android_webview/browser/find_helper.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef ANDROID_WEBVIEW_BROWSER_FIND_HELPER_H_
#define ANDROID_WEBVIEW_BROWSER_FIND_HELPER_H_

#include <string>

#include "base/memory/raw_ptr.h"

namespace content {
class WebContents;
}  // namespace content

namespace android_webview {

// Handles the WebView find-in-page API requests.
// Lifetime: WebView
class FindHelper {
 public:
  class Listener {
   public:
    // Called when receiving a new find-in-page update.
    // This will be triggered when the results of FindAllSync, FindAllAsync and
    // FindNext are available. The value provided in active_ordinal is 0-based.
    virtual void OnFindResultReceived(int active_ordinal,
                                      int match_count,
                                      bool finished) = 0;
    virtual ~Listener() {}
  };

  explicit FindHelper(content::WebContents* web_contents);

  FindHelper(const FindHelper&) = delete;
  FindHelper& operator=(const FindHelper&) = delete;

  ~FindHelper();

  // Sets the listener to receive find result updates.
  // Does not own the listener and must set to nullptr when invalid.
  void SetListener(Listener* listener);

  // Asynchronous API.
  void FindAllAsync(const std::u16string& search_string);
  void HandleFindReply(int request_id,
                       int match_count,
                       int active_ordinal,
                       bool finished);

  // Methods valid in both synchronous and asynchronous modes.
  void FindNext(bool forward);
  void ClearMatches();

 private:
  void StartNewSession(const std::u16string& search_string);
  bool MaybeHandleEmptySearch(const std::u16string& search_string);
  void NotifyResults(int active_ordinal, int match_count, bool finished);

  const raw_ptr<content::WebContents> web_contents_;

  // Listener results are reported to.
  raw_ptr<Listener> listener_ = nullptr;

  // Used to check the validity of FindNext operations.
  bool async_find_started_ = false;

  // Used to provide different IDs to each request and for result
  // verification in asynchronous calls.
  int find_request_id_counter_ = 0;
  int current_request_id_ = 0;

  // Used to mark the beginning of the current find session. This is the ID of
  // the first find request in the current session.
  int current_session_id_ = 0;

  // Required by FindNext and the incremental find replies.
  std::u16string last_search_string_;
  int last_match_count_ = -1;
  int last_active_ordinal_ = -1;
};

}  // namespace android_webview

#endif  // ANDROID_WEBVIEW_BROWSER_FIND_HELPER_H_