loadPdf method

Future<void> loadPdf(String url)

Implementation

Future<void> loadPdf(String url) async {
  try {
    appState.isLoading = true;

    /// Download PDF as bytes
    final bytes = await fetchPdfAsBytes(url);

    if (bytes.isEmpty) {
      throw Exception("PDF file is empty or could not be downloaded.");
    }

    /// Validate PDF format by checking magic bytes
    if (bytes.length < 4 ||
        !(bytes[0] == 0x25 &&
            bytes[1] == 0x50 &&
            bytes[2] == 0x44 &&
            bytes[3] == 0x46)) {
      throw Exception(
          "Invalid PDF format. File does not appear to be a valid PDF.");
    }

    /// Open PDF document
    final document = await PdfDocument.openData(bytes);

    if (document.pagesCount == 0) {
      throw Exception("PDF document has no pages.");
    }

    /// Save in your app state
    appState.document = document;
    appState.totalPages = document.pagesCount;
    appState.isLoading = false;

    /// Load initial pages
    await loadPages(0, null);
  } catch (e) {
    appState.isLoading = false;
    throw Exception("Failed to load PDF: $e");
  }
}