Password-protected PDF causes UI freeze when opening

[kylqVTN]

Bug description

When opening a password-protected PDF file, the UI freezes noticeably after the password is entered.

This happens even with relatively small PDF files (~1–5MB).
Non-password-protected PDFs open smoothly.

Opening a password-protected PDF should not block the UI thread.
At minimum, the UI should remain responsive while the document is being decrypted and opened.

Steps to reproduce

1. Prepare a PDF file protected with a password (e.g. 3–5MB)
2. Open the PDF using PdfViewer
3. Enter the correct password
4. Observe that the UI freezes until the document is fully opened

Code sample

SfPdfViewer.file(
pdfFile.file,
key: _pdfViewerKey,
controller: _pdfViewerController,
password: _password,
canShowScrollHead: false,
canShowScrollStatus: false,
canShowTextSelectionMenu: false,
canShowPageLoadingIndicator: false,
)

Screenshots or Video

document_6228699286490585541.mp4

Stack Traces

Stack Traces

[Add the Stack Traces here]

On which target platforms have you observed this bug?

Android

Flutter Doctor output

[immankumarsync]

Hi @kylqVTN,

We were unable to reproduce the reported issue where the UI freezes when opening a password-protected PDF file. Please find attached the sample we used to replicate the issue, along with a video recording.

Could you please check the attached sample and let us know if the issue still occurs on your end? If so, could you kindly share the PDF document in which the issue occurred?

Sample

Screen.Recording.798842.mp4

Regards,
Imman Kumar P

[kylqVTN]

Hi @immankumarsync 5-mb-example-file (1).pdf You can try this file with password : 1234 .Larger files result in longer UI blocking time when opening with a password.