Desktop chrome tab capture-chooseDesktopMedia()

chrome/browser/media/desktop_media_list_ash.cc

 // 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/desktop_media_list_ash.h"
 
 #include <stddef.h>
 
 #include <set>
 
 #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 "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/media/desktop_media_list_observer.h"
+#include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/browser/ui/browser_finder.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/grit/generated_resources.h"
+#include "components/favicon/content/content_favicon_driver.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_process_host.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 {
@@ skipping 134 matching lines @@
         content::DesktopMediaID::TYPE_WINDOW, *it);
     if (id.aura_id == view_dialog_id_.aura_id)
       continue;
     SourceDescription window_source(id, (*it)->title());
     sources->push_back(window_source);
 
     CaptureThumbnail(window_source.id, *it);
   }
 }
 
+void DesktopMediaListAsh::EnumerateTabs(
+    std::vector<DesktopMediaListAsh::SourceDescription>* sources) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  std::map<base::TimeTicks, SourceDescription> tab_map;
+
+  // Get all tabs/webcontents' ids for a user profile

[Avi (use Gerrit), 2016/01/08 17:11:38]

Full sentences; end it with a period.

[GeorgeZ, 2016/01/08 19:39:02]

Done.

+  Profile* profile = ProfileManager::GetLastUsedProfileAllowedByPolicy();
+  std::vector<Browser*> browsers = FindAllTabbedBrowsersWithProfile(
+      profile, chrome::HOST_DESKTOP_TYPE_NATIVE);
+
+  std::vector<scoped_ptr<MediaListWebContentsObserver>> observers;
+  for (auto browser : browsers) {
+    TabStripModel* tab_strip_model = browser->tab_strip_model();
+    DCHECK(tab_strip_model);
+
+    for (int i = 0; i < tab_strip_model->count(); i++) {
+      content::WebContents* contents = tab_strip_model->GetWebContentsAt(i);
+      // Use observer to keep track the state of WebContents.
+      scoped_ptr<MediaListWebContentsObserver> observer(
+          new MediaListWebContentsObserver(contents));
+      observers.push_back(std::move(observer));
+    }
+  }
+
+  // For each tab, get its title and favicon.
+  for (size_t i = 0; i < observers.size(); i++) {
+    // If the WebContents has been destroyed, a nullptr will return;

[Avi (use Gerrit), 2016/01/08 17:11:38]

How could the WebContents have been destroyed from the time you grabbed it ten
lines up, and now? We're on the UI thread, and WebContents creation and
destruction happens on that thread.

It's completely OK to walk the TabStripModel, get all the WebContents, and do
stuff with them. There's no danger of them disappearing on you, so don't worry
:)

Remove the MediaListWebContentsObserver class and all of this paranoid code.
It's not needed.

[GeorgeZ, 2016/01/08 19:39:02]

Thanks for the explanation here.

Done.

+    content::WebContents* contents = observers[i]->web_contents();
+    if (contents == nullptr)
+      continue;
+
+    content::RenderFrameHost* const main_frame = contents->GetMainFrame();
+    DCHECK(main_frame);
+    DesktopMediaID media_id(
+        DesktopMediaID::TYPE_TAB, DesktopMediaID::kNullId,
+        content::WebContentsMediaCaptureId(main_frame->GetProcess()->GetID(),
+                                           main_frame->GetRoutingID()));
+
+    // Create display tab title.
+    base::string16 title = l10n_util::GetStringFUTF16(
+        IDS_DESKTOP_MEDIA_PICKER_CHROME_TAB_TITLE, contents->GetTitle());
+
+    // Get tab's last active time stamp.
+    base::TimeTicks t = contents->GetLastActiveTime();
+    tab_map.insert(std::make_pair(t, SourceDescription(media_id, title)));
+
+    // Create thumbnail based on favicon for tab.
+    favicon::FaviconDriver* favicon_driver =
+        favicon::ContentFaviconDriver::FromWebContents(contents);
+    if (favicon_driver) {
+      gfx::Image tab_icon = favicon_driver->GetFavicon();
+      tab_map[t].thumbnail =
+          CreateEnlargedFaviconImage(thumbnail_size_, tab_icon);
+    }
+  }
+
+  // Add timely sorted tab sources into vector. Most recent one first.
+  for (auto it = tab_map.rbegin(); it != tab_map.rend(); ++it) {
+    SourceDescription& source = it->second;
+    sources->push_back(source);
+    if (!it->second.thumbnail.isNull())
+      OnThumbnailCaptured(source.id, gfx::Image(source.thumbnail));
+  }
+}
+
 void DesktopMediaListAsh::EnumerateSources(
     std::vector<DesktopMediaListAsh::SourceDescription>* sources) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   aura::Window::Windows root_windows = ash::Shell::GetAllRootWindows();
 
   for (size_t i = 0; i < root_windows.size(); ++i) {
     if (source_types_ & SCREENS) {
       SourceDescription screen_source(
           content::DesktopMediaID::RegisterAuraWindow(
@@ skipping 20 matching lines @@
     }
 
     if (source_types_ & WINDOWS) {
       EnumerateWindowsForRoot(
           sources, root_windows[i], ash::kShellWindowId_DefaultContainer);
       EnumerateWindowsForRoot(
           sources, root_windows[i], ash::kShellWindowId_AlwaysOnTopContainer);
       EnumerateWindowsForRoot(
           sources, root_windows[i], ash::kShellWindowId_DockedContainer);
     }
+
+    if (source_types_ & TABS)
+      EnumerateTabs(sources);
   }
 }
 
 void DesktopMediaListAsh::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_;
@@ skipping 23 matching lines @@
   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(&DesktopMediaListAsh::Refresh,
                    weak_factory_.GetWeakPtr()),
         update_period_);
   }
 }