Subversion Repositories fastphp

unit WebBrowserUtils;

{$Include 'FastPHP.inc'}

interface

uses

  // TODO: "{$IFDEF USE_SHDOCVW_TLB}ShDocVw_TLB{$ELSE}ShDocVw{$ENDIF}" does not work with Delphi 10.2

  Windows, ShDocVw, SysUtils, Forms, Classes;

procedure WaitForBrowser(AWebBrowser: TWebbrowser);

function WebBrowserLoadHTML(AWebBrowser: TWebBrowser; const AHTML: string;

                            const AFakeURL: string=''): boolean;

function WebBrowserLoadStream(AWebBrowser: TWebBrowser; const AStream: TStream;

                            const AFakeURL: string=''): boolean;

type

  TWebBrowserEx = class helper for TWebBrowser

  public

    procedure Clear;

    procedure Wait;

    function LoadHTML(const HTML: string; const AFakeURL: string=''): boolean;

    function LoadStream(const Stream: TStream; const AFakeURL: string=''): boolean;

    procedure ReadMetaTags(outSL: TStringList);

  end;

implementation

uses

  ActiveX, urlmon;

type

  (*

  ILoadHTMLMoniker = interface(IMoniker)

    ['{DCAE3F41-9B38-40EB-B7D0-4AF0FBFBE5AB}']

    procedure InitLoader(sContent, sBaseUrl: string);

  end;

  *)

  TLoadHTMLMoniker = class (TInterfacedObject, IMoniker{, ILoadHTMLMoniker})

  private

    m_stream: IStream;

    m_sBaseName: string;

  public

    procedure InitLoader(sContent, sBaseUrl: string);

    procedure InitLoaderStream(sStream: TStream; sBaseUrl: string);

    {$REGION 'IMoniker members'}

    function BindToObject(const bc: IBindCtx; const mkToLeft: IMoniker;

      const iidResult: TIID; out vResult): HResult; stdcall;

    function BindToStorage(const bc: IBindCtx; const mkToLeft: IMoniker;

      const iid: TIID; out vObj): HResult; stdcall;

    function Reduce(const bc: IBindCtx; dwReduceHowFar: Longint;

      mkToLeft: PIMoniker; out mkReduced: IMoniker): HResult; stdcall;

    function ComposeWith(const mkRight: IMoniker; fOnlyIfNotGeneric: BOOL;

      out mkComposite: IMoniker): HResult; stdcall;

    function Enum(fForward: BOOL; out enumMoniker: IEnumMoniker): HResult;

      stdcall;

    function IsEqual(const mkOtherMoniker: IMoniker): HResult; stdcall;

    function Hash(out dwHash: Longint): HResult; stdcall;

    function IsRunning(const bc: IBindCtx; const mkToLeft: IMoniker;

      const mkNewlyRunning: IMoniker): HResult; stdcall;

    function GetTimeOfLastChange(const bc: IBindCtx; const mkToLeft: IMoniker;

      out filetime: TFileTime): HResult; stdcall;

    function Inverse(out mk: IMoniker): HResult; stdcall;

    function CommonPrefixWith(const mkOther: IMoniker;

      out mkPrefix: IMoniker): HResult; stdcall;

    function RelativePathTo(const mkOther: IMoniker;

      out mkRelPath: IMoniker): HResult; stdcall;

    function GetDisplayName(const bc: IBindCtx; const mkToLeft: IMoniker;

      out pszDisplayName: POleStr): HResult; stdcall;

    function ParseDisplayName(const bc: IBindCtx; const mkToLeft: IMoniker;

      pszDisplayName: POleStr; out chEaten: Longint;

      out mkOut: IMoniker): HResult; stdcall;

    function IsSystemMoniker(out dwMksys: Longint): HResult; stdcall;

    {$ENDREGION}

    {$REGION 'IPersistStream members'}

    function IsDirty: HResult; stdcall;

    function Load(const stm: IStream): HResult; stdcall;

    function Save(const stm: IStream; fClearDirty: BOOL): HResult; stdcall;

    function GetSizeMax(out cbSize: Largeint): HResult; stdcall;

    {$ENDREGION}

    {$REGION 'IPersist members'}

    function GetClassID(out classID: TCLSID): HResult; stdcall;

    {$ENDREGION}

  end;

// http://stackoverflow.com/questions/12605323/globalalloc-causes-my-delphi-app-hang

function StrToGlobalHandle(const aText: string): HGLOBAL;

var

  ptr: PChar;

begin

  Result := 0;

  if aText <> '' then

  begin

    Result := GlobalAlloc(GMEM_MOVEABLE or GMEM_ZEROINIT, (length(aText) + 1) * SizeOf(Char));

    if Result <> 0 then

    begin

      ptr := GlobalLock(Result);

      if Assigned(ptr) then

      begin

        StrCopy(ptr, PChar(aText));

        GlobalUnlock(Result);

      end

    end;

  end;

end;

procedure WaitForBrowser(AWebBrowser: TWebbrowser);

begin

  while (AWebBrowser.ReadyState <> READYSTATE_COMPLETE) and

        (not Assigned(Application) or not Application.Terminated) do

  begin

    if Assigned(Application) then Application.ProcessMessages;

    Sleep(50);

  end;

end;

function WebBrowserLoadHTML(AWebBrowser: TWebBrowser; const AHTML: string;

                            const AFakeURL: string=''): boolean;

var

  bindctx: IBindCtx;

  pPM: IPersistMoniker;

  loader: TLoadHTMLMoniker;

  url: string;

begin

  if AFakeURL <> '' then

    url := AFakeURL

  else if AWebBrowser.LocationURL <> '' then

    url := AWebBrowser.LocationURL

  else

    url := 'about:blank';

  if AWebBrowser.Document = nil then

  begin

    AWebBrowser.Navigate('about:blank');

    WaitForBrowser(AWebBrowser);

  end;

  pPM := AWebBrowser.Document as IPersistMoniker;

  if (pPM = nil) then

  begin

    result := false;

    exit;

  end;

  bindctx := nil;

  CreateBindCtx(0, bindctx);

  if (bindctx = nil) then

  begin

    result := false;

    exit;

  end;

  try

    // TODO: Delphi2007 and FastMM4 say that here we have a memory leak

    loader := TLoadHTMLMoniker.Create;

    loader.InitLoader(AHTML, url);

  except

    if Assigned(loader) then FreeAndNil(loader);

    result := false;

    exit;

  end;

  result := pPM.Load(true, loader, bindctx, STGM_READ) = S_OK;

  if not result and Assigned(loader) then FreeAndNil(loader);

end;

function WebBrowserLoadStream(AWebBrowser: TWebBrowser; const AStream: TStream;

                            const AFakeURL: string=''): boolean;

var

  bindctx: IBindCtx;

  pPM: IPersistMoniker;

  loader: TLoadHTMLMoniker;

  url: string;

begin

  if AFakeURL <> '' then

    url := AFakeURL

  else if AWebBrowser.LocationURL <> '' then

    url := AWebBrowser.LocationURL

  else

    url := 'about:blank';

  if AWebBrowser.Document = nil then

  begin

    AWebBrowser.Navigate('about:blank');

    WaitForBrowser(AWebBrowser);

  end;

  pPM := AWebBrowser.Document as IPersistMoniker;

  if (pPM = nil) then

  begin

    result := false;

    exit;

  end;

  bindctx := nil;

  CreateBindCtx(0, bindctx);

  if (bindctx = nil) then

  begin

    result := false;

    exit;

  end;

  try

    // TODO: Delphi2007 and FastMM4 say that here we have a memory leak

    loader := TLoadHTMLMoniker.Create;

    loader.InitLoaderStream(AStream, url);

  except

    if Assigned(loader) then FreeAndNil(loader);

    result := false;

    exit;

  end;

  result := pPM.Load(true, loader, bindctx, STGM_READ) = S_OK;

  if not result and Assigned(loader) then FreeAndNil(loader);

end;

{ TLoadHTMLMoniker }

// TLoadHTMLMoniker. Translated from C# to Delphi by Daniel Marschall

// Resources:

// - http://stackoverflow.com/questions/40927080/relative-urls-in-a-twebbrowser-containing-custom-html-code

// - https://github.com/kuza55/csexwb2/blob/master/General_Classes/LoadHTMLMoniker.cs

// - https://github.com/kuza55/csexwb2/blob/master/cEXWB.cs#L1769

procedure TLoadHTMLMoniker.InitLoader(sContent, sBaseUrl: string);

resourcestring

  SCannotAllocMemory = 'Cannot create IStream.';

var

  hr: integer;

begin

  m_sBaseName := sBaseUrl;

  hr := CreateStreamOnHGlobal(StrToGlobalHandle(sContent), true, m_stream);

  if ((hr <> S_OK) or (m_stream = nil)) then raise Exception.Create(SCannotAllocMemory);

end;

procedure TLoadHTMLMoniker.InitLoaderStream(sStream: TStream; sBaseUrl: string);

resourcestring

  SCannotAllocMemory = 'Cannot create IStream.';

begin

  m_sBaseName := sBaseUrl;

  m_stream := TStreamAdapter.Create(sStream, soReference) as IStream;

  if (m_stream = nil) then raise Exception.Create(SCannotAllocMemory);

end;

function TLoadHTMLMoniker.GetDisplayName(const bc: IBindCtx;

  const mkToLeft: IMoniker; out pszDisplayName: POleStr): HResult;

var

  bufSize: integer;

  wTest: WideString;

begin

//  pszDisplayName := PWideChar(WideString(m_sBaseName));

  // I am not sure if that is correct......

  bufSize := (Length(m_sBaseName)+1) * SizeOf(WideChar);

  pszDisplayName := CoTaskMemAlloc(bufSize);

  wTest := m_sBaseName;

  CopyMemory(pszDisplayName, PWideChar(wTest), bufSize);

  result := S_OK;

end;

function TLoadHTMLMoniker.BindToStorage(const bc: IBindCtx;

  const mkToLeft: IMoniker; const iid: TIID; out vObj): HResult;

const

  IID_IStream: TGUID = '{0000000C-0000-0000-C000-000000000046}';

begin

  if IsEqualIID(iid, IID_IStream) then

  begin

    IStream(vObj) := m_stream;

    result := S_OK;

  end

  else

  begin

    IStream(vObj) := nil;

    result := E_NOINTERFACE;

  end;

end;

{$REGION 'Not implemented'}

function TLoadHTMLMoniker.BindToObject(const bc: IBindCtx;

  const mkToLeft: IMoniker; const iidResult: TIID; out vResult): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.CommonPrefixWith(const mkOther: IMoniker;

  out mkPrefix: IMoniker): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.ComposeWith(const mkRight: IMoniker;

  fOnlyIfNotGeneric: BOOL; out mkComposite: IMoniker): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.Enum(fForward: BOOL;

  out enumMoniker: IEnumMoniker): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.GetClassID(out classID: TCLSID): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.GetSizeMax(out cbSize: Largeint): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.GetTimeOfLastChange(const bc: IBindCtx;

  const mkToLeft: IMoniker; out filetime: TFileTime): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.Hash(out dwHash: Integer): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.Inverse(out mk: IMoniker): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.IsDirty: HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.IsEqual(const mkOtherMoniker: IMoniker): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.IsRunning(const bc: IBindCtx; const mkToLeft,

  mkNewlyRunning: IMoniker): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.IsSystemMoniker(out dwMksys: Integer): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.Load(const stm: IStream): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.ParseDisplayName(const bc: IBindCtx;

  const mkToLeft: IMoniker; pszDisplayName: POleStr; out chEaten: Integer;

  out mkOut: IMoniker): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.Reduce(const bc: IBindCtx; dwReduceHowFar: Integer;

  mkToLeft: PIMoniker; out mkReduced: IMoniker): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.RelativePathTo(const mkOther: IMoniker;

  out mkRelPath: IMoniker): HResult;

begin

  result := E_NOTIMPL;

end;

function TLoadHTMLMoniker.Save(const stm: IStream; fClearDirty: BOOL): HResult;

begin

  result := E_NOTIMPL;

end;

{$ENDREGION}

{ TWebBrowserEx }

procedure TWebBrowserEx.Wait;

begin

  WaitForBrowser(Self);

end;

function TWebBrowserEx.LoadHTML(const HTML: string; const AFakeURL: string=''): boolean;

begin

  result := WebBrowserLoadHTML(Self, HTML, AFakeURL);

  Self.Wait;

end;

function TWebBrowserEx.LoadStream(const Stream: TStream; const AFakeURL: string=''): boolean;

begin

  result := WebBrowserLoadStream(Self, Stream, AFakeURL);

  Self.Wait;

end;

procedure TWebBrowserEx.ReadMetaTags(outSL: TStringList);

var

  vDocument: OleVariant;

  vMetas: OleVariant;

  vMetaItem: OleVariant;

  i: Integer;

begin

  vDocument := Self.Document;

  vMetas := vDocument.GetElementsByTagName('meta');

  for i := 0 to vMetas.Length-1 do

  begin

    vMetaItem := vMetas.Item(i);

    if string(vMetaItem.httpequiv) = '' then

      outSL.Values[vMetaItem.Name] := vMetaItem.Content

    else

      outSL.Values[vMetaItem.httpequiv] := vMetaItem.Content;

  end;

end;

procedure TWebBrowserEx.Clear;

begin

  Self.LoadHTML('', 'about:blank');

end;

end.