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//---------------------------------------------------------------------------
// <copyright file="FixedFindEngine.cs" company="Microsoft">
// Copyright (C) 2004 by Microsoft Corporation. All rights reserved.
// </copyright>
//
// Description:
// Implements fast, paginated search functionality for Fixed documents
//
//
// History:
// 03/13/2006 AGurcan - Created
//
//---------------------------------------------------------------------------
namespace System.Windows.Documents
{
using System;
using System.IO;
using System.Xml;
using System.Text;
using System.Globalization;
using System.Diagnostics;
using System.Windows.Markup;
internal sealed class FixedFindEngine
{
//Searches for the specified pattern and updates start *or* end pointers depending on search direction
//At the end of the operation, start or end should be pointing to the beginning/end of the page
//of occurance of pattern respectively
internal static TextRange Find ( ITextPointer start,
ITextPointer end,
string findPattern,
CultureInfo cultureInfo,
bool matchCase,
bool matchWholeWord,
bool matchLast,
bool matchDiacritics,
bool matchKashida,
bool matchAlefHamza)
{
Debug.Assert(start != null);
Debug.Assert(end != null);
Debug.Assert( ((start is DocumentSequenceTextPointer) && (end is DocumentSequenceTextPointer)) ||
((start is FixedTextPointer) && (end is FixedTextPointer)) );
Debug.Assert(findPattern != null);
if (findPattern.Length == 0)
{
return null;
}
IDocumentPaginatorSource paginatorSource = start.TextContainer.Parent as IDocumentPaginatorSource;
DynamicDocumentPaginator paginator = paginatorSource.DocumentPaginator as DynamicDocumentPaginator;
Debug.Assert(paginator != null);
int pageNumber = -1;
int endPageNumber = -1;
if (matchLast)
{
endPageNumber = paginator.GetPageNumber( (ContentPosition) start);
pageNumber = paginator.GetPageNumber( (ContentPosition) end);
}
else
{
endPageNumber = paginator.GetPageNumber( (ContentPosition) end);
pageNumber = paginator.GetPageNumber( (ContentPosition) start);
}
TextRange result = null;
CompareInfo compareInfo = cultureInfo.CompareInfo;
bool replaceAlefWithAlefHamza = false;
CompareOptions compareOptions = _InitializeSearch(cultureInfo, matchCase, matchAlefHamza, matchDiacritics, ref findPattern, out replaceAlefWithAlefHamza);
//Translate the page number
int translatedPageNumber = pageNumber;
//If this is a DocumentSequence, we need to pass translated page number to the below call
FixedDocumentSequence documentSequence = paginatorSource as FixedDocumentSequence;
DynamicDocumentPaginator childPaginator = null;
if (documentSequence != null)
{
documentSequence.TranslatePageNumber(pageNumber, out childPaginator, out translatedPageNumber);
}
if (pageNumber - endPageNumber != 0)
{
ITextPointer firstSearchPageStart = null;
ITextPointer firstSearchPageEnd = null;
_GetFirstPageSearchPointers(start, end, translatedPageNumber, matchLast, out firstSearchPageStart, out firstSearchPageEnd);
Debug.Assert(firstSearchPageStart != null);
Debug.Assert(firstSearchPageEnd != null);
//Need to search the first page using TextFindEngine to start exactly from the requested search location to avoid false positives
result = TextFindEngine.InternalFind( firstSearchPageStart,
firstSearchPageEnd,
findPattern,
cultureInfo,
matchCase,
matchWholeWord,
matchLast,
matchDiacritics,
matchKashida,
matchAlefHamza);
if (result == null)
{
//Start from the next page and check all pages until the end
pageNumber = matchLast ? pageNumber-1 : pageNumber+1;
int increment = matchLast ? -1 : 1;
for (; matchLast ? pageNumber >= endPageNumber : pageNumber <= endPageNumber; pageNumber+=increment)
{
FixedDocument fixedDoc = null;
translatedPageNumber = pageNumber;
childPaginator = null;
if (documentSequence != null)
{
documentSequence.TranslatePageNumber(pageNumber, out childPaginator, out translatedPageNumber);
fixedDoc = (FixedDocument) childPaginator.Source;
}
else
{
fixedDoc = paginatorSource as FixedDocument;
}
Debug.Assert(fixedDoc != null);
String pageString = _GetPageString(fixedDoc, translatedPageNumber, replaceAlefWithAlefHamza);
if (pageString == null)
{
//This is not a page-per-stream
//Default back to slow search
return TextFindEngine.InternalFind( start,
end,
findPattern,
cultureInfo,
matchCase,
matchWholeWord,
matchLast,
matchDiacritics,
matchKashida,
matchAlefHamza);
}
if ( _FoundOnPage(pageString, findPattern, cultureInfo, compareOptions) )
{
//Update end or start pointer depending on search direction
if (documentSequence != null)
{
ChildDocumentBlock childBlock = documentSequence.TextContainer.FindChildBlock(fixedDoc.DocumentReference);
if (matchLast)
{
end = new DocumentSequenceTextPointer(childBlock, new FixedTextPointer(false, LogicalDirection.Backward, fixedDoc.FixedContainer.FixedTextBuilder.GetPageEndFlowPosition(translatedPageNumber)));
start = new DocumentSequenceTextPointer(childBlock, new FixedTextPointer(false, LogicalDirection.Forward, fixedDoc.FixedContainer.FixedTextBuilder.GetPageStartFlowPosition(translatedPageNumber)));
}
else
{
start = new DocumentSequenceTextPointer(childBlock, new FixedTextPointer(false, LogicalDirection.Forward, fixedDoc.FixedContainer.FixedTextBuilder.GetPageStartFlowPosition(translatedPageNumber)));
end = new DocumentSequenceTextPointer(childBlock, new FixedTextPointer(false, LogicalDirection.Backward, fixedDoc.FixedContainer.FixedTextBuilder.GetPageEndFlowPosition(translatedPageNumber)));
}
}
else
{
//We are working on a FixedDocument
FixedTextBuilder textBuilder = ((FixedDocument)(paginatorSource)).FixedContainer.FixedTextBuilder;
if (matchLast)
{
end = new FixedTextPointer(false, LogicalDirection.Backward, textBuilder.GetPageEndFlowPosition(pageNumber));
start = new FixedTextPointer(false, LogicalDirection.Forward, textBuilder.GetPageStartFlowPosition(pageNumber));
}
else
{
start = new FixedTextPointer(false, LogicalDirection.Forward, textBuilder.GetPageStartFlowPosition(pageNumber));
end = new FixedTextPointer(false, LogicalDirection.Backward, textBuilder.GetPageEndFlowPosition(pageNumber));
}
}
result = TextFindEngine.InternalFind( start,
end,
findPattern,
cultureInfo,
matchCase,
matchWholeWord,
matchLast,
matchDiacritics,
matchKashida,
matchAlefHamza);
//If the result is null, this means we had a false positive
if (result != null)
{
return result;
}
}
}
}
}
else
{
//Make sure fast search result and slow search result are consistent
FixedDocument fixedDoc = childPaginator != null ? childPaginator.Source as FixedDocument : paginatorSource as FixedDocument;
String pageString = _GetPageString(fixedDoc, translatedPageNumber, replaceAlefWithAlefHamza);
if (pageString == null ||
_FoundOnPage(pageString, findPattern, cultureInfo, compareOptions))
{
//The search is only limited to the current page
result = TextFindEngine.InternalFind( start,
end,
findPattern,
cultureInfo,
matchCase,
matchWholeWord,
matchLast,
matchDiacritics,
matchKashida,
matchAlefHamza);
}
}
return result;
}
private static bool _FoundOnPage(string pageString,
string findPattern,
CultureInfo cultureInfo,
CompareOptions compareOptions)
{
CompareInfo compareInfo = cultureInfo.CompareInfo;
//We don't need to use LastIndexOf in this function even if mathcLast is true because
//we are only trying to determine whether the pattern exists on a specific page or not.
//Exact location will be determined in TextFindEngine.InternalFind
string[] tokens = findPattern.Split(null);
if (tokens != null)
{
foreach (string token in tokens)
{
if (!String.IsNullOrEmpty(token) &&
compareInfo.IndexOf(pageString, token, compareOptions) == -1)
{
return false;
}
}
}
return true;
}
private static CompareOptions _InitializeSearch (CultureInfo cultureInfo,
bool matchCase,
bool matchAlefHamza,
bool matchDiacritics,
ref string findPattern,
out bool replaceAlefWithAlefHamza)
{
CompareOptions compareOptions = CompareOptions.None;
replaceAlefWithAlefHamza = false;
if (!matchCase)
{
compareOptions |= CompareOptions.IgnoreCase;
}
bool stringContainedBidiCharacter;
bool stringContainedAlefCharacter;
// Initialize Bidi flags whether the string contains the bidi characters
// or alef character.
TextFindEngine.InitializeBidiFlags(
findPattern,
out stringContainedBidiCharacter,
out stringContainedAlefCharacter);
if (stringContainedAlefCharacter && !matchAlefHamza)
{
// Replace the alef-hamza with the alef.
findPattern = TextFindEngine.ReplaceAlefHamzaWithAlef(findPattern);
replaceAlefWithAlefHamza = true;
}
// Ignore Bidi diacritics that use for only Bidi language.
if (!matchDiacritics && stringContainedBidiCharacter)
{
// Ignore Bidi diacritics with checking non-space character.
compareOptions |= CompareOptions.IgnoreNonSpace;
}
return compareOptions;
}
private static void _GetFirstPageSearchPointers ( ITextPointer start,
ITextPointer end,
int pageNumber,
bool matchLast,
out ITextPointer firstSearchPageStart,
out ITextPointer firstSearchPageEnd)
{
if (matchLast)
{
//The page in question is the last page
//Need to search between the start of the last page and the end pointer
DocumentSequenceTextPointer endAsDSTP = end as DocumentSequenceTextPointer;
if (endAsDSTP != null)
{
FlowPosition pageStartFlowPosition = ((FixedTextContainer)(endAsDSTP.ChildBlock.ChildContainer)).FixedTextBuilder.GetPageStartFlowPosition(pageNumber);
firstSearchPageStart = new DocumentSequenceTextPointer(endAsDSTP.ChildBlock,
new FixedTextPointer(false, LogicalDirection.Forward,pageStartFlowPosition));
}
else
{
FixedTextPointer endAsFTP = end as FixedTextPointer;
Debug.Assert(endAsFTP != null);
firstSearchPageStart = new FixedTextPointer(false, LogicalDirection.Forward, endAsFTP.FixedTextContainer.FixedTextBuilder.GetPageStartFlowPosition(pageNumber));
}
firstSearchPageEnd = end;
}
else
{
//The page in question is the first page
//Need to search between the start pointer and the end of the first page
DocumentSequenceTextPointer startAsDSTP = start as DocumentSequenceTextPointer;
if (startAsDSTP != null)
{
FlowPosition pageEndFlowPosition = ((FixedTextContainer)startAsDSTP.ChildBlock.ChildContainer).FixedTextBuilder.GetPageEndFlowPosition(pageNumber);
firstSearchPageEnd = new DocumentSequenceTextPointer( startAsDSTP.ChildBlock,
new FixedTextPointer(false, LogicalDirection.Backward, pageEndFlowPosition));
}
else
{
FixedTextPointer startAsFTP = start as FixedTextPointer;
Debug.Assert(startAsFTP != null);
firstSearchPageEnd = new FixedTextPointer(false, LogicalDirection.Backward, startAsFTP.FixedTextContainer.FixedTextBuilder.GetPageEndFlowPosition(pageNumber));
}
firstSearchPageStart = start;
}
}
private static String _GetPageString(FixedDocument doc, int translatedPageNo, bool replaceAlefWithAlefHamza)
{
String pageString = null;
Debug.Assert(doc != null);
Debug.Assert(translatedPageNo >= 0 && translatedPageNo < doc.PageCount);
PageContent pageContent = doc.Pages[translatedPageNo];
Stream pageStream = pageContent.GetPageStream();
bool reverseRTL = true;
if (doc.HasExplicitStructure)
{
reverseRTL = false;
}
if (pageStream != null)
{
pageString = _ConstructPageString(pageStream, reverseRTL);
if (replaceAlefWithAlefHamza)
{
// Replace the alef-hamza with the alef.
pageString = TextFindEngine.ReplaceAlefHamzaWithAlef(pageString);
}
}
return pageString;
}
private static String _ConstructPageString(Stream pageStream, bool reverseRTL)
{
Debug.Assert(pageStream != null);
XmlTextReader xmlTextReader = new XmlTextReader(pageStream);
//Wrap around a compatibility reader
XmlReader xmlReader = new XmlCompatibilityReader(xmlTextReader, _predefinedNamespaces);
XmlReaderSettings settings = new XmlReaderSettings();
settings.IgnoreWhitespace = true;
settings.IgnoreComments = true;
settings.ProhibitDtd = true;
xmlReader = XmlReader.Create(xmlReader, settings);
xmlReader.MoveToContent();
StringBuilder pageString = new StringBuilder();
bool isSideways = false;
string unicodeStr = null;
while (xmlReader.Read())
{
switch (xmlReader.NodeType)
{
case XmlNodeType.Element:
{
if (xmlReader.Name == "Glyphs")
{
unicodeStr = xmlReader.GetAttribute("UnicodeString");
if (!String.IsNullOrEmpty(unicodeStr))
{
string sidewaysString = xmlReader.GetAttribute("IsSideways");
isSideways = false;
if (sidewaysString != null &&
String.Compare(sidewaysString, Boolean.TrueString, StringComparison.OrdinalIgnoreCase) == 0)
{
isSideways = true;
}
if (reverseRTL)
{
//This is to cover for MXDW generation
//RTL Glyphs are saved LTR and bidi level is not set
//In this case we need to reverse the UnicodeString
string bidiLevelAsString = xmlReader.GetAttribute("BidiLevel");
int bidiLevel = 0;
if (!String.IsNullOrEmpty(bidiLevelAsString))
{
try
{
bidiLevel = Convert.ToInt32(bidiLevelAsString, CultureInfo.InvariantCulture);
}
catch (Exception)
{
}
}
string caretStops = xmlReader.GetAttribute("CaretStops");
if (bidiLevel == 0 &&
!isSideways &&
String.IsNullOrEmpty(caretStops) &&
FixedTextBuilder.MostlyRTL(unicodeStr))
{
char[] chars = unicodeStr.ToCharArray();
Array.Reverse(chars);
unicodeStr = new String(chars);
}
}
pageString.Append(unicodeStr);
}
}
}
break;
}
}
return pageString.ToString();
}
//Private constructor to prevent the compiler from generating a default constructor (fxcop)
private FixedFindEngine()
{
}
static private string [] _predefinedNamespaces = new string [2] {
"http://schemas.microsoft.com/xps/2005/06",
XamlReaderHelper.DefinitionMetroNamespaceURI
};
}
}
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