lazarus/components/chmhelp/lhelp/chmdataprovider.pas
2017-10-18 17:49:55 +00:00

277 lines
6.7 KiB
ObjectPascal

{
*****************************************************************************
See the file COPYING.modifiedLGPL.txt, included in this distribution,
for details about the license.
*****************************************************************************
Copyright (C) <2005> <Andrew Haines> chmdataprovider.pas
}
unit ChmDataProvider;
{$mode objfpc}{$H+}
interface
uses
Classes, SysUtils, IpHtml, iputils, IpMsg, Graphics, chmreader,
LCLType, Controls,
FPImage,
{$IF FPC_FULLVERSION>=20602} //fpreadgif exists since at least this version
FPReadgif,
{$ENDIF}
FPReadbmp,
FPReadxpm,
FPReadJPEG,
FPReadpng,
FPWritebmp,
FPWritePNG,
IntFGraphics,
lhelpstrconsts;
type
THelpPopupEvent = procedure(HelpFile: String; URL: String);
THtmlPageLoadStreamEvent = procedure (var AStream: TStream) of object;
{ TIpChmDataProvider }
TIpChmDataProvider = class(TIpAbstractHtmlDataProvider)
private
fChm: TChmFileList;
fCurrentPage: String;
fCurrentPath: String;
FOnGetHtmlPage: THtmlPageLoadStreamEvent;
fOnHelpPopup: THelpPopupEvent;
function StripInPageLink(AURL: String): String;
protected
function DoGetHtmlStream(const URL: string;
{%H-}PostData: TIpFormDataEntity) : TStream; override;
function DoCheckURL(const URL: string;
var ContentType: string): Boolean; override;
procedure DoLeave({%H-}Html: TIpHtml); override;
procedure DoReference(const {%H-}URL: string); override;
procedure DoGetImage(Sender: TIpHtmlNode; const URL: string;
var Picture: TPicture); override;
function CanHandle(const URL: string): Boolean; override;
function BuildURL(const OldURL, NewURL: string): string; override;
function GetDirsParents(ADir: String): TStringList;
function DoGetStream(const URL: string): TStream; override;
public
constructor Create(AOwner: TComponent; AChm: TChmFileList); reintroduce;
destructor Destroy; override;
property Chm: TChmFileList read fChm write fChm;
property OnHelpPopup: THelpPopupEvent read fOnHelpPopup write fOnHelpPopup;
property CurrentPage: String read fCurrentPage;
property CurrentPath: String read fCurrentPath write fCurrentPath;
property OnGetHtmlPage: THtmlPageLoadStreamEvent read FOnGetHtmlPage write FOnGetHtmlPage;
end;
implementation
{ TIpChmDataProvider }
function TIpChmDataProvider.StripInPageLink ( AURL: String ) : String;
var
i: LongInt;
begin
Result := AURL;
i := Pos('#', Result);
if i > 0 then
Result := Copy(Result, 1, i-1);
end;
function TIpChmDataProvider.DoGetHtmlStream(const URL: string;
PostData: TIpFormDataEntity): TStream;
var Tmp:string;
begin
Result := fChm.GetObject(StripInPageLink(URL));
// If for some reason we were not able to get the page return something so that
// we don't cause an AV
if Result = nil then begin
Result := TMemoryStream.Create;
Tmp := '<HTML>' + slhelp_PageCannotBeFound + '</HTML>';
Result.Write(Tmp,Length(tmp));
end;
if Assigned(FOnGetHtmlPage) then
FOnGetHtmlPage(Result);
end;
function TIpChmDataProvider.DoCheckURL(const URL: string;
var ContentType: string): Boolean;
var
Reader: TChmReader = nil;
begin
//DebugLn('RequestedUrl: ',URL);
Result := fChm.ObjectExists(StripInPageLink(Url), Reader) > 0;
if Result then begin
ContentType := 'text/html';
fCurrentPath := ExtractFilePath(Url);
Result := True;
fCurrentPage := URL;
end;
end;
procedure TIpChmDataProvider.DoLeave(Html: TIpHtml);
begin
//
// //DebugLn('Left: ');
end;
procedure TIpChmDataProvider.DoReference(const URL: string);
begin
//
////DebugLn('Reference=',URL);
end;
procedure TIpChmDataProvider.DoGetImage(Sender: TIpHtmlNode; const URL: string;
var Picture: TPicture);
var
Stream: TMemoryStream;
FileExt: String;
begin
//DebugLn('Getting Image ',(Url));
Picture := nil;
FileExt := ExtractFileExt(URL);
Picture := TPicture.Create;
Stream := fChm.GetObject('/'+URL);
try
if Assigned(Stream) then
begin
Stream.Position := 0;
Picture.LoadFromStreamWithFileExt(Stream, FileExt);
end;
except
// only happens if it's an image type we can't handle
end;
if Stream <> nil then
Stream.Free;
end;
function TIpChmDataProvider.CanHandle(const URL: string): Boolean;
var
Reader: TChmReader = nil;
begin
Result := True;
if Pos('Java', URL) = 1 then
Result := False;
if (fChm.ObjectExists(StripInPageLink(url), Reader)= 0) and
(fChm.ObjectExists(StripInPageLink(BuildUrl(fCurrentPath,Url)), Reader) = 0)
then
Result := False;
//DebugLn('CanHandle ',Url,' = ', Result);
//if not Result then if fChm.ObjectExists(BuildURL('', URL)) > 0 Then result := true;
if (not Result) and (Pos('#', URL) = 1) then
Result := True;
end;
function TIpChmDataProvider.BuildURL(const OldURL, NewURL: string): string;
var
X: LongInt;
fNewURL: String;
ParentDirs: TStringList;
RemoveDirCount: Integer;
begin
Result := NewURL;
fNewURL := NewURL;
if OldURL = '' then
exit;
if Pos('ms-its:', NewURL) = 1 then begin
if Pos('#', NewURL) = 0 then
exit;
X := Pos('::', NewURL);
if NewURL[X+2] = '/' then // NewURL is complete and absolute --> nothing to do
exit;
fNewURL := Copy(fNewURL, X+3, MaxInt);
end;
ParentDirs := GetDirsParents(OldURL);
try
RemoveDirCount := 0;
repeat
X := Pos('../', fNewURL);
if X > 0 then
begin
Delete(fNewURL, X, 3);
Inc(RemoveDirCount);
end;
until X = 0;
repeat
X := Pos('./', fNewURL);
if X > 0 then
Delete(fNewURL, X, 2);
until X = 0;
Result := '';
for X := 0 to ParentDirs.Count-RemoveDirCount-1 do
Result := Result + ParentDirs[X] + '/';
Result := Result+fNewURL;
repeat
X := Pos('//', Result);
if X > 0 then
Delete(Result, X, 1);
until X = 0;
finally
ParentDirs.Free;
//WriteLn('res = ', Result);
end;
end;
function TIpChmDataProvider.GetDirsParents(ADir: String): TStringList;
var
LastName: String;
begin
Result := TStringList.Create;
Result.Delimiter := '/';
Result.StrictDelimiter := true;
Result.DelimitedText := ADir;
LastName := ExtractFileName(ADir);
if LastName <> '' then
Result.Delete(Result.Count-1);
if Result[Result.Count-1] = '' then
Result.Delete(Result.Count-1);
end;
function TIpChmDataProvider.DoGetStream(const URL: string): TStream;
var
NewURL: String;
begin
Result := nil;
if Length(URL) = 0 then
Exit;
if not (URL[1] in ['/']) then
NewURL := BuildUrl(fCurrentPath,URL)
else
NewURL := URL;
Result := fChm.GetObject(NewURL);
end;
constructor TIpChmDataProvider.Create(AOwner: TComponent; AChm: TChmFileList);
begin
inherited Create(AOwner);
fChm := AChm;
end;
destructor TIpChmDataProvider.Destroy;
begin
inherited Destroy;
end;
end.