Add AshDesktopMediaList and enable Desktop Capture API on Chrome OS.

chrome/browser/media/ash_desktop_media_list.cc

Index: chrome/browser/media/ash_desktop_media_list.cc
diff --git a/chrome/browser/media/ash_desktop_media_list.cc b/chrome/browser/media/ash_desktop_media_list.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3e932b0cc9554ce670d74a63dd0ed36f995be73b
--- /dev/null
+++ b/chrome/browser/media/ash_desktop_media_list.cc
@@ -0,0 +1,269 @@
+// 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/ash_desktop_media_list.h"
+
+#include <map>
+
+#include "ash/shell.h"
+#include "ash/shell_window_ids.h"
+#include "base/hash.h"
+#include "base/logging.h"
+#include "base/strings/utf_string_conversions.h"
+#include "cc/output/copy_output_request.h"
+#include "cc/output/copy_output_result.h"
+#include "chrome/browser/media/desktop_media_list_observer.h"
+#include "content/public/browser/browser_thread.h"
+#include "grit/generated_resources.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/skia/include/core/SkBitmap.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/compositor/dip_util.h"
+#include "ui/gfx/skia_util.h"
+
+using content::BrowserThread;
+using content::DesktopMediaID;
+
+namespace {
+
+// Update the list twice per second.
+const int kDefaultUpdatePeriod = 500;
+
+void ScaleBitmap(SkBitmap* captured_bitmap, SkBitmap* scaled_bitmap) {
+  libyuv::ARGBScale(reinterpret_cast<uint8*>(captured_bitmap->getPixels()),
+                    captured_bitmap->rowBytes(),
+                    captured_bitmap->width(), captured_bitmap->height(),
+                    reinterpret_cast<uint8*>(scaled_bitmap->getPixels()),
+                    scaled_bitmap->rowBytes(),
+                    scaled_bitmap->width(), scaled_bitmap->height(),
+                    libyuv::kFilterBilinear);

[hshi1, 2013/12/13 01:28:51]

I am not familiar enough with libyuv and skia but it seems strange to use libyuv
to scale SkBitmaps. Shouldn't there be a skia routine to scale SkBitmaps? 

[Sergey Ulanov, 2013/12/13 02:54:29]

Done. I used libyuv for scaling here because that's what we use in
content::DesktopCaptureDevice (if I remember correctly we use it there because
it's provides better quality/performance tradeoff, also DesktopCaptureDevice
doesn't use skia). I agree that skia is more appropriate here. It also makes
code cleaner.

+}
+
+}  // namespace
+
+AshDesktopMediaList::SourceDescription::SourceDescription(
+    DesktopMediaID id,
+    const string16& name)
+    : id(id),
+      name(name) {
+}
+
+AshDesktopMediaList::AshDesktopMediaList(int source_types)
+    : source_types_(source_types),
+      update_period_(base::TimeDelta::FromMilliseconds(kDefaultUpdatePeriod)),
+      thumbnail_size_(100, 100),
+      view_dialog_id_(-1),
+      observer_(NULL),
+      pending_window_capture_requests_(0),
+      weak_factory_(this) {
+}
+
+AshDesktopMediaList::~AshDesktopMediaList() {}
+
+void AshDesktopMediaList::SetUpdatePeriod(base::TimeDelta period) {
+  DCHECK(!observer_);
+  update_period_ = period;
+}
+
+void AshDesktopMediaList::SetThumbnailSize(
+    const gfx::Size& thumbnail_size) {
+  thumbnail_size_ = thumbnail_size;
+}
+
+void AshDesktopMediaList::SetViewDialogWindowId(
+    content::DesktopMediaID::Id dialog_id) {
+  view_dialog_id_ = dialog_id;
+}
+
+void AshDesktopMediaList::StartUpdating(DesktopMediaListObserver* observer) {
+  DCHECK(!observer_);
+
+  observer_ = observer;
+  Refresh();
+}
+
+int AshDesktopMediaList::GetSourceCount() const {
+  return sources_.size();
+}
+
+const DesktopMediaList::Source& AshDesktopMediaList::GetSource(
+    int index) const {
+  return sources_[index];
+}
+
+// static
+bool AshDesktopMediaList::CompareSources(const SourceDescription& a,
+                                         const SourceDescription& b) {
+  return a.id < b.id;
+}
+
+void AshDesktopMediaList::Refresh() {
+  std::vector<SourceDescription> new_sources;
+  EnumerateSources(&new_sources);
+
+  // Sort the list of sources so that they appear in a predictable order.
+  std::sort(new_sources.begin(), new_sources.end(), CompareSources);
+
+  // Step through |new_sources| adding and removing entries from |sources_|, and
+  // notifying the |observer_|, until two match. Requires that |sources| and
+  // |sources_| have the same ordering.
+  size_t pos = 0;
+  while (pos < sources_.size() || pos < new_sources.size()) {
+    // If |sources_[pos]| is not in |new_sources| then remove it.
+    if (pos < sources_.size() &&
+        (pos == new_sources.size() || sources_[pos].id < new_sources[pos].id)) {
+      sources_.erase(sources_.begin() + pos);
+      observer_->OnSourceRemoved(pos);
+      continue;
+    }
+
+    if (pos == sources_.size() || !(sources_[pos].id == new_sources[pos].id)) {
+      sources_.insert(sources_.begin() + pos, Source());
+      sources_[pos].id = new_sources[pos].id;
+      sources_[pos].name = new_sources[pos].name;
+      observer_->OnSourceAdded(pos);
+    } else if (sources_[pos].name != new_sources[pos].name) {
+      sources_[pos].name = new_sources[pos].name;
+      observer_->OnSourceNameChanged(pos);
+    }
+
+    ++pos;
+  }
+
+  DCHECK_EQ(new_sources.size(), sources_.size());
+}
+
+void AshDesktopMediaList::EnumerateWindowsForRoot(
+    std::vector<AshDesktopMediaList::SourceDescription>* sources,
+    aura::Window* root_window,
+    int container_id) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+
+  aura::Window* container = ash::Shell::GetContainer(root_window, container_id);
+  if (!container)
+    return;
+  for (aura::Window::Windows::const_iterator it = container->children().begin();
+       it != container->children().end(); ++it) {
+    if (!(*it)->IsVisible() || !(*it)->CanFocus())
+      continue;
+    content::DesktopMediaID id =
+        content::DesktopMediaID::RegisterAuraWindow(*it);
+    if (id.id == view_dialog_id_)
+      continue;
+    SourceDescription window_source(id, (*it)->title());
+    sources->push_back(window_source);
+
+    CaptureThumbnail(window_source.id, *it);
+  }
+}
+
+void AshDesktopMediaList::EnumerateSources(
+    std::vector<AshDesktopMediaList::SourceDescription>* sources) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+
+  aura::Window::Windows root_windows = ash::Shell::GetAllRootWindows();
+
+  for (aura::Window::Windows::const_iterator iter = root_windows.begin();
+       iter != root_windows.end(); ++iter) {
+    if (source_types_ & SCREENS) {
+      SourceDescription screen_source(
+          content::DesktopMediaID::RegisterAuraWindow(*iter), (*iter)->title());
+      sources->push_back(screen_source);
+
+      CaptureThumbnail(screen_source.id, *iter);
+    }
+
+    if (source_types_ & WINDOWS) {
+      EnumerateWindowsForRoot(
+          sources, *iter, ash::internal::kShellWindowId_DefaultContainer);
+      EnumerateWindowsForRoot(
+          sources, *iter, ash::internal::kShellWindowId_AlwaysOnTopContainer);
+      EnumerateWindowsForRoot(
+          sources, *iter, ash::internal::kShellWindowId_DockedContainer);
+    }
+  }
+}
+
+void AshDesktopMediaList::CaptureThumbnail(content::DesktopMediaID id,
+                                           aura::Window* window) {
+  scoped_ptr<cc::CopyOutputRequest> request =
+      cc::CopyOutputRequest::CreateBitmapRequest(
+          base::Bind(&AshDesktopMediaList::OnThumbnailCaptured,
+                     weak_factory_.GetWeakPtr(), id));
+  gfx::Rect window_rect = ui::ConvertRectToPixel(
+      window->layer(),
+      gfx::Rect(window->bounds().width(), window->bounds().height()));
+  request->set_area(window_rect);
+  window->layer()->RequestCopyOfOutput(request.Pass());
+  ++pending_window_capture_requests_;
+}
+
+void AshDesktopMediaList::OnThumbnailCaptured(
+    content::DesktopMediaID id,
+    scoped_ptr<cc::CopyOutputResult> result) {
+  if (result->IsEmpty()) {
+    OnFrameCaptureFinished();
+    return;
+  }
+
+  scoped_ptr<SkBitmap> captured_bitmap = result->TakeBitmap();
+
+  gfx::Rect scaled_rect = media::ComputeLetterboxRegion(
+      gfx::Rect(thumbnail_size_),
+      gfx::Size(result->size().width(), result->size().height()));
+
+  scoped_ptr<SkBitmap> scaled_bitmap(new SkBitmap);
+  scaled_bitmap->setConfig(SkBitmap::kARGB_8888_Config,
+                           scaled_rect.width(), scaled_rect.height(),
+                           0, kOpaque_SkAlphaType);
+  scaled_bitmap->allocPixels();
+
+  scaled_bitmap->lockPixels();
+  captured_bitmap->lockPixels();
+
+  // TODO(sergeyu): Potentially images can be scaled on GPU before reading it
+  // from GPU. Image scaling is implemented in content::GlHelper, but it's can't
+  // be used here because it's not in content/public. Move the scaling code
+  // somewhere so that it can be reused here.
+  BrowserThread::PostBlockingPoolTaskAndReply(
+      FROM_HERE,
+      base::Bind(&ScaleBitmap, captured_bitmap.get(), scaled_bitmap.get()),
+      base::Bind(&AshDesktopMediaList::OnFrameScalingFinished,
+                 weak_factory_.GetWeakPtr(), id,
+                 base::Passed(&captured_bitmap),
+                 base::Passed(&scaled_bitmap)));
+}
+
+void AshDesktopMediaList::OnFrameScalingFinished(
+    content::DesktopMediaID id,
+    scoped_ptr<SkBitmap> captured_bitmap,
+    scoped_ptr<SkBitmap> scaled_bitmap) {
+  scaled_bitmap->unlockPixels();
+  captured_bitmap->unlockPixels();
+
+  for (size_t i = 0; i < sources_.size(); ++i) {
+    if (sources_[i].id == id) {
+      sources_[i].thumbnail =
+          gfx::ImageSkia::CreateFrom1xBitmap(*scaled_bitmap);
+      observer_->OnSourceThumbnailChanged(i);
+      break;
+    }
+  }
+
+  OnFrameCaptureFinished();
+}
+
+void AshDesktopMediaList::OnFrameCaptureFinished() {
+  --pending_window_capture_requests_;
+  DCHECK_GE(pending_window_capture_requests_, 0);
+  if (!pending_window_capture_requests_) {
+    BrowserThread::PostDelayedTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&AshDesktopMediaList::Refresh,
+                   weak_factory_.GetWeakPtr()),
+        update_period_);
+  }
+}