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#include <TextSearch.h>
Public Types | |
enum | { e_reg_expression = 0x0001, e_case_sensitive = e_reg_expression << 1, e_whole_word = e_case_sensitive << 1, e_search_up = e_whole_word << 1, e_page_stop = e_search_up << 1, e_highlight = e_page_stop << 1, e_ambient_string = e_highlight << 1 } |
Search modes that control how searching is conducted. More... | |
enum | ResultCode { e_done = 0, e_page = 1, e_found = 2 } |
The code indicating the reason that the search process returns. More... | |
typedef TRN_UInt32 | Mode |
Typedef the search mode. | |
Public Member Functions | |
TextSearch () | |
Constructor and destructor. | |
~TextSearch () | |
bool | Begin (PDFDoc &doc, const UString &pattern, Mode mode, int start_page=-1, int end_page=-1) |
Initialize for search process. | |
ResultCode | Run (int &page_num, UString &result_str, UString &ambient_str, Highlights &hlts) |
Search the document and returns upon the following circumstances: a)Reached the end of the document; b)Reached the end of a page (if set to return by specifying mode 'e_page_stop' ); c)Found an instance matching the search pattern. | |
bool | SetPattern (const UString &pattern) |
Set the current search pattern. | |
Mode | GetMode () const |
Retrieve the current search mode. | |
void | SetMode (Mode mode) |
Set the current search mode. | |
int | GetCurrentPage () const |
Retrieve the number of the current page that is searched in. |
The current implementation supports both verbatim search and the search using regular expressions, whose detailed syntax can be found at:
http://www.boost.org/doc/libs/1_42_0/libs/regex/doc/html/boost_regex/syntax/perl_syntax.html
TextSearch also provides users with several useful search modes and extra information besides the found string that matches the pattern. TextSearch can either keep running until a matched string is found or be set to return periodically in order for the caller to perform any necessary updates (e.g., UI updates). It is also worth mentioning that the search modes can be changed on the fly while searching through a document.
Possible use case scenarios for TextSearch include:
Note:
"TextSearch is powerful for finding patterns in PDF files; yes, it is really pow- erful."
a search for "powerful" should return both instances. However, not all end-of-line hyphens are hyphens added to connect a broken word; some of them could be "real" hyphens. In addition, an input search pattern may also contain hyphens that complicate the situation. To tackle this problem, the following conventions are adopted:
a)When in the verbatim search mode and the pattern contains no hyphen, a matching string is returned if it is exactly the same or it contains end-of-line or start-of-line hyphens. For example, as mentioned above, a search for "powerful" would return both instances. b)When in verbatim search mode and the pattern contains one or multiple hyphens, a matching string is returned only if the string matches the pattern exactly. For example, a search for "pow-erful" will only return the second instance, and a search for "power-ful" will return nothing. c)When searching using regular expressions, hyphens are not taken care implicitly. Users should take care of it themselves. For example, in order to find both the "powerful" instances, the input pattern can be "pow-{0,1}erful".
A sample use case (in C++):
... Initialize PDFNet ... PDFDoc doc(filein); doc.InitSecurityHandler(); int page_num; char buf[32]; UString result_str, ambient_string; Highlights hlts; TextSearch txt_search; TextSearch::Mode mode = TextSearch::e_whole_word | TextSearch::e_page_stop; UString pattern( "joHn sMiTh" ); while ( true ) { TextSearch::ResultCode code = txt_search.Run(page_num, result_str, ambient_string, hlts ); if ( code == TextSearch::e_found ) { result_str.ConvertToAscii(buf, 32, true); cout << "found one instance: " << char_buf << endl; } else { break; } }
For a full sample, please take a look at the TextSearch sample project.
typedef TRN_UInt32 pdftron::PDF::TextSearch::Mode |
Typedef the search mode.
anonymous enum |
pdftron::PDF::TextSearch::TextSearch | ( | ) |
Constructor and destructor.
pdftron::PDF::TextSearch::~TextSearch | ( | ) |
bool pdftron::PDF::TextSearch::Begin | ( | PDFDoc & | doc, | |
const UString & | pattern, | |||
Mode | mode, | |||
int | start_page = -1 , |
|||
int | end_page = -1 | |||
) |
Initialize for search process.
This should be called before starting the actual search with method Run().
doc | the PDF document to search in. | |
pattern | the pattern to search for. When regular expression is used, it contains the expression, and in verbatim mode, it is the exact string to search for. | |
mode | the mode of the search process. | |
start_page | the start page of the page range to search in. The default value is -1 indicating the range starts from the first page. | |
end_page | the end page of the page range to search in. The default value is -1 indicating the range ends at the last page. |
ResultCode pdftron::PDF::TextSearch::Run | ( | int & | page_num, | |
UString & | result_str, | |||
UString & | ambient_str, | |||
Highlights & | hlts | |||
) |
Search the document and returns upon the following circumstances: a)Reached the end of the document; b)Reached the end of a page (if set to return by specifying mode 'e_page_stop' ); c)Found an instance matching the search pattern.
Note that this method should be called in a loop in order to find all matching instances; in other words, the search is conducted in an incremental fashion. In addition, the resulting information only makes sense when the returned code is 'e_found'.
page_num | the number of the page the found instance is on. | |
result_str | the found string that matches the search pattern. | |
ambient_str | the ambient string of the found string (computed if 'e_ambient_string' is set). | |
hlts | the Highlights info associated with the found string (computed if 'e_highlight' is set). |
bool pdftron::PDF::TextSearch::SetPattern | ( | const UString & | pattern | ) |
Set the current search pattern.
Note that it is not necessary to call this method since the search pattern is already set when calling the Begin() method. This method is provided for users to change the search pattern while searching through a document.
pattern | the search pattern to set. |
Mode pdftron::PDF::TextSearch::GetMode | ( | ) | const |
Retrieve the current search mode.
void pdftron::PDF::TextSearch::SetMode | ( | Mode | mode | ) |
Set the current search mode.
For example, the following code turns on the regular expressions:
TextSearch ts; ... TextSearch::Mode mode = ts.GetMode(); mode |= TextSearch::e_reg_expression; ts.SetMode(mode); ...
mode | the search mode to set. |
int pdftron::PDF::TextSearch::GetCurrentPage | ( | ) | const |
Retrieve the number of the current page that is searched in.
If the returned value is -1, it indicates the search process has not been initialized (e.g., Begin() is not called yet); if the returned value is 0, it indicates the search process has finished, and if the returned value is positive, it is a valid page number.