Fix/video upload flicker #5949

Ticket(s) / Related Merge Requests

#5949 (closed)

Summary of Changes

Don't refresh the entire preview object every time the progress bar changes. Only update relevant information at the right time.

Works for videos and also images/multi-images posts in composer.

Testing Considerations

Composer media uploads (videos, images, multi-images), editing existing media posts

Occasionally there will be ONE flicker as a measure to ensure that we have a preview thumbnail visible, but this shouldn't hold up the MR.

Deployment Considerations

N/A

Regression Scope

User's ability to create/edit a media post. During testing I had an issue with particularly long videos stopping/disappearing uploading partway through. I suspect this is a separate issue.

Platform Affected (web, mobile, etc)

Web

Developer Testing Completed

• Uploading a short video
• Uploading a long video (various formats)
• Uploading an image
• Uploading multiple images
• Uploading 1-2 images and then adding 1-2 more images while the first ones are uploading
• Uploading 1-2 images and then adding 1-2 more images while the first ones are finished uploading
• Removing multi-image images in various states of upload progress
• Stopping an inProgress video upload and adding another video instead

Screenshots / Screen Recording

_multiImageUploadDeleteAdd_singleImageUpload _longAndShortVidUpload _shortVidUpload

Does this impact

• Localization
• Dark/light mode
• Guest mode

Definition of Done Checklist

• The Acceptance Criteria has been met
• Code is tested: Testing includes unit/spec, E2E/automated and manual testing
• Merge requests description has been filled out