Add "Open with <ARC-app-name>" items to the context menu

chrome/browser/renderer_context_menu/arc_app_menu_observer_chromeos.cc

Index: chrome/browser/renderer_context_menu/arc_app_menu_observer_chromeos.cc
diff --git a/chrome/browser/renderer_context_menu/arc_app_menu_observer_chromeos.cc b/chrome/browser/renderer_context_menu/arc_app_menu_observer_chromeos.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ebfa63bef0afaa15a342953322b5467a28bf38ea
--- /dev/null
+++ b/chrome/browser/renderer_context_menu/arc_app_menu_observer_chromeos.cc
@@ -0,0 +1,288 @@
+// Copyright 2016 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/renderer_context_menu/arc_app_menu_observer_chromeos.h"
+
+#include <algorithm>
+
+#include "base/bind.h"
+#include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "chrome/app/chrome_command_ids.h"
+#include "chrome/browser/renderer_context_menu/render_view_context_menu.h"
+#include "chrome/grit/generated_resources.h"
+#include "components/arc/arc_bridge_service.h"
+#include "content/public/common/context_menu_params.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/base/models/simple_menu_model.h"
+
+namespace {
+
+const size_t kMaxArcAppsInMainMenu =
+    IDC_CONTENT_CONTEXT_ARC_APP_LAST - IDC_CONTENT_CONTEXT_ARC_APP1 + 1;
+const size_t kMaxArcAppsInSubMenu =
+    IDC_CONTENT_CONTEXT_ARC_SUB_APP_LAST - IDC_CONTENT_CONTEXT_ARC_SUB_APP1 + 1;
+
+const int kMinInstanceVersion = 2;  // see intent_helper.mojom
+
+std::set<int> GetAllCommandIds() {
+  std::set<int> ids;
+
+  for (size_t i = 0; i < kMaxArcAppsInMainMenu; ++i) {
+    ids.insert(IDC_CONTENT_CONTEXT_ARC_APP1 + i);
+  }
+  ids.insert(IDC_CONTENT_CONTEXT_ARC_SUB_MENU);
+  for (size_t i = 0; i < kMaxArcAppsInSubMenu; ++i) {
+    ids.insert(IDC_CONTENT_CONTEXT_ARC_SUB_APP1 + i);
+  }
+
+  return ids;
+}
+
+// Returns a set of command IDs to enable when the total number of ARC apps to
+// show in the main and sub menus is |num_apps|.
+std::set<int> GetCommandIdsToEnable(size_t num_apps) {
+  std::set<int> ids;
+
+  if (num_apps <= kMaxArcAppsInMainMenu) {
+    // When |num_apps| fits in the main menu, do not enable
+    // IDC_CONTENT_CONTEXT_ARC_SUB_MENU and IDC_CONTENT_CONTEXT_ARC_SUB_APP*.
+    for (size_t i = 0; i < num_apps; ++i) {
+      ids.insert(IDC_CONTENT_CONTEXT_ARC_APP1 + i);
+    }
+  } else {
+    // When |num_apps| does not fit in the main menu, enable
+    // IDC_CONTENT_CONTEXT_ARC_SUB_MENU and some of
+    // IDC_CONTENT_CONTEXT_ARC_SUB_APP* IDs. In this case, do NOT enable
+    // IDC_CONTENT_CONTEXT_ARC_APP_LAST, hence the '-1'.
+    for (size_t i = 0; i < kMaxArcAppsInMainMenu - 1; ++i) {
+      ids.insert(IDC_CONTENT_CONTEXT_ARC_APP1 + i);
+    }
+
+    ids.insert(IDC_CONTENT_CONTEXT_ARC_SUB_MENU);
+    size_t sub_items = std::min(num_apps - (kMaxArcAppsInMainMenu - 1),
+                                kMaxArcAppsInSubMenu);
+    for (size_t i = 0; i < sub_items; ++i) {
+      ids.insert(IDC_CONTENT_CONTEXT_ARC_SUB_APP1 + i);
+    }
+  }
+
+  return ids;
+}
+
+// The same as GetCommandIdsToEnable except that the function returns a set of
+// IDs to disable.
+std::set<int> GetCommandIdsToDisable(size_t num_apps,
+                                     const std::set<int>& all_ids) {
+  std::set<int> ids;
+  std::set<int> enabled(GetCommandIdsToEnable(num_apps));
+  std::set_difference(all_ids.begin(), all_ids.end(), enabled.begin(),
+                      enabled.end(), std::inserter(ids, ids.begin()));
+  return ids;
+}
+
+int GetIndexForCommandId(int command_id) {
+  int index = -1;
+  if (command_id >= IDC_CONTENT_CONTEXT_ARC_APP1 &&
+      command_id <= IDC_CONTENT_CONTEXT_ARC_APP_LAST) {
+    index = command_id - IDC_CONTENT_CONTEXT_ARC_APP1;
+  } else if (command_id >= IDC_CONTENT_CONTEXT_ARC_SUB_APP1 &&
+             command_id <= IDC_CONTENT_CONTEXT_ARC_SUB_APP_LAST) {
+    const int offset = kMaxArcAppsInMainMenu - 1;
+    index = command_id - IDC_CONTENT_CONTEXT_ARC_SUB_APP1 + offset;
+  }
+  return index;
+}
+
+class SubMenuDelegate : public ui::SimpleMenuModel::Delegate {
+ public:
+  explicit SubMenuDelegate(ArcAppMenuObserver* parent_menu)
+      : parent_menu_(parent_menu) {}
+  ~SubMenuDelegate() override {}
+
+  // ui::SimpleMenuModel::Delegate overrides:
+  bool IsCommandIdChecked(int command_id) const override { return false; }
+  bool IsCommandIdEnabled(int command_id) const override { return true; }
+  bool GetAcceleratorForCommandId(int command_id,
+                                  ui::Accelerator* accelerator) override {
+    return false;
+  }
+  void ExecuteCommand(int command_id, int event_flags) override {
+    parent_menu_->ExecuteCommand(command_id);
+  }
+
+ private:
+  ArcAppMenuObserver* parent_menu_;
+
+  DISALLOW_COPY_AND_ASSIGN(SubMenuDelegate);
+};
+
+}  // namespace
+
+ArcAppMenuObserver::ArcAppMenuObserver(RenderViewContextMenuProxy* proxy)
+    : proxy_(proxy),
+      all_command_ids_(GetAllCommandIds()),
+      sub_menu_(new SubMenuDelegate(this)),
+      loading_frame_(0),
+      weak_ptr_factory_(this) {}
+
+ArcAppMenuObserver::~ArcAppMenuObserver() {}
+
+arc::IntentHelperInstance* ArcAppMenuObserver::GetIntentHelper() {
+  arc::ArcBridgeService* bridge = arc::ArcBridgeService::Get();
+  if (!bridge) {
+    DLOG(WARNING) << "ARC bridge is not ready.";
+    return nullptr;
+  }
+  arc::IntentHelperInstance* intent_helper_instance =
+      bridge->intent_helper_instance();
+  if (!intent_helper_instance) {
+    DLOG(WARNING) << "ARC intent helper instance is not ready.";
+    return nullptr;
+  }
+  if (bridge->intent_helper_version() < kMinInstanceVersion) {
+    DLOG(WARNING) << "ARC intent helper instance is too old.";
+    return nullptr;
+  }
+  return intent_helper_instance;
+}
+
+void ArcAppMenuObserver::InitMenu(const content::ContextMenuParams& params) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  arc::IntentHelperInstance* intent_helper_instance = GetIntentHelper();
+  if (!intent_helper_instance) {
+    return;
+  }
+
+  if (params.link_url.is_empty()) {
+    return;
+  }
+  link_url_ = params.link_url;
+
+  loading_message_ =
+      l10n_util::GetStringUTF16(IDS_CONTENT_CONTEXT_LOADING_ARC_APP_NAMES);
+
+  // Add placeholder items.
+  for (size_t i = 0; i < kMaxArcAppsInMainMenu; ++i) {
+    proxy_->AddMenuItem(IDC_CONTENT_CONTEXT_ARC_APP1 + i,
+                        loading_message_);
+  }
+  // Add a placeholder sub menu.
+  proxy_->AddSubMenu(IDC_CONTENT_CONTEXT_ARC_SUB_MENU, loading_message_,
+                     &sub_menu_);
+  // Add placeholder sub items.
+  for (size_t i = 0; i < kMaxArcAppsInSubMenu; ++i) {
+    sub_menu_.AddItem(IDC_CONTENT_CONTEXT_ARC_SUB_APP1 + i,
+                      loading_message_);
+  }
+
+  // Check if ARC apps can handle the |link_url_|. Sicne the information is

[hidehiko, 2016/03/07 14:40:07]

nit: s/Sicne/Since/

[Yusuke Sato, 2016/03/07 22:25:16]

Done.

+  // held in a different (ARC) process, issue a mojo IPC request. Usually, the
+  // callback function, OnUrlHandlerList, is called within a few milliseconds
+  // even on a slowest Chromebook we support.
+  intent_helper_instance->RequestUrlHandlerList(
+      link_url_.spec(), base::Bind(&ArcAppMenuObserver::OnUrlHandlerList,
+                                   weak_ptr_factory_.GetWeakPtr()));
+
+  // Start the animation just in case. Since the IPC above almost always returns
+  // within a few milliseconds, the user will unlikely see the anination.
+  animation_timer_.Start(FROM_HERE, base::TimeDelta::FromSeconds(1),
+                         this, &ArcAppMenuObserver::OnAnimationTimerExpired);
+}
+
+bool ArcAppMenuObserver::IsCommandIdSupported(int command_id) {
+  return all_command_ids_.count(command_id);
+}
+
+bool ArcAppMenuObserver::IsCommandIdChecked(int command_id) {
+  return false;
+}
+
+bool ArcAppMenuObserver::IsCommandIdEnabled(int command_id) {
+  // Items will be enabled later in OnUrlHandlerList() as needed.
+  return false;
+}
+
+void ArcAppMenuObserver::ExecuteCommand(int command_id) {
+  arc::IntentHelperInstance* intent_helper_instance = GetIntentHelper();
+  if (!intent_helper_instance) {
+    return;
+  }
+
+  const size_t index = GetIndexForCommandId(command_id);
+  if (index < handlers_.size()) {
+    intent_helper_instance->HandleUrl(link_url_.spec(),
+                                      handlers_[index]->package_name);
+  }
+}
+
+void ArcAppMenuObserver::OnMenuCancel() {}
+
+std::set<int> ArcAppMenuObserver::GetCommandIdsToEnableForTesting(
+    size_t num_apps) {
+  return GetCommandIdsToEnable(num_apps);
+}
+
+std::set<int> ArcAppMenuObserver::GetCommandIdsToDisableForTesting(
+    size_t num_apps) {
+  return GetCommandIdsToDisable(num_apps, GetAllCommandIds());
+}
+
+int ArcAppMenuObserver::GetIndexForCommandIdForTesting(int command_id) {
+  return GetIndexForCommandId(command_id);
+}
+
+base::string16 ArcAppMenuObserver::GetLabelForCommandId(int command_id) const {
+  if (command_id == IDC_CONTENT_CONTEXT_ARC_SUB_MENU)
+    return l10n_util::GetStringUTF16(IDS_CONTENT_CONTEXT_MORE_ARC_APPS);
+
+  const size_t index = GetIndexForCommandId(command_id);

[hidehiko, 2016/03/07 14:40:07]

nit: GetIndexForCommandId can return a negative value on error. So, accepting by
size_t somehow looks a bit confusing. Maybe comment?

[Yusuke Sato, 2016/03/07 22:25:16]

Done.

+  if (index < handlers_.size()) {
+    return l10n_util::GetStringFUTF16(
+        IDS_CONTENT_CONTEXT_OPEN_WITH_ARC_APP,
+        base::UTF8ToUTF16(handlers_[index]->name.get()));
+  }
+  return base::EmptyString16();
+}
+
+void ArcAppMenuObserver::OnUrlHandlerList(
+    mojo::Array<arc::UrlHandlerInfoPtr> handlers) {
+  animation_timer_.Stop();
+  handlers_ = std::move(handlers);

[hidehiko, 2016/03/07 14:40:07]

nit: I'm ok with the current code, but how about having a map from CommandId to
UrlHandlerInfoPtr?
Then, the map would release you from index management? It's totally up to you.

[Yusuke Sato, 2016/03/07 22:25:16]

That allows us to remove GetIndexForCommandId() as you said, but then I think we
need to provide a way to map i (from 0 to handlers.size()) to command id to
convert the mojo array to the map. We could use |enabled| to convert i to
command id assuming that IDC_CONTENT_CONTEXT_ARC_* are properly sorted in
chrome_command_ids.h and |enabled| is an ordered set, but the assumptions
(especially the former) seem to make the code a bit harder to read IMO. So let
me continue to use the current way.

[hidehiko, 2016/03/14 12:07:05]

FYI: what I imagined was;

unordered_map<int /* command id */, UrlHandlerInfoPtr> command_map;

max_main_commands = min(num_main_commands - 1, handlers.size());
for (i = 0; i < max_main_commands; ++i) {
  command_map[main_start_command + i] = std::move(handlers[i]);
}
for (i = max_main_commands; i < handlers.size(); ++i) {
  command_map[IDS_..._ARC_APP1 + i - max_main_commands] =
std::move(handlers[i]);
}

// Update main menu items.
for (i = main_start_command; i < main_start_command + num_main_commands - 1;
++i) {
  if (command_map.find(i) != command_map.end()) {
    proxy_->UpdateMenuItem(i, true, false, GetLabelForCommandId(command_id)); 
// enable
  } else {
    proxy_->UpdateMenuItem(i, false, true, EmptyString16());  // disable
  }
}

// Update "more"
if (num_main_commands <= handlers.size()) {
  proxy_->UpdateMenuItem(...) // enable.
} else {
  proxy_->UpdateMenuItem(...) // disable.
}

// Update sub menu items.
for (i = IDC_..._ARC_APP1; i < IDC_..._ARC_APP_LAST; ++i) {
  if (command_map.find(i) != command_map.end()) {
    proxy_->UpdateMenuItem(i, true, false, GetLabelForCommandId(command_id)); 
// enable
  } else {
    proxy_->UpdateMenuItem(i, false, true, EmptyString16());  // disable
  }
}

or something. So that, we can encapsulate indexing work only in this method.
Probably, I'd extract "building a map" part into a function, for testing
convenience.

[Yusuke Sato, 2016/03/15 00:00:13]

Ah okay, I guess I misunderstood your comment. Thanks for the clarification,
this works. Done.

+
+  const size_t num_apps = handlers_.size();
+  std::set<int> disabled(GetCommandIdsToDisable(num_apps, all_command_ids_));
+  for (const auto& command_id : disabled) {
+    proxy_->UpdateMenuItem(command_id,
+                           false,  // enabled
+                           true,   // hidden
+                           base::EmptyString16());
+  }
+
+  std::set<int> enabled(GetCommandIdsToEnable(num_apps));
+  for (const auto& command_id : enabled) {
+    // TODO(yusukes): Show icon of the app.
+    proxy_->UpdateMenuItem(command_id,
+                           true,   // enabled
+                           false,  // hidden
+                           GetLabelForCommandId(command_id));
+  }
+}
+
+void ArcAppMenuObserver::OnAnimationTimerExpired() {
+  // Append '.' characters to the end of "Checking".
+  loading_frame_ = (loading_frame_ + 1) & 3;
+  base::string16 loading_message =
+      loading_message_ + base::string16(loading_frame_, '.');
+
+  // Update the menu item with the text. We disable this item to prevent users
+  // from selecting it.
+  for (const auto& command_id : all_command_ids_) {
+    proxy_->UpdateMenuItem(command_id,
+                           false,  // enabled
+                           false,  // hidden
+                           loading_message);
+  }
+}