File indexing completed on 2024-04-14 03:56:07

 /*
     This file is part of the KDE project
     SPDX-FileCopyrightText: 2001 S.R. Haque <srhaque@iee.org>.
     SPDX-FileCopyrightText: 2002 David Faure <david@mandrakesoft.com>
 
     SPDX-License-Identifier: LGPL-2.0-only
 */
 
 #ifndef KFIND_H
 #define KFIND_H
 
 #include "ktextwidgets_export.h"
 
 #include <QObject>
 #include <memory>
 
 class QDialog;
 class KFindPrivate;
 
 /**
  * @class KFind kfind.h <KFind>
  *
  * @brief A generic implementation of the "find" function.
  *
  * @author S.R.Haque <srhaque@iee.org>, David Faure <faure@kde.org>,
  *         Arend van Beelen jr. <arend@auton.nl>
  *
  * \b Detail:
  *
  * This class includes prompt handling etc. Also provides some
  * static functions which can be used to create custom behavior
  * instead of using the class directly.
  *
  * \b Example:
  *
  * To use the class to implement a complete find feature:
  *
  * In the slot connected to the find action, after using KFindDialog:
  * \code
  *
  *  // This creates a find-next-prompt dialog if needed.
  *  m_find = new KFind(pattern, options, this);
  *
  *  // Connect textFound() signal to code which handles highlighting of found text.
  *  connect(m_find, &KFind::textFound, this, [this](const QString &text, int matchingIndex, int matchedLength) {
  *      slotHighlight(text, matchingIndex, matchedLength);
  *  }));
  *  // Connect findNext signal - called when pressing the button in the dialog
  *  connect(m_find, SIGNAL(findNext()),
  *          this, SLOT(slotFindNext()));
  * \endcode
  *
  *  Then initialize the variables determining the "current position"
  *  (to the cursor, if the option FromCursor is set,
  *   to the beginning of the selection if the option SelectedText is set,
  *   and to the beginning of the document otherwise).
  *  Initialize the "end of search" variables as well (end of doc or end of selection).
  *  Swap begin and end if FindBackwards.
  *  Finally, call slotFindNext();
  *
  * \code
  *  void slotFindNext()
  *  {
  *      KFind::Result res = KFind::NoMatch;
  *      while (res == KFind::NoMatch && <position not at end>) {
  *          if (m_find->needData())
  *              m_find->setData(<current text fragment>);
  *
  *          // Let KFind inspect the text fragment, and display a dialog if a match is found
  *          res = m_find->find();
  *
  *          if (res == KFind::NoMatch) {
  *              <Move to the next text fragment, honoring the FindBackwards setting for the direction>
  *          }
  *      }
  *
  *      if (res == KFind::NoMatch) // i.e. at end
  *          <Call either  m_find->displayFinalDialog(); m_find->deleteLater(); m_find = nullptr;
  *           or           if (m_find->shouldRestart()) { reinit (w/o FromCursor); m_find->resetCounts(); slotFindNext(); }
  *                        else { m_find->closeFindNextDialog(); }>
  *  }
  * \endcode
  *
  *  Don't forget to delete m_find in the destructor of your class,
  *  unless you gave it a parent widget on construction.
  *
  *  This implementation allows to have a "Find Next" action, which resumes the
  *  search, even if the user closed the "Find Next" dialog.
  *
  *  A "Find Previous" action can simply switch temporarily the value of
  *  FindBackwards and call slotFindNext() - and reset the value afterwards.
  */
 class KTEXTWIDGETS_EXPORT KFind : public QObject
 {
     Q_OBJECT
 
 public:
     /**
      * @see SearchOptions
      */
     enum Options {
         WholeWordsOnly = 1, ///< Match whole words only.
         FromCursor = 2, ///< Start from current cursor position.
         SelectedText = 4, ///< Only search selected area.
         CaseSensitive = 8, ///< Consider case when matching.
         FindBackwards = 16, ///< Go backwards.
         RegularExpression = 32, ///< Interpret the pattern as a regular expression.
         FindIncremental = 64, ///< Find incremental.
         // Note that KReplaceDialog uses 256 and 512
         // User extensions can use boolean options above this value.
         MinimumUserOption = 65536, ///< user options start with this bit
     };
     /**
      * Stores a combination of #Options values.
      */
     Q_DECLARE_FLAGS(SearchOptions, Options)
 
     /**
      * Only use this constructor if you don't use KFindDialog, or if
      * you use it as a modal dialog.
      */
     KFind(const QString &pattern, long options, QWidget *parent);
 
     /**
      * This is the recommended constructor if you also use KFindDialog (non-modal).
      * You should pass the pointer to it here, so that when a message box
      * appears it has the right parent. Don't worry about deletion, KFind
      * will notice if the find dialog is closed.
      */
     KFind(const QString &pattern, long options, QWidget *parent, QWidget *findDialog);
     ~KFind() override;
 
     enum Result {
         NoMatch,
         Match,
     };
 
     /**
      * @return true if the application must supply a new text fragment
      * It also means the last call returned "NoMatch". But by storing this here
      * the application doesn't have to store it in a member variable (between
      * calls to slotFindNext()).
      */
     bool needData() const;
 
     /**
      * Call this when needData returns true, before calling find().
      * @param data the text fragment (line)
      * @param startPos if set, the index at which the search should start.
      * This is only necessary for the very first call to setData usually,
      * for the 'find in selection' feature. A value of -1 (the default value)
      * means "process all the data", i.e. either 0 or data.length()-1 depending
      * on FindBackwards.
      */
     void setData(const QString &data, int startPos = -1);
 
     /**
      * Call this when needData returns true, before calling find(). The use of
      * ID's is especially useful if you're using the FindIncremental option.
      * @param id the id of the text fragment
      * @param data the text fragment (line)
      * @param startPos if set, the index at which the search should start.
      * This is only necessary for the very first call to setData usually,
      * for the 'find in selection' feature. A value of -1 (the default value)
      * means "process all the data", i.e. either 0 or data.length()-1 depending
      * on FindBackwards.
      */
     void setData(int id, const QString &data, int startPos = -1);
 
     /**
      * Walk the text fragment (e.g. in a text-processor line or spreadsheet
      * cell ...etc) looking for matches.
      * For each match, emits the textFound() signal and displays the find-again
      * dialog to ask if the user wants to find the same text again.
      */
     Result find();
 
     /**
      * Return the current options.
      *
      * Warning: this is usually the same value as the one passed to the constructor,
      * but options might change _during_ the replace operation:
      * e.g. the "All" button resets the PromptOnReplace flag.
      *
      * @see KFind::Options
      */
     long options() const;
 
     /**
      * Set new options. Usually this is used for setting or clearing the
      * FindBackwards options.
      *
      * @see KFind::Options
      */
     virtual void setOptions(long options);
 
     /**
      * @return the pattern we're currently looking for
      */
     QString pattern() const;
 
     /**
      * Change the pattern we're looking for
      */
     void setPattern(const QString &pattern);
 
     /**
      * Returns the number of matches found (i.e. the number of times the textFound()
      * signal was emitted).
      * If 0, can be used in a dialog box to tell the user "no match was found".
      * The final dialog does so already, unless you used setDisplayFinalDialog(false).
      */
     int numMatches() const;
 
     /**
      * Call this to reset the numMatches count
      * (and the numReplacements count for a KReplace).
      * Can be useful if reusing the same KReplace for different operations,
      * or when restarting from the beginning of the document.
      */
     virtual void resetCounts();
 
     /**
      * Virtual method, which allows applications to add extra checks for
      * validating a candidate match. It's only necessary to reimplement this
      * if the find dialog extension has been used to provide additional
      * criteria.
      *
      * @param text  The current text fragment
      * @param index The starting index where the candidate match was found
      * @param matchedlength The length of the candidate match
      */
     virtual bool validateMatch(const QString &text, int index, int matchedlength);
 
     /**
      * Returns true if we should restart the search from scratch.
      * Can ask the user, or return false (if we already searched the whole document).
      *
      * @param forceAsking set to true if the user modified the document during the
      * search. In that case it makes sense to restart the search again.
      *
      * @param showNumMatches set to true if the dialog should show the number of
      * matches. Set to false if the application provides a "find previous" action,
      * in which case the match count will be erroneous when hitting the end,
      * and we could even be hitting the beginning of the document (so not all
      * matches have even been seen).
      */
     virtual bool shouldRestart(bool forceAsking = false, bool showNumMatches = true) const;
 
     /**
      * Search @p text for @p pattern. If a match is found, the length of the matched
      * string will be stored in @p matchedLength and the index of the matched string
      * will be returned. If no match is found -1 is returned.
      *
      * If the KFind::RegularExpression flag is set, the @p pattern will be iterpreted
      * as a regular expression (using QRegularExpression).
      *
      * @note Unicode support is always enabled (by setting the QRegularExpression::UseUnicodePropertiesOption flag).
      *
      * @param text The string to search in
      * @param pattern The pattern to search for
      * @param index  The index in @p text from which to start the search
      * @param options The options to use
      * @param matchedlength If there is a match, its length will be stored in this parameter
      * @param rmatch If there is a regular expression match (implies that the KFind::RegularExpression
      *               flag is set) and @p rmatch is not a nullptr the match result will be stored
      *               in this QRegularExpressionMatch object
      * @return The index at which a match was found otherwise -1
      *
      * @since 5.70
      */
     static int find(const QString &text, const QString &pattern, int index, long options, int *matchedLength, QRegularExpressionMatch *rmatch);
 
     /**
      * Displays the final dialog saying "no match was found", if that was the case.
      * Call either this or shouldRestart().
      */
     virtual void displayFinalDialog() const;
 
     /**
      * Return (or create) the dialog that shows the "find next?" prompt.
      * Usually you don't need to call this.
      * One case where it can be useful, is when the user selects the "Find"
      * menu item while a find operation is under way. In that case, the
      * program may want to call setActiveWindow() on that dialog.
      */
     QDialog *findNextDialog(bool create = false);
 
     /**
      * Close the "find next?" dialog. The application should do this when
      * the last match was hit. If the application deletes the KFind, then
      * "find previous" won't be possible anymore.
      *
      * IMPORTANT: you should also call this if you are using a non-modal
      * find dialog, to tell KFind not to pop up its own dialog.
      */
     void closeFindNextDialog();
 
     /**
      * @return the current matching index (or -1).
      * Same as the matchingIndex parameter passed to the textFound() signal.
      * You usually don't need to use this, except maybe when updating the current data,
      * so you need to call setData(newData, index()).
      */
     int index() const;
 
 Q_SIGNALS:
     /**
      * Connect to this signal to implement highlighting of found text during the find
      * operation.
      *
      * If you've set data with setData(id, text), use the textFoundAtId(int, int, int) signal.
      *
      * WARNING: If you're using the FindIncremental option, the text argument
      * passed by this signal is not necessarily the data last set through
      * setData(), but can also be an earlier set data block.
      *
      * @see setData()
      *
      * @since 5.81
      */
     void textFound(const QString &text, int matchingIndex, int matchedLength);
 
     /**
      * Connect to this signal to implement highlighting of found text during
      * the find operation.
      *
      * Use this signal if you've set your data with setData(id, text),
      * otherwise use the textFound(text, matchingIndex, matchedLength) signal.
      *
      * WARNING: If you're using the FindIncremental option, the id argument
      * passed by this signal is not necessarily the id of the data last set
      * through setData(), but can also be of an earlier set data block.
      *
      * @see setData()
      *
      * @since 5.81
      */
     void textFoundAtId(int id, int matchingIndex, int matchedLength);
 
     // ## TODO docu
     // findprevious will also emit findNext, after temporarily switching the value
     // of FindBackwards
     void findNext();
 
     /**
      * Emitted when the options have changed.
      * This can happen e.g. with "Replace All", or if our 'find next' dialog
      * gets a "find previous" one day.
      */
     void optionsChanged();
 
     /**
      * Emitted when the 'find next' dialog is being closed.
      * Some apps might want to remove the highlighted text when this happens.
      * Apps without support for "Find Next" can also do m_find->deleteLater()
      * to terminate the find operation.
      */
     void dialogClosed();
 
 protected:
     QWidget *parentWidget() const;
     QWidget *dialogsParent() const;
 
 protected:
     KTEXTWIDGETS_NO_EXPORT KFind(KFindPrivate &dd, const QString &pattern, long options, QWidget *parent);
     KTEXTWIDGETS_NO_EXPORT KFind(KFindPrivate &dd, const QString &pattern, long options, QWidget *parent, QWidget *findDialog);
 
 protected:
     std::unique_ptr<class KFindPrivate> const d_ptr;
 
 private:
     Q_DECLARE_PRIVATE(KFind)
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(KFind::SearchOptions)
 
 #endif