[HOLD for payment 2024-05-09] [$250] Chat - PDF is displayed closer to the top

[izarutskaya]

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Version Number: v1.4.47-0
Reproducible in staging?: Y
Reproducible in production?: Y
Email or phone of affected tester (no customers): vdargentotest+mweb030424@gmail.com
Logs: https://stackoverflow.com/c/expensify/questions/4856
Issue reported by: Applause-Internal Team

Action Performed:

Pre-requisite: the user must be logged in.

1. Go to any chat.
2. Send the attached PDF.
3. Tap on the PDF preview to open it.
4. Verify it is displayed closer to the top.

Expected Result:

The PDF should be displayed in the middle of the viewer section.

Actual Result:

The PDF is displayed closer to the top.

Workaround:

Unknown

Platforms:

Which of our officially supported platforms is this issue occurring on?

• Android: Native
• Android: mWeb Chrome
• iOS: Native
• iOS: mWeb Safari
• MacOS: Chrome / Safari
• MacOS: Desktop

Screenshots/Videos

Bug6402389_1709617684018!pdf.pdf

View all open jobs on GitHub

Upwork Automation - Do Not Edit

• Upwork Job URL: https://www.upwork.com/jobs/~012ce46bd1a9c35b0c
• Upwork Job ID: 1767225873928306688
• Last Price Increase: 2024-03-18
• Automatic offers:
• mollfpr | Reviewer | 0
• abzokhattab | Contributor | 0

[melvin-bot]

Triggered auto assignment to @sakluger (Bug), see https://stackoverflow.com/c/expensify/questions/14418 for more details.

[izarutskaya]

@sakluger I haven't added the External label as I wasn't 100% sure about this issue. Please take a look and add the label if you agree it's a bug and can be handled by external contributors.

[sakluger]

@Expensify/design this is a bug, right? I assume we want images to be vertically center-aligned.

[shawnborton]

Hmm I'm not entirely sure... it's a PDF, and I think I would expect viewing a document to be aligned to the top. Curious what others think though.

[shawnborton]

@izarutskaya can you help us understand why you decided that this was a bug?

[dannymcclain]

I'm honestly not sure about this one. It looks like if a PDF will fit in the viewport, we center it. If it's too long, we align it to the top and let you scroll to see the whole thing?

[shawnborton]

Yeah that's fair... this is also a super tricky PDF because the PDF itself is cropped:

[dannymcclain]

Here's a screenshot of that attachment from the app. I feel like this is how we'd expect it to display.

[shawnborton]

Yeah, that makes sense to me. So it seems like this is just an mWeb thing?

[dannymcclain]

Yeah that's what it looks like to me.

[sakluger]

@shawnborton @dannymcclain, just to confirm, are you saying that this is an mWeb bug, or that it's expected mWeb behavior?

[shawnborton]

Yup, seems like an mWeb bug.

[sakluger]

Thanks Shawn! I'll mark as external and add to #vip-vsb. I'm going to set the price at $250 since this is just an alignment issue on a single platform.

[melvin-bot]

Job added to Upwork: https://www.upwork.com/jobs/~012ce46bd1a9c35b0c

[melvin-bot]

Triggered auto assignment to Contributor-plus team member for initial proposal review - @mollfpr (External)

[melvin-bot]

Upwork job price has been updated to $250

[abzokhattab]

Proposal

Please re-state the problem that we are trying to solve in this issue.

PDF is aligned to the top in mWeb

What is the root cause of that problem?

the VariableSizeList component that is provided by the react-window library is used in web platforms to display the PDF.
this component always returns the top padding (style.top) as zero here:

App/src/components/PDFView/WebPDFPageRenderer.js

Lines 29 to 40 in 26ecf68

	const WebPDFPageRenderer = memo(
	({index: pageIndex, data, style}) => {
	const {pageWidth, calculatePageHeight, getDevicePixelRatio, estimatedItemSize} = data;
	const pageHeight = calculatePageHeight(pageIndex);
	const devicePixelRatio = getDevicePixelRatio(pageWidth, pageHeight);
	return (
	<View style={{...style, top: `${parseFloat(style.top) + PDFViewConstants.PAGE_BORDER}px`}}>
	<Page
	key={`page_${pageIndex}`}
	width={pageWidth}

What changes do you think we should make in order to solve the problem?

we need to use the parent container height and the pdf height to decide the top padding because the default offset provided by the library is 0

also we need to keep the current behaviour for muliple pages pdfs, since there is no/small offset on the native device

to acheive that:

1. we need to add the containerHeight and the numPages to the itemData prop in the List component:
   

   App/src/components/PDFView/WebPDFDocument.js

   Line 117 in 2148716

   itemData={{pageWidth, calculatePageHeight, getDevicePixelRatio, estimatedItemSize}}

2. then we can access them in the WebPDFPageRenderer by extracting it from the data component:

        const {pageWidth, calculatePageHeight, getDevicePixelRatio, estimatedItemSize, numPages, containerHeight} = data;

3. then we modify the top padding to:

        const topPadding = numPages > 1 ? parseFloat(style.top) + PDFViewConstants.PAGE_BORDER : parseFloat((containerHeight - style.height) / 2);
        return (
            <View style={{...style, top: `${topPadding}px`}}>

Result

Screen.Recording.2024-03-16.at.6.03.13.AM.mov

[abzokhattab]

The PR is ready! please check it out and let me know if you have any comments.

[parasharrajat]

@mollfpr Could you please review #40289?

[melvin-bot]

Reviewing label has been removed, please complete the "BugZero Checklist".

[melvin-bot]

The solution for this issue has been 🚀 deployed to production 🚀 in version 1.4.69-2 and is now subject to a 7-day regression period 📆. Here is the list of pull requests that resolve this issue:

• Bumping react-fast-pdf to v1.0.12 #40289

If no regressions arise, payment will be issued on 2024-05-09. 🎊

For reference, here are some details about the assignees on this issue:

• @mollfpr requires payment automatic offer (Reviewer)
• @abzokhattab requires payment automatic offer (Contributor)

[melvin-bot]

BugZero Checklist: The PR fixing this issue has been merged! The following checklist (instructions) will need to be completed before the issue can be closed:

• [@mollfpr] The PR that introduced the bug has been identified. Link to the PR:
• [@mollfpr] The offending PR has been commented on, pointing out the bug it caused and why, so the author and reviewers can learn from the mistake. Link to comment:
• [@mollfpr] A discussion in #expensify-bugs has been started about whether any other steps should be taken (e.g. updating the PR review checklist) in order to catch this type of bug sooner. Link to discussion:
• [@mollfpr] Determine if we should create a regression test for this bug.
• [@mollfpr] If we decide to create a regression test for the bug, please propose the regression test steps to ensure the same bug will not reach production again.
• [@sakluger] Link the GH issue for creating/updating the regression test once above steps have been agreed upon:

[Beamanator]

Looks like payment is due here, yeah? No regressions i believe?

[sakluger]

Summarizing payment on this issue:

Contributor: @abzokhattab $250, paid via Upwork
Contributor+: @mollfpr $250, please request on Newdot

[sakluger]

@mollfpr could you also please complete the BZ checklist?

[mollfpr]

[@mollfpr] The PR that introduced the bug has been identified. Link to the PR:
[@mollfpr] The offending PR has been commented on, pointing out the bug it caused and why, so the author and reviewers can learn from the mistake. Link to comment:

No offending PR.

[@mollfpr] A discussion in #expensify-bugs has been started about whether any other steps should be taken (e.g. updating the PR review checklist) in order to catch this type of bug sooner. Link to discussion:

The regression step should be enough.

[@mollfpr] Determine if we should create a regression test for this bug.
[@mollfpr] If we decide to create a regression test for the bug, please propose the regression test steps to ensure the same bug will not reach production again.

1. Go to any chat.
2. Upload two single-page PDFs: one with a long page and another with a short page.
3. Click on the PDF preview to open each document.
4. Ensure that both PDFs are centered properly. Check that the longer PDF displays correctly without the top padding being chopped off.
5. 👍 or 👎

[JmillsExpensify]

$250 approved for @mollfpr

[sakluger]

Thanks!