[Android Client] Break down multi-threaded classes by thread

remoting/client/jni/jni_display_handler.cc

+// Copyright 2016 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 "remoting/client/jni/jni_display_handler.h"
+
+#include "base/android/jni_android.h"
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/stl_util.h"
+#include "jni/Display_jni.h"
+#include "remoting/client/jni/chromoting_jni_runtime.h"
+#include "remoting/client/jni/jni_client.h"
+
+using base::android::JavaParamRef;
+
+namespace {
+
+const int kBytesPerPixel = 4;
+}
+
+namespace remoting {
+
+JniDisplayHandler::JniDisplayHandler(
+    scoped_refptr<base::SingleThreadTaskRunner> display_runner,
+    base::android::ScopedJavaGlobalRef<jobject> java_display)
+    : display_runner_(display_runner),
+      java_display_(java_display),
+      weak_factory_(this) {}
+
+JniDisplayHandler::~JniDisplayHandler() {
+  DCHECK(display_runner_->BelongsToCurrentThread());
+}
+
+// static
+base::android::ScopedJavaLocalRef<jobject> JniDisplayHandler::NewBitmap(
+    int width,
+    int height) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  return Java_Display_newBitmap(env, width, height);
+}
+
+void JniDisplayHandler::UpdateFrameBitmap(
+    base::android::ScopedJavaGlobalRef<jobject> bitmap) {
+  DCHECK(display_runner_->BelongsToCurrentThread());
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_Display_setVideoFrame(env, java_display_.obj(), bitmap.obj());
+}
+
+void JniDisplayHandler::UpdateCursorShape(
+    const protocol::CursorShapeInfo& cursor_shape) {
+  DCHECK(display_runner_->BelongsToCurrentThread());
+
+  // const_cast<> is safe as long as the Java updateCursorShape() method copies
+  // the data out of the buffer without mutating it, and doesn't keep any
+  // reference to the buffer afterwards. Unfortunately, there seems to be no way
+  // to create a read-only ByteBuffer from a pointer-to-const.
+  char* data = string_as_array(const_cast<std::string*>(&cursor_shape.data()));
+  int cursor_total_bytes =
+      cursor_shape.width() * cursor_shape.height() * kBytesPerPixel;
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  base::android::ScopedJavaLocalRef<jobject> buffer(
+      env, env->NewDirectByteBuffer(data, cursor_total_bytes));
+  Java_Display_updateCursorShape(
+      env, java_display_.obj(), cursor_shape.width(), cursor_shape.height(),
+      cursor_shape.hotspot_x(), cursor_shape.hotspot_y(), buffer.obj());
+}
+
+void JniDisplayHandler::RedrawCanvas() {
+  DCHECK(display_runner_->BelongsToCurrentThread());
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_Display_redrawGraphicsInternal(env, java_display_.obj());
+}
+
+base::WeakPtr<JniDisplayHandler> JniDisplayHandler::GetWeakPtr() {
+  return weak_factory_.GetWeakPtr();
+}
+
+// static
+bool JniDisplayHandler::RegisterJni(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+void JniDisplayHandler::Destroy(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jobject>& caller) {
+  if (display_runner_->BelongsToCurrentThread()) {
+    delete this;
+  } else {
+    display_runner_->DeleteSoon(FROM_HERE, this);
+  }
+}
+
+void JniDisplayHandler::ScheduleRedraw(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jobject>& caller) {
+  display_runner_->PostTask(
+      FROM_HERE, base::Bind(&JniDisplayHandler::RedrawCanvas, GetWeakPtr()));
+}
+
+static jlong Init(JNIEnv* env, const JavaParamRef<jobject>& caller) {
+  return reinterpret_cast<intptr_t>(new JniDisplayHandler(
+      ChromotingJniRuntime::GetInstance()->display_task_runner(),
+      base::android::ScopedJavaGlobalRef<jobject>(env, caller)));
+}
+
+}  // namespace remoting