Encapsulate all used java classes

Summary:
@public

Moves all Java classes used from C++ to their own header + implementation file. In `YGJNI.cpp`, we only call methods on these objects deriving from `jni::JavaClass`.

This is only a bit of cleanup, no functional change.

Reviewed By: SidharthGuglani

Differential Revision: D14261043

fbshipit-source-id: 2db1d81cb7f56a4cdc24b182b2166e1d7e24ba3c

java/jni/YGJTypes.cpp

@@ -0,0 +1,44 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include "YGJTypes.h"
+
+using facebook::jni::alias_ref;
+using facebook::jni::local_ref;
+
+jfloat JYogaNode::baseline(jfloat width, jfloat height) {
+  static auto javaMethod =
+      javaClassLocal()->getMethod<jfloat(jfloat, jfloat)>("baseline");
+  return javaMethod(self(), width, height);
+}
+
+jlong JYogaNode::measure(
+    jfloat width,
+    jint widthMode,
+    jfloat height,
+    jint heightMode) {
+  static auto javaMethod =
+      javaClassLocal()->getMethod<jlong(jfloat, jint, jfloat, jint)>("measure");
+  return javaMethod(self(), width, widthMode, height, heightMode);
+}
+
+facebook::jni::local_ref<JYogaLogLevel> JYogaLogLevel::fromInt(jint logLevel) {
+  static auto javaMethod =
+      javaClassStatic()->getStaticMethod<alias_ref<JYogaLogLevel>(jint)>(
+          "fromInt");
+  return javaMethod(javaClassStatic(), logLevel);
+}
+
+void JYogaLogger::log(
+    facebook::jni::alias_ref<JYogaNode> node,
+    facebook::jni::alias_ref<JYogaLogLevel> logLevel,
+    jstring message) {
+  static auto javaMethod =
+      javaClassLocal()
+          ->getMethod<void(
+              alias_ref<JYogaNode>, alias_ref<JYogaLogLevel>, jstring)>("log");
+  javaMethod(self(), node, logLevel, message);
+}