From c76c993ce49f7d5b8c4c4d319f599e05c2df5a31 Mon Sep 17 00:00:00 2001
From: Luke De Feo <lukedefeo@fb.com>
Date: Mon, 12 Sep 2022 03:48:43 -0700
Subject: [PATCH] Introduced concept of active child

Summary: A node can have an active child, if present we assume all others are inactive and we don't traverse them. This means the activities not on top and view pager views not active will not be scanned. Additionally on the desktop we are automatically collapsing these views. The net result is a lot less work done on the main thread

Reviewed By: lblasa

Differential Revision: D39310126

fbshipit-source-id: ebd0c69d46f2d42fe42e678c8327fcdc73d08385
---
 .../uidebugger/core/LayoutTraversal.kt        | 22 +++++++++++++--
 .../uidebugger/core/NativeScanScheduler.kt    |  8 +-----
 .../descriptors/AbstractChainedDescriptor.kt  |  8 ++++++
 .../descriptors/ActivityDescriptor.kt         |  3 +++
 .../descriptors/ApplicationRefDescriptor.kt   |  4 ++-
 .../descriptors/ButtonDescriptor.kt           |  3 +++
 .../uidebugger/descriptors/Descriptor.kt      | 27 -------------------
 .../descriptors/DescriptorRegister.kt         |  2 ++
 .../uidebugger/descriptors/NodeDescriptor.kt  |  6 +++++
 .../descriptors/ObjectDescriptor.kt           |  3 +++
 .../descriptors/TextViewDescriptor.kt         |  4 +++
 .../uidebugger/descriptors/ViewDescriptor.kt  |  4 +++
 .../descriptors/ViewGroupDescriptor.kt        |  4 +++
 .../descriptors/ViewPagerDescriptor.kt        | 19 +++++++++++++
 .../descriptors/WindowDescriptor.kt           |  4 +++
 .../flipper/plugins/uidebugger/model/Node.kt  |  3 ++-
 .../public/ui-debugger/components/main.tsx    | 21 ++++++++++++---
 desktop/plugins/public/ui-debugger/types.tsx  |  1 +
 18 files changed, 104 insertions(+), 42 deletions(-)
 create mode 100644 android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewPagerDescriptor.kt

diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/LayoutTraversal.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/LayoutTraversal.kt
index 31de1cd28..e90f4f58a 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/LayoutTraversal.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/LayoutTraversal.kt
@@ -40,19 +40,37 @@ class LayoutTraversal(
         descriptor.getChildren(node, children)
 
         val childrenIds = mutableListOf<String>()
+
+        val activeChild = descriptor.getActiveChild(node)
         for (child in children) {
           // it might make sense one day to remove id from the descriptor since its always the
           // hash code
           val childDescriptor =
               descriptorRegister.descriptorForClassUnsafe(child::class.java).asAny()
           childrenIds.add(childDescriptor.getId(child))
-          stack.add(child)
+          // if there is an active child then dont traverse it
+          if (activeChild == null) {
+            stack.add(child)
+          }
+        }
+
+        var activeChildId: String? = null
+        if (activeChild != null) {
+          stack.add(activeChild)
+          activeChildId =
+              descriptorRegister.descriptorForClassUnsafe(activeChild.javaClass).getId(activeChild)
         }
 
         val attributes = mutableMapOf<String, InspectableObject>()
         descriptor.getData(node, attributes)
 
-        result.add(Node(descriptor.getId(node), descriptor.getName(node), attributes, childrenIds))
+        result.add(
+            Node(
+                descriptor.getId(node),
+                descriptor.getName(node),
+                attributes,
+                childrenIds,
+                activeChildId))
       } catch (exception: Exception) {
         Log.e(LogTag, "Error while processing node ${node.javaClass.name} ${node} ", exception)
       }
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/NativeScanScheduler.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/NativeScanScheduler.kt
index ca64f169a..0406d2803 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/NativeScanScheduler.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/core/NativeScanScheduler.kt
@@ -33,13 +33,7 @@ class NativeScanScheduler(val context: Context) : Scheduler.Task<ScanResult> {
 
     Log.d(
         "LAYOUT_SCHEDULER",
-        Thread.currentThread().name +
-            Looper.myLooper() +
-            ", produced: " +
-            {
-              nodes.count()
-            } +
-            " nodes")
+        "${Thread.currentThread().name}${Looper.myLooper()} produced: ${nodes.count()} nodes")
 
     return ScanResult(txId++, start, scanEnd, nodes)
   }
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/AbstractChainedDescriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/AbstractChainedDescriptor.kt
index 2d57d301b..51896a363 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/AbstractChainedDescriptor.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/AbstractChainedDescriptor.kt
@@ -34,6 +34,12 @@ abstract class AbstractChainedDescriptor<T> : Descriptor<T>(), ChainedDescriptor
 
   open fun onInit() {}
 
+  final override fun getActiveChild(node: T): Any? {
+    // ask each descriptor in the chain for an active child, if none available look up the chain
+    // until no more super descriptors
+    return onGetActiveChild(node) ?: mSuper?.getActiveChild(node)
+  }
+
   /**
    * A globally unique ID used to identify a node in a hierarchy. If your node does not have a
    * globally unique ID it is fine to rely on [System.identityHashCode].
@@ -52,6 +58,8 @@ abstract class AbstractChainedDescriptor<T> : Descriptor<T>(), ChainedDescriptor
     return onGetName(node)
   }
 
+  abstract fun onGetActiveChild(node: T): Any?
+
   abstract fun onGetName(node: T): String
 
   /** The children this node exposes in the inspector. */
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ActivityDescriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ActivityDescriptor.kt
index dcb8089a0..69d958979 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ActivityDescriptor.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ActivityDescriptor.kt
@@ -13,6 +13,9 @@ import com.facebook.flipper.plugins.uidebugger.stetho.FragmentCompat
 
 class ActivityDescriptor : AbstractChainedDescriptor<Activity>() {
   override fun onInit() {}
+  override fun onGetActiveChild(node: Activity): Any? {
+    return null
+  }
 
   override fun onGetId(activity: Activity): String {
     return Integer.toString(System.identityHashCode(activity))
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ApplicationRefDescriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ApplicationRefDescriptor.kt
index 8fe43684f..19d6e4b68 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ApplicationRefDescriptor.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ApplicationRefDescriptor.kt
@@ -16,6 +16,9 @@ class ApplicationRefDescriptor : AbstractChainedDescriptor<ApplicationRef>() {
   val rootResolver = RootViewResolver()
 
   override fun onInit() {}
+  override fun onGetActiveChild(node: ApplicationRef): Any? {
+    return if (node.activitiesStack.size > 0) node.activitiesStack.last() else null
+  }
 
   override fun onGetId(applicationRef: ApplicationRef): String {
     return applicationRef.application.packageName
@@ -38,7 +41,6 @@ class ApplicationRefDescriptor : AbstractChainedDescriptor<ApplicationRef>() {
           if (activity.window.decorView == root.view) {
             children.add(activity)
             added = true
-
             break
           }
         }
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ButtonDescriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ButtonDescriptor.kt
index e7c3af119..740e4a548 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ButtonDescriptor.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ButtonDescriptor.kt
@@ -26,4 +26,7 @@ class ButtonDescriptor : AbstractChainedDescriptor<Button>() {
   ) {}
 
   override fun onGetChildren(button: Button, children: MutableList<Any>) {}
+  override fun onGetActiveChild(node: Button): Any? {
+    return null
+  }
 }
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/Descriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/Descriptor.kt
index 1578272f5..4547e95e7 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/Descriptor.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/Descriptor.kt
@@ -26,31 +26,4 @@ abstract class Descriptor<T> : NodeDescriptor<T> {
     }
     return null
   }
-
-  //  override fun inspect(obj: Any): FlipperObject {
-  //    val descriptor = descriptorForObject(obj)
-  //    descriptor?.let { descriptor ->
-  //      return (descriptor as Descriptor<Any>).get(obj)
-  //    }
-  //
-  //    return FlipperObject.Builder().build()
-  //  }
-  //
-  //  override fun get(node: T): FlipperObject {
-  //    val builder = FlipperObject.Builder()
-  //
-  //    val propsBuilder = FlipperObject.Builder()
-  //    getData(node, propsBuilder)
-  //
-  //    val childrenBuilder = FlipperArray.Builder()
-  //    getChildren(node, childrenBuilder)
-  //
-  //    builder
-  //        .put("key", getId(node))
-  //        .put("title", getName(node))
-  //        .put("data", propsBuilder)
-  //        .put("children", childrenBuilder)
-  //
-  //    return builder.build()
-  //  }
 }
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/DescriptorRegister.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/DescriptorRegister.kt
index 4297138db..7dc90dc04 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/DescriptorRegister.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/DescriptorRegister.kt
@@ -13,6 +13,7 @@ import android.view.ViewGroup
 import android.view.Window
 import android.widget.Button
 import android.widget.TextView
+import androidx.viewpager.widget.ViewPager
 import com.facebook.flipper.plugins.uidebugger.common.UIDebuggerException
 import com.facebook.flipper.plugins.uidebugger.core.ApplicationRef
 
@@ -31,6 +32,7 @@ class DescriptorRegister {
       mapping.register(View::class.java, ViewDescriptor())
       mapping.register(TextView::class.java, TextViewDescriptor())
       mapping.register(Button::class.java, ButtonDescriptor())
+      mapping.register(ViewPager::class.java, ViewPagerDescriptor())
 
       for (clazz in mapping.register.keys) {
         val descriptor: Descriptor<*>? = mapping.register[clazz]
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/NodeDescriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/NodeDescriptor.kt
index 87e7cd6c2..c6f196f31 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/NodeDescriptor.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/NodeDescriptor.kt
@@ -28,6 +28,12 @@ interface NodeDescriptor<T> {
   /** The children this node exposes in the inspector. */
   fun getChildren(node: T, children: MutableList<Any>)
 
+  /**
+   * If you have overlapping children this indicates which child is active / on top, we will only
+   * listen to / traverse this child. If return null we assume all children are 'active'
+   */
+  fun getActiveChild(node: T): Any?
+
   /**
    * Get the data to show for this node in the sidebar of the inspector. The object will be shown in
    * order and with a header matching the given name.
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ObjectDescriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ObjectDescriptor.kt
index 270bfcdf7..95eeeebca 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ObjectDescriptor.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ObjectDescriptor.kt
@@ -11,6 +11,9 @@ import com.facebook.flipper.plugins.uidebugger.common.InspectableObject
 
 class ObjectDescriptor : Descriptor<Any>() {
   override fun init() {}
+  override fun getActiveChild(node: Any): Any? {
+    return null
+  }
 
   override fun getId(obj: Any): String {
     return Integer.toString(System.identityHashCode(obj))
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/TextViewDescriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/TextViewDescriptor.kt
index 3c4e2f3e9..0dcfd9e2d 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/TextViewDescriptor.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/TextViewDescriptor.kt
@@ -26,4 +26,8 @@ class TextViewDescriptor : AbstractChainedDescriptor<TextView>() {
       textView: TextView,
       attributeSections: MutableMap<String, InspectableObject>
   ) {}
+
+  override fun onGetActiveChild(node: TextView): Any? {
+    return null
+  }
 }
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewDescriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewDescriptor.kt
index 645960113..8953e3b4a 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewDescriptor.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewDescriptor.kt
@@ -256,4 +256,8 @@ class ViewDescriptor : AbstractChainedDescriptor<View>() {
       } catch (ignored: Exception) {}
     }
   }
+
+  override fun onGetActiveChild(node: View): Any? {
+    return null
+  }
 }
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewGroupDescriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewGroupDescriptor.kt
index 52b395241..9184efb6b 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewGroupDescriptor.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewGroupDescriptor.kt
@@ -85,4 +85,8 @@ class ViewGroupDescriptor : AbstractChainedDescriptor<ViewGroup>() {
       }
     }
   }
+
+  override fun onGetActiveChild(node: ViewGroup): Any? {
+    return null
+  }
 }
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewPagerDescriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewPagerDescriptor.kt
new file mode 100644
index 000000000..09d08d1da
--- /dev/null
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ViewPagerDescriptor.kt
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.flipper.plugins.uidebugger.descriptors
+
+import androidx.viewpager.widget.ViewPager
+
+class ViewPagerDescriptor : AbstractChainedDescriptor<ViewPager>() {
+
+  override fun onGetId(node: ViewPager): String = System.identityHashCode(node).toString()
+
+  override fun onGetName(node: ViewPager): String = node.javaClass.simpleName
+
+  override fun onGetActiveChild(node: ViewPager): Any? = node.getChildAt(node.currentItem)
+}
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/WindowDescriptor.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/WindowDescriptor.kt
index 8e67897b2..8e74a57ae 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/WindowDescriptor.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/WindowDescriptor.kt
@@ -28,4 +28,8 @@ class WindowDescriptor : AbstractChainedDescriptor<Window>() {
       window: Window,
       attributeSections: MutableMap<String, InspectableObject>
   ) {}
+
+  override fun onGetActiveChild(node: Window): Any? {
+    return null
+  }
 }
diff --git a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/model/Node.kt b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/model/Node.kt
index e0eaf1aa8..4051252a2 100644
--- a/android/src/main/java/com/facebook/flipper/plugins/uidebugger/model/Node.kt
+++ b/android/src/main/java/com/facebook/flipper/plugins/uidebugger/model/Node.kt
@@ -14,5 +14,6 @@ data class Node(
     val id: String,
     val name: String,
     val attributes: Map<String, InspectableObject>,
-    val children: List<String>
+    val children: List<String>,
+    val activeChild: String?,
 )
diff --git a/desktop/plugins/public/ui-debugger/components/main.tsx b/desktop/plugins/public/ui-debugger/components/main.tsx
index e13bf1965..f98f43c54 100644
--- a/desktop/plugins/public/ui-debugger/components/main.tsx
+++ b/desktop/plugins/public/ui-debugger/components/main.tsx
@@ -24,9 +24,20 @@ import {DownOutlined} from '@ant-design/icons';
 import {useHotkeys} from 'react-hotkeys-hook';
 import {Id, UINode} from '../types';
 
-function nodesToAntTree(root: Id, nodes: Map<Id, UINode>): DataNode {
+function nodesToAntTree(root: Id, nodes: Map<Id, UINode>): [DataNode, Id[]] {
+  const inactive: Id[] = [];
+
   function uiNodeToAntNode(id: Id): DataNode {
     const node = nodes.get(id);
+
+    if (node?.activeChild) {
+      for (const child of node.children) {
+        if (child !== node?.activeChild) {
+          inactive.push(child);
+        }
+      }
+    }
+
     return {
       key: id,
       title: node?.name,
@@ -34,7 +45,7 @@ function nodesToAntTree(root: Id, nodes: Map<Id, UINode>): DataNode {
     };
   }
 
-  return uiNodeToAntNode(root);
+  return [uiNodeToAntNode(root), inactive];
 }
 
 function formatDiff(start: number, end: number): string {
@@ -119,7 +130,7 @@ export function Component() {
     );
 
   if (rootId) {
-    const antTree = nodesToAntTree(rootId, nodes);
+    const [antTree, inactive] = nodesToAntTree(rootId, nodes);
     return (
       <>
         <Layout.ScrollContainer>
@@ -130,7 +141,9 @@ export function Component() {
               setSelectedNode(selected[0] as string);
             }}
             defaultExpandAll
-            expandedKeys={[...nodes.keys()]}
+            expandedKeys={[...nodes.keys()].filter(
+              (key) => !inactive.includes(key),
+            )}
             switcherIcon={<DownOutlined />}
             treeData={[antTree]}
           />
diff --git a/desktop/plugins/public/ui-debugger/types.tsx b/desktop/plugins/public/ui-debugger/types.tsx
index 2997b12f0..e079f7280 100644
--- a/desktop/plugins/public/ui-debugger/types.tsx
+++ b/desktop/plugins/public/ui-debugger/types.tsx
@@ -42,4 +42,5 @@ export type UINode = {
   name: string;
   attributes: Record<string, Inspectable>;
   children: Id[];
+  activeChild?: Id;
 };