media/midi/usb_midi_device_factory_android.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/midi/usb_midi_device_factory_android.h"
   6
   7 #include <jni.h>
   8 #include <vector>
   9
  10 #include "base/android/scoped_java_ref.h"
  11 #include "base/bind.h"
  12 #include "base/containers/hash_tables.h"
  13 #include "base/lazy_instance.h"
  14 #include "base/memory/scoped_vector.h"
  15 #include "base/message_loop/message_loop.h"
  16 #include "base/synchronization/lock.h"
  17 #include "jni/UsbMidiDeviceFactoryAndroid_jni.h"
  18 #include "media/midi/usb_midi_device_android.h"
  19
  20 namespace media {
  21
  22 namespace {
  23
  24 typedef UsbMidiDevice::Factory::Callback Callback;
  25
  26 }  // namespace
  27
  28 UsbMidiDeviceFactoryAndroid::UsbMidiDeviceFactoryAndroid() : delegate_(NULL) {}
  29
  30 UsbMidiDeviceFactoryAndroid::~UsbMidiDeviceFactoryAndroid() {
  31   JNIEnv* env = base::android::AttachCurrentThread();
  32   if (!raw_factory_.is_null())
  33     Java_UsbMidiDeviceFactoryAndroid_close(env, raw_factory_.obj());
  34 }
  35
  36 void UsbMidiDeviceFactoryAndroid::EnumerateDevices(
  37     UsbMidiDeviceDelegate* delegate,
  38     Callback callback) {
  39   DCHECK(!delegate_);
  40   JNIEnv* env = base::android::AttachCurrentThread();
  41   uintptr_t pointer = reinterpret_cast<uintptr_t>(this);
  42   raw_factory_.Reset(Java_UsbMidiDeviceFactoryAndroid_create(env, pointer));
  43
  44   delegate_ = delegate;
  45   callback_ = callback;
  46
  47   if (Java_UsbMidiDeviceFactoryAndroid_enumerateDevices(
  48           env, raw_factory_.obj(), base::android::GetApplicationContext())) {
  49     // Asynchronous operation.
  50     return;
  51   }
  52   // No devices are found.
  53   ScopedVector<UsbMidiDevice> devices;
  54   callback.Run(true, &devices);
  55 }
  56
  57 // Called from the Java world.
  58 void UsbMidiDeviceFactoryAndroid::OnUsbMidiDeviceRequestDone(
  59     JNIEnv* env,
  60     jobject caller,
  61     jobjectArray devices) {
  62   size_t size = env->GetArrayLength(devices);
  63   ScopedVector<UsbMidiDevice> devices_to_pass;
  64   for (size_t i = 0; i < size; ++i) {
  65     UsbMidiDeviceAndroid::ObjectRef raw_device(
  66         env, env->GetObjectArrayElement(devices, i));
  67     devices_to_pass.push_back(new UsbMidiDeviceAndroid(raw_device, delegate_));
  68   }
  69
  70   callback_.Run(true, &devices_to_pass);
  71 }
  72
  73 bool UsbMidiDeviceFactoryAndroid::RegisterUsbMidiDeviceFactory(JNIEnv* env) {
  74   return RegisterNativesImpl(env);
  75 }
  76
  77 }  // namespace media