Implement device enumeration for PPB_VideoCapture_Dev.

ppapi/examples/video_capture/video_capture.cc

Index: ppapi/examples/video_capture/video_capture.cc
diff --git a/ppapi/examples/video_capture/video_capture.cc b/ppapi/examples/video_capture/video_capture.cc
index 63e2cb80312a3dbaf17959e08625add21afb4409..c0d96eba15e4c10318730e40118547556bdb8397 100644
--- a/ppapi/examples/video_capture/video_capture.cc
+++ b/ppapi/examples/video_capture/video_capture.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -11,6 +11,7 @@
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_opengles2.h"
 #include "ppapi/cpp/dev/buffer_dev.h"
+#include "ppapi/cpp/dev/device_ref_dev.h"
 #include "ppapi/cpp/dev/video_capture_dev.h"
 #include "ppapi/cpp/dev/video_capture_client_dev.h"
 #include "ppapi/cpp/completion_callback.h"
@@ -19,6 +20,7 @@
 #include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/rect.h"
+#include "ppapi/cpp/var.h"
 #include "ppapi/lib/gl/include/GLES2/gl2.h"
 #include "ppapi/utility/completion_callback_factory.h"
 
@@ -49,6 +51,7 @@ class VCDemoInstance : public pp::Instance,
   // pp::Instance implementation (see PPP_Instance).
   virtual void DidChangeView(const pp::Rect& position,
                              const pp::Rect& clip_ignored);
+  virtual void HandleMessage(const pp::Var& message_data);
 
   // pp::Graphics3DClient implementation.
   virtual void Graphics3DContextLost() {
@@ -66,6 +69,9 @@ class VCDemoInstance : public pp::Instance,
   }
 
   virtual void OnStatus(PP_Resource resource, uint32_t status) {
+    status_ = static_cast<PP_VideoCaptureStatus_Dev>(status);
+    if (status_ == PP_VIDEO_CAPTURE_STATUS_STOPPED)
+      StartCapture();
   }
 
   virtual void OnError(PP_Resource resource, uint32_t error) {
@@ -107,13 +113,15 @@ class VCDemoInstance : public pp::Instance,
 
   // GL-related functions.
   void InitGL();
-  void InitializeCapture();
   GLuint CreateTexture(int32_t width, int32_t height, int unit);
   void CreateGLObjects();
   void CreateShader(GLuint program, GLenum type, const char* source, int size);
   void PaintFinished(int32_t result);
   void CreateYUVTextures();
 
+  void EnumerateDevicesFinished(int32_t result);
+  void StartCapture();
+
   pp::Size position_size_;
   bool is_painting_;
   bool needs_paint_;
@@ -130,6 +138,15 @@ class VCDemoInstance : public pp::Instance,
 
   // Owned data.
   pp::Graphics3D* context_;
+
+  bool page_initialized_;
+  PP_VideoCaptureStatus_Dev status_;
+  std::vector<pp::DeviceRef_Dev> devices_;
+
+  // >= 0 means index of |devices_|;
+  // -1 means the default device;
+  // -2 means no pending request to start capture.
+  int pending_start_capture_device_;
 };
 
 VCDemoInstance::VCDemoInstance(PP_Instance instance, pp::Module* module)
@@ -143,11 +160,17 @@ VCDemoInstance::VCDemoInstance(PP_Instance instance, pp::Module* module)
       texture_v_(0),
       video_capture_(*this),
       callback_factory_(this),
-      context_(NULL) {
+      context_(NULL),
+      page_initialized_(false),
+      status_(PP_VIDEO_CAPTURE_STATUS_STOPPED),
+      pending_start_capture_device_(-2) {
   gles2_if_ = static_cast<const struct PPB_OpenGLES2*>(
       module->GetBrowserInterface(PPB_OPENGLES2_INTERFACE));
   assert(gles2_if_);
-  InitializeCapture();
+
+  capture_info_.width = 320;
+  capture_info_.height = 240;
+  capture_info_.frames_per_second = 30;
 }
 
 VCDemoInstance::~VCDemoInstance() {
@@ -169,12 +192,26 @@ void VCDemoInstance::DidChangeView(
   Render();
 }
 
-void VCDemoInstance::InitializeCapture() {
-  capture_info_.width = 320;
-  capture_info_.height = 240;
-  capture_info_.frames_per_second = 30;
-
-  video_capture_.StartCapture(capture_info_, 4);
+void VCDemoInstance::HandleMessage(const pp::Var& message_data) {
+  if (message_data.is_string()) {
+    std::string event = message_data.AsString();
+    if (event == "PageInitialized") {
+      pp::CompletionCallback callback = callback_factory_.NewCallback(
+          &VCDemoInstance::EnumerateDevicesFinished);
+      video_capture_.EnumerateDevices(callback);
+    } else if (event == "UseDefault") {
+      pending_start_capture_device_ = -1;
+      StartCapture();
+    }
+  } else if (message_data.is_number()) {
+    int index = message_data.AsInt();
+    if (index >= 0 && index < static_cast<int>(devices_.size())) {
+      pending_start_capture_device_= index;
+      StartCapture();
+    } else {
+      assert(false);
+    }
+  }
 }
 
 void VCDemoInstance::InitGL() {
@@ -364,6 +401,42 @@ void VCDemoInstance::CreateYUVTextures() {
   texture_v_ = CreateTexture(width, height, 2);
 }
 
+void VCDemoInstance::EnumerateDevicesFinished(int32_t result) {
+  static const char* const kDelimiter = "#__#";
+
+  if (result == PP_OK) {
+    std::string device_names;
+    video_capture_.GetDevices(&devices_);
+    for (size_t index = 0; index < devices_.size(); ++index) {
+      pp::Var name = devices_[index].GetName();
+      assert(name.is_string());
+
+      if (index != 0)
+        device_names += kDelimiter;
+      device_names += name.AsString();
+    }
+    PostMessage(pp::Var(device_names));
+  } else {
+    PostMessage(pp::Var("EnumerationFailed"));
+  }
+}
+
+void VCDemoInstance::StartCapture() {
+  if (status_ != PP_VIDEO_CAPTURE_STATUS_STOPPED) {
+    video_capture_.StopCapture();
+    return;
+  }
+
+  if (pending_start_capture_device_ > -2 &&
+      pending_start_capture_device_ < static_cast<int>(devices_.size())) {
+    video_capture_.StartCapture(
+        pending_start_capture_device_ == -1 ?
+            pp::DeviceRef_Dev() : devices_[pending_start_capture_device_],
+        capture_info_, 4);
+  }
+  pending_start_capture_device_ = -2;
+}
+
 pp::Instance* VCDemoModule::CreateInstance(PP_Instance instance) {
   return new VCDemoInstance(instance, this);
 }