/// <summary>
/// Start a search.
/// </summary>
/// <param name="text_page">Handle to a text page information structure. Returned by FPDFText_LoadPage function.</param>
/// <param name="findwhat">A unicode match pattern.</param>
/// <param name="flags">Option flags.</param>
/// <param name="start_index">Start from this character. -1 for end of the page.</param>
/// <returns>A handle for the search context. FPDFText_FindClose must be called to release this handle.</returns>
/// <remarks>
/// FPDF_EXPORT FPDF_SCHHANDLE FPDF_CALLCONV FPDFText_FindStart(FPDF_TEXTPAGE text_page, FPDF_WIDESTRING findwhat, unsigned long flags, int start_index);.
/// </remarks>
public FPDF_SCHHANDLE FPDFText_FindStart(FPDF_TEXTPAGE text_page, IntPtr findwhat, FPDF_FIND_FLAGS flags, int start_index)
{
lock (_syncObject)
{
return(FPDFText_FindStartStatic(text_page, findwhat, flags, start_index));
}
}
/// <summary>
/// <inheritdoc/>
/// </summary>
public bool FindText(
string text,
bool caseSensitive,
bool wholeWords,
Func <int, bool> progress,
Func <IPDFFindPage, bool> addPage,
Func <IPDFFindPage, IPDFFindPosition, bool> addPosition)
{
if (string.IsNullOrEmpty(text))
{
return(false);
}
if (progress == null && addPage == null && addPosition == null)
{
return(false);
}
if (_mainComponent.PageComponent is PDFPageComponent pageComponent)
{
pageComponent.ClearSelectionRectangles();
}
FPDF_FIND_FLAGS flags = FPDF_FIND_FLAGS.FPDF_NONE;
if (caseSensitive)
{
flags |= FPDF_FIND_FLAGS.FPDF_MATCHCASE;
}
if (wholeWords)
{
flags |= FPDF_FIND_FLAGS.FPDF_MATCHWHOLEWORD;
}
var somethingFound = false;
var cancelFind = false;
foreach (var page in _mainComponent.PageComponent.Pages)
{
if (cancelFind || (progress != null && !progress(page.PageIndex)))
{
break;
}
var pageHandle = _mainComponent.PDFiumBridge.FPDF_LoadPage(_mainComponent.PDFiumDocument, page.PageIndex);
var textPageHandle = _mainComponent.PDFiumBridge.FPDFText_LoadPage(pageHandle);
var globalText = Marshal.StringToHGlobalUni(text);
var findHandle = _mainComponent.PDFiumBridge.FPDFText_FindStart(textPageHandle, globalText, flags, 0);
Marshal.FreeHGlobal(globalText);
PDFFindPage findPage = null;
var charsOnPage = _mainComponent.PDFiumBridge.FPDFText_CountChars(textPageHandle);
while (_mainComponent.PDFiumBridge.FPDFText_FindNext(findHandle))
{
somethingFound = true;
if (findPage == null)
{
findPage = new PDFFindPage(page);
if (addPage != null && !addPage(findPage))
{
cancelFind = true;
break;
}
}
var contextLength = 20;
var foundPosition = _mainComponent.PDFiumBridge.FPDFText_GetSchResultIndex(findHandle);
var foundCount = _mainComponent.PDFiumBridge.FPDFText_GetSchCount(findHandle);
int startPosition = Math.Max(foundPosition - contextLength, 0);
int endPosition = Math.Min(foundPosition + foundCount + contextLength, charsOnPage);
var contextGlobal = Marshal.AllocHGlobal((2 * (endPosition - startPosition)) + 2);
var writtenCount = _mainComponent.PDFiumBridge.FPDFText_GetText(textPageHandle, startPosition, endPosition - startPosition, contextGlobal);
var context = text;
if (writtenCount > 0)
{
context = Marshal.PtrToStringUni(contextGlobal);
}
context = context.Replace('\r', ' ').Replace('\n', ' ').Replace('\t', ' ');
Marshal.FreeHGlobal(contextGlobal);
var position = new PDFFindPosition(findPage)
{
Position = foundPosition,
Length = foundCount,
Context = context,
};
if (addPosition != null && !addPosition(findPage, position))
{
cancelFind = true;
break;
}
}
_mainComponent.PDFiumBridge.FPDFText_FindClose(findHandle);
_mainComponent.PDFiumBridge.FPDFText_ClosePage(textPageHandle);
_mainComponent.PDFiumBridge.FPDF_ClosePage(pageHandle);
}
return(somethingFound);
}
