fix: LoadingSnackBar consistently remains visible until the upload is complete

[dohoanggiahuy317]

• Adjusted the SendFileDialogState file to ensure that the showLoadingSnackBar remains visible throughout the file upload process.
• the SnackBar is cleared only after the image/file is uploaded and displayed in the chat.

Thank you so much for your contribution to FluffyChat ❤️❤️❤️

Please make sure that your Pull Request meet the following acceptance criteria:

• Code formatting and import sorting has been done with dart format lib/ test/ and dart run import_sorter:main --no-comments
• The commit message uses the format of Conventional Commits
• The commit message describes what has been changed, why it has been changed and how it has been changed
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[dohoanggiahuy317]

This change addresses a UX issue where the loading SnackBar was not visible during critical operations like file compression and uploading, making the app appear frozen to the user.

The root cause of this issue is the blocking of the main thread. For example:

• Heavy operations like reading large files (await xfile.readAsBytes()) or compressing videos (await xfile.resizeVideo()) block the main thread, preventing the UI from updating and showing the SnackBar in time.

• Additionally, the showSnackBar call is made, but the synchronous or blocking nature of these operations doesn't give Flutter a chance to render the UI before the next task begins.

• Flutter’s rendering pipeline prioritizes certain tasks, meaning expensive computations can delay the SnackBar’s visibility.

Previously, the SnackBar was cleared and replaced multiple times (e.g., for preparing uploads, compressing, and uploading). This approach not only caused redundant updates but also compounded the blocking issue, making the UI seem unresponsive.

To resolve this, the SnackBar now stays visible throughout the entire process, providing consistent feedback from start to finish. By not clearing and replacing it repeatedly, I ensure that the UI remains informative and responsive, giving users confidence that the app is working and their file will be uploaded successfully.

[krille-chan]

Works fine for me :) Thank you very much

[krille-chan]

@dohoanggiahuy317 Can you please sign your commit?

[dohoanggiahuy317]

@dohoanggiahuy317 Can you please sign your commit?

Thank you so much for your approval! I’ve successfully signed the commit. Please let me know if there’s anything further I need to complete 😊