QScintilla/QsciScintillaCompat.py

# -*- coding: utf-8 -*-

# Copyright (c) 2004 - 2013 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a compatability interface class to QsciScintilla.
"""

from PyQt4.QtCore import pyqtSignal, Qt
from PyQt4.QtGui import QPalette, QColor, QApplication
from PyQt4.Qsci import QsciScintilla, \
    QSCINTILLA_VERSION as QsciQSCINTILLA_VERSION, QSCINTILLA_VERSION_STR, \
    QsciScintillaBase

###############################################################################


def QSCINTILLA_VERSION():
    """
    Module function to return the QScintilla version.
    
    If the installed QScintilla is a snapshot version, then assume it is
    of the latest release and return a version number of 0x99999.
    
    @return QScintilla version (integer)
    """
    if '-snapshot-' in QSCINTILLA_VERSION_STR:
        return 0x99999
    else:
        return QsciQSCINTILLA_VERSION
    
###############################################################################


class QsciScintillaCompat(QsciScintilla):
    """
    Class implementing a compatability interface to QsciScintilla.
    
    This class implements all the functions, that were added to
    QsciScintilla incrementally. This class ensures compatibility
    to older versions of QsciScintilla.
    
    @signal zoomValueChanged(int) emitted to signal a change of the zoom value
    """
    zoomValueChanged = pyqtSignal(int)
    
    ArrowFoldStyle = QsciScintilla.BoxedTreeFoldStyle + 1
    ArrowTreeFoldStyle = ArrowFoldStyle + 1
    
    UserSeparator = '\x04'
    
    def __init__(self, parent=None):
        """
        Constructor
        
        @param parent parent widget (QWidget)
        """
        super().__init__(parent)
        
        self.zoom = 0
        
        self.__targetSearchFlags = 0
        self.__targetSearchExpr = ""
        self.__targetSearchStart = 0
        self.__targetSearchEnd = -1
        self.__targetSearchActive = False
    
    def setLexer(self, lex=None):
        """
        Public method to set the lexer.
        
        @param lex the lexer to be set or None to reset it.
        """
        super().setLexer(lex)
        if lex is None:
            self.clearStyles()
    
    def clearStyles(self):
        """
        Public method to set the styles according the selected Qt style.
        """
        palette = QApplication.palette()
        self.SendScintilla(QsciScintilla.SCI_STYLESETFORE,
            QsciScintilla.STYLE_DEFAULT, palette.color(QPalette.Text))
        self.SendScintilla(QsciScintilla.SCI_STYLESETBACK,
            QsciScintilla.STYLE_DEFAULT, palette.color(QPalette.Base))
        self.SendScintilla(QsciScintilla.SCI_STYLECLEARALL)
        self.SendScintilla(QsciScintilla.SCI_CLEARDOCUMENTSTYLE)
    
    def monospacedStyles(self, font):
        """
        Public method to set the current style to be monospaced.
        
        @param font font to be used (QFont)
        """
        try:
            rangeLow = list(range(self.STYLE_DEFAULT))
        except AttributeError:
            rangeLow = list(range(32))
        try:
            rangeHigh = list(range(self.STYLE_LASTPREDEFINED + 1,
                              self.STYLE_MAX + 1))
        except AttributeError:
            rangeHigh = list(range(40, 128))
        
        f = font.family().encode()
        ps = font.pointSize()
        weight = -font.weight()
        italic = font.italic()
        underline = font.underline()
        bold = font.bold()
        for style in rangeLow + rangeHigh:
            self.SendScintilla(QsciScintilla.SCI_STYLESETFONT, style, f)
            self.SendScintilla(QsciScintilla.SCI_STYLESETSIZE, style, ps)
            try:
                self.SendScintilla(QsciScintilla.SCI_STYLESETWEIGHT, style, weight)
            except AttributeError:
                self.SendScintilla(QsciScintilla.SCI_STYLESETBOLD, style, bold)
            self.SendScintilla(QsciScintilla.SCI_STYLESETITALIC, style, italic)
            self.SendScintilla(QsciScintilla.SCI_STYLESETUNDERLINE, style, underline)
    
    def linesOnScreen(self):
        """
        Public method to get the amount of visible lines.
        
        @return amount of visible lines (integer)
        """
        return self.SendScintilla(QsciScintilla.SCI_LINESONSCREEN)
    
    def lineAt(self, pos):
        """
        Public method to calculate the line at a position.
        
        This variant is able to calculate the line for positions in the
        margins and for empty lines.
        
        @param pos position to calculate the line for (integer or QPoint)
        @return linenumber at position or -1, if there is no line at pos
            (integer, zero based)
        """
        if isinstance(pos, int):
            scipos = pos
        else:
            scipos = \
                self.SendScintilla(QsciScintilla.SCI_POSITIONFROMPOINT,
                                   pos.x(), pos.y())
        line = self.SendScintilla(QsciScintilla.SCI_LINEFROMPOSITION, scipos)
        if line >= self.lines():
            line = -1
        return line
    
    def currentPosition(self):
        """
        Public method to get the current position.
        
        @return absolute position of the cursor (integer)
        """
        return self.SendScintilla(QsciScintilla.SCI_GETCURRENTPOS)
    
    def styleAt(self, pos):
        """
        Public method to get the style at a position in the text.
        
        @param pos position in the text (integer)
        @return style at the requested position or 0, if the position
            is negative or past the end of the document (integer)
        """
        return self.SendScintilla(QsciScintilla.SCI_GETSTYLEAT, pos)
    
    def currentStyle(self):
        """
        Public method to get the style at the current position.
        
        @return style at the current position (integer)
        """
        return self.styleAt(self.currentPosition())
    
    def getEndStyled(self):
        """
        Public method to get the last styled position.
        
        @return end position of the last styling run (integer)
        """
        return self.SendScintilla(QsciScintilla.SCI_GETENDSTYLED)
    
    def startStyling(self, pos, mask):
        """
        Public method to prepare styling.
        
        @param pos styling positition to start at (integer)
        @param mask mask of bits to use for styling (integer)
        """
        self.SendScintilla(QsciScintilla.SCI_STARTSTYLING, pos, mask)
    
    def setStyling(self, length, style):
        """
        Public method to style some text.
        
        @param length length of text to style (integer)
        @param style style to set for text (integer)
        """
        self.SendScintilla(QsciScintilla.SCI_SETSTYLING, length, style)
    
    def setStyleBits(self, bits):
        """
        Public method to set the number of bits to be used for styling.
        
        @param bits number of style bits (integer)
        """
        self.SendScintilla(QsciScintilla.SCI_SETSTYLEBITS, bits)
    
    def charAt(self, pos):
        """
        Public method to get the character at a position in the text observing
        multibyte characters.
        
        @param pos position in the text (integer)
        @return character at the requested position or empty string, if the
            position is negative or past the end of the document (string)
        """
        ch = self.byteAt(pos)
        if ch and ord(ch) > 127 and self.isUtf8():
            if (ch[0] & 0xF0) == 0xF0:
                utf8Len = 4
            elif (ch[0] & 0xE0) == 0xE0:
                utf8Len = 3
            elif (ch[0] & 0xC0) == 0xC0:
                utf8Len = 2
            while len(ch) < utf8Len:
                pos += 1
                ch += self.byteAt(pos)
            return ch.decode('utf8')
        else:
            return ch.decode()
    
    def byteAt(self, pos):
        """
        Public method to get the raw character (bytes) at a position in the
        text.
        
        @param pos position in the text (integer)
        @return raw character at the requested position or empty bytes, if the
            position is negative or past the end of the document (bytes)
        """
        char = self.SendScintilla(QsciScintilla.SCI_GETCHARAT, pos)
        if char == 0:
            return b""
        if char < 0:
            char += 256
        return bytes.fromhex("{0:02x}".format(char))
    
    def foldLevelAt(self, line):
        """
        Public method to get the fold level of a line of the document.
        
        @param line line number (integer)
        @return fold level of the given line (integer)
        """
        lvl = self.SendScintilla(QsciScintilla.SCI_GETFOLDLEVEL, line)
        return \
            (lvl & QsciScintilla.SC_FOLDLEVELNUMBERMASK) - \
            QsciScintilla.SC_FOLDLEVELBASE
    
    def foldFlagsAt(self, line):
        """
        Public method to get the fold flags of a line of the document.
        
        @param line line number (integer)
        @return fold flags of the given line (integer)
        """
        lvl = self.SendScintilla(QsciScintilla.SCI_GETFOLDLEVEL, line)
        return lvl & ~QsciScintilla.SC_FOLDLEVELNUMBERMASK
    
    def foldHeaderAt(self, line):
        """
        Public method to determine, if a line of the document is a fold header
        line.
        
        @param line line number (integer)
        @return flag indicating a fold header line (boolean)
        """
        lvl = self.SendScintilla(QsciScintilla.SCI_GETFOLDLEVEL, line)
        return lvl & QsciScintilla.SC_FOLDLEVELHEADERFLAG
    
    def foldExpandedAt(self, line):
        """
        Public method to determine, if a fold is expanded.
        
        @param line line number (integer)
        @return flag indicating the fold expansion state of the line (boolean)
        """
        return self.SendScintilla(QsciScintilla.SCI_GETFOLDEXPANDED, line)
    
    def setIndentationGuideView(self, view):
        """
        Public method to set the view of the indentation guides.
        
        @param view view of the indentation guides (SC_IV_NONE, SC_IV_REAL,
            SC_IV_LOOKFORWARD or SC_IV_LOOKBOTH)
        """
        self.SendScintilla(QsciScintilla.SCI_SETINDENTATIONGUIDES, view)
    
    def indentationGuideView(self):
        """
        Public method to get the indentation guide view.
        
        @return indentation guide view (SC_IV_NONE, SC_IV_REAL,
            SC_IV_LOOKFORWARD or SC_IV_LOOKBOTH)
        """
        return self.SendScintilla(QsciScintilla.SCI_GETINDENTATIONGUIDES)
    
    ###########################################################################
    ## methods below are missing from QScintilla
    ###########################################################################

    def zoomIn(self, zoom=1):
        """
        Public method used to increase the zoom factor.
        
        @param zoom zoom factor increment (integer)
        """
        super().zoomIn(zoom)
    
    def zoomOut(self, zoom=1):
        """
        Public method used to decrease the zoom factor.
        
        @param zoom zoom factor decrement (integer)
        """
        super().zoomOut(zoom)
    
    def zoomTo(self, zoom):
        """
        Public method used to zoom to a specific zoom factor.
        
        @param zoom zoom factor (integer)
        """
        self.zoom = zoom
        super().zoomTo(zoom)
        self.zoomValueChanged.emit(self.zoom)
    
    def getZoom(self):
        """
        Public method used to retrieve the current zoom factor.
        
        @return zoom factor (integer)
        """
        return self.zoom
    
    def editorCommand(self, cmd):
        """
        Public method to perform a simple editor command.
        
        @param cmd the scintilla command to be performed (integer)
        """
        self.SendScintilla(cmd)
    
    def scrollVertical(self, lines):
        """
        Public method to scroll the text area.
        
        @param lines number of lines to scroll (negative scrolls up,
            positive scrolls down) (integer)
        """
        self.SendScintilla(QsciScintilla.SCI_LINESCROLL, 0, lines)
    
    def moveCursorToEOL(self):
        """
        Public method to move the cursor to the end of line.
        """
        self.SendScintilla(QsciScintilla.SCI_LINEEND)
    
    def moveCursorLeft(self):
        """
        Public method to move the cursor left.
        """
        self.SendScintilla(QsciScintilla.SCI_CHARLEFT)
    
    def moveCursorRight(self):
        """
        Public method to move the cursor right.
        """
        self.SendScintilla(QsciScintilla.SCI_CHARRIGHT)
    
    def moveCursorWordLeft(self):
        """
        Public method to move the cursor left one word.
        """
        self.SendScintilla(QsciScintilla.SCI_WORDLEFT)
    
    def moveCursorWordRight(self):
        """
        Public method to move the cursor right one word.
        """
        self.SendScintilla(QsciScintilla.SCI_WORDRIGHT)
    
    def newLineBelow(self):
        """
        Public method to insert a new line below the current one.
        """
        self.SendScintilla(QsciScintilla.SCI_LINEEND)
        self.SendScintilla(QsciScintilla.SCI_NEWLINE)
    
    def deleteBack(self):
        """
        Public method to delete the character to the left of the cursor.
        """
        self.SendScintilla(QsciScintilla.SCI_DELETEBACK)
    
    def delete(self):
        """
        Public method to delete the character to the right of the cursor.
        """
        self.SendScintilla(QsciScintilla.SCI_CLEAR)
    
    def deleteWordLeft(self):
        """
        Public method to delete the word to the left of the cursor.
        """
        self.SendScintilla(QsciScintilla.SCI_DELWORDLEFT)
    
    def deleteWordRight(self):
        """
        Public method to delete the word to the right of the cursor.
        """
        self.SendScintilla(QsciScintilla.SCI_DELWORDRIGHT)
    
    def deleteLineLeft(self):
        """
        Public method to delete the line to the left of the cursor.
        """
        self.SendScintilla(QsciScintilla.SCI_DELLINELEFT)
    
    def deleteLineRight(self):
        """
        Public method to delete the line to the right of the cursor.
        """
        self.SendScintilla(QsciScintilla.SCI_DELLINERIGHT)
    
    def extendSelectionLeft(self):
        """
        Public method to extend the selection one character to the left.
        """
        self.SendScintilla(QsciScintilla.SCI_CHARLEFTEXTEND)
    
    def extendSelectionRight(self):
        """
        Public method to extend the selection one character to the right.
        """
        self.SendScintilla(QsciScintilla.SCI_CHARRIGHTEXTEND)
    
    def extendSelectionWordLeft(self):
        """
        Public method to extend the selection one word to the left.
        """
        self.SendScintilla(QsciScintilla.SCI_WORDLEFTEXTEND)
    
    def extendSelectionWordRight(self):
        """
        Public method to extend the selection one word to the right.
        """
        self.SendScintilla(QsciScintilla.SCI_WORDRIGHTEXTEND)
    
    def extendSelectionToBOL(self):
        """
        Public method to extend the selection to the beginning of the line.
        """
        self.SendScintilla(QsciScintilla.SCI_VCHOMEEXTEND)
    
    def extendSelectionToEOL(self):
        """
        Public method to extend the selection to the end of the line.
        """
        self.SendScintilla(QsciScintilla.SCI_LINEENDEXTEND)
    
    def hasSelection(self):
        """
        Public method to check for a selection.
        
        @return flag indicating the presence of a selection (boolean)
        """
        return self.getSelection()[0] != -1
    
    def selectionIsRectangle(self):
        """
        Public method to check, if the current selection is rectangular.
        
        @return flag indicating a rectangular selection (boolean)
        """
        startLine, startIndex, endLine, endIndex = self.getSelection()
        return startLine != -1 and \
               startLine != endLine and \
               self.SendScintilla(QsciScintilla.SCI_SELECTIONISRECTANGLE)
    
    def getRectangularSelection(self):
        """
        Public method to retrieve the start and end of a rectangular selection.
        
        @return tuple with start line and index and end line and index
            (tuple of four int)
        """
        if not self.selectionIsRectangle():
            return (-1, -1, -1, -1)
        
        startPos = self.SendScintilla(QsciScintilla.SCI_GETRECTANGULARSELECTIONANCHOR)
        endPos = self.SendScintilla(QsciScintilla.SCI_GETRECTANGULARSELECTIONCARET)
        startLine, startIndex = self.lineIndexFromPosition(startPos)
        endLine, endIndex = self.lineIndexFromPosition(endPos)
        
        return (startLine, startIndex, endLine, endIndex)
    
    def setRectangularSelection(self, startLine, startIndex, endLine, endIndex):
        """
        Public method to set a rectangular selection.
        
        @param startLine line number of the start of the selection (int)
        @param startIndex index number of the start of the selection (int)
        @param endLine line number of the end of the selection (int)
        @param endIndex index number of the end of the selection (int)
        """
        startPos = self.positionFromLineIndex(startLine, startIndex)
        endPos = self.positionFromLineIndex(endLine, endIndex)
        
        self.SendScintilla(QsciScintilla.SCI_SETRECTANGULARSELECTIONANCHOR, startPos)
        self.SendScintilla(QsciScintilla.SCI_SETRECTANGULARSELECTIONCARET, endPos)
    
    def getSelectionCount(self):
        """
        Public method to get the number of active selections.
        
        @return number of active selection (integer)
        """
        return self.SendScintilla(QsciScintilla.SCI_GETSELECTIONS)
    
    def getSelectionN(self, index):
        """
        Public method to get the start and end of a selection given by its
        index.
        
        @param index index of the selection (integer)
        @return tuple with start line and index and end line and index
            (tuple of four int) for the given selection
        """
        startPos = self.SendScintilla(QsciScintilla.SCI_GETSELECTIONNSTART, index)
        endPos = self.SendScintilla(QsciScintilla.SCI_GETSELECTIONNEND, index)
        startLine, startIndex = self.lineIndexFromPosition(startPos)
        endLine, endIndex = self.lineIndexFromPosition(endPos)
        
        return (startLine, startIndex, endLine, endIndex)
    
    def getSelections(self):
        """
        Public method to get the start and end coordinates of all active selections.
        
        @return list of tuples with start line and index and end line and index
            of each active selection (list of tuples of four int)
        """
        selections = []
        for index in range(self.getSelectionCount()):
            selections.append(self.getSelectionN(index))
        return selections
    
    def setVirtualSpaceOptions(self, options):
        """
        Public method to set the virtual space usage options.
        
        @param options usage options to set (integer, 0 to 3)
        """
        self.SendScintilla(QsciScintilla.SCI_SETVIRTUALSPACEOPTIONS, options)
    
    def getLineSeparator(self):
        """
        Public method to get the line separator for the current eol mode.
        
        @return eol string (string)
        """
        m = self.eolMode()
        if m == QsciScintilla.EolWindows:
            eol = '\r\n'
        elif m == QsciScintilla.EolUnix:
            eol = '\n'
        elif m == QsciScintilla.EolMac:
            eol = '\r'
        else:
            eol = ''
        return eol
    
    def getEolIndicator(self):
        """
        Public method to get the eol indicator for the current eol mode.
        
        @return eol indicator (string)
        """
        m = self.eolMode()
        if m == QsciScintilla.EolWindows:
            eol = 'CRLF'
        elif m == QsciScintilla.EolUnix:
            eol = 'LF'
        elif m == QsciScintilla.EolMac:
            eol = 'CR'
        else:
            eol = ''
        return eol
    
    def setEolModeByEolString(self, eolStr):
        """
        Public method to set the eol mode given the eol string.
        
        @param eolStr eol string (string)
        """
        if eolStr == '\r\n':
            self.setEolMode(QsciScintilla.EolMode(QsciScintilla.EolWindows))
        elif eolStr == '\n':
            self.setEolMode(QsciScintilla.EolMode(QsciScintilla.EolUnix))
        elif eolStr == '\r':
            self.setEolMode(QsciScintilla.EolMode(QsciScintilla.EolMac))
    
    def detectEolString(self, txt):
        """
        Public method to determine the eol string used.
        
        @param txt text from which to determine the eol string (string)
        @return eol string (string)
        """
        if len(txt.split("\r\n", 1)) == 2:
            return '\r\n'
        elif len(txt.split("\n", 1)) == 2:
            return '\n'
        elif len(txt.split("\r", 1)) == 2:
            return '\r'
        else:
            return None
    
    def getCursorFlashTime(self):
        """
        Public method to get the flash (blink) time of the cursor in
        milliseconds.
        
        The flash time is the time required to display, invert and restore the
        caret display. Usually the text cursor is displayed for half the cursor
        flash time, then hidden for the same amount of time.
        
        @return flash time of the cursor in milliseconds (integer)
        """
        return 2 * self.SendScintilla(QsciScintilla.SCI_GETCARETPERIOD)
    
    def setCursorFlashTime(self, time):
        """
        Public method to get the flash (blink) time of the cursor in
        milliseconds.
        
        The flash time is the time required to display, invert and restore the
        caret display. Usually the text cursor is displayed for half the cursor
        flash time, then hidden for the same amount of time.
        
        @param time flash time of the cursor in milliseconds (integer)
        """
        self.SendScintilla(QsciScintilla.SCI_SETCARETPERIOD, time // 2)
    
    ###########################################################################
    # methods to perform searches in target range
    ###########################################################################
    
    def positionFromPoint(self, point):
        """
        Public method to calculate the scintilla position from a point in the
        window.
        
        @param point point in the window (QPoint)
        @return scintilla position (integer) or -1 to indicate, that the point
            is not near any character
        """
        return self.SendScintilla(QsciScintilla.SCI_POSITIONFROMPOINTCLOSE,
                                  point.x(), point.y())
    
    def positionBefore(self, pos):
        """
        Public method to get the position before the given position taking into
        account multibyte characters.
        
        @param pos position (integer)
        @return position before the given one (integer)
        """
        return self.SendScintilla(QsciScintilla.SCI_POSITIONBEFORE, pos)
    
    def positionAfter(self, pos):
        """
        Public method to get the position after the given position taking into
        account multibyte characters.
        
        @param pos position (integer)
        @return position after the given one (integer)
        """
        return self.SendScintilla(QsciScintilla.SCI_POSITIONAFTER, pos)
    
    def lineEndPosition(self, line):
        """
        Public method to determine the line end position of the given line.
        
        @param line line number (integer)
        @return position of the line end disregarding line end characters
            (integer)
        """
        return self.SendScintilla(QsciScintilla.SCI_GETLINEENDPOSITION, line)
    
    def __doSearchTarget(self):
        """
        Private method to perform the search in target.
        
        @return flag indicating a successful search (boolean)
        """
        if self.__targetSearchStart == self.__targetSearchEnd:
            self.__targetSearchActive = False
            return False
        
        self.SendScintilla(QsciScintilla.SCI_SETTARGETSTART,
                           self.__targetSearchStart)
        self.SendScintilla(QsciScintilla.SCI_SETTARGETEND,
                           self.__targetSearchEnd)
        self.SendScintilla(QsciScintilla.SCI_SETSEARCHFLAGS,
                           self.__targetSearchFlags)
        targetSearchExpr = self._encodeString(self.__targetSearchExpr)
        pos = self.SendScintilla(QsciScintilla.SCI_SEARCHINTARGET,
                                 len(targetSearchExpr),
                                 targetSearchExpr)
        
        if pos == -1:
            self.__targetSearchActive = False
            return False
        
        targend = self.SendScintilla(QsciScintilla.SCI_GETTARGETEND)
        self.__targetSearchStart = targend
        
        return True
    
    def getFoundTarget(self):
        """
        Public method to get the recently found target.
        
        @return found target as a tuple of starting position and target length
            (integer, integer)
        """
        if self.__targetSearchActive:
            spos = self.SendScintilla(QsciScintilla.SCI_GETTARGETSTART)
            epos = self.SendScintilla(QsciScintilla.SCI_GETTARGETEND)
            return (spos, epos - spos)
        else:
            return (0, 0)
    
    def findFirstTarget(self, expr_, re_, cs_, wo_,
            begline=-1, begindex=-1, endline=-1, endindex=-1,
            ws_=False):
        """
        Public method to search in a specified range of text without
        setting the selection.
        
        @param expr_ search expression (string)
        @param re_ flag indicating a regular expression (boolean)
        @param cs_ flag indicating a case sensitive search (boolean)
        @param wo_ flag indicating a word only search (boolean)
        @keyparam begline line number to start from (-1 to indicate current
            position) (integer)
        @keyparam begindex index to start from (-1 to indicate current
            position) (integer)
        @keyparam endline line number to stop at (-1 to indicate end of
            document) (integer)
        @keyparam endindex index number to stop at (-1 to indicate end of
            document) (integer)
        @keyparam ws_ flag indicating a word start search (boolean)
        @return flag indicating a successful search (boolean)
        """
        self.__targetSearchFlags = 0
        if re_:
            self.__targetSearchFlags |= QsciScintilla.SCFIND_REGEXP
        if cs_:
            self.__targetSearchFlags |= QsciScintilla.SCFIND_MATCHCASE
        if wo_:
            self.__targetSearchFlags |= QsciScintilla.SCFIND_WHOLEWORD
        if ws_:
            self.__targetSearchFlags |= QsciScintilla.SCFIND_WORDSTART
        
        if begline < 0 or begindex < 0:
            self.__targetSearchStart = self.SendScintilla(
                QsciScintilla.SCI_GETCURRENTPOS)
        else:
            self.__targetSearchStart = self.positionFromLineIndex(
                begline, begindex)
        
        if endline < 0 or endindex < 0:
            self.__targetSearchEnd = self.SendScintilla(
                QsciScintilla.SCI_GETTEXTLENGTH)
        else:
            self.__targetSearchEnd = self.positionFromLineIndex(
                endline, endindex)
        
        self.__targetSearchExpr = expr_
        
        if self.__targetSearchExpr:
            self.__targetSearchActive = True
            
            return self.__doSearchTarget()
        
        return False
    
    def findNextTarget(self):
        """
        Public method to find the next occurrence in the target range.
        
        @return flag indicating a successful search (boolean)
        """
        if not self.__targetSearchActive:
            return False
        
        return self.__doSearchTarget()
    
    def replaceTarget(self, replaceStr):
        """
        Public method to replace the string found by the last search in target.
        
        @param replaceStr replacement string or regexp (string)
        """
        if not self.__targetSearchActive:
            return
        
        if self.__targetSearchFlags & QsciScintilla.SCFIND_REGEXP:
            cmd = QsciScintilla.SCI_REPLACETARGETRE
        else:
            cmd = QsciScintilla.SCI_REPLACETARGET
        r = self._encodeString(replaceStr)
        
        start = self.SendScintilla(QsciScintilla.SCI_GETTARGETSTART)
        self.SendScintilla(cmd, len(r), r)
        
        self.__targetSearchStart = start + len(r)
    
    ###########################################################################
    # indicator handling methods
    ###########################################################################
    
    def indicatorDefine(self, indicator, style, color):
        """
        Public method to define the appearance of an indicator.
        
        @param indicator number of the indicator (integer,
            QsciScintilla.INDIC_CONTAINER .. QsciScintilla.INDIC_MAX)
        @param style style to be used for the indicator
            (QsciScintilla.INDIC_PLAIN, QsciScintilla.INDIC_SQUIGGLE,
            QsciScintilla.INDIC_TT, QsciScintilla.INDIC_DIAGONAL,
            QsciScintilla.INDIC_STRIKE, QsciScintilla.INDIC_HIDDEN,
            QsciScintilla.INDIC_BOX, QsciScintilla.INDIC_ROUNDBOX)
        @param color color to be used by the indicator (QColor)
        @exception ValueError the indicator or style are not valid
        """
        if indicator < QsciScintilla.INDIC_CONTAINER or \
           indicator > QsciScintilla.INDIC_MAX:
            raise ValueError("indicator number out of range")
        
        if style < QsciScintilla.INDIC_PLAIN or \
           style > QsciScintilla.INDIC_ROUNDBOX:
            raise ValueError("style out of range")
        
        self.SendScintilla(QsciScintilla.SCI_INDICSETSTYLE, indicator, style)
        self.SendScintilla(QsciScintilla.SCI_INDICSETFORE, indicator, color)
        try:
            self.SendScintilla(QsciScintilla.SCI_INDICSETALPHA, indicator,
                               color.alpha())
        except AttributeError:
            pass
    
    def setCurrentIndicator(self, indicator):
        """
        Public method to set the current indicator.
        
        @param indicator number of the indicator (integer,
            QsciScintilla.INDIC_CONTAINER .. QsciScintilla.INDIC_MAX)
        @exception ValueError the indicator or style are not valid
        """
        if indicator < QsciScintilla.INDIC_CONTAINER or \
           indicator > QsciScintilla.INDIC_MAX:
            raise ValueError("indicator number out of range")
        
        self.SendScintilla(QsciScintilla.SCI_SETINDICATORCURRENT, indicator)
    
    def setIndicatorRange(self, indicator, spos, length):
        """
        Public method to set an indicator for the given range.
        
        @param indicator number of the indicator (integer,
            QsciScintilla.INDIC_CONTAINER .. QsciScintilla.INDIC_MAX)
        @param spos position of the indicator start (integer)
        @param length length of the indicator (integer)
        """
        self.setCurrentIndicator(indicator)
        self.SendScintilla(QsciScintilla.SCI_INDICATORFILLRANGE, spos, length)
    
    def setIndicator(self, indicator, sline, sindex, eline, eindex):
        """
        Public method to set an indicator for the given range.
        
        @param indicator number of the indicator (integer,
            QsciScintilla.INDIC_CONTAINER .. QsciScintilla.INDIC_MAX)
        @param sline line number of the indicator start (integer)
        @param sindex index of the indicator start (integer)
        @param eline line number of the indicator end (integer)
        @param eindex index of the indicator end (integer)
        """
        spos = self.positionFromLineIndex(sline, sindex)
        epos = self.positionFromLineIndex(eline, eindex)
        self.setIndicatorRange(indicator, spos, epos - spos)
    
    def clearIndicatorRange(self, indicator, spos, length):
        """
        Public method to clear an indicator for the given range.
        
        @param indicator number of the indicator (integer,
            QsciScintilla.INDIC_CONTAINER .. QsciScintilla.INDIC_MAX)
        @param spos position of the indicator start (integer)
        @param length length of the indicator (integer)
        """
        self.setCurrentIndicator(indicator)
        self.SendScintilla(QsciScintilla.SCI_INDICATORCLEARRANGE, spos, length)
    
    def clearIndicator(self, indicator, sline, sindex, eline, eindex):
        """
        Public method to clear an indicator for the given range.
        
        @param indicator number of the indicator (integer,
            QsciScintilla.INDIC_CONTAINER .. QsciScintilla.INDIC_MAX)
        @param sline line number of the indicator start (integer)
        @param sindex index of the indicator start (integer)
        @param eline line number of the indicator end (integer)
        @param eindex index of the indicator end (integer)
        """
        spos = self.positionFromLineIndex(sline, sindex)
        epos = self.positionFromLineIndex(eline, eindex)
        self.clearIndicatorRange(indicator, spos, epos - spos)
    
    def clearAllIndicators(self, indicator):
        """
        Public method to clear all occurrences of an indicator.
        
        @param indicator number of the indicator (integer,
            QsciScintilla.INDIC_CONTAINER .. QsciScintilla.INDIC_MAX)
        """
        self.clearIndicatorRange(indicator, 0, self.length())
    
    def hasIndicator(self, indicator, pos):
        """
        Public method to test for the existence of an indicator.
        
        @param indicator number of the indicator (integer,
            QsciScintilla.INDIC_CONTAINER .. QsciScintilla.INDIC_MAX)
        @param pos position to test (integer)
        @return flag indicating the existence of the indicator (boolean)
        """
        res = self.SendScintilla(QsciScintilla.SCI_INDICATORVALUEAT,
                                 indicator, pos)
        return res
    
    ###########################################################################
    # methods to perform folding related stuff
    ###########################################################################
    
    def __setFoldMarker(self, marknr, mark=QsciScintilla.SC_MARK_EMPTY):
        """
        Private method to define a fold marker.
        
        @param marknr marker number to define (integer)
        @param mark fold mark symbol to be used (integer)
        """
        self.SendScintilla(QsciScintilla.SCI_MARKERDEFINE, marknr, mark)
        
        if mark != QsciScintilla.SC_MARK_EMPTY:
            self.SendScintilla(QsciScintilla.SCI_MARKERSETFORE,
                marknr, QColor(Qt.white))
            self.SendScintilla(QsciScintilla.SCI_MARKERSETBACK,
                marknr, QColor(Qt.black))
    
    def setFolding(self, style, margin=2):
        """
        Public method to set the folding style and margin.
        
        @param style folding style to set (integer)
        @param margin margin number (integer)
        """
        if style < self.ArrowFoldStyle:
            super().setFolding(style, margin)
        else:
            super().setFolding(
                QsciScintilla.PlainFoldStyle, margin)
            
            if style == self.ArrowFoldStyle:
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDER,
                                     QsciScintilla.SC_MARK_ARROW)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDEROPEN,
                                     QsciScintilla.SC_MARK_ARROWDOWN)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDERSUB)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDERTAIL)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDEREND)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDEROPENMID)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDERMIDTAIL)
            elif style == self.ArrowTreeFoldStyle:
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDER,
                                     QsciScintilla.SC_MARK_ARROW)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDEROPEN,
                                     QsciScintilla.SC_MARK_ARROWDOWN)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDERSUB,
                                     QsciScintilla.SC_MARK_VLINE)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDERTAIL,
                                     QsciScintilla.SC_MARK_LCORNER)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDEREND,
                                     QsciScintilla.SC_MARK_ARROW)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDEROPENMID,
                                     QsciScintilla.SC_MARK_ARROWDOWN)
                self.__setFoldMarker(QsciScintilla.SC_MARKNUM_FOLDERMIDTAIL,
                                     QsciScintilla.SC_MARK_TCORNER)
    
    def setFoldMarkersColors(self, foreColor, backColor):
        """
        Public method to set the foreground and background colors of the
        fold markers.
        
        @param foreColor foreground color (QColor)
        @param backColor background color (QColor)
        """
        self.SendScintilla(QsciScintilla.SCI_MARKERSETFORE,
            QsciScintilla.SC_MARKNUM_FOLDER, foreColor)
        self.SendScintilla(QsciScintilla.SCI_MARKERSETBACK,
            QsciScintilla.SC_MARKNUM_FOLDER, backColor)
        
        self.SendScintilla(QsciScintilla.SCI_MARKERSETFORE,
            QsciScintilla.SC_MARKNUM_FOLDEROPEN, foreColor)
        self.SendScintilla(QsciScintilla.SCI_MARKERSETBACK,
            QsciScintilla.SC_MARKNUM_FOLDEROPEN, backColor)
        
        self.SendScintilla(QsciScintilla.SCI_MARKERSETFORE,
            QsciScintilla.SC_MARKNUM_FOLDEROPENMID, foreColor)
        self.SendScintilla(QsciScintilla.SCI_MARKERSETBACK,
            QsciScintilla.SC_MARKNUM_FOLDEROPENMID, backColor)
        
        self.SendScintilla(QsciScintilla.SCI_MARKERSETFORE,
            QsciScintilla.SC_MARKNUM_FOLDERSUB, foreColor)
        self.SendScintilla(QsciScintilla.SCI_MARKERSETBACK,
            QsciScintilla.SC_MARKNUM_FOLDERSUB, backColor)
        
        self.SendScintilla(QsciScintilla.SCI_MARKERSETFORE,
            QsciScintilla.SC_MARKNUM_FOLDERTAIL, foreColor)
        self.SendScintilla(QsciScintilla.SCI_MARKERSETBACK,
            QsciScintilla.SC_MARKNUM_FOLDERTAIL, backColor)
        
        self.SendScintilla(QsciScintilla.SCI_MARKERSETFORE,
            QsciScintilla.SC_MARKNUM_FOLDERMIDTAIL, foreColor)
        self.SendScintilla(QsciScintilla.SCI_MARKERSETBACK,
            QsciScintilla.SC_MARKNUM_FOLDERMIDTAIL, backColor)
        
        self.SendScintilla(QsciScintilla.SCI_MARKERSETFORE,
            QsciScintilla.SC_MARKNUM_FOLDEREND, foreColor)
        self.SendScintilla(QsciScintilla.SCI_MARKERSETBACK,
            QsciScintilla.SC_MARKNUM_FOLDEREND, backColor)
    
    ###########################################################################
    # interface methods to the standard keyboard command set
    ###########################################################################
    
    def clearKeys(self):
        """
        Protected method to clear the key commands.
        """
        # call into the QsciCommandSet
        self.standardCommands().clearKeys()
        
    def clearAlternateKeys(self):
        """
        Protected method to clear the alternate key commands.
        """
        # call into the QsciCommandSet
        self.standardCommands().clearAlternateKeys()

    ###########################################################################
    # specialized event handlers
    ###########################################################################
    
    def focusOutEvent(self, event):
        """
        Public method called when the editor loses focus.
        
        @param event event object (QFocusEvent)
        """
        if self.isListActive():
            self.cancelList()
        
        super().focusOutEvent(event)
    
    def event(self, evt):
        """
        Protected method to handle events.
        
        Note: We are not interested in the standard QsciScintilla event
        handling because we do it our self.
        
        @param evt event object to handle (QEvent)
        @return result of the event handling (boolean)
        """
        return QsciScintillaBase.event(self, evt)

    ###########################################################################
    # interface methods to the mini editor
    ###########################################################################

    def getFileName(self):
        """
        Public method to return the name of the file being displayed.
        
        @return filename of the displayed file (string)
        """
        p = self.parent()
        if p is None:
            return ""
        else:
            try:
                return p.getFileName()
            except AttributeError:
                return ""
    
    ###########################################################################
    # replacements for buggy methods
    ###########################################################################
    
    def showUserList(self, id, lst):
        """
        Public method to show a user supplied list.
        
        @param id id of the list (integer)
        @param lst list to be show (list of strings)
        """
        if id <= 0:
            return
        
        self.SendScintilla(QsciScintilla.SCI_AUTOCSETSEPARATOR,
                           ord(self.UserSeparator))
        self.SendScintilla(QsciScintilla.SCI_USERLISTSHOW, id,
            self._encodeString(self.UserSeparator.join(lst)))
    
    ###########################################################################
    # utility methods
    ###########################################################################
    
    def _encodeString(self, string):
        """
        Protected method to encode a string depending on the current mode.
        
        @param string string to be encoded (str)
        @return encoded string (bytes)
        """
        if isinstance(string, bytes):
            return string
        else:
            if self.isUtf8():
                return string.encode("utf-8")
            else:
                return string.encode("latin-1")
    
    ###########################################################################
    # methods below have been added to QScintilla starting with version 2.5
    ###########################################################################
    
    if "positionFromLineIndex" not in QsciScintilla.__dict__:
        def positionFromLineIndex(self, line, index):
            """
            Public method to convert line and index to an absolute position.
            
            @param line line number (integer)
            @param index index number (integer)
            @return absolute position in the editor (integer)
            """
            pos = self.SendScintilla(QsciScintilla.SCI_POSITIONFROMLINE, line)
            
            # Allow for multi-byte characters
            for i in range(index):
                pos = self.positionAfter(pos)
            
            return pos
    
    if "lineIndexFromPosition" not in QsciScintilla.__dict__:
        def lineIndexFromPosition(self, pos):
            """
            Public method to convert an absolute position to line and index.
            
            @param pos absolute position in the editor (integer)
            @return tuple of line number (integer) and index number (integer)
            """
            lin = self.SendScintilla(QsciScintilla.SCI_LINEFROMPOSITION, pos)
            linpos = self.SendScintilla(
                QsciScintilla.SCI_POSITIONFROMLINE, lin)
            indx = 0
            
            # Allow for multi-byte characters.
            while linpos < pos:
                new_linpos = self.positionAfter(linpos)
                
                # If the position hasn't moved then we must be at the end of
                # the text (which implies that the position passed was beyond
                # the end of the text).
                if new_linpos == linpos:
                    break
                
                linpos = new_linpos
                indx += 1
            
            return lin, indx
    
    if "contractedFolds" not in QsciScintilla.__dict__:
        def contractedFolds(self):
            """
            Public method to get a list of line numbers of collapsed folds.
            
            @return list of line numbers of folded lines (list of integer)
            """
            line = 0
            folds = []
            maxline = self.lines()
            while line < maxline:
                if self.foldHeaderAt(line) and not self.foldExpandedAt(line):
                    folds.append(line)
                line += 1
            return folds
    
    if "setContractedFolds" not in QsciScintilla.__dict__:
        def setContractedFolds(self, folds):
            """
            Public method to set a list of line numbers of collapsed folds.
            
            @param folds list of line numbers of folded lines (list of integer)
            """
            for line in folds:
                self.foldLine(line)
    
##    #########################################################################
##    # methods below have been added to QScintilla starting with version 2.x
##    #########################################################################
##
##    if "newMethod" not in QsciScintilla.__dict__:
##        def newMethod(self, param):
##            """
##            Public method to do something.
##
##            @param param parameter for method
##            """
##            pass
##