{ПРИМЕР :
[...]
implementation
uses Search;}
{$R *.DFM}
{procedure TForm1.Button1Click(Sender: TObject);
begin
SearchMemo(RichEdit1, 'Найди меня', [frDown]);
end;
В опции поиска можно подключать, отключать, комбинировать следующие
параметры:
frDown - указывает на то, что происходит поиск вниз по тексту от курсора(при
отключенном frDown'е будет происходит поиск вверх по тексту).
frMatchCase - указывает на то, что следует проводить поиск с учетом
регистра.
frWholeWord - указывает на то, что следует искать только слово целиком.
[...]
Авторские права на этот юнит пренадлежат неизвесно кому.
В каком виде этот юнит попал мне, практически в этом же
виде я отдаю его вам. Пользуйтесь и благодарите неизвесного
героя.}
unit Search;
interface
uses
WinProcs, SysUtils, StdCtrls, Dialogs;
const
{****************************************************************************
* Default word delimiters are any character except the core alphanumerics. *
****************************************************************************}
WordDelimiters: set of Char = [#0..#255] - ['a'..'z', 'A'..'Z', '1'..'9',
'0'];
{******************************************************************************
* SearchMemo scans the text of a TEdit, TMemo, or other TCustomEdit-derived *
* component for a given search string. The search starts at the current *
* caret position in the control. The Options parameter determines whether *
* the search runs forward (frDown) or backward from the caret position, *
* whether or not the text comparison is case sensitive, and whether the *
* matching string must be a whole word. If text is already selected in the *
* control, the search starts at the 'far end' of the selection (SelStart if *
* searching backwards, SelEnd if searching forwards). If a match is found, *
* the control's text selection is changed to select the found text and the *
* function returns True. If no match is found, the function returns False. *
******************************************************************************}
function SearchMemo(Memo: TCustomEdit;
const SearchString: string;
Options: TFindOptions): Boolean;
{******************************************************************************
* SearchBuf is a lower-level search routine for arbitrary text buffers. *
* Same rules as SearchMemo above. If a match is found, the function returns *
* a pointer to the start of the matching string in the buffer. If no match, *
* the function returns nil. *
******************************************************************************}
function SearchBuf(Buf: PChar; BufLen: Integer;
SelStart, SelLength: Integer;
SearchString: string;
Options: TFindOptions): PChar;
implementation
function SearchMemo(Memo: TCustomEdit;
const SearchString: string;
Options: TFindOptions): Boolean;
var
Buffer, P: PChar;
Size: Word;
begin
Result := False;
if (Length(SearchString) = 0) then
Exit;
Size := Memo.GetTextLen;
if Size = 0 then
Exit;
Buffer := StrAlloc(Size + 1);
try
Memo.GetTextBuf(Buffer, Size + 1);
P := SearchBuf(Buffer, Size, Memo.SelStart, Memo.SelLength, SearchString,
Options);
if P <> nil then
begin
Memo.SelStart := P - Buffer;
Memo.SelLength := Length(SearchString);
Result := True;
end;
finally
StrDispose(Buffer);
end;
end;
function SearchBuf(Buf: PChar; BufLen: Integer;
SelStart, SelLength: Integer;
SearchString: string;
Options: TFindOptions): PChar;
var
SearchCount, I: Integer;
C: Char;
Direction: Shortint;
CharMap: array[Char] of Char;
function FindNextWordStart(var BufPtr: PChar): Boolean;
begin { (True XOR N) is equivalent to (not N) }
// Result := False; { (False XOR N) is equivalent to (N) }
{ When Direction is forward (1), skip non delimiters, then skip delimiters. }
{ When Direction is backward (-1), skip delims, then skip non delims }
while (SearchCount > 0) and
((Direction = 1) xor
(BufPtr^ in WordDelimiters)) do
begin
Inc(BufPtr, Direction);
Dec(SearchCount);
end;
while (SearchCount > 0) and
((Direction = -1) xor
(BufPtr^ in WordDelimiters)) do
begin
Inc(BufPtr, Direction);
Dec(SearchCount);
end;
Result := SearchCount > 0;
if Direction = -1 then
begin {back up one char, to leave ptr on first non delim}
Dec(BufPtr, Direction);
Inc(SearchCount);
end;
end;
begin
Result := nil;
if BufLen <= 0 then
Exit;
if frDown in Options then
begin {if frDown...}
Direction := 1;
Inc(SelStart, SelLength); { start search past end of selection }
SearchCount := BufLen - SelStart - Length(SearchString);
if SearchCount < 0 then
Exit;
if Longint(SelStart) + SearchCount > BufLen then
Exit;
end {if frDown...}
else
begin {else}
Direction := -1;
Dec(SelStart, Length(SearchString));
SearchCount := SelStart;
end; {else}
if (SelStart < 0) or (SelStart > BufLen) then
Exit;
Result := @Buf[SelStart];
{ Using a Char map array is faster than calling AnsiUpper on every character }
for C := Low(CharMap) to High(CharMap) do
CharMap[C] := C;
if not (frMatchCase in Options) then
begin {if not (frMatchCase}
AnsiUpperBuff(PChar(@CharMap), sizeof(CharMap));
AnsiUpperBuff(@SearchString[1], Length(SearchString));
end; {if not (frMatchCase}
while SearchCount > 0 do
begin {while SearchCount}
if frWholeWord in Options then
begin
if not FindNextWordStart(Result) then
Break;
end;
I := 0;
while (CharMap[Result[I]] = SearchString[I + 1]) do
begin {while (CharMap...}
Inc(I);
if I >= Length(SearchString) then
begin {if I >=...}
if (not (frWholeWord in Options)) or
(SearchCount = 0) or
(Result[I] in WordDelimiters) then
Exit;
Break;
end; {if I >=...}
end; {while (CharMap...}
Inc(Result, Direction);
Dec(SearchCount);
end; {while SearchCount}
Result := nil;
end;
end.
|
Поиск строки текста в наследниках TCustomEdit