[Bug] 16:9 slides get cut-off on left and right side of presentation screen if the latter has not the same ratio

[maehne]

Describe the bug

After loading a PDF slide deck with 16:9 page ratio, the slide is not suitably zoomed to fit fully on the presentation screen if the latter one has not the same ratio. E.g, the left and right sides get cut off when the presentation is has 16:10 ratio.

To Reproduce

Import a PDF slide deck with 16:9 page ratio. Primary screen has 3440x1440 resolution. The presentation screen has 1920x1200 resolution.

Expected behavior

OpenBoard should always guarantee that the whole slide is displayed on the presentation screen after loading a slide deck.

Actual behavior

OpenBoard seems to zoom slides to fit the whole height of the screen causing the left and right side to get cut off.

Screenshots

Here's a screenshot of my primary screen:

Here's a screenshot of the presentation screen:

Additional resources

16-to-9-sample-slide.pdf

Context

• reproducibility : systematic
• OpenBoard version :
  • bug happens with : 1.7.2
  • didn't check : 1.6.4 1.7.0 1.7.1
• OS :
  • bug happens with : Windows, Linux
  • didn't check : macOS
• Installation source : OpenBoard download page for Windows, AUR on Arch Linux

Additional context

• OS(es) detailed version (for the ones you reproduced the bug on)
  • Linux: up-to-date Arch Linux as of 2024-12-05
  • Windows: Windows 11 Pro 24H2 26100.2454
• number and resolution of monitors : 2, Primary screen has 3440x1440 resolution. The presentation screen has 1920x1200 resolution.

[letsfindaway]

Actually OpenBoard tries to fit the slide to the control (primary) screen. Depending on the format, it either fits the height or the width. It does not take the presentation screen into account during this process.

When a presentation screen is present, it at least indicates (with the gray overlays to the left and right) how much of the slide is visible on the presentation screen. So one could easily adapt the zoom to fit the content to the presentation screen. But there is no built-in "fit to presentation screen" function.

In fact, multi-monitor mode can be switched on and off while running OpenBoard, or even screens could be reconfigured. We would have to take that into account and zoom the control screen accordingly, if "whole scene fits to presentation screen" would be the main rule.

I cannot list PROs and CONs for such an automatic zoom, but I would suggest to consider multiple scenarios to find the most appropriate default zoom handling.

[maehne]

Thanks for your feedback to my bug report @letsfindaway!

The current behaviour to fit to the primary screen is not very helpful. I am aware that I can zoom out, but I have to do this for each slide again. This is too tedious! It also disturbs our PDF slide decks that contain overlay animations spanning multiple PDF pages.

At least from my primary use case fitting slides to the presentation screen should be the sensible default. OpenBoard allows to set the page format. That ratio setting should be the guidance for appropriate zooming of all imported slides on both screens.

Once I present, I appreciate a lot that I am able to zoom out and pan the tablet area to make annotations next to the slides.