Replace hand-written JNI in fling_animator with generated bindings.

webkit/glue/fling_animator_impl_android.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/glue/fling_animator_impl_android.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/logging.h"
+#include "jni/OverScroller_jni.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebFloatSize.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGestureCurveTarget.h"
 #include "ui/gfx/screen.h"
 #include "ui/gfx/vector2d.h"
 
-using base::android::AttachCurrentThread;
-using base::android::CheckException;
-using base::android::GetApplicationContext;
-using base::android::GetClass;
-using base::android::MethodID;
-using base::android::ScopedJavaLocalRef;
-
 namespace webkit_glue {
 
 FlingAnimatorImpl::FlingAnimatorImpl()
     : is_active_(false) {
   // hold the global reference of the Java objects.
-  JNIEnv* env = AttachCurrentThread();
-  DCHECK(env);
-  ScopedJavaLocalRef<jclass> cls(GetClass(env, "android/widget/OverScroller"));
-  jmethodID constructor = MethodID::Get<MethodID::TYPE_INSTANCE>(
-      env, cls.obj(), "<init>", "(Landroid/content/Context;)V");
-  ScopedJavaLocalRef<jobject> tmp(env, env->NewObject(cls.obj(), constructor,
-                                                      GetApplicationContext()));
-  DCHECK(tmp.obj());
-  java_scroller_.Reset(tmp);
-
-  fling_method_id_ = MethodID::Get<MethodID::TYPE_INSTANCE>(
-      env, cls.obj(), "fling", "(IIIIIIII)V");
-  abort_method_id_ = MethodID::Get<MethodID::TYPE_INSTANCE>(
-      env, cls.obj(), "abortAnimation", "()V");
-  compute_method_id_ = MethodID::Get<MethodID::TYPE_INSTANCE>(
-      env, cls.obj(), "computeScrollOffset", "()Z");
-  getX_method_id_ = MethodID::Get<MethodID::TYPE_INSTANCE>(
-      env, cls.obj(), "getCurrX", "()I");
-  getY_method_id_ = MethodID::Get<MethodID::TYPE_INSTANCE>(
-      env, cls.obj(), "getCurrY", "()I");
+  JNIEnv* env = base::android::AttachCurrentThread();
+  java_scroller_.Reset(JNI_OverScroller::Java_OverScroller_ConstructorAWOS_ACC(
+      env,
+      base::android::GetApplicationContext()));
 }
 
 FlingAnimatorImpl::~FlingAnimatorImpl()
 {
 }
 
+//static
+bool FlingAnimatorImpl::RegisterJni(JNIEnv* env) {
+  return JNI_OverScroller::RegisterNativesImpl(env);
+}
+
 void FlingAnimatorImpl::StartFling(const gfx::PointF& velocity)
 {
   // No bounds on the fling. See http://webkit.org/b/96403
   // Instead, use the largest possible bounds for minX/maxX/minY/maxY. The
   // compositor will ignore any attempt to scroll beyond the end of the page.
 
   DCHECK(velocity.x() || velocity.y());
   if (is_active_)
     CancelFling();
 
   is_active_ = true;
 
-  JNIEnv* env = AttachCurrentThread();
+  JNIEnv* env = base::android::AttachCurrentThread();
 
-  env->CallVoidMethod(java_scroller_.obj(), fling_method_id_, 0, 0,
-                      static_cast<int>(velocity.x()),
-                      static_cast<int>(velocity.y()),
-                      INT_MIN, INT_MAX, INT_MIN, INT_MAX);
-  CheckException(env);
+  JNI_OverScroller::Java_OverScroller_flingV_I_I_I_I_I_I_I_I(
+      env, java_scroller_.obj(), 0, 0,
+      static_cast<int>(velocity.x()),
+      static_cast<int>(velocity.y()),
+      INT_MIN, INT_MAX, INT_MIN, INT_MAX);
 }
 
 void FlingAnimatorImpl::CancelFling()
 {
   if (!is_active_)
     return;
 
   is_active_ = false;
-  JNIEnv* env = AttachCurrentThread();
-  env->CallVoidMethod(java_scroller_.obj(), abort_method_id_);
-  CheckException(env);
+  JNIEnv* env = base::android::AttachCurrentThread();
+  JNI_OverScroller::Java_OverScroller_abortAnimation(env, java_scroller_.obj());
 }
 
 bool FlingAnimatorImpl::UpdatePosition()
 {
-  JNIEnv* env = AttachCurrentThread();
-  bool result = env->CallBooleanMethod(java_scroller_.obj(),
-                                       compute_method_id_);
-  CheckException(env);
+  JNIEnv* env = base::android::AttachCurrentThread();
+  bool result = JNI_OverScroller::Java_OverScroller_computeScrollOffset(
+      env,
+      java_scroller_.obj());
   return is_active_ = result;
 }
 
 gfx::Point FlingAnimatorImpl::GetCurrentPosition()
 {
-  JNIEnv* env = AttachCurrentThread();
+  JNIEnv* env = base::android::AttachCurrentThread();
   gfx::Point position(
-      env->CallIntMethod(java_scroller_.obj(), getX_method_id_),

[Yaron, 2013/03/07 19:51:56]

Example problem with manual binding. Any issue here (i.e. if java_scroller_ got
messed up, would then crash with a deadd00d assert on the getY call on the next
line.

-      env->CallIntMethod(java_scroller_.obj(), getY_method_id_));
-  CheckException(env);
+      JNI_OverScroller::Java_OverScroller_getCurrX(env, java_scroller_.obj()),
+      JNI_OverScroller::Java_OverScroller_getCurrY(env, java_scroller_.obj()));
   return position;
 }
 
 bool FlingAnimatorImpl::apply(double time,
                               WebKit::WebGestureCurveTarget* target) {
   if (!UpdatePosition())
     return false;
 
   gfx::Point current_position = GetCurrentPosition();
   gfx::Vector2d diff(current_position - last_position_);
@@ skipping 10 matching lines @@
 
 FlingAnimatorImpl* FlingAnimatorImpl::CreateAndroidGestureCurve(
     const WebKit::WebFloatPoint& velocity,
     const WebKit::WebSize&) {
   FlingAnimatorImpl* gesture_curve = new FlingAnimatorImpl();
   gesture_curve->StartFling(velocity);
   return gesture_curve;
 }
 
 } // namespace webkit_glue