This adds in the ability for Chrome to generate windows with snapshots of all...

chrome/browser/chromeos/wm_overview_controller.cc

+// Copyright (c) 2010 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/chromeos/wm_overview_controller.h"
+
+#include <algorithm>
+#include <vector>
+
+#include "base/linked_ptr.h"
+#include "chrome/browser/browser.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/chromeos/wm_ipc.h"
+#include "chrome/browser/chromeos/wm_overview_snapshot.h"
+#include "chrome/browser/renderer_host/render_view_host.h"
+#include "chrome/browser/tab_contents/tab_contents.h"
+#include "chrome/browser/tab_contents/tab_contents_view.h"
+#include "chrome/browser/tab_contents/thumbnail_generator.h"
+#include "chrome/browser/views/frame/browser_extender.h"
+#include "chrome/browser/views/frame/browser_view.h"
+#include "chrome/common/notification_service.h"
+#include "views/widget/root_view.h"
+#include "views/widget/widget_gtk.h"
+#include "views/window/window.h"
+
+using std::vector;
+
+#if !defined(OS_CHROMEOS)
+#error This file is only meant to be compiled for ChromeOS
+#endif
+
+namespace chromeos {
+
+class BrowserListener : public TabStripModelObserver {
+ public:
+  BrowserListener(Browser* browser, WmOverviewController* parent);
+  ~BrowserListener();
+
+  // Begin TabStripModelObserver methods
+  virtual void TabInsertedAt(TabContents* contents,
+                             int index,
+                             bool foreground);
+  virtual void TabClosingAt(TabContents* contents, int index) {}
+  virtual void TabDetachedAt(TabContents* contents, int index);
+  virtual void TabMoved(TabContents* contents,
+                        int from_index,
+                        int to_index);
+  virtual void TabChangedAt(TabContents* contents, int index,
+                            TabStripModelObserver::TabChangeType change_type);
+  virtual void TabStripEmpty();
+  virtual void TabDeselectedAt(TabContents* contents, int index) {}
+  virtual void TabSelectedAt(TabContents* old_contents,
+                             TabContents* new_contents,
+                             int index,
+                             bool user_gesture);
+  // End TabStripModelObserver methods
+
+  // Returns the number of tabs in this child.
+  int count() const { return browser_->tabstrip_model()->count(); }
+
+  // Returns the browser that this child gets its data from.
+  Browser* browser() const { return browser_; }
+
+  // Removes all the snapshots and re-populates them from the browser.
+  void RecreateSnapshots();
+
+  // Updates the selected index and tab count on the toplevel window.
+  void UpdateSelectedIndex(int index);
+
+  // Finds the first cell with no snapshot and invokes ConfigureCell
+  // for it.  Returns false if there are no more cells to configure on
+  // this listener.
+  bool ConfigureNextUnconfiguredSnapshot();
+
+  // Saves the currently selected tab.
+  void SaveCurrentTab() { original_selected_tab_ = browser_->selected_index(); }
+
+  // Reverts the selected browser tab to the tab that was selected
+  // when This BrowserListener was created, or the last time
+  // SaveCurrentTab was called.
+  void RestoreOriginalSelectedTab();
+
+  // Selects the tab at the given index.
+  void SelectTab(int index);
+
+  // Shows any snapshots that are not visible, and updates their
+  // bitmaps.
+  void ShowSnapshots();
+
+ private:
+  // Returns the tab contents from the tab model for this child at index.
+  TabContents* GetTabContentsAt(int index) const  {
+    return browser_->tabstrip_model()->GetTabContentsAt(index);
+  }
+
+  // Configures a cell from the tab contents.
+  void ConfigureCell(WmOverviewSnapshot* cell, TabContents* contents);
+
+  // Configures a cell from the model.
+  void ConfigureCell(WmOverviewSnapshot* cell, int index) {
+    ConfigureCell(cell, GetTabContentsAt(index));
+  }
+
+  // Inserts a new snapshot, initialized from the model, at the given
+  // index, and renumbers any following snapshots.
+  void InsertSnapshot(int index);
+
+  // Removes the snapshot at index.
+  void ClearSnapshot(int index);
+
+  // Renumbers the index atom in the snapshots starting at the given
+  // index.
+  void RenumberSnapshots(int start_index);
+
+  Browser* browser_;  // Not owned
+  WmOverviewController* controller_;  // Not owned
+
+  // Widgets containing snapshot images for this browser.
+  typedef std::vector<WmOverviewSnapshot* > SnapshotVector;
+  SnapshotVector snapshots_;
+
+  // True if the snapshots are showing.
+  bool snapshots_showing_;
+
+  // The tab selected the last time SaveCurrentTab is called.
+  int original_selected_tab_;
+
+  DISALLOW_COPY_AND_ASSIGN(BrowserListener);
+};
+
+BrowserListener::BrowserListener(Browser* browser,
+                                 WmOverviewController* controller)
+    : browser_(browser),
+      controller_(controller),
+      snapshots_showing_(false),
+      original_selected_tab_(-1) {
+  CHECK(browser_);
+  CHECK(controller_);
+  browser_->tabstrip_model()->AddObserver(this);
+}
+
+BrowserListener::~BrowserListener() {
+  browser_->tabstrip_model()->RemoveObserver(this);
+}
+
+void BrowserListener::TabInsertedAt(TabContents* contents,
+                                    int index,
+                                    bool foreground) {
+  InsertSnapshot(index);
+  RenumberSnapshots(index);
+  UpdateSelectedIndex(browser_->selected_index());
+}
+
+void BrowserListener::TabDetachedAt(TabContents* contents, int index) {
+  ClearSnapshot(index);
+  UpdateSelectedIndex(browser_->selected_index());
+  RenumberSnapshots(index);
+}
+
+void BrowserListener::TabMoved(TabContents* contents,
+                               int from_index,
+                               int to_index) {
+  // Need to reorder tab in the snapshots list, and reset the window
+  // type atom on the affected snapshots (the one moved, and all the
+  // ones after it), so that their indices are correct.
+  WmOverviewSnapshot* snapshot = snapshots_[from_index];
+  snapshots_.erase(snapshots_.begin() + from_index);
+  snapshots_.insert(snapshots_.begin() + to_index, snapshot);
+
+  RenumberSnapshots(std::min(to_index, from_index));
+}
+
+void BrowserListener::TabChangedAt(
+    TabContents* contents,
+    int index,
+    TabStripModelObserver::TabChangeType change_type) {
+  snapshots_[index]->reload_snapshot();
+  controller_->StartDelayTimer();
+}
+
+void BrowserListener::TabStripEmpty() {
+  snapshots_.clear();
+}
+
+void BrowserListener::TabSelectedAt(TabContents* old_contents,
+                                    TabContents* new_contents,
+                                    int index,
+                                    bool user_gesture) {
+  UpdateSelectedIndex(index);
+}
+
+void BrowserListener::RecreateSnapshots() {
+  snapshots_.clear();
+
+  for (int i = 0; i < count(); ++i) {
+    InsertSnapshot(i);
+  }
+
+  RenumberSnapshots(0);
+}
+
+void BrowserListener::UpdateSelectedIndex(int index) {
+  // Get the window params and check to make sure that they are
+  // different from what we know before we set them, to avoid extra
+  // notifications.
+  std::vector<int> params;
+  WmIpc::WindowType type = WmIpc::instance()->GetWindowType(
+      GTK_WIDGET(browser_->window()->GetNativeHandle()),
+      &params);
+  DCHECK(type == WmIpc::WINDOW_TYPE_CHROME_TOPLEVEL);
+  if (params.size() > 1) {
+    if (params[0] == browser_->tab_count() &&
+        params[0] == index)
+      return;
+  }
+
+  params.clear();
+  params.push_back(browser_->tab_count());
+  params.push_back(index);
+  WmIpc::instance()->SetWindowType(
+      GTK_WIDGET(browser_->window()->GetNativeHandle()),
+      WmIpc::WINDOW_TYPE_CHROME_TOPLEVEL,
+      &params);
+}
+
+bool BrowserListener::ConfigureNextUnconfiguredSnapshot() {
+  for (SnapshotVector::size_type i = 0; i < snapshots_.size(); ++i) {
+    WmOverviewSnapshot* cell = snapshots_[i];
+    if (!cell->configured_snapshot()) {
+      ConfigureCell(cell, GetTabContentsAt(i));
+      return true;
+    }
+  }
+  return false;
+}
+
+void BrowserListener::RestoreOriginalSelectedTab() {
+  if (original_selected_tab_ >= 0) {
+    browser_->SelectTabContentsAt(original_selected_tab_, false);
+  }
+}
+
+void BrowserListener::ShowSnapshots() {
+  for (SnapshotVector::size_type i = 0; i < snapshots_.size(); ++i) {
+    WmOverviewSnapshot* snapshot = snapshots_[i];
+    snapshot->reload_snapshot();
+    if (!snapshot->IsVisible()) {
+      snapshot->Show();
+    }
+  }
+}
+
+void BrowserListener::SelectTab(int index) {
+  browser_->SelectTabContentsAt(index, true);
+}
+
+void BrowserListener::ConfigureCell(WmOverviewSnapshot* cell,
+                                    TabContents* contents) {
+  if (contents) {
+    if (controller_->allow_show_snapshots()) {
+      ThumbnailGenerator* generator =
+          g_browser_process->GetThumbnailGenerator();
+      // TODO: Make sure that if the cell gets deleted before the
+      // callback is called that it sticks around until it gets
+      // called.  (some kind of "in flight" list that uses linked_ptr
+      // to make sure they don't actually get deleted?)  Also, make
+      // sure that any request for a thumbnail eventually returns
+      // (even if it has bogus data), so we don't leak orphaned cells.
+      ThumbnailGenerator::ThumbnailReadyCallback* callback =
+          NewCallback(cell, &WmOverviewSnapshot::SetImage);
+      generator->AskForThumbnail(contents->render_view_host(),
+                                 callback, cell->size());
+    }
+  } else {
+    // This happens because the contents haven't been loaded yet.
+
+    // Make sure we set the snapshot image to something, otherwise
+    // configured_snapshot remains false and ConfigureNextUnconfiguredSnapshot
+    // would get stuck.
+    if (controller_->allow_show_snapshots()) {
+      cell->SetImage(SkBitmap());
+    }
+  }
+}
+
+void BrowserListener::InsertSnapshot(int index) {
+  WmOverviewSnapshot* snapshot = new WmOverviewSnapshot;
+  gfx::Rect bounds =
+      static_cast<BrowserView*>(browser_->window())->GetClientAreaBounds();
+  gfx::Size size(bounds.width()/2, bounds.height()/2);
+  snapshot->Init(size, browser_, index);
+  snapshots_.insert(snapshots_.begin() + index, snapshot);
+  snapshot->reload_snapshot();
+  controller_->StartDelayTimer();
+}
+
+// Removes the snapshot at index.
+void BrowserListener::ClearSnapshot(int index) {
+  snapshots_[index]->CloseNow();
+  snapshots_.erase(snapshots_.begin() + index);
+}
+
+void BrowserListener::RenumberSnapshots(int start_index) {
+  int changes = 0;
+  for (SnapshotVector::size_type i = start_index; i < snapshots_.size(); ++i) {
+    if (snapshots_[i]->index() != static_cast<int>(i)) {
+      snapshots_[i]->UpdateIndex(browser_, i);
+      changes++;
+    }
+  }
+}
+
+///////////////////////////////////
+// WmOverviewController methods
+
+// static
+WmOverviewController* WmOverviewController::instance() {
+  static WmOverviewController* instance = NULL;
+  if (!instance) {
+    instance = Singleton<WmOverviewController>::get();
+  }
+  return instance;
+}
+
+WmOverviewController::WmOverviewController()
+    : allow_show_snapshots_(false) {
+  AddAllBrowsers();
+  BrowserList::AddObserver(this);
+  WmMessageListener::instance()->AddObserver(this);
+}
+
+WmOverviewController::~WmOverviewController() {
+  WmMessageListener::instance()->RemoveObserver(this);
+  BrowserList::RemoveObserver(this);
+  listeners_.clear();
+}
+
+void WmOverviewController::Observe(NotificationType type,
+                                   const NotificationSource& source,
+                                   const NotificationDetails& details) {
+  // Now that the browser window is ready, we create the snapshots.
+  if (type == NotificationType::BROWSER_WINDOW_READY) {
+    const Browser* browser = Source<const Browser>(source).ptr();
+    BrowserListenerVector::value_type new_listener(
+        new BrowserListener(const_cast<Browser*>(browser), this));
+    listeners_.push_back(new_listener);
+    new_listener->RecreateSnapshots();
+
+    // This makes sure that the new listener is in the right order (to
+    // match the order in the browser list).
+    AddAllBrowsers();
+  }
+}
+
+// Called immediately before a browser is removed from the list.
+void WmOverviewController::OnBrowserRemoving(const Browser* browser) {
+  for (BrowserListenerVector::iterator i = listeners_.begin();
+       i != listeners_.end(); ++i) {
+    if ((*i)->browser() == browser) {
+      listeners_.erase(i);
+      return;
+    }
+  }
+}
+
+BrowserView* GetBrowserViewForGdkWindow(GdkWindow* gdk_window) {
+  gpointer data = NULL;
+  gdk_window_get_user_data(gdk_window, &data);
+  GtkWidget* widget = reinterpret_cast<GtkWidget*>(data);
+  if (widget) {
+    GtkWindow* gtk_window = GTK_WINDOW(widget);
+    return BrowserView::GetBrowserViewForNativeWindow(gtk_window);
+  } else {
+    return NULL;
+  }
+}
+
+void WmOverviewController::ProcessWmMessage(const WmIpc::Message& message,
+                                            GdkWindow* window) {
+  switch (message.type()) {
+    case WmIpc::Message::CHROME_NOTIFY_LAYOUT_MODE: {
+      if (message.param(0) == 0 || BrowserList::size() == 0) {
+        Hide(message.param(1) != 0);
+      } else {
+        Show();
+      }
+      break;
+    }
+    case WmIpc::Message::CHROME_NOTIFY_TAB_SELECT: {
+      BrowserView* browser_window = GetBrowserViewForGdkWindow(window);
+      // Find out which listener this goes to, and send it there.
+      for (BrowserListenerVector::iterator i = listeners_.begin();
+           i != listeners_.end(); ++i) {
+        if ((*i)->browser()->window() == browser_window) {
+          (*i)->SelectTab(message.param(0));
+          break;
+        }
+      }
+      break;
+    }
+    default:
+      break;
+  }
+}
+
+void WmOverviewController::StartDelayTimer() {
+  // We leave the delay timer running if it already is -- this means
+  // we're rate limiting the number of times we can reconfigure the
+  // snapshots (at most once every 350ms).  If we were to restart the
+  // delay timer, it could result in a very long delay until they get
+  // configured if tabs keep changing.
+  if (!delay_timer_.IsRunning()) {
+    configure_timer_.Stop();
+    // Note that this pause is kind of a hack: it's just long enough
+    // that the overview-mode transitions will have finished happening
+    // before we start refreshing snapshots, so we don't bog the CPU
+    // while it's trying to animate the overview transitions.
+    delay_timer_.Start(
+        base::TimeDelta::FromMilliseconds(350), this,
+        &WmOverviewController::StartConfiguring);
+  }
+}
+
+void WmOverviewController::RestoreTabSelections() {
+  for (BrowserListenerVector::iterator i = listeners_.begin();
+       i != listeners_.end(); ++i) {
+    (*i)->RestoreOriginalSelectedTab();
+  }
+}
+
+void WmOverviewController::SaveTabSelections() {
+  for (BrowserListenerVector::iterator i = listeners_.begin();
+       i != listeners_.end(); ++i) {
+    (*i)->SaveCurrentTab();
+  }
+}
+
+void WmOverviewController::Show() {
+  SaveTabSelections();
+  for (BrowserListenerVector::iterator i = listeners_.begin();
+       i != listeners_.end(); ++i) {
+    (*i)->ShowSnapshots();
+  }
+  allow_show_snapshots_ = false;
+  StartDelayTimer();
+}
+
+void WmOverviewController::Hide(bool cancelled) {
+  configure_timer_.Stop();
+  delay_timer_.Stop();
+  if (cancelled) {
+    RestoreTabSelections();
+  }
+}
+
+void WmOverviewController::StartConfiguring() {
+  allow_show_snapshots_ = true;
+  configure_timer_.Stop();
+  configure_timer_.Start(
+      base::TimeDelta::FromMilliseconds(10), this,
+      &WmOverviewController::ConfigureNextUnconfiguredSnapshot);
+}
+
+// Just configure one unconfigured cell.  If there aren't any left,
+// then stop the timer.
+void WmOverviewController::ConfigureNextUnconfiguredSnapshot() {
+  for (BrowserListenerVector::size_type i = 0; i < listeners_.size(); ++i) {
+    BrowserListener* listener = listeners_[i].get();
+    if (listener->ConfigureNextUnconfiguredSnapshot())
+      return;
+  }
+  configure_timer_.Stop();
+}
+
+void WmOverviewController::AddAllBrowsers() {
+  // Make a copy so the old ones aren't deleted yet.
+  BrowserListenerVector old_listeners;
+
+  listeners_.swap(old_listeners);
+
+  // Iterator through the browser list, adding all the browsers in the
+  // new order.  If they were in the old list of listeners, just copy
+  // that linked pointer, instead of making a new listener, so that we
+  // can avoid lots of spurious destroy/create messages.
+  BrowserList::const_iterator iterator = BrowserList::begin();
+  while (iterator != BrowserList::end()) {
+    BrowserListenerVector::value_type item(
+        BrowserListenerVector::value_type(NULL));
+    for (BrowserListenerVector::iterator old_iter = old_listeners.begin();
+         old_iter != old_listeners.end(); ++old_iter) {
+      if ((*old_iter)->browser() == *iterator) {
+        item = *old_iter;
+        break;
+      }
+    }
+
+    // This browser isn't owned by any listener, so create it.
+    if (item.get() == NULL) {
+      item = BrowserListenerVector::value_type(
+          new BrowserListener(*iterator, this));
+
+      // This browser didn't already exist, and so we haven't been
+      // watching it for tab insertions, so we need to create the
+      // snapshots associated with it.
+      item->RecreateSnapshots();
+    }
+    listeners_.push_back(item);
+    ++iterator;
+  }
+
+  // Make sure we get notifications for when browser windows are ready.
+  if (registrar_.IsEmpty())
+    registrar_.Add(this, NotificationType::BROWSER_WINDOW_READY,
+                   NotificationService::AllSources());
+}
+
+}  // namespace chromeos