Upstream Chrome on iOS source code [4/11].

ios/chrome/browser/ui/contextual_search/contextual_search_delegate.h

+// Copyright 2014 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.
+
+#ifndef IOS_CHROME_BROWSER_UI_CONTEXTUAL_SEARCH_CONTEXTUAL_SEARCH_DELEGATE_H_
+#define IOS_CHROME_BROWSER_UI_CONTEXTUAL_SEARCH_CONTEXTUAL_SEARCH_DELEGATE_H_
+
+#include <memory>
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
+#include "ios/chrome/browser/ui/contextual_search/contextual_search_context.h"
+#include "net/url_request/url_fetcher_delegate.h"
+
+class TemplateURLService;
+
+namespace ios {
+class ChromeBrowserState;
+}
+
+// Handles tasks for the ContextualSearchManager in a separable and testable
+// way, without the complication of being connected to a Java object.
+class ContextualSearchDelegate
+    : public net::URLFetcherDelegate,
+      public base::SupportsWeakPtr<ContextualSearchDelegate> {
+ public:
+  typedef struct {
+    bool is_invalid;
+    int response_code;
+    std::string search_term;
+    std::string display_text;
+    std::string alternate_term;
+    bool prevent_preload;
+    int start_offset;
+    int end_offset;
+  } SearchResolution;
+
+  typedef base::Callback<void(SearchResolution)> SearchTermResolutionCallback;
+
+  // ID used in creating URLFetcher for Contextual Search results.
+  static const int kContextualSearchURLFetcherID;
+
+  // Constructs a delegate for the given user browser state that will always
+  // call back to the given callbacks when search term resolution or surrounding
+  // text responses are available.
+  ContextualSearchDelegate(
+      ios::ChromeBrowserState* browser_state,
+      const SearchTermResolutionCallback& search_term_callback);
+  ~ContextualSearchDelegate() override;
+
+  // Requests the search term using |context| and parameters that specify the
+  // surrounding text. if |context| represents a local text selection, then no
+  // server request is made and the selection contents are returned as the
+  // relevant text.
+  // When the response is available the callback specified in the constructor
+  // is run.
+  // This method is asynchronous and may delay the request to avoid sending
+  // too many requests to the server. If this function is called multiple times
+  // during that delay, only the latest request is executed. Each new call
+  // cancels previous requests.
+  void PostSearchTermRequest(std::shared_ptr<ContextualSearchContext> context);
+
+  // This method will immediately start the pending request previously posted by
+  // |PostSearchTermRequest|.
+  void StartPendingSearchTermRequest();
+
+  // Cancels the current search term network request.
+  void CancelSearchTermRequest();
+
+  // Get the URL for the search to be run for the query in |resolution|.
+  GURL GetURLForResolvedSearch(SearchResolution resolution,
+                               bool should_prefetch);
+
+ private:
+  // net::URLFetcherDelegate:
+  void OnURLFetchComplete(const net::URLFetcher* source) override;
+
+  // Builds the request URL.
+  GURL BuildRequestUrl();
+
+  // Copy search context term as SearchResolution and calls the
+  // search_term_callback_.
+  void RequestLocalSearchTerm();
+
+  // Initiates a network request to get the relevant query context.
+  void RequestServerSearchTerm();
+
+  // Uses the TemplateURL service to construct a search term resolution URL from
+  // the given parameters.
+  std::string GetSearchTermResolutionUrlString(
+      const std::string& selected_text,
+      const std::string& base_page_url,
+      const bool use_resolved_search_term);
+
+  // Populates the discourse context and adds it to the HTTP header of the
+  // search term resolution request.
+  void SetDiscourseContextAndAddToHeader(
+      const ContextualSearchContext& context);
+
+  // The current request in progress, or NULL.
+  std::unique_ptr<net::URLFetcher> search_term_fetcher_;
+
+  // Holds the TemplateURLService. Not owned.
+  TemplateURLService* template_url_service_;
+
+  // The browser state associated with the Contextual Search Manager.
+  // This reference is not owned by us.
+  ios::ChromeBrowserState* browser_state_;
+
+  // The callback for notifications of completed URL fetches.
+  SearchTermResolutionCallback search_term_callback_;
+
+  // Used to hold the context until an upcoming search term request is started.
+  std::shared_ptr<ContextualSearchContext> context_;
+
+  base::Time last_request_startup_time_;
+  bool request_pending_;
+
+  // Used to ensure |StartRequestSearchTerm()| is not run when this object is
+  // destroyed.
+  base::WeakPtrFactory<ContextualSearchDelegate> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ContextualSearchDelegate);
+};
+
+#endif  // IOS_CHROME_BROWSER_UI_CONTEXTUAL_SEARCH_CONTEXTUAL_SEARCH_DELEGATE_H_