Implement standard interface for toggling experimental features

Summary: We want to start experimenting with changes to the library in a more controlled and easier to measure manner. This diff adds the basics of an experiment layer to csslayout.

Reviewed By: gkassabli

Differential Revision: D4174260

fbshipit-source-id: ad3667183810c02833fba9a1276f89286e848fcd

java/com/facebook/csslayout/CSSExperimentalFeature.java

@@ -0,0 +1,13 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.csslayout;
+
+public enum CSSExperimentalFeature {
+}

java/com/facebook/csslayout/CSSNode.java

@@ -40,6 +40,20 @@ public class CSSNode implements CSSNodeAPI<CSSNode> {
     jni_CSSLayoutSetLogger(logger);
   }
 
+  private static native void jni_CSSLayoutSetExperimentalFeatureEnabled(
+      int feature,
+      boolean enabled);
+  public static void setExperimentalFeatureEnabled(
+      CSSExperimentalFeature feature,
+      boolean enabled) {
+    jni_CSSLayoutSetExperimentalFeatureEnabled(feature.ordinal(), enabled);
+  }
+
+  private static native boolean jni_CSSLayoutIsExperimentalFeatureEnabled(int feature);
+  public static boolean isExperimentalFeatureEnabled(CSSExperimentalFeature feature) {
+    return jni_CSSLayoutIsExperimentalFeatureEnabled(feature.ordinal());
+  }
+
   private CSSNode mParent;
   private List<CSSNode> mChildren;
   private MeasureFunction mMeasureFunction;

java/jni/CSSJNI.cpp

@@ -105,6 +105,14 @@ void jni_CSSLog(alias_ref<jclass> clazz, jint level, jstring message) {
   Environment::current()->ReleaseStringUTFChars(message, nMessage);
 }
 
+void jni_CSSLayoutSetExperimentalFeatureEnabled(alias_ref<jclass> clazz, jint feature, jboolean enabled) {
+  CSSLayoutSetExperimentalFeatureEnabled(static_cast<CSSExperimentalFeature>(feature), enabled);
+}
+
+jboolean jni_CSSLayoutIsExperimentalFeatureEnabled(alias_ref<jclass> clazz, jint feature) {
+  return CSSLayoutIsExperimentalFeatureEnabled(static_cast<CSSExperimentalFeature>(feature));
+}
+
 jint jni_CSSNodeGetInstanceCount(alias_ref<jclass> clazz) {
   return CSSNodeGetInstanceCount();
 }
@@ -291,6 +299,8 @@ jint JNI_OnLoad(JavaVM *vm, void *) {
                         CSSMakeNativeMethod(jni_CSSNodeGetInstanceCount),
                         CSSMakeNativeMethod(jni_CSSLayoutSetLogger),
                         CSSMakeNativeMethod(jni_CSSLog),
+                        CSSMakeNativeMethod(jni_CSSLayoutSetExperimentalFeatureEnabled),
+                        CSSMakeNativeMethod(jni_CSSLayoutIsExperimentalFeatureEnabled),
                     });
   });
 }