Paris improvements (#310)

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

@@ -33,7 +33,6 @@
 import javax.lang.model.util.Types;
 
 import static com.airbnb.epoxy.ClassNames.ANDROID_ASYNC_TASK;
-import static com.airbnb.epoxy.ModelViewWriterKt.addStyleApplierCode;
 import static com.airbnb.epoxy.ParisStyleAttributeInfoKt.PARIS_DEFAULT_STYLE_CONSTANT_NAME;
 import static com.airbnb.epoxy.ParisStyleAttributeInfoKt.PARIS_STYLE_ATTR_NAME;
 import static com.airbnb.epoxy.ParisStyleAttributeInfoKt.weakReferenceFieldForStyle;
@@ -251,11 +250,11 @@ private Iterable<FieldSpec> buildStyleConstant(GeneratedModelInfo info) {
 
     // We store styles in a weak reference since if a controller uses it
     // once it is likely to be used in other models and when models are rebuilt
-    for (String styleName : styleBuilderInfo.getStyleNames()) {
+    for (ParisStyle style : styleBuilderInfo.getStyles()) {
       constantFields.add(
           FieldSpec.builder(
               ParameterizedTypeName.get(ClassName.get(WeakReference.class), ClassNames.PARIS_STYLE),
-              weakReferenceFieldForStyle(styleName),
+              weakReferenceFieldForStyle(style.getName()),
               PRIVATE, STATIC
           )
               .build());
@@ -468,11 +467,6 @@ private Iterable<MethodSpec> generateProgrammaticViewMethods(GeneratedModelInfo
         .addStatement("v.setLayoutParams(new $T($L, $L))",
             ClassNames.ANDROID_MARGIN_LAYOUT_PARAMS, layoutWidth, layoutHeight);
 
-    ParisStyleAttributeInfo styleBuilderInfo = modelInfo.getStyleBuilderInfo();
-    if (styleBuilderInfo != null) {
-      addStyleApplierCode(builder, styleBuilderInfo, "v");
-    }
-
     methods.add(builder.addStatement("return v").build());
 
     return methods;
@@ -629,6 +623,8 @@ private MethodSpec buildPreBindMethod(GeneratedModelInfo modelInfo,
       // recycling will not work correctly. It is done in the background since it is fairly slow
       // and can noticeably add jank to scrolling in dev
       preBindBuilder
+          .beginControlFlow("if ($L != $L.getTag($T.id.epoxy_saved_view_style))",
+              PARIS_STYLE_ATTR_NAME, boundObjectParam.name, ClassNames.EPOXY_R)
           .beginControlFlow("$T.THREAD_POOL_EXECUTOR.execute(new $T()", ANDROID_ASYNC_TASK,
               Runnable.class)
           .beginControlFlow("public void run()")
@@ -645,7 +641,8 @@ private MethodSpec buildPreBindMethod(GeneratedModelInfo modelInfo,
               positionParamName)
           .endControlFlow()
           .endControlFlow()
-          .endControlFlow(")");
+          .endControlFlow(")")
+          .endControlFlow();
     }
 
     ClassName clickWrapperType = getClassName(WRAPPED_LISTENER_TYPE);
@@ -703,14 +700,20 @@ private Iterable<MethodSpec> generateStyleableViewMethods(GeneratedModelInfo mod
         .build());
 
     // Methods for setting each defined style directly
-    for (String styleName : styleBuilderInfo.getStyleNames()) {
-      String capitalizedStyle = Utils.capitalizeFirstLetter(styleName);
+    for (ParisStyle style : styleBuilderInfo.getStyles()) {
+      String capitalizedStyle = Utils.capitalizeFirstLetter(style.getName());
       String methodName = "with" + capitalizedStyle + "Style";
-      String fieldName = weakReferenceFieldForStyle(styleName);
+      String fieldName = weakReferenceFieldForStyle(style.getName());
 
       // The style is stored in a static weak reference since it is likely to be reused in other
       // models are when models are rebuilt.
-      methods.add(MethodSpec.methodBuilder(methodName)
+      Builder styleMethodBuilder = MethodSpec.methodBuilder(methodName);
+
+      if (style.getJavadoc() != null) {
+        styleMethodBuilder.addJavadoc(style.getJavadoc());
+      }
+
+      methods.add(styleMethodBuilder
           .addModifiers(PUBLIC)
           .returns(modelInfo.getParameterizedGeneratedName())
           .addStatement("$T style = $L != null ? $L.get() : null", ClassNames.PARIS_STYLE,

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

@@ -291,10 +291,10 @@ internal class ModelViewWriter(
             // Compare against the style on the previous model if it exists,
             // otherwise we look up the saved style from the view tag
             if (hasPreviousModel) {
-                beginControlFlow("\nif (!\$L.equals(that.\$L))",
+                beginControlFlow("\nif (\$L != that.\$L)",
                                  PARIS_STYLE_ATTR_NAME, PARIS_STYLE_ATTR_NAME)
             } else {
-                beginControlFlow("\nif (!\$L.equals(\$L.getTag(\$T.id.epoxy_saved_view_style)))",
+                beginControlFlow("\nif (\$L != \$L.getTag(\$T.id.epoxy_saved_view_style))",
                                  PARIS_STYLE_ATTR_NAME, boundObjectParam.name, ClassNames.EPOXY_R)
             }
 

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

@@ -17,14 +17,14 @@ fun weakReferenceFieldForStyle(styleName: String) = "parisStyleReference_$styleN
  */
 internal class ParisStyleAttributeInfo(
         modelInfo: ModelViewInfo,
-        elements: Elements,
+        val elements: Elements,
         val types: Types,
         packageName: String,
         styleBuilderClassName: ClassName,
         styleBuilderElement: TypeMirror
 ) : AttributeInfo() {
 
-    val styleNames: List<String>
+    val styles: List<ParisStyle>
     val styleApplierClass: ClassName
     val styleBuilderClass: ClassName
 
@@ -38,27 +38,34 @@ internal class ParisStyleAttributeInfo(
         isGenerated = true
         useInHash = true
         isNullable = false
-        styleNames = findStyleNames(styleBuilderElement)
+        styles = findStyleNames(styleBuilderElement)
 
         // the builder is nested in the style applier class
         styleApplierClass = styleBuilderClassName.topLevelClassName()
 
         codeToSetDefault.explicit = CodeBlock.of(PARIS_DEFAULT_STYLE_CONSTANT_NAME)
     }
 
-    private fun findStyleNames(typeMirror: TypeMirror): List<String> {
+    private fun findStyleNames(typeMirror: TypeMirror): List<ParisStyle> {
         return types.asElement(typeMirror)
                 .enclosedElements
                 .filter {
                     it.kind == ElementKind.METHOD
                             && it.simpleName.startsWith(BUILDER_STYLE_METHOD_PREFIX)
                 }
                 .map {
-                    it.simpleName
+                    val name = it.simpleName
                             .toString()
                             .removePrefix(BUILDER_STYLE_METHOD_PREFIX)
                             .lowerCaseFirstLetter()
+
+                    ParisStyle(name, elements.getDocComment(it))
                 }
     }
 
-}
+}
+
+data class ParisStyle(
+        val name: String,
+        val javadoc: String?
+)

epoxy-sample/build.gradle

@@ -12,7 +12,7 @@ android {
 
   defaultConfig {
     applicationId "com.airbnb.android.epoxysample"
-    minSdkVersion rootProject.MIN_SDK_VERSION_LITHO
+    minSdkVersion 16
     targetSdkVersion rootProject.TARGET_SDK_VERSION
     vectorDrawables.useSupportLibrary = true
     versionCode 1
@@ -44,6 +44,9 @@ dependencies {
   compile project(':epoxy-adapter')
   annotationProcessor project(':epoxy-processor')
 
+//  compile "com.airbnb.android:paris:0.2.0"
+//  annotationProcessor "com.airbnb.android:paris-processor:0.2.0"
+
   // Dependencies for the optional litho integration
   compile project(':epoxy-litho')
   annotationProcessor rootProject.deps.lithoProcessor