New view annotation for hook after view bound (#242)

epoxy-annotations/src/main/java/com/airbnb/epoxy/AfterPropsSet.java

@@ -0,0 +1,21 @@
+package com.airbnb.epoxy;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * This can be used to annotate methods inside classes with a {@link com.airbnb.epoxy.ModelView}
+ * annotation. Methods with this annotation will be called after a view instance  is bound to a
+ * model and all model props have been set. This is useful if you need to wait until multiple props
+ * are set before doing certain initialization.
+ * <p>
+ * Methods with this annotation will be called after both the initial bind when the view comes on
+ * screen, and after partial binds when an onscreen view is updated.
+ */
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.CLASS)
+public @interface AfterPropsSet {
+}
+

epoxy-annotations/src/main/java/com/airbnb/epoxy/OnViewRecycled.java

@@ -5,6 +5,11 @@
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+/**
+ * This can be used to annotate methods inside classes with a {@link com.airbnb.epoxy.ModelView}
+ * annotation. Methods with this annotation will be called when the view is recycled by the
+ * RecyclerView.
+ */
 @Target(ElementType.METHOD)
 @Retention(RetentionPolicy.CLASS)
 public @interface OnViewRecycled {

epoxy-processor/src/main/java/com/airbnb/epoxy/GeneratedModelWriter.java

@@ -100,6 +100,10 @@ boolean addToBindWithDiffMethod(Builder methodBuilder, ParameterSpec boundObject
         ParameterSpec previousModelParam) {
       return false;
     }
+
+    public void addToHandlePostBindMethod(Builder postBindBuilder, ParameterSpec boundObjectParam) {
+
+    }
   }
 
   GeneratedModelWriter(Filer filer, Types typeUtils, ErrorLogger errorLogger,
@@ -429,6 +433,8 @@ private Iterable<MethodSpec> generateBindMethods(GeneratedModelInfo classInfo) {
     addHashCodeValidationIfNecessary(postBindBuilder,
         "The model was changed during the bind call.");
 
+    builderHooks.addToHandlePostBindMethod(postBindBuilder, boundObjectParam);
+
     methods.add(postBindBuilder
         .build());
 

epoxy-processor/src/main/java/com/airbnb/epoxy/LithoModelInfo.kt

@@ -1,19 +1,18 @@
 package com.airbnb.epoxy
 
+import com.airbnb.epoxy.ClassNames.EPOXY_LITHO_MODEL
 import com.squareup.javapoet.ClassName
 import com.squareup.javapoet.ParameterizedTypeName
-
 import javax.lang.model.element.Element
 import javax.lang.model.element.TypeElement
 import javax.lang.model.util.Elements
 import javax.lang.model.util.Types
 
-import com.airbnb.epoxy.ClassNames.EPOXY_LITHO_MODEL
-
 internal class LithoModelInfo(
         typeUtils: Types,
         elementUtils: Elements,
-        layoutSpecClassElement: TypeElement) : GeneratedModelInfo() {
+        layoutSpecClassElement: TypeElement
+) : GeneratedModelInfo() {
 
     val lithoComponentName: ClassName
 
@@ -39,7 +38,7 @@ internal class LithoModelInfo(
      * package, and with the "Spec" term removed from the name.
      */
     fun getLithoComponentName(elementUtils: Elements,
-                                      layoutSpecClassElement: TypeElement): ClassName {
+                              layoutSpecClassElement: TypeElement): ClassName {
         val packageName = elementUtils.getPackageOf(layoutSpecClassElement).qualifiedName.toString()
 
         // Litho doesn't appear to allow specs as nested classes, so we don't check for nested

epoxy-processor/src/main/java/com/airbnb/epoxy/ModelViewInfo.java

@@ -22,6 +22,7 @@
 
 class ModelViewInfo extends GeneratedModelInfo {
   final List<String> resetMethodNames = new ArrayList<>();
+  final List<String> afterPropsSetMethodNames = new ArrayList<>();
   final TypeElement viewElement;
   final Types typeUtils;
   final Elements elements;
@@ -144,6 +145,10 @@ void addOnRecycleMethod(ExecutableElement resetMethod) {
     resetMethodNames.add(resetMethod.getSimpleName().toString());
   }
 
+  void addAfterPropsSetMethod(ExecutableElement afterPropsSetMethod) {
+    afterPropsSetMethodNames.add(afterPropsSetMethod.getSimpleName().toString());
+  }
+
   LayoutResource getLayoutResource(LayoutResourceProcessor layoutResourceProcessor) {
     ModelView annotation = viewElement.getAnnotation(ModelView.class);
     int layoutValue = annotation.defaultLayout();
@@ -166,6 +171,10 @@ List<String> getResetMethodNames() {
     return resetMethodNames;
   }
 
+  List<String> getAfterPropsSetMethodNames() {
+    return afterPropsSetMethodNames;
+  }
+
   List<ViewAttributeInfo> getViewAttributes() {
     List<ViewAttributeInfo> result = new ArrayList<>(attributeInfo.size());
     for (AttributeInfo info : attributeInfo) {

epoxy-processor/src/main/java/com/airbnb/epoxy/ModelViewProcessor.java

@@ -69,6 +69,7 @@ Collection<? extends GeneratedModelInfo> process(RoundEnvironment roundEnv,
 
     processSetterAnnotations(roundEnv);
     processResetAnnotations(roundEnv);
+    processAfterBindAnnotations(roundEnv);
 
     updateViewsForInheritedViewAnnotations();
 
@@ -242,14 +243,35 @@ private void processResetAnnotations(RoundEnvironment roundEnv) {
       ModelViewInfo info = getModelInfoForMethodElement(recycleMethod);
       if (info == null) {
         errorLogger.logError("%s annotation can only be used in classes annotated with %s",
-            ModelProp.class, ModelView.class);
+            OnViewRecycled.class, ModelView.class);
         continue;
       }
 
       info.addOnRecycleMethod((ExecutableElement) recycleMethod);
     }
   }
 
+  private void processAfterBindAnnotations(RoundEnvironment roundEnv) {
+    for (Element afterPropsMethod : roundEnv.getElementsAnnotatedWith(AfterPropsSet.class)) {
+      if (!validateAfterPropsMethod(afterPropsMethod)) {
+        continue;
+      }
+
+      ModelViewInfo info = getModelInfoForMethodElement(afterPropsMethod);
+      if (info == null) {
+        errorLogger.logError("%s annotation can only be used in classes annotated with %s",
+            AfterPropsSet.class, ModelView.class);
+        continue;
+      }
+
+      info.addAfterPropsSetMethod((ExecutableElement) afterPropsMethod);
+    }
+  }
+
+  private boolean validateAfterPropsMethod(Element resetMethod) {
+    return validateExecutableElement(resetMethod, AfterPropsSet.class, 0);
+  }
+
   /** Include props and reset methods from super class views. */
   private void updateViewsForInheritedViewAnnotations() {
     for (ModelViewInfo view : modelClassMap.values()) {
@@ -262,6 +284,7 @@ private void updateViewsForInheritedViewAnnotations() {
         }
 
         view.resetMethodNames.addAll(otherView.resetMethodNames);
+        view.afterPropsSetMethodNames.addAll(otherView.afterPropsSetMethodNames);
 
         boolean samePackage =
             belongToTheSamePackage(view.viewElement, otherView.viewElement, elements);
@@ -462,6 +485,13 @@ boolean addToBindWithDiffMethod(Builder methodBuilder, ParameterSpec boundObject
             return true;
           }
 
+          @Override
+          public void addToHandlePostBindMethod(Builder postBindBuilder,
+              ParameterSpec boundObjectParam) {
+
+            addAfterPropsAddedMethodsToBuilder(postBindBuilder, modelInfo, boundObjectParam);
+          }
+
           @Override
           void addToUnbindMethod(MethodSpec.Builder unbindBuilder, String unbindParamName) {
             for (ViewAttributeInfo viewAttribute : modelInfo.getViewAttributes()) {
@@ -558,6 +588,13 @@ private void addResetMethodsToBuilder(Builder builder, ModelViewInfo modelViewIn
     }
   }
 
+  private void addAfterPropsAddedMethodsToBuilder(Builder methodBuilder, ModelViewInfo modelInfo,
+      ParameterSpec boundObjectParam) {
+    for (String methodName : modelInfo.getAfterPropsSetMethodNames()) {
+      methodBuilder.addStatement(boundObjectParam.name + "." + methodName + "()");
+    }
+  }
+
   private ModelViewInfo getModelInfoForMethodElement(Element element) {
     Element enclosingElement = element.getEnclosingElement();
     if (enclosingElement == null) {

epoxy-processortest/src/test/java/com/airbnb/epoxy/ViewProcessorTest.java

@@ -857,4 +857,23 @@ public void layoutOverloads() {
         .and()
         .generatesSources(generatedModel);
   }
+
+  @Test
+  public void afterBindProps() {
+    JavaFileObject model = JavaFileObjects
+        .forResource("TestAfterBindPropsView.java");
+
+    JavaFileObject superModel = JavaFileObjects
+        .forResource("TestAfterBindPropsSuperView.java");
+
+    JavaFileObject generatedModel =
+        JavaFileObjects.forResource("TestAfterBindPropsViewModel_.java");
+
+    assert_().about(javaSources())
+        .that(asList(model, superModel))
+        .processedWith(new EpoxyProcessor())
+        .compilesWithoutError()
+        .and()
+        .generatesSources(generatedModel);
+  }
 }

epoxy-processortest/src/test/resources/TestAfterBindPropsSuperView.java

@@ -0,0 +1,22 @@
+package com.airbnb.epoxy;
+
+import android.content.Context;
+import android.view.View;
+
+@ModelView(defaultLayout = 1)
+public abstract class TestAfterBindPropsSuperView extends View {
+
+  public TestAfterBindPropsSuperView(Context context) {
+    super(context);
+  }
+
+  @ModelProp
+  public void setFlagSuper(boolean flag) {
+
+  }
+
+  @AfterPropsSet
+  public void afterFlagSetSuper() {
+
+  }
+}

epoxy-processortest/src/test/resources/TestAfterBindPropsView.java

@@ -0,0 +1,21 @@
+package com.airbnb.epoxy;
+
+import android.content.Context;
+
+@ModelView(defaultLayout = 1)
+public class TestAfterBindPropsView extends TestAfterBindPropsSuperView {
+
+  public TestAfterBindPropsView(Context context) {
+    super(context);
+  }
+
+  @ModelProp
+  public void setFlag(boolean flag) {
+
+  }
+
+  @AfterPropsSet
+  public void afterFlagSet() {
+
+  }
+}