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..166dd2f91315a5e7fbb6179a8e680e0f92801dfb
--- /dev/null
+++ b/chrome/browser/media/ash_desktop_media_list.cc
@@ -0,0 +1,214 @@
+// 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 "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 "ui/base/l10n/l10n_util.h"
+#include "ui/compositor/dip_util.h"
+#include "ui/gfx/image/image.h"
+#include "ui/snapshot/snapshot.h"
+
+using content::BrowserThread;
+using content::DesktopMediaID;
+
+namespace {
+
+// Update the list twice per second.
+const int kDefaultUpdatePeriod = 500;
+
+}  // namespace
+
+AshDesktopMediaList::SourceDescription::SourceDescription(
+    DesktopMediaID id,
+    const base::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) {
+  gfx::Rect window_rect(window->bounds().width(), window->bounds().height());
+  gfx::Rect scaled_rect = media::ComputeLetterboxRegion(
+      gfx::Rect(thumbnail_size_), window_rect.size());
+
+  ++pending_window_capture_requests_;
+  ui::GrapWindowSnapshotAsync(
+      window, window_rect,
+      scaled_rect.size(),
+      BrowserThread::GetBlockingPool(),
+      base::Bind(&AshDesktopMediaList::OnThumbnailCaptured,
+                 weak_factory_.GetWeakPtr(),
+                 id));
+}
+
+void AshDesktopMediaList::OnThumbnailCaptured(content::DesktopMediaID id,
+                                              const gfx::Image& image) {
+  for (size_t i = 0; i < sources_.size(); ++i) {
+    if (sources_[i].id == id) {
+      sources_[i].thumbnail = image.AsImageSkia();
+      observer_->OnSourceThumbnailChanged(i);
+      break;
+    }
+  }
+
+  --pending_window_capture_requests_;
+  DCHECK_GE(pending_window_capture_requests_, 0);
+
+  if (!pending_window_capture_requests_) {
+    // Once we've finished capturing all windows post a task for the next list
+    // update.
+    BrowserThread::PostDelayedTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&AshDesktopMediaList::Refresh,
+                   weak_factory_.GetWeakPtr()),
+        update_period_);
+  }
+}