[Vega] PDF reports do not have good dimensions compared to PNG reports

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[Vega] PDF reports do not have good dimensions compared to PNG reports #183550

Open rshen91 opened 6 months ago

rshen91 commented 6 months ago

Kibana version: 8.15.0 local

Browser: Chrome Version 124.0.6367.201 (Official Build) (arm64)

Describe the bug: Vega reports only for PDFs have strange dimensions

PDF:

[Logs] Visitors Map (5).pdf

PNG:

Logs Visitors Map (2)

We believe it might have something to do with the screenshotting plugin or the dimensions are not be respected for PDFs.

Steps to reproduce:

Load sample data - web logs has a vega map but any vega visualization shows this issue
Go to vega and hit share and then PDF and export file
Once the PDF report finishes you can see that the dimensions are very squished.

Expected behavior: I would expect that the PDF would look similar to the PNG example and be more human readable.

elasticmachine commented 6 months ago

Pinging @elastic/appex-sharedux (Team:SharedUX)

elasticmachine commented 5 months ago

Pinging @elastic/kibana-visualizations (Team:Visualizations)

petrklapka commented 5 months ago

I've asked the Viz folks to take a look at their specific reporting code first and volley it back to us if they don't find anything. Sticking this in "discussion" and "soon" for us so we don't loose track of it.

markov00 commented 5 months ago

@petrklapka @rshen91 a couple of observations:

this doesn't happen only when printing a Vega chart, but also a Lens (is also worst in Lens), TSVB and a Visualize one.
this happens only when you click share as PDF from within each editor, not when sharing from the dashboard.
The problem seems to be caused by the fact that in these cases we are taking a "screenshot" of the chart DOM element and then we are stretching this screenshot into a PDF page that seems, in most case, in landscape mode. For squared charts like the vega map o some Lens charts, this results in a stretched image (below some examples).
Because the PNG seems to have, at least, the correct aspect ratio, I believe the problem is on the way each image is attached to the PDF page.
if you play around with the PNG and with the browser page sizing, you can also notice that the resulting PDF/PNG image size depends a bit on the current browser size, but also depends on other factors that seems to be unpredictable. This is also another factor to check when considering the final chart aspect ratio.

petrklapka commented 5 months ago

Thanks for taking a look @markov00 ! We'll take this one back then and prioritize at next triage.
cc: @rshen91 & @tsullivan

tsullivan commented 3 months ago

I'm moving this to the icebox since this is an internally-reported issue and PDF reports from the visualize app do not seem to be used very much.