Add parent id to decor view

Summary: This whole nested observer approach can be simplified massively, but for now we are just threading the parent id through so its set for observer roots too

Reviewed By: lblasa

Differential Revision: D47915504

fbshipit-source-id: 924f722f38bb202b42ea9ef6da15e685f6c75e02

android/src/main/java/com/facebook/flipper/plugins/uidebugger/observers/ApplicationTreeObserver.kt

@@ -13,6 +13,7 @@ import com.facebook.flipper.plugins.uidebugger.LogTag
 import com.facebook.flipper.plugins.uidebugger.core.ApplicationRef
 import com.facebook.flipper.plugins.uidebugger.core.RootViewResolver
 import com.facebook.flipper.plugins.uidebugger.core.UIDContext
+import com.facebook.flipper.plugins.uidebugger.descriptors.Id
 import com.facebook.flipper.plugins.uidebugger.util.objectIdentity
 
 /**
@@ -23,7 +24,7 @@ class ApplicationTreeObserver(val context: UIDContext) : TreeObserver<Applicatio
 
   override val type = "Application"
 
-  override fun subscribe(node: Any) {
+  override fun subscribe(node: Any, parentId: Id?) {
     Log.i(LogTag, "Subscribing activity / root view changes")
 
     val applicationRef = node as ApplicationRef
@@ -41,7 +42,7 @@ class ApplicationTreeObserver(val context: UIDContext) : TreeObserver<Applicatio
         }
 
     context.sharedThrottle.registerCallback(this.objectIdentity()) {
-      traverseAndSend(context, applicationRef)
+      traverseAndSend(null, context, applicationRef)
     }
 
     context.applicationRef.rootsResolver.attachListener(rootViewListener)

android/src/main/java/com/facebook/flipper/plugins/uidebugger/observers/DecorViewTreeObserver.kt

@@ -13,6 +13,7 @@ import android.view.ViewTreeObserver
 import com.facebook.flipper.plugins.uidebugger.LogTag
 import com.facebook.flipper.plugins.uidebugger.common.BitmapPool
 import com.facebook.flipper.plugins.uidebugger.core.UIDContext
+import com.facebook.flipper.plugins.uidebugger.descriptors.Id
 import com.facebook.flipper.plugins.uidebugger.util.objectIdentity
 import java.lang.ref.WeakReference
 
@@ -26,14 +27,14 @@ class DecorViewObserver(val context: UIDContext) : TreeObserver<DecorView>() {
 
   override val type = "DecorView"
 
-  override fun subscribe(node: Any) {
+  override fun subscribe(node: Any, parentId: Id?) {
     node as View
     nodeRef = WeakReference(node)
 
     Log.i(LogTag, "Subscribing to decor view changes")
 
     context.sharedThrottle.registerCallback(this.objectIdentity()) {
-      nodeRef?.get()?.let { traverseAndSendWithSnapshot() }
+      nodeRef?.get()?.let { traverseAndSendWithSnapshot(parentId) }
     }
 
     preDrawListener =
@@ -46,16 +47,21 @@ class DecorViewObserver(val context: UIDContext) : TreeObserver<DecorView>() {
 
     // It can be the case that the DecorView the current observer owns has already
     // drawn. In this case, manually trigger an update.
-    traverseAndSendWithSnapshot()
+    traverseAndSendWithSnapshot(parentId)
   }
 
-  private fun traverseAndSendWithSnapshot() {
+  private fun traverseAndSendWithSnapshot(parentId: Id?) {
     nodeRef?.get()?.let { view ->
       var snapshotBitmap: BitmapPool.ReusableBitmap? = null
       if (view.width > 0 && view.height > 0) {
         snapshotBitmap = context.bitmapPool.getBitmap(view.width, view.height)
       }
-      traverseAndSend(context, view, snapshotBitmap)
+      traverseAndSend(
+          parentId,
+          context,
+          view,
+          snapshotBitmap,
+      )
     }
   }
 

android/src/main/java/com/facebook/flipper/plugins/uidebugger/observers/TreeObserver.kt

@@ -35,35 +35,37 @@ abstract class TreeObserver<T> {
 
   abstract val type: String
 
-  abstract fun subscribe(node: Any)
+  abstract fun subscribe(node: Any, parentId: Id?)
 
   abstract fun unsubscribe()
 
   /** Traverses the layout hierarchy while managing any encountered child observers. */
   fun traverseAndSend(
+      parentId: Id?,
       context: UIDContext,
       root: Any,
       snapshotBitmap: BitmapPool.ReusableBitmap? = null,
       frameworkEvents: List<FrameworkEvent>? = null
   ) {
     val traversalStartTimestamp = System.currentTimeMillis()
-    val (visitedNodes, observableRoots) = context.layoutTraversal.traverse(root)
+    val (visitedNodes, observableRoots) = context.layoutTraversal.traverse(root, parentId)
 
     // Add any new observers
-    observableRoots.forEach { observable ->
+    observableRoots.forEach { (observable, parentId) ->
       if (!children.containsKey(observable.objectIdentity())) {
         context.observerFactory.createObserver(observable, context)?.let { observer ->
           Log.d(
               LogTag,
               "Observer ${this.type} discovered new child of type ${observer.type} Node ID ${observable.objectIdentity()}")
-          observer.subscribe(observable)
+          observer.subscribe(observable, parentId)
           children[observable.objectIdentity()] = observer
         }
       }
     }
 
     // Remove any old observers
-    val observableRootsIdentifiers = observableRoots.map { it.objectIdentity() }
+    val observableRootsIdentifiers =
+        observableRoots.map { (observable, _) -> observable.objectIdentity() }
     val removables = mutableListOf<Id>()
     children.keys.forEach { key ->
       if (!observableRootsIdentifiers.contains(key)) {

android/src/main/java/com/facebook/flipper/plugins/uidebugger/observers/TreeObserverManager.kt

@@ -78,7 +78,7 @@ class TreeObserverManager(val context: UIDContext) {
       mainScope.launch { start() }
     }
     batchedUpdates = Channel(Channel.UNLIMITED)
-    rootObserver.subscribe(context.applicationRef)
+    rootObserver.subscribe(context.applicationRef, null)
 
     job =
         workerScope.launch {

android/src/main/java/com/facebook/flipper/plugins/uidebugger/traversal/PartialLayoutTraversal.kt

@@ -31,14 +31,14 @@ class PartialLayoutTraversal(
   @Suppress("unchecked_cast")
   internal fun NodeDescriptor<*>.asAny(): NodeDescriptor<Any> = this as NodeDescriptor<Any>
 
-  fun traverse(root: Any): Pair<List<MaybeDeferred<Node>>, List<Any>> {
+  fun traverse(root: Any, parentId: Id?): Pair<List<MaybeDeferred<Node>>, List<Pair<Any, Id?>>> {
 
     val visited = mutableListOf<MaybeDeferred<Node>>()
-    val observableRoots = mutableListOf<Any>()
+    val observableRoots = mutableListOf<Pair<Any, Id?>>()
 
     // cur and parent Id
     val stack = mutableListOf<Pair<Any, Id?>>()
-    stack.add(Pair(root, null))
+    stack.add(Pair(root, parentId))
 
     val shallow = mutableSetOf<Any>()
 
@@ -48,7 +48,7 @@ class PartialLayoutTraversal(
       try {
         // If we encounter a node that has it own observer, don't traverse
         if (node != root && treeObserverFactory.hasObserverFor(node)) {
-          observableRoots.add(node)
+          observableRoots.add((node to parentId))
           continue
         }