Implement desktop capture API on OS X.

chromium_src/chrome/browser/media/desktop_media_list.h

@@ -0,0 +1,60 @@
+// Copyright 2013 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.
+
+#ifndef CHROME_BROWSER_MEDIA_DESKTOP_MEDIA_LIST_H_
+#define CHROME_BROWSER_MEDIA_DESKTOP_MEDIA_LIST_H_
+
+#include "base/basictypes.h"
+#include "base/time/time.h"
+#include "content/public/browser/desktop_media_id.h"
+#include "ui/gfx/image/image_skia.h"
+
+class DesktopMediaListObserver;
+
+// DesktopMediaList provides the list of desktop media source (screens, windows,
+// tabs), and their thumbnails, to the desktop media picker dialog. It
+// transparently updates the list in the background, and notifies the desktop
+// media picker when something changes.
+class DesktopMediaList {
+ public:
+  // Struct used to represent each entry in the list.
+  struct Source {
+    // Id of the source.
+    content::DesktopMediaID id;
+
+    // Name of the source that should be shown to the user.
+    base::string16 name;
+
+    // The thumbnail for the source.
+    gfx::ImageSkia thumbnail;
+  };
+
+  virtual ~DesktopMediaList() {}
+
+  // Sets time interval between updates. By default list of sources and their
+  // thumbnail are updated once per second. If called after StartUpdating() then
+  // it will take effect only after the next update.
+  virtual void SetUpdatePeriod(base::TimeDelta period) = 0;
+
+  // Sets size to which the thumbnails should be scaled. If called after
+  // StartUpdating() then some thumbnails may be still scaled to the old size
+  // until they are updated.
+  virtual void SetThumbnailSize(const gfx::Size& thumbnail_size) = 0;
+
+  // Sets ID of the hosting desktop picker dialog. The window with this ID will
+  // be filtered out from the list of sources.
+  virtual void SetViewDialogWindowId(content::DesktopMediaID::Id dialog_id) = 0;
+
+  // Starts updating the model. The model is initially empty, so OnSourceAdded()
+  // notifications will be generated for each existing source as it is
+  // enumerated. After the initial enumeration the model will be refreshed based
+  // on the update period, and notifications generated only for changes in the
+  // model.
+  virtual void StartUpdating(DesktopMediaListObserver* observer) = 0;
+
+  virtual int GetSourceCount() const = 0;
+  virtual const Source& GetSource(int index) const = 0;
+};
+
+#endif  // CHROME_BROWSER_MEDIA_DESKTOP_MEDIA_LIST_H_

chromium_src/chrome/browser/media/desktop_media_list_observer.h

@@ -0,0 +1,22 @@
+// Copyright 2013 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.
+
+#ifndef CHROME_BROWSER_MEDIA_DESKTOP_MEDIA_LIST_OBSERVER_H_
+#define CHROME_BROWSER_MEDIA_DESKTOP_MEDIA_LIST_OBSERVER_H_
+
+// Interface implemented by the desktop media picker dialog to receive
+// notifications about changes in DesktopMediaList.
+class DesktopMediaListObserver {
+ public:
+  virtual void OnSourceAdded(int index) = 0;
+  virtual void OnSourceRemoved(int index) = 0;
+  virtual void OnSourceMoved(int old_index, int new_index) = 0;
+  virtual void OnSourceNameChanged(int index) = 0;
+  virtual void OnSourceThumbnailChanged(int index) = 0;
+
+ protected:
+  virtual ~DesktopMediaListObserver() {}
+};
+
+#endif  // CHROME_BROWSER_MEDIA_DESKTOP_MEDIA_LIST_OBSERVER_H_

chromium_src/chrome/browser/media/native_desktop_media_list.cc

@@ -0,0 +1,366 @@
+// Copyright 2013 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 "chrome/browser/media/native_desktop_media_list.h"
+
+#include <map>
+#include <set>
+#include <sstream>
+
+#include "base/hash.h"
+#include "base/logging.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/threading/sequenced_worker_pool.h"
+#include "chrome/browser/media/desktop_media_list_observer.h"
+#include "content/public/browser/browser_thread.h"
+#include "media/base/video_util.h"
+#include "third_party/libyuv/include/libyuv/scale_argb.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
+#include "third_party/webrtc/modules/desktop_capture/screen_capturer.h"
+#include "third_party/webrtc/modules/desktop_capture/window_capturer.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/gfx/skia_util.h"
+
+using content::BrowserThread;
+using content::DesktopMediaID;
+
+namespace {
+
+// Update the list every second.
+const int kDefaultUpdatePeriod = 1000;
+
+// Returns a hash of a DesktopFrame content to detect when image for a desktop
+// media source has changed.
+uint32 GetFrameHash(webrtc::DesktopFrame* frame) {
+  int data_size = frame->stride() * frame->size().height();
+  return base::SuperFastHash(reinterpret_cast<char*>(frame->data()), data_size);
+}
+
+gfx::ImageSkia ScaleDesktopFrame(scoped_ptr<webrtc::DesktopFrame> frame,
+                                 gfx::Size size) {
+  gfx::Rect scaled_rect = media::ComputeLetterboxRegion(
+      gfx::Rect(0, 0, size.width(), size.height()),
+      gfx::Size(frame->size().width(), frame->size().height()));
+
+  SkBitmap result;
+  result.allocN32Pixels(scaled_rect.width(), scaled_rect.height(), true);
+  result.lockPixels();
+
+  uint8* pixels_data = reinterpret_cast<uint8*>(result.getPixels());
+  libyuv::ARGBScale(frame->data(), frame->stride(),
+                    frame->size().width(), frame->size().height(),
+                    pixels_data, result.rowBytes(),
+                    scaled_rect.width(), scaled_rect.height(),
+                    libyuv::kFilterBilinear);
+
+  // Set alpha channel values to 255 for all pixels.
+  // TODO(sergeyu): Fix screen/window capturers to capture alpha channel and
+  // remove this code. Currently screen/window capturers (at least some
+  // implementations) only capture R, G and B channels and set Alpha to 0.
+  // crbug.com/264424
+  for (int y = 0; y < result.height(); ++y) {
+    for (int x = 0; x < result.width(); ++x) {
+      pixels_data[result.rowBytes() * y + x * result.bytesPerPixel() + 3] =
+          0xff;
+    }
+  }
+
+  result.unlockPixels();
+
+  return gfx::ImageSkia::CreateFrom1xBitmap(result);
+}
+
+}  // namespace
+
+NativeDesktopMediaList::SourceDescription::SourceDescription(
+    DesktopMediaID id,
+    const base::string16& name)
+    : id(id),
+      name(name) {
+}
+
+class NativeDesktopMediaList::Worker
+    : public webrtc::DesktopCapturer::Callback {
+ public:
+  Worker(base::WeakPtr<NativeDesktopMediaList> media_list,
+         scoped_ptr<webrtc::ScreenCapturer> screen_capturer,
+         scoped_ptr<webrtc::WindowCapturer> window_capturer);
+  ~Worker() override;
+
+  void Refresh(const gfx::Size& thumbnail_size,
+               content::DesktopMediaID::Id view_dialog_id);
+
+ private:
+  typedef std::map<DesktopMediaID, uint32> ImageHashesMap;
+
+  // webrtc::DesktopCapturer::Callback interface.
+  webrtc::SharedMemory* CreateSharedMemory(size_t size) override;
+  void OnCaptureCompleted(webrtc::DesktopFrame* frame) override;
+
+  base::WeakPtr<NativeDesktopMediaList> media_list_;
+
+  scoped_ptr<webrtc::ScreenCapturer> screen_capturer_;
+  scoped_ptr<webrtc::WindowCapturer> window_capturer_;
+
+  scoped_ptr<webrtc::DesktopFrame> current_frame_;
+
+  ImageHashesMap image_hashes_;
+
+  DISALLOW_COPY_AND_ASSIGN(Worker);
+};
+
+NativeDesktopMediaList::Worker::Worker(
+    base::WeakPtr<NativeDesktopMediaList> media_list,
+    scoped_ptr<webrtc::ScreenCapturer> screen_capturer,
+    scoped_ptr<webrtc::WindowCapturer> window_capturer)
+    : media_list_(media_list),
+      screen_capturer_(screen_capturer.Pass()),
+      window_capturer_(window_capturer.Pass()) {
+  if (screen_capturer_)
+    screen_capturer_->Start(this);
+  if (window_capturer_)
+    window_capturer_->Start(this);
+}
+
+NativeDesktopMediaList::Worker::~Worker() {}
+
+void NativeDesktopMediaList::Worker::Refresh(
+    const gfx::Size& thumbnail_size,
+    content::DesktopMediaID::Id view_dialog_id) {
+  std::vector<SourceDescription> sources;
+
+  if (screen_capturer_) {
+    webrtc::ScreenCapturer::ScreenList screens;
+    if (screen_capturer_->GetScreenList(&screens)) {
+      bool mutiple_screens = screens.size() > 1;
+      base::string16 title;
+      for (size_t i = 0; i < screens.size(); ++i) {
+        if (mutiple_screens) {
+          title = base::UTF8ToUTF16("Screen " + base::IntToString(i+1));
+        } else {
+          title = base::UTF8ToUTF16("Entire screen");
+        }
+        sources.push_back(SourceDescription(DesktopMediaID(
+            DesktopMediaID::TYPE_SCREEN, screens[i].id), title));
+      }
+    }
+  }
+
+  if (window_capturer_) {
+    webrtc::WindowCapturer::WindowList windows;
+    if (window_capturer_->GetWindowList(&windows)) {
+      for (webrtc::WindowCapturer::WindowList::iterator it = windows.begin();
+           it != windows.end(); ++it) {
+        // Skip the picker dialog window.
+        if (it->id != view_dialog_id) {
+          sources.push_back(SourceDescription(
+              DesktopMediaID(DesktopMediaID::TYPE_WINDOW, it->id),
+              base::UTF8ToUTF16(it->title)));
+        }
+      }
+    }
+  }
+  // Update list of windows before updating thumbnails.
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&NativeDesktopMediaList::OnSourcesList,
+                 media_list_, sources));
+
+  ImageHashesMap new_image_hashes;
+
+  // Get a thumbnail for each source.
+  for (size_t i = 0; i < sources.size(); ++i) {
+    SourceDescription& source = sources[i];
+    switch (source.id.type) {
+      case DesktopMediaID::TYPE_SCREEN:
+        if (!screen_capturer_->SelectScreen(source.id.id))
+          continue;
+        screen_capturer_->Capture(webrtc::DesktopRegion());
+        break;
+
+      case DesktopMediaID::TYPE_WINDOW:
+        if (!window_capturer_->SelectWindow(source.id.id))
+          continue;
+        window_capturer_->Capture(webrtc::DesktopRegion());
+        break;
+
+      default:
+        NOTREACHED();
+    }
+
+    // Expect that DesktopCapturer to always captures frames synchronously.
+    // |current_frame_| may be NULL if capture failed (e.g. because window has
+    // been closed).
+    if (current_frame_) {
+      uint32 frame_hash = GetFrameHash(current_frame_.get());
+      new_image_hashes[source.id] = frame_hash;
+
+      // Scale the image only if it has changed.
+      ImageHashesMap::iterator it = image_hashes_.find(source.id);
+      if (it == image_hashes_.end() || it->second != frame_hash) {
+        gfx::ImageSkia thumbnail =
+            ScaleDesktopFrame(current_frame_.Pass(), thumbnail_size);
+        BrowserThread::PostTask(
+            BrowserThread::UI, FROM_HERE,
+            base::Bind(&NativeDesktopMediaList::OnSourceThumbnail,
+                        media_list_, i, thumbnail));
+      }
+    }
+  }
+
+  image_hashes_.swap(new_image_hashes);
+
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&NativeDesktopMediaList::OnRefreshFinished, media_list_));
+}
+
+webrtc::SharedMemory* NativeDesktopMediaList::Worker::CreateSharedMemory(
+    size_t size) {
+  return NULL;
+}
+
+void NativeDesktopMediaList::Worker::OnCaptureCompleted(
+    webrtc::DesktopFrame* frame) {
+  current_frame_.reset(frame);
+}
+
+NativeDesktopMediaList::NativeDesktopMediaList(
+    scoped_ptr<webrtc::ScreenCapturer> screen_capturer,
+    scoped_ptr<webrtc::WindowCapturer> window_capturer)
+    : screen_capturer_(screen_capturer.Pass()),
+      window_capturer_(window_capturer.Pass()),
+      update_period_(base::TimeDelta::FromMilliseconds(kDefaultUpdatePeriod)),
+      thumbnail_size_(100, 100),
+      view_dialog_id_(-1),
+      observer_(NULL),
+      weak_factory_(this) {
+  base::SequencedWorkerPool* worker_pool = BrowserThread::GetBlockingPool();
+  capture_task_runner_ = worker_pool->GetSequencedTaskRunner(
+      worker_pool->GetSequenceToken());
+}
+
+NativeDesktopMediaList::~NativeDesktopMediaList() {
+  capture_task_runner_->DeleteSoon(FROM_HERE, worker_.release());
+}
+
+void NativeDesktopMediaList::SetUpdatePeriod(base::TimeDelta period) {
+  DCHECK(!observer_);
+  update_period_ = period;
+}
+
+void NativeDesktopMediaList::SetThumbnailSize(
+    const gfx::Size& thumbnail_size) {
+  thumbnail_size_ = thumbnail_size;
+}
+
+void NativeDesktopMediaList::SetViewDialogWindowId(
+    content::DesktopMediaID::Id dialog_id) {
+  view_dialog_id_ = dialog_id;
+}
+
+void NativeDesktopMediaList::StartUpdating(DesktopMediaListObserver* observer) {
+  DCHECK(!observer_);
+  DCHECK(screen_capturer_ || window_capturer_);
+
+  observer_ = observer;
+
+  worker_.reset(new Worker(weak_factory_.GetWeakPtr(),
+                           screen_capturer_.Pass(), window_capturer_.Pass()));
+  Refresh();
+}
+
+int NativeDesktopMediaList::GetSourceCount() const {
+  return sources_.size();
+}
+
+const DesktopMediaList::Source& NativeDesktopMediaList::GetSource(
+    int index) const {
+  return sources_[index];
+}
+
+void NativeDesktopMediaList::Refresh() {
+  capture_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&Worker::Refresh, base::Unretained(worker_.get()),
+                            thumbnail_size_, view_dialog_id_));
+}
+
+void NativeDesktopMediaList::OnSourcesList(
+    const std::vector<SourceDescription>& new_sources) {
+  typedef std::set<content::DesktopMediaID> SourceSet;
+  SourceSet new_source_set;
+  for (size_t i = 0; i < new_sources.size(); ++i) {
+    new_source_set.insert(new_sources[i].id);
+  }
+  // Iterate through the old sources to find the removed sources.
+  for (size_t i = 0; i < sources_.size(); ++i) {
+    if (new_source_set.find(sources_[i].id) == new_source_set.end()) {
+      sources_.erase(sources_.begin() + i);
+      observer_->OnSourceRemoved(i);
+      --i;
+    }
+  }
+  // Iterate through the new sources to find the added sources.
+  if (new_sources.size() > sources_.size()) {
+    SourceSet old_source_set;
+    for (size_t i = 0; i < sources_.size(); ++i) {
+      old_source_set.insert(sources_[i].id);
+    }
+
+    for (size_t i = 0; i < new_sources.size(); ++i) {
+      if (old_source_set.find(new_sources[i].id) == old_source_set.end()) {
+        sources_.insert(sources_.begin() + i, Source());
+        sources_[i].id = new_sources[i].id;
+        sources_[i].name = new_sources[i].name;
+        observer_->OnSourceAdded(i);
+      }
+    }
+  }
+  DCHECK_EQ(new_sources.size(), sources_.size());
+
+  // Find the moved/changed sources.
+  size_t pos = 0;
+  while (pos < sources_.size()) {
+    if (!(sources_[pos].id == new_sources[pos].id)) {
+      // Find the source that should be moved to |pos|, starting from |pos + 1|
+      // of |sources_|, because entries before |pos| should have been sorted.
+      size_t old_pos = pos + 1;
+      for (; old_pos < sources_.size(); ++old_pos) {
+        if (sources_[old_pos].id == new_sources[pos].id)
+          break;
+      }
+      DCHECK(sources_[old_pos].id == new_sources[pos].id);
+
+      // Move the source from |old_pos| to |pos|.
+      Source temp = sources_[old_pos];
+      sources_.erase(sources_.begin() + old_pos);
+      sources_.insert(sources_.begin() + pos, temp);
+
+      observer_->OnSourceMoved(old_pos, pos);
+    }
+
+    if (sources_[pos].name != new_sources[pos].name) {
+      sources_[pos].name = new_sources[pos].name;
+      observer_->OnSourceNameChanged(pos);
+    }
+    ++pos;
+  }
+}
+
+void NativeDesktopMediaList::OnSourceThumbnail(
+    int index,
+    const gfx::ImageSkia& image) {
+  DCHECK_LT(index, static_cast<int>(sources_.size()));
+  sources_[index].thumbnail = image;
+  observer_->OnSourceThumbnailChanged(index);
+}
+
+void NativeDesktopMediaList::OnRefreshFinished() {
+  BrowserThread::PostDelayedTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&NativeDesktopMediaList::Refresh,
+                 weak_factory_.GetWeakPtr()),
+      update_period_);
+}

chromium_src/chrome/browser/media/native_desktop_media_list.h

@@ -0,0 +1,100 @@
+// Copyright 2013 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.
+
+#ifndef CHROME_BROWSER_MEDIA_NATIVE_DESKTOP_MEDIA_LIST_H_
+#define CHROME_BROWSER_MEDIA_NATIVE_DESKTOP_MEDIA_LIST_H_
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/sequenced_task_runner.h"
+#include "chrome/browser/media/desktop_media_list.h"
+#include "content/public/browser/desktop_media_id.h"
+#include "ui/gfx/image/image_skia.h"
+
+namespace webrtc {
+class ScreenCapturer;
+class WindowCapturer;
+}
+
+// Implementation of DesktopMediaList that shows native screens and
+// native windows.
+class NativeDesktopMediaList : public DesktopMediaList {
+ public:
+  // Caller may pass NULL for either of the arguments in case when only some
+  // types of sources the model should be populated with (e.g. it will only
+  // contain windows, if |screen_capturer| is NULL).
+  NativeDesktopMediaList(
+      scoped_ptr<webrtc::ScreenCapturer> screen_capturer,
+      scoped_ptr<webrtc::WindowCapturer> window_capturer);
+  ~NativeDesktopMediaList() override;
+
+  // DesktopMediaList interface.
+  void SetUpdatePeriod(base::TimeDelta period) override;
+  void SetThumbnailSize(const gfx::Size& thumbnail_size) override;
+  void StartUpdating(DesktopMediaListObserver* observer) override;
+  int GetSourceCount() const override;
+  const Source& GetSource(int index) const override;
+  void SetViewDialogWindowId(content::DesktopMediaID::Id dialog_id) override;
+
+ private:
+  class Worker;
+  friend class Worker;
+
+  // Struct used to represent sources list the model gets from the Worker.
+  struct SourceDescription {
+    SourceDescription(content::DesktopMediaID id, const base::string16& name);
+
+    content::DesktopMediaID id;
+    base::string16 name;
+  };
+
+  // Order comparator for sources. Used to sort list of sources.
+  static bool CompareSources(const SourceDescription& a,
+                             const SourceDescription& b);
+
+  // Post a task for the |worker_| to update list of windows and get thumbnails.
+  void Refresh();
+
+  // Called by |worker_| to refresh the model. First it posts tasks for
+  // OnSourcesList() with the fresh list of sources, then follows with
+  // OnSourceThumbnail() for each changed thumbnail and then calls
+  // OnRefreshFinished() at the end.
+  void OnSourcesList(const std::vector<SourceDescription>& sources);
+  void OnSourceThumbnail(int index, const gfx::ImageSkia& thumbnail);
+  void OnRefreshFinished();
+
+  // Capturers specified in SetCapturers() and passed to the |worker_| later.
+  scoped_ptr<webrtc::ScreenCapturer> screen_capturer_;
+  scoped_ptr<webrtc::WindowCapturer> window_capturer_;
+
+  // Time interval between mode updates.
+  base::TimeDelta update_period_;
+
+  // Size of thumbnails generated by the model.
+  gfx::Size thumbnail_size_;
+
+  // ID of the hosting dialog.
+  content::DesktopMediaID::Id view_dialog_id_;
+
+  // The observer passed to StartUpdating().
+  DesktopMediaListObserver* observer_;
+
+  // Task runner used for the |worker_|.
+  scoped_refptr<base::SequencedTaskRunner> capture_task_runner_;
+
+  // An object that does all the work of getting list of sources on a background
+  // thread (see |capture_task_runner_|). Destroyed on |capture_task_runner_|
+  // after the model is destroyed.
+  scoped_ptr<Worker> worker_;
+
+  // Current list of sources.
+  std::vector<Source> sources_;
+
+  base::WeakPtrFactory<NativeDesktopMediaList> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(NativeDesktopMediaList);
+};
+
+#endif  // CHROME_BROWSER_MEDIA_NATIVE_DESKTOP_MEDIA_LIST_H_