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

components/arc/intent_helper/open_with_menu_observer.cc

Index: components/arc/intent_helper/open_with_menu_observer.cc
diff --git a/components/arc/intent_helper/open_with_menu_observer.cc b/components/arc/intent_helper/open_with_menu_observer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4905baf6aae5207860c1fbd264e0c2e8fe92e20c
--- /dev/null
+++ b/components/arc/intent_helper/open_with_menu_observer.cc
@@ -0,0 +1,274 @@
+// 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 "components/arc/intent_helper/open_with_menu_observer.h"
+
+#include <algorithm>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "components/arc/arc_bridge_service.h"
+#include "components/renderer_context_menu/render_view_context_menu_proxy.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/common/context_menu_params.h"
+#include "grit/components_strings.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/base/models/simple_menu_model.h"
+
+namespace arc {
+
+namespace {
+
+const int kInvalidCommandId = -1;
+const int kMinInstanceVersion = 2;  // see intent_helper.mojom
+
+// Converts |handlers| into HandlerMap which is a map from a command ID to a
+// UrlHandlerInfoPtr and returns the map. Also returns a command id for the
+// parent of the sub menu. When the sub menu is not needed, the function
+// returns |kInvalidCommandId|.
+std::pair<OpenWithMenuObserver::HandlerMap, int> BuildHandlersMap(
+    int menu_id_start,
+    size_t num_menu_items,
+    int sub_menu_id_start,
+    size_t num_sub_menu_items,
+    mojo::Array<UrlHandlerInfoPtr> handlers) {
+  // We assume |num_menu_items| is always >=3.
+  DCHECK_GE(num_menu_items, 3U);
+
+  OpenWithMenuObserver::HandlerMap handler_map;
+  int sub_menu_parent_command_id = kInvalidCommandId;
+
+  const size_t num_apps = handlers.size();
+  size_t handlers_index = 0;
+  // We use the last item in the main menu (menu_id_start + num_menu_items - 1)
+  // as a parent of a sub menu, and others as regular menu items.
+  if (num_apps < num_menu_items) {
+    // All apps can be shown with the regular main menu items.
+    for (size_t i = 0; i < num_apps; ++i) {
+      handler_map[menu_id_start + i] = std::move(handlers[handlers_index++]);
+    }
+  } else {
+    // Otherwise, use the sub menu too. In this case, disable the last item of
+    // the regular main menu (hence '-2').
+    for (size_t i = 0; i < num_menu_items - 2; ++i) {
+      handler_map[menu_id_start + i] = std::move(handlers[handlers_index++]);
+    }
+    sub_menu_parent_command_id = menu_id_start + num_menu_items - 1;
+    const size_t sub_items =
+        std::min(num_apps - (num_menu_items - 2), num_sub_menu_items);
+    for (size_t i = 0; i < sub_items; ++i) {
+      handler_map[sub_menu_id_start + i] =
+          std::move(handlers[handlers_index++]);
+    }
+  }
+
+  return std::make_pair(std::move(handler_map), sub_menu_parent_command_id);
+}
+
+class SubMenuDelegate : public ui::SimpleMenuModel::Delegate {
+ public:
+  explicit SubMenuDelegate(OpenWithMenuObserver* 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:
+  OpenWithMenuObserver* const parent_menu_;
+
+  DISALLOW_COPY_AND_ASSIGN(SubMenuDelegate);
+};
+
+}  // namespace
+
+OpenWithMenuObserver::OpenWithMenuObserver(ArcBridgeService* bridge_service,
+                                           RenderViewContextMenuProxy* proxy,
+                                           int main_menu_id_start,
+                                           size_t num_main_menu_items,
+                                           int sub_menu_id_start,
+                                           size_t num_sub_menu_items)
+    : bridge_service_(bridge_service),
+      proxy_(proxy),
+      main_menu_id_start_(main_menu_id_start),
+      num_main_menu_items_(num_main_menu_items),
+      sub_menu_id_start_(sub_menu_id_start),
+      num_sub_menu_items_(num_sub_menu_items),
+      sub_menu_(new SubMenuDelegate(this)),
+      loading_frame_(0),
+      weak_ptr_factory_(this) {
+  DCHECK(bridge_service_);
+}
+
+OpenWithMenuObserver::~OpenWithMenuObserver() {}
+
+void OpenWithMenuObserver::InitMenu(const content::ContextMenuParams& params) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  link_url_ = params.link_url;
+  if (link_url_.is_empty() || !link_url_.is_valid())
+    return;
+
+  IntentHelperInstance* intent_helper_instance = GetIntentHelper();
+  if (!intent_helper_instance || num_main_menu_items_ < 3)
+    return;
+
+  loading_message_ =
+      l10n_util::GetStringUTF16(IDS_CONTENT_CONTEXT_LOADING_APP_NAMES);
+
+  // Add placeholder items.
+  for (size_t i = 0; i < num_main_menu_items_; ++i) {
+    const int id = main_menu_id_start_ + i;
+    if (i == (num_main_menu_items_ - 1))
+      proxy_->AddSubMenu(id, loading_message_, &sub_menu_);
+    else
+      proxy_->AddMenuItem(id, loading_message_);
+    all_command_ids_.insert(id);
+  }
+
+  // Add placeholder sub items.
+  for (size_t i = 0; i < num_sub_menu_items_; ++i) {
+    const int id = sub_menu_id_start_ + i;
+    sub_menu_.AddItem(id, loading_message_);
+    all_command_ids_.insert(id);
+  }
+
+  // Check if ARC apps can handle the |link_url_|. Since the information is
+  // 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(&OpenWithMenuObserver::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,
+                         &OpenWithMenuObserver::OnAnimationTimerExpired);
+}
+
+bool OpenWithMenuObserver::IsCommandIdSupported(int command_id) {
+  return all_command_ids_.count(command_id);
+}
+
+bool OpenWithMenuObserver::IsCommandIdChecked(int command_id) {
+  return false;
+}
+
+bool OpenWithMenuObserver::IsCommandIdEnabled(int command_id) {
+  return false;
+}
+
+void OpenWithMenuObserver::OnMenuCancel() {}
+
+IntentHelperInstance* OpenWithMenuObserver::GetIntentHelper() {
+  if (!bridge_service_) {
+    DLOG(WARNING) << "ARC bridge is not ready.";
+    return nullptr;
+  }
+  IntentHelperInstance* intent_helper_instance =
+      bridge_service_->intent_helper_instance();
+  if (!intent_helper_instance) {
+    DLOG(WARNING) << "ARC intent helper instance is not ready.";
+    return nullptr;
+  }
+  if (bridge_service_->intent_helper_version() < kMinInstanceVersion) {
+    DLOG(WARNING) << "ARC intent helper instance is too old.";
+    return nullptr;
+  }
+  return intent_helper_instance;
+}
+
+void OpenWithMenuObserver::ExecuteCommand(int command_id) {
+  IntentHelperInstance* intent_helper_instance = GetIntentHelper();
+  if (!intent_helper_instance)
+    return;
+
+  const auto iter = handlers_.find(command_id);
+  if (iter != handlers_.end()) {
+    intent_helper_instance->HandleUrl(link_url_.spec(),
+                                      iter->second->package_name);
+  }
+}
+
+std::pair<OpenWithMenuObserver::HandlerMap, int>
+OpenWithMenuObserver::BuildHandlersMapForTesting(
+    int menu_id_start,
+    size_t num_menu_items,
+    int sub_menu_id_start,
+    size_t num_sub_menu_items,
+    mojo::Array<UrlHandlerInfoPtr> handlers) {
+  return BuildHandlersMap(menu_id_start, num_menu_items, sub_menu_id_start,
+                          num_sub_menu_items, std::move(handlers));
+}
+
+base::string16 OpenWithMenuObserver::GetLabelForCommandId(
+    int command_id) const {
+  if (static_cast<size_t>(command_id) ==
+      (main_menu_id_start_ + num_main_menu_items_ - 1)) {
+    return l10n_util::GetStringUTF16(IDS_CONTENT_CONTEXT_MORE_APPS);
+  }
+
+  const auto iter = handlers_.find(command_id);
+  if (iter != handlers_.end()) {
+    return l10n_util::GetStringFUTF16(
+        IDS_CONTENT_CONTEXT_OPEN_WITH_APP,
+        base::UTF8ToUTF16(iter->second->name.get()));
+  }
+  return base::EmptyString16();
+}
+
+void OpenWithMenuObserver::OnUrlHandlerList(
+    mojo::Array<UrlHandlerInfoPtr> handlers) {
+  animation_timer_.Stop();
+
+  auto result = BuildHandlersMap(main_menu_id_start_, num_main_menu_items_,
+                                 sub_menu_id_start_, num_sub_menu_items_,
+                                 std::move(handlers));
+  handlers_ = std::move(result.first);
+  int sub_menu_parent = result.second;
+
+  for (const auto& command_id : all_command_ids_) {
+    if (command_id == sub_menu_parent || handlers_.count(command_id)) {
+      // TODO(yusukes): Show icon of the app.
+      proxy_->UpdateMenuItem(command_id,
+                             true,   // enabled
+                             false,  // hidden
+                             GetLabelForCommandId(command_id));
+    } else {
+      proxy_->UpdateMenuItem(command_id,
+                             false,  // enabled
+                             true,   // hidden
+                             base::EmptyString16());
+    }
+  }
+}
+
+void OpenWithMenuObserver::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);
+  }
+}
+
+}  // namespace arc