WIP Create a LayoutRunner binding function that works with AndroidX V…

…iewBindings. Related to #984.
square · Feb 26, 2020 · 52db35c · 52db35c
1 parent 9e98500
commit 52db35c
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diff --git a/kotlin/samples/hello-workflow/build.gradle b/kotlin/samples/hello-workflow/build.gradle
@@ -28,6 +28,8 @@ android {
 
     testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
   }
+
+  buildFeatures.viewBinding = true
 }
 
 dependencies {

diff --git a/...mples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloLayoutRunner.kt b/...mples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloLayoutRunner.kt
@@ -15,25 +15,26 @@
  */
 package com.squareup.sample.helloworkflow
 
-import android.view.View
-import android.widget.TextView
+import android.view.LayoutInflater
+import com.squareup.sample.helloworkflow.databinding.HelloGoodbyeLayoutBinding
 import com.squareup.workflow.ui.ContainerHints
 import com.squareup.workflow.ui.LayoutRunner
 import com.squareup.workflow.ui.LayoutRunner.Companion.bind
 import com.squareup.workflow.ui.ViewBinding
 
-class HelloLayoutRunner(view: View) : LayoutRunner<HelloWorkflow.Rendering> {
-  private val messageView: TextView = view.findViewById(R.id.hello_message)
+class HelloLayoutRunner(
+  private val binding: HelloGoodbyeLayoutBinding
+) : LayoutRunner<HelloWorkflow.Rendering> {
 
   override fun showRendering(
     rendering: HelloWorkflow.Rendering,
     containerHints: ContainerHints
   ) {
-    messageView.text = rendering.message
-    messageView.setOnClickListener { rendering.onClick() }
+    binding.helloMessage.text = rendering.message
+    binding.helloMessage.setOnClickListener { rendering.onClick() }
   }
 
   companion object : ViewBinding<HelloWorkflow.Rendering> by bind(
-      R.layout.hello_goodbye_layout, ::HelloLayoutRunner
+      HelloGoodbyeLayoutBinding::inflate, ::HelloLayoutRunner
   )
 }
diff --git a/kotlin/workflow-ui/core-android/build.gradle b/kotlin/workflow-ui/core-android/build.gradle
@@ -26,6 +26,8 @@ apply from: rootProject.file('.buildscript/configure-dokka.gradle')
 android rootProject.ext.defaultAndroidConfig
 
 dependencies {
+  compileOnly "androidx.databinding:viewbinding:4.0.0-beta01"
+
   api project(':workflow-core')
   api project(':workflow-ui:core-common')
 

diff --git a/kotlin/workflow-ui/core-android/src/main/java/com/squareup/workflow/ui/LayoutRunner.kt b/kotlin/workflow-ui/core-android/src/main/java/com/squareup/workflow/ui/LayoutRunner.kt
@@ -22,6 +22,8 @@ import android.view.ViewGroup
 import androidx.annotation.LayoutRes
 import kotlin.reflect.KClass
 
+typealias ViewBindingInflater<BindingT> = (LayoutInflater, ViewGroup, Boolean) -> BindingT
+
 /**
  * A delegate that implements a [showRendering] method to be called when a workflow rendering
  * of type [RenderingT] is ready to be displayed in a view inflated from a layout resource
@@ -82,6 +84,32 @@ interface LayoutRunner<RenderingT : Any> {
     }
   }
 
+  class ViewBindingBinding<BindingT : androidx.viewbinding.ViewBinding, RenderingT : Any>(
+    override val type: KClass<RenderingT>,
+    private val bindingInflater: ViewBindingInflater<BindingT>,
+    private val runnerConstructor: (BindingT) -> LayoutRunner<RenderingT>
+  ) : ViewBinding<RenderingT> {
+    override fun buildView(
+      initialRendering: RenderingT,
+      initialContainerHints: ContainerHints,
+      contextForNewView: Context,
+      container: ViewGroup?
+    ): View {
+      return LayoutInflater.from(container?.context ?: contextForNewView)
+          .cloneInContext(contextForNewView)
+          // This !! is problematic. Can we use the overload that only takes an inflater?
+          .let { bindingInflater(it, container!!, false) }
+          .also { binding ->
+            binding.root.bindShowRendering(
+                initialRendering,
+                initialContainerHints,
+                runnerConstructor.invoke(binding)::showRendering
+            )
+          }
+          .root
+    }
+  }
+
   companion object {
     /**
      * Creates a [ViewBinding] that inflates [layoutId] to show renderings of type [RenderingT],
@@ -92,6 +120,11 @@ interface LayoutRunner<RenderingT : Any> {
       noinline constructor: (View) -> LayoutRunner<RenderingT>
     ): ViewBinding<RenderingT> = Binding(RenderingT::class, layoutId, constructor)
 
+    inline fun <BindingT : androidx.viewbinding.ViewBinding, reified RenderingT : Any> bind(
+      noinline bindingInflater: ViewBindingInflater<BindingT>,
+      noinline constructor: (BindingT) -> LayoutRunner<RenderingT>
+    ): ViewBinding<RenderingT> = ViewBindingBinding(RenderingT::class, bindingInflater, constructor)
+
     /**
      * Creates a [ViewBinding] that inflates [layoutId] to "show" renderings of type [RenderingT],
      * with a no-op [LayoutRunner]. Handy for showing static views.