# class KFind

###

Module | kdeui
Namespace |
Class | KFind
Inherits | QObject

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>

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.

Example:

To use the class to implement a complete find feature:

In the slot connected to the find action, after using KFindDialog:

    // This creates a find-next-prompt dialog if needed.
    m_find = new KFind(pattern, options, this);

    // Connect highlight signal to code which handles highlighting
    // of found text.
    connect( m_find, SIGNAL( highlight( const QString &, int, int ) ),
    this, SLOT( slotHighlight( const QString &, int, int ) ) );
    // Connect findNext signal - called when pressing the button in the dialog
    connect( m_find, SIGNAL( findNext() ),
    this, SLOT( slotFindNext() ) );

If you are using a non-modal find dialog (the recommended new way in KDE-3.2), you should call right away m_find->closeFindNextDialog().

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();

    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(); delete m_find; m_find = 0;
    or if ( m_find->shouldRestart() ) { reinit (w/o FromCursor) and call slotFindNext(); }
    else { m_find->closeFindNextDialog(); }>
    }

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.

### enums

- Options { WholeWordsOnly, FromCursor, SelectedText, CaseSensitive, FindBackwards, RegularExpression, FindIncremental, MinimumUserOption }
- Result { NoMatch, Match }

enum details

### methods

- KFind (pattern, options, parent)

  returns ctor

  Argument | Type | Default
  --- | --- | ---
  pattern | QString |
  options | long |
  parent | QWidget |

  Only use this constructor if you don't use KFindDialog, or if you use it as a modal dialog.

- KFind (pattern, options, parent, findDialog)

  returns ctor

  Argument | Type | Default
  --- | --- | ---
  pattern | QString |
  options | long |
  parent | QWidget |
  findDialog | QWidget |

  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.

- closeFindNextDialog ( )

  returns Nothing

  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.

- dialogClosed ( )

  returns Nothing
  SIGNAL ("dialogClosed ()")

  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.

- dialogsParent ( )

  returns QWidget

- displayFinalDialog ( )

  returns Nothing

  Displays the final dialog saying "no match was found", if that was the case. Call either this or shouldRestart().

- find ( )

  returns KFind.Result

  Walk the text fragment (e.g. text-processor line, kspread cell) looking for matches. For each match, emits the highlight() signal and displays the find-again dialog proceeding.

- find (text, pattern, index, options)

  returns int, int (matchedlength)
  static

  Argument | Type | Default
  --- | --- | ---
  text | QString |
  pattern | QString |
  index | int |
  options | long |

  Search the given string, and returns whether a match was found. If one is, the length of the string matched is also returned.

  A performance optimised version of the function is provided for use with regular expressions.

  text - The string to search.

  pattern - The pattern to look for.

  index - The starting index into the string.

  options - The options to use.

  matchedlength - The length of the string that was matched Returns The index at which a match was found, or -1 if no match was found.

- find (text, pattern, index, options)

  returns int, int (matchedlength)
  static

  Argument | Type | Default
  --- | --- | ---
  text | QString |
  pattern | QRegExp |
  index | int |
  options | long |

- findNext ( )

  returns Nothing
  SIGNAL ("findNext ()")

- findNextDialog (create)

  returns KDialog

  Argument | Type | Default
  --- | --- | ---
  create | bool | 0

  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.

- highlight (text, matchingIndex, matchedLength)

  returns Nothing
  SIGNAL ("highlight (const QString&, int, int)")

  Argument | Type | Default
  --- | --- | ---
  text | QString |
  matchingIndex | int |
  matchedLength | int |

  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 signal highlight(id, matchingIndex, matchedLength)

  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 also setData()

- highlight (id, matchingIndex, matchedLength)

  returns Nothing
  SIGNAL ("highlight (int, int, int)")

  Argument | Type | Default
  --- | --- | ---
  id | int |
  matchingIndex | int |
  matchedLength | int |

  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 signal with highlight(text, matchingIndex, matchedLength).

  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 also setData()

- index ( )

  returns int

  Returns the current matching index ( or -1 ). Same as the matchingIndex parameter passed to highlight. You usually don't need to use this, except maybe when updating the current data, so you need to call setData( newData, index() ).

- needData ( )

  returns bool

  Returns 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()).

- numMatches ( )

  returns int

  Return the number of matches found (i.e. the number of times the highlight 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).

- options ( )

  returns long

  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 also KFind.Options

- optionsChanged ( )

  returns Nothing
  SIGNAL ("optionsChanged ()")

  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.

- parentWidget ( )

  returns QWidget

- pattern ( )

  returns QString

  Returns the pattern we're currently looking for

- resetCounts ( )

  returns Nothing

  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.

- setData (data, startPos)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  data | QString |
  startPos | int | -1

  Call this when needData returns true, before calling find().

  data - the text fragment (line)

  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.

- setData (id, data, startPos)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  id | int |
  data | QString |
  startPos | int | -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.

  id - the id of the text fragment

  data - the text fragment (line)

  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.

- setOptions (options)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  options | long |

  Set new options. Usually this is used for setting or clearing the FindBackwards options.

  See also KFind.Options

- setPattern (pattern)

  returns Nothing

  Argument | Type | Default
  --- | --- | ---
  pattern | QString |

  Change the pattern we're looking for

- shouldRestart (forceAsking, showNumMatches)

  returns bool

  Argument | Type | Default
  --- | --- | ---
  forceAsking | bool | 0
  showNumMatches | bool | 1

  Returns true if we should restart the search from scratch. Can ask the user, or return false (if we already searched the whole document).

  forceAsking - set to true if the user modified the document during the search. In that case it makes sense to restart the search again.

  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).

- validateMatch (text, index, matchedlength)

  returns bool

  Argument | Type | Default
  --- | --- | ---
  text | QString |
  index | int |
  matchedlength | int |

  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 criterias.

  text - The current text fragment

  index - The starting index where the candidate match was found

  matchedlength - The length of the candidate match

### enums - detail

- Options { WholeWordsOnly, FromCursor, SelectedText, CaseSensitive, FindBackwards, RegularExpression, FindIncremental, MinimumUserOption }

  the options

  | WholeWordsOnly | - 1 | - |
  | FromCursor | - 2 | - |
  | SelectedText | - 4 | - |
  | CaseSensitive | - 8 | - |
  | FindBackwards | - 16 | - |
  | RegularExpression | - 32 | - |
  | FindIncremental | - 64 | - |
  | MinimumUserOption | - 65536 | - |

- Result { NoMatch, Match }

  | NoMatch | - | - |
  | Match | - | - |