saveDrawing method

Future<void> saveDrawing({ required dynamic pdfFile, required int totalPages, required BuildContext context, required DrawingController drawingController, required ImageController imageController, required TextBoxController textBoxController, required HighlightController highlightController, required UnderlineController underlineController, required Function refresh, })

Saves the current edits (drawings, images, annotations, and text boxes) to a new PDF file.

pdfFile - the original PDF file, totalPages - number of pages in the document, context - BuildContext for getting MediaQuery, drawingController, imageController, textBoxController, highlightController, underlineController - various controllers managing different edit types, refresh - callback to refresh UI if needed.

Implementation

Future<void> saveDrawing({
  required pdfFile,
  required int totalPages,
  required BuildContext context,
  required DrawingController drawingController,
  required ImageController imageController,
  required TextBoxController textBoxController,
  required HighlightController highlightController,
  required UnderlineController underlineController,
  required Function refresh,
}) async {
  if (isSaving) {
    return;
  }
  try {
    isSaving = true; // Start loading

    final pdfDoc = PdfDocument(inputBytes: await pdfFile.readAsBytes());

    for (int i = 0; i < totalPages; i++) {
      // Set the current page in the drawing controller
      drawingController.setPage(i + 1);
      PdfPage page = pdfDoc.pages[i];

      // Allow time for page switch to complete
      await Future.delayed(const Duration(milliseconds: 200));

      // --- Add highlight annotations ---
      for (AnnotationAction action
          in highlightController.getHighlightHistory[i + 1] ?? []) {
        if (action.isAdd) {
          for (int j = 0; j < action.pdfAnnotation.length; j++) {
            if (i < pdfDoc.pages.count) {
              pdfDoc.pages[i].annotations.add(action.pdfAnnotation[j]);
            }
          }
        }
      }

      // --- Add underline annotations ---
      for (AnnotationAction action
          in underlineController.getUnderlineHistory[i + 1] ?? []) {
        if (action.isAdd) {
          for (int j = 0; j < action.pdfAnnotation.length; j++) {
            if (i < pdfDoc.pages.count) {
              pdfDoc.pages[i].annotations.add(action.pdfAnnotation[j]);
            }
          }
        }
      }

      // --- Add images onto PDF page ---
      for (var imageBox in imageController.getAllImageBoxes()[i + 1] ?? []) {
        final imgData = await _convertImageToUint8List(imageBox.image);
        final PdfImage pdfImage = PdfBitmap(imgData);

        final double scaleFactorX =
            page.getClientSize().width / MediaQuery.of(context).size.width;
        final double scaleFactorY =
            page.getClientSize().height /
            (MediaQuery.of(context).size.width * 1.414);

        double scaledX = imageBox.position.dx * scaleFactorX;
        double scaledY = imageBox.position.dy * scaleFactorY;
        double scaledWidth = imageBox.width * scaleFactorX;
        double scaledHeight = imageBox.height * scaleFactorY;

        // Save the current graphics state before transformations
        page.graphics.save();

        // Apply rotation and translation
        page.graphics.translateTransform(
          scaledX + scaledWidth / 2,
          scaledY + scaledHeight / 2,
        );
        page.graphics.rotateTransform(imageBox.rotation * (180 / pi));

        // Draw the image
        page.graphics.drawImage(
          pdfImage,
          Rect.fromLTWH(
            (-scaledWidth / 2) + 14,
            (-scaledHeight / 2) + 14,
            scaledWidth,
            scaledHeight,
          ),
        );

        // Restore the graphics state
        page.graphics.restore();
      }

      // --- Add freehand drawing on the PDF page ---
      ByteData? imageData = await drawingController.getImageData(i + 1);
      if (imageData != null) {
        final PdfImage image = PdfBitmap(imageData.buffer.asUint8List());

        final double pageWidth = page.getClientSize().width;
        final double pageHeight = page.getClientSize().height;

        page.graphics.drawImage(
          image,
          Rect.fromLTWH(0, 0, pageWidth, pageHeight),
        );
      }

      // --- Add text boxes on the PDF page ---
      for (TextBox textBox
          in textBoxController.getAllTextBoxes()[i + 1] ?? []) {
        final double scaleFactorX =
            page.getClientSize().width / MediaQuery.of(context).size.width;
        final double scaleFactorY =
            page.getClientSize().height /
            (MediaQuery.of(context).size.width * 1.414);

        double scaledX = textBox.position.dx * scaleFactorX;
        double scaledY = textBox.position.dy * scaleFactorY;
        double scaledWidth = textBox.width * scaleFactorX;
        double scaledHeight = textBox.height * scaleFactorY;

        page.graphics.drawString(
          textBox.text,
          PdfStandardFont(PdfFontFamily.helvetica, textBox.fontSize),
          brush: PdfSolidBrush(
            PdfColor(
              textBox.color?.red ?? 0,
              textBox.color?.green ?? 0,
              textBox.color?.blue ?? 0,
            ),
          ),
          bounds: Rect.fromLTWH(
            scaledX + 10, // Padding for better text visibility
            scaledY + 10,
            scaledWidth,
            scaledHeight,
          ),
          format: PdfStringFormat(
            alignment: PdfTextAlignment.center,
            lineAlignment: PdfVerticalAlignment.middle,
          ),
        );
      }
    }

    // --- Save the modified PDF file ---
    final output = await getTemporaryDirectory();
    final String originalName = pdfFile.path.split('/').last.split('.').first;
    final String timestamp = DateTime.now().millisecondsSinceEpoch.toString();
    final String savedPath = '${output.path}/${originalName}_$timestamp.pdf';
    final file = File(savedPath);

    await file.writeAsBytes(await pdfDoc.save());
    pdfDoc.dispose();

    // Pop with result file
    Navigator.pop(context, file);

    // Optionally, you can open the saved file
    // OpenFile.open(savedPath);
  } catch (e) {
    debugPrint('Error while saving drawing and text: $e');
  } finally {
    isSaving = false; // End loading
  }
}