @@ buildscript {
   }
 
   dependencies {
-    classpath 'com.android.tools.build:gradle:3.2.0'
+    classpath 'com.android.tools.build:gradle:3.3.0'
     classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:${versions.kotlin}"
     classpath 'com.github.ben-manes:gradle-versions-plugin:0.17.0'
     classpath 'net.ltgt.gradle:gradle-errorprone-plugin:0.0.16'

butterknife-gradle-plugin/src/main/java/butterknife/plugin/ButterKnifePlugin.kt

@@ -61,26 +61,26 @@ class ButterKnifePlugin : Plugin<Project> {
       val rPackage = getPackageName(variant)
       val once = AtomicBoolean()
       variant.outputs.all { output ->
-        val processResources = output.processResources
+        val processResources = output.processResourcesProvider
 
         // Though there might be multiple outputs, their R files are all the same. Thus, we only
         // need to configure the task once with the R.java input and action.
         if (once.compareAndSet(false, true)) {
-          // TODO: switch to better API once exists in AGP (https://issuetracker.google.com/118668005)
-          val rFile =
-              project.files(
-                  when (processResources) {
-                    is GenerateLibraryRFileTask -> processResources.textSymbolOutputFile
-                    is LinkApplicationAndroidResourcesTask -> processResources.textSymbolOutputFile
-                    else -> throw RuntimeException(
-                        "Minimum supported Android Gradle Plugin is 3.1.0")
-                  })
-                  .builtBy(processResources)
           project.tasks.create("generate${variant.name.capitalize()}R2", R2Generator::class.java) {
+            val processResourcesTask = processResources.get()
             it.outputDir = outputDir
-            it.rFile = rFile
+            // TODO: switch to better API once exists in AGP (https://issuetracker.google.com/118668005)
+            it.rFile = project.files(
+                    when (processResourcesTask) {
+                      is GenerateLibraryRFileTask -> processResourcesTask.textSymbolOutputFile
+                      is LinkApplicationAndroidResourcesTask -> processResourcesTask.textSymbolOutputFile
+                      else -> throw RuntimeException(
+                              "Minimum supported Android Gradle Plugin is 3.3.0")
+                    })
+                    .builtBy(processResourcesTask)
             it.packageName = rPackage
             it.className = "R2"
+            // TODO: switch to as task provider when AGP supports it: (https://issuetracker.google.com/issues/123655659)
             variant.registerJavaGeneratingTask(it, outputDir)
           }
         }

butterknife/src/main/AndroidManifest.xml

@@ -1,2 +1 @@
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="butterknife"/>
+<manifest package="butterknife.core"/>