Add OnLayoutCalculated component lifecycle method

litho-annotations/src/main/java/com/facebook/litho/annotations/OnLayoutCalculated.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.facebook.litho.annotations;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.RUNTIME)
+public @interface OnLayoutCalculated {}

litho-core/src/main/java/com/facebook/litho/ComponentLifecycle.java

@@ -394,6 +394,13 @@ protected void onBind(ComponentContext c, Object mountedContent) {
    */
   protected void onBoundsDefined(ComponentContext c, ComponentLayout layout) {}
 
+  /**
+   * Called after the layout calculation is finished.
+   *
+   * @param c The {@link Context} used by this component.
+   */
+  protected void onLayoutCalculated(ComponentContext c) {}
+
   /**
    * Generate a tree of {@link ComponentLayout} representing the layout structure of the {@link
    * Component} and its sub-components.

litho-core/src/main/java/com/facebook/litho/DefaultInternalNode.java

@@ -411,6 +411,10 @@ && isLayoutDirectionRTL(c.getAndroidContext())) {
 
     mYogaNode.calculateLayout(width, height);
 
+    for (Component component : mComponents) {
+      component.onLayoutCalculated(mComponentContext);
+    }
+
     return this;
   }
 

litho-processor/src/main/java/com/facebook/litho/specmodels/model/DelegateMethodDescriptions.java

@@ -46,6 +46,7 @@
 import com.facebook.litho.annotations.OnCreateMountContentPool;
 import com.facebook.litho.annotations.OnCreateTransition;
 import com.facebook.litho.annotations.OnDetached;
+import com.facebook.litho.annotations.OnLayoutCalculated;
 import com.facebook.litho.annotations.OnError;
 import com.facebook.litho.annotations.OnLoadStyle;
 import com.facebook.litho.annotations.OnMeasure;
@@ -162,6 +163,18 @@ public final class DelegateMethodDescriptions {
                       .build()))
           .build();
 
+  public static final DelegateMethodDescription ON_LAYOUT_CALCULATED =
+      DelegateMethodDescription.newBuilder()
+          .annotations(ImmutableList.of(AnnotationSpec.builder(Override.class).build()))
+          .accessType(Modifier.PROTECTED)
+          .returnType(TypeName.VOID)
+          .name("onLayoutCalculated")
+          .definedParameterTypes(
+              ImmutableList.<TypeName>of(ClassNames.COMPONENT_CONTEXT))
+          .optionalParameterTypes(
+              ImmutableList.of(PROP, TREE_PROP, STATE, INJECT_PROP, CACHED_VALUE))
+          .build();
+
   public static final DelegateMethodDescription ON_CREATE_INITIAL_STATE =
       DelegateMethodDescription.newBuilder()
           .annotations(ImmutableList.of(AnnotationSpec.builder(Override.class).build()))
@@ -521,6 +534,7 @@ public int compare(Class<? extends Annotation> lhs, Class<? extends Annotation>
     layoutSpecDelegateMethodsMap.put(ShouldUpdate.class, SHOULD_UPDATE);
     layoutSpecDelegateMethodsMap.put(OnAttached.class, ON_ATTACHED);
     layoutSpecDelegateMethodsMap.put(OnDetached.class, ON_DETACHED);
+    layoutSpecDelegateMethodsMap.put(OnLayoutCalculated.class, ON_LAYOUT_CALCULATED);
     LAYOUT_SPEC_DELEGATE_METHODS_MAP = Collections.unmodifiableMap(layoutSpecDelegateMethodsMap);
 
     Map<Class<? extends Annotation>, DelegateMethodDescription> mountSpecDelegateMethodsMap =