TTMSFNCWXPDFViewer

The TTMSFNCWXPDFViewer is a component for displaying PDF files inside your application. It supports page navigation, zoom, rotation, text search, thumbnail generation, form field extraction, and page-to-image export. It uses the PDF.js JavaScript library.

Notice

With the default settings this component requires internet connection. If you'd like to run the component in an offline environment, please change the LibraryLocation property. Read more about this at the Loading modes paragraph of this documentation.

Loading a PDF

From a URL

CORS-protected URLs cannot be loaded this way. The PDF is fetched via an HTTP request.

procedure TForm1.Button1Click(Sender: TObject);
begin
  TMSFNCWXPDFViewer1.LoadFromUrl('https://example.com/document.pdf');
end;

From a file (VCL, FMX, LCL)

TMSFNCWXPDFViewer1.LoadFromFile('C:\Documents\report.pdf');

From a Base64 string

TMSFNCWXPDFViewer1.LoadFromBase64(myBase64EncodedString);

The OnLoaded event fires when the PDF is ready. OnLoadError fires if loading fails.

Password-protected PDFs

Set the Password property before calling a load method:

TMSFNCWXPDFViewer1.Password := 'secret';
TMSFNCWXPDFViewer1.LoadFromFile('protected.pdf');

// Navigate page by page
TMSFNCWXPDFViewer1.NextPage;
TMSFNCWXPDFViewer1.PreviousPage;

// Jump to a specific page (1-based)
TMSFNCWXPDFViewer1.ShowPage(5);

// Read current page and total pages
Label1.Caption := IntToStr(TMSFNCWXPDFViewer1.ActivePage) + ' / ' +
                  IntToStr(TMSFNCWXPDFViewer1.PageCount);

Zoom and rotation

TMSFNCWXPDFViewer1.ZoomIn;
TMSFNCWXPDFViewer1.ZoomOut;
TMSFNCWXPDFViewer1.FitToPage(True, False);  // Fit to height

TMSFNCWXPDFViewer1.TurnAngleLeft;   // Rotate 90° counter-clockwise
TMSFNCWXPDFViewer1.TurnAngleRight;  // Rotate 90° clockwise

Text search

procedure TForm1.Button2Click(Sender: TObject);
begin
  TMSFNCWXPDFViewer1.SearchText('annual report');
end;

procedure TForm1.TMSFNCWXPDFViewer1FoundSearchText(Sender: TObject;
  AText: string; APage, AIndex: Integer);
begin
  Memo1.Lines.Add('Found "' + AText + '" on page ' + IntToStr(APage));
end;

procedure TForm1.TMSFNCWXPDFViewer1NotFoundSearchText(Sender: TObject;
  AText: string);
begin
  ShowMessage('Text not found: ' + AText);
end;

Thumbnails

Thumbnails are disabled by default. Enable them before loading a PDF:

TMSFNCWXPDFViewer1.CalculateThumbnails := True;
TMSFNCWXPDFViewer1.ThumbnailSize := 128;
TMSFNCWXPDFViewer1.LoadFromFile('report.pdf');

Each thumbnail is delivered through OnGenerateThumbnail as a Base64 data URI:

procedure TForm1.TMSFNCWXPDFViewer1GenerateThumbnail(Sender: TObject;
  NumPage: Integer; Base64Img: string);
var
  base64Data: string;
  bytes: TBytes;
  ms: TMemoryStream;
begin
  // Strip the data URI prefix: "data:image/png;base64,"
  base64Data := Copy(Base64Img, Pos(',', Base64Img) + 1, Length(Base64Img));
  bytes := TTMSFNCUtils.Decode64ToBytes(base64Data);
  ms := TMemoryStream.Create;
  try
    ms.Write(bytes[0], Length(bytes));
    ms.Position := 0;
    // Load into a bitmap, image control, etc.
  finally
    ms.Free;
  end;
end;

Alternatively, connect a TTMSFNCWXPDFThumbnailList which handles thumbnail display automatically.

Getting page text

// Get text for the current page:
TMSFNCWXPDFViewer1.GetPageAsText;

// Get text for a specific page:
TMSFNCWXPDFViewer1.GetPageAsText(3);

// Result arrives in OnGetPageText:
procedure TForm1.TMSFNCWXPDFViewer1GetPageText(Sender: TObject;
  AText: string; APage: Integer);
begin
  Memo1.Text := AText;
end;

Exporting the current page as an image

TMSFNCWXPDFViewer1.GenerateImageActualPage;

procedure TForm1.TMSFNCWXPDFViewer1GenerateImagePage(Sender: TObject;
  APage: Integer; Base64Img: string);
begin
  // Decode Base64Img and load into an image control
end;

Form fields

TMSFNCWXPDFViewer1.GetFormFields;

procedure TForm1.TMSFNCWXPDFViewer1GetFormFields(Sender: TObject;
  AFields: string);
begin
  // AFields is a JSON string describing all form fields in the PDF
  Memo1.Text := AFields;
end;

Loading modes (LibraryLocation)

Most of the WX components offer the option to load the JavaScript library it depends on either online or offline. This option can be set via the LibraryLocation property. The available options means the following:

llOnline: The JavaScript library will be loaded live from an external URL. This allows a faster loading of the library, decreasing the loading time of the component and providing a better performance. However, this option also requires an active internet connection.
llOffline: The JavaScript library will be loaded from resources. This guarantees the component is going to work in offline mode, but performance can decrease, especially on less powerful devices.

When you are ready to deploy your application, consider the differences above and make a choice based on them.

Properties

Property	Type	Default	Description
`ActivePage`	`Integer`	`1`	Gets or sets the current page number (1-based).
`CalculateThumbnails`	`Boolean`	`False`	When `True`, thumbnails are generated after each PDF load.
`LibraryLocation`	`TTMSFNCWXLibraryLocation`	`llOnline`	Controls whether PDF.js loads from CDN or embedded resources.
`PageCount`	`Integer`	—	Read-only. Total number of pages in the loaded PDF.
`Password`	`string`	`''`	Password for encrypted PDFs. Set before calling a load method.
`PDFRotationAngle`	`Integer`	`0`	Current rotation angle in degrees (0, 90, 180, 270).
`ThumbnailSize`	`Integer`	`96`	Size in pixels of the generated thumbnail images.
`Zoom`	`Double`	`1.0`	Current zoom level.

Methods

Loading

Method	Description
`LoadFromBase64(FileBase64, PageNumber, AZoom, RotateAngle)`	Loads a PDF from a Base64 string. Optional parameters set the initial page, zoom, and rotation.
`LoadFromFile(FilePath)`	Loads a PDF from a file path. Not available for WEB.
`LoadFromUrl(FileUrl, PageNumber, AZoom, RotateAngle)`	Loads a PDF from a URL. CORS-protected URLs are not supported.

Method	Description
`FitToPage(AHeight, AWidth)`	Zooms to fit the page height (`AHeight=True`) or width (`AWidth=True`).
`NextPage`	Navigates to the next page.
`PreviousPage`	Navigates to the previous page.
`ShowPage(AIndex: Integer)`	Navigates to the specified page (1-based).
`TurnAngleLeft`	Rotates the view 90° counter-clockwise.
`TurnAngleRight`	Rotates the view 90° clockwise.
`ZoomIn`	Increases the zoom level.
`ZoomOut`	Decreases the zoom level.

Content extraction

Method	Description
`GenerateImageActualPage`	Exports the current page as an image. Result via `OnGenerateImagePage`.
`GenerateThumbnails`	Generates thumbnails for all pages. Result via `OnGenerateThumbnail`.
`GenerateThumbnails(StartPage, EndPage)`	Generates thumbnails for a page range.
`GetFormFields`	Extracts form field data from the PDF. Result via `OnGetFormFields`.
`GetPageAsText(APageNumber)`	Extracts text from the specified page. Defaults to the current page when `APageNumber = -1`. Result via `OnGetPageText`.
`SavePageTextAsJSON`	Saves the current page's text as a JSON object.
`SearchText(TextToSearch: string)`	Searches all pages for the given text. Results via `OnFoundSearchText`.

Events

Event	Description
`OnFoundSearchText`	Fires for each search result from `SearchText`.
`OnGenerateImagePage`	Fires with the current page as a Base64 image after `GenerateImageActualPage`.
`OnGenerateThumbnail`	Fires for each generated thumbnail with the page number and Base64 image.
`OnGetFormFields`	Fires with JSON form field data after `GetFormFields`.
`OnGetPageText`	Fires with extracted text after `GetPageAsText`.
`OnHyperlinkClick`	Fires when a hyperlink in the PDF is clicked.
`OnLoadError`	Fires when an error occurs during loading.
`OnLoaded`	Fires when the PDF has fully loaded. Receives the total page count.
`OnNotFoundSearchText`	Fires when `SearchText` finds no matches.
`OnPageLoaded`	Fires when the current page content has been loaded.
`OnPageRendered`	Fires when the current page has been rendered.
`OnPinchIn`	Fires on pinch-in gesture (not WEB).
`OnPinchOut`	Fires on pinch-out gesture (not WEB).
`OnSearchTextFinished`	Fires when the search across all pages is complete.
`OnShowPage`	Fires when `ShowPage` is called. Receives the new page number.
`OnThumbnailProgress`	Fires during thumbnail generation with current position and total count.
`OnTouchEnd`	Fires when a touch gesture ends (not WEB).
`OnTouchMove`	Fires during a touch gesture (not WEB).
`OnTouchStart`	Fires when a touch gesture starts (not WEB).
`OnViewerInitialized`	Fires when the PDF.js viewer has fully initialized and is ready to load.