resultiterator.h

// File:        resultiterator.h
// Description: Iterator for tesseract results that is capable of
//              iterating in proper reading order over Bi Directional
//              (e.g. mixed Hebrew and English) text.
// Author:      David Eger
// Created:     Fri May 27 13:58:06 PST 2011
//
// (C) Copyright 2011, Google Inc.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

#ifndef TESSERACT_CCMAIN_RESULT_ITERATOR_H_
#define TESSERACT_CCMAIN_RESULT_ITERATOR_H_

#include <set>                  // for std::pair
#include <vector>               // for std::vector
#include "ltrresultiterator.h"  // for LTRResultIterator
#include "platform.h"           // for TESS_API, TESS_LOCAL
#include "publictypes.h"        // for PageIteratorLevel
#include "unichar.h"            // for StrongScriptDirection

template <typename T> class GenericVector;
template <typename T> class GenericVectorEqEq;

class STRING;

namespace tesseract {

class Tesseract;

class TESS_API ResultIterator : public LTRResultIterator {
 public:
  static ResultIterator *StartOfParagraph(const LTRResultIterator &resit);

  virtual ~ResultIterator() = default;

  // ============= Moving around within the page ============.
  virtual void Begin();

  virtual bool Next(PageIteratorLevel level);

  virtual bool IsAtBeginningOf(PageIteratorLevel level) const;

  virtual bool IsAtFinalElement(PageIteratorLevel level,
                                PageIteratorLevel element) const;

  // ============= Functions that refer to words only ============.
  // Returns the number of blanks before the current word.
  int BlanksBeforeWord() const;

  // ============= Accessing data ==============.

  virtual char* GetUTF8Text(PageIteratorLevel level) const;

  virtual std::vector<std::vector<std::pair<const char*, float>>>* GetBestLSTMSymbolChoices() const;

  bool ParagraphIsLtr() const;

  // ============= Exposed only for testing =============.

  static void CalculateTextlineOrder(
      bool paragraph_is_ltr,
      const GenericVector<StrongScriptDirection> &word_dirs,
      GenericVectorEqEq<int> *reading_order);

  static const int kMinorRunStart;
  static const int kMinorRunEnd;
  static const int kComplexWord;

 protected:
  TESS_LOCAL explicit ResultIterator(const LTRResultIterator &resit);

 private:
  bool CurrentParagraphIsLtr() const;

  void CalculateTextlineOrder(bool paragraph_is_ltr,
                              const LTRResultIterator &resit,
                              GenericVectorEqEq<int> *indices) const;
  void CalculateTextlineOrder(bool paragraph_is_ltr,
                              const LTRResultIterator &resit,
                              GenericVector<StrongScriptDirection> *ssd,
                              GenericVectorEqEq<int> *indices) const;

  int LTRWordIndex() const;

  void CalculateBlobOrder(GenericVector<int> *blob_indices) const;

  void MoveToLogicalStartOfTextline();

  void MoveToLogicalStartOfWord();

  bool IsAtFinalSymbolOfWord() const;

  bool IsAtFirstSymbolOfWord() const;

  void AppendSuffixMarks(STRING *text) const;

  void AppendUTF8WordText(STRING *text) const;

  void IterateAndAppendUTF8TextlineText(STRING *text);

  void AppendUTF8ParagraphText(STRING *text) const;

  bool BidiDebug(int min_level) const;

  bool current_paragraph_is_ltr_;

  bool at_beginning_of_minor_run_;

  bool in_minor_direction_;

  bool preserve_interword_spaces_;
};

}  // namespace tesseract.

#endif  // TESSERACT_CCMAIN_RESULT_ITERATOR_H_