Add auto-wrap after setting for layout legends

[nyalldawson]

Allows legend text to be automatically wrapped after a set line length (in millimeters).

This can prevent very wide auto-generated legends.

Sponsored by North Road, thanks to SLYR

Peek.2025-04-07.15-36.mp4

[qgis-bot]

@nyalldawson

This pull request has been tagged for the changelog.

• The description will be harvested so please provide a "nearly-ready" text for the final changelog
• If possible, add a nice illustration of the feature. Only the first one in the description will be harvested (GIF accepted as well)
• If you can, it's better to give credits to your sponsor, see below for different formats.

You can edit the description.

Format available for credits

• Funded by NAME
• Funded by URL
• Funded by NAME URL
• Sponsored by NAME
• Sponsored by URL
• Sponsored by NAME URL

Thank you!

[qgis-bot]

@nyalldawson
This pull request has been tagged as requiring documentation.

A documentation ticket will be opened at https://github.com/qgis/QGIS-Documentation when this PR is merged.

Please update the description (not the comments) with helpful description and screenshot to help the work from documentors.
Also, any commit having [needs-doc] or [Needs Documentation] in will see its message pushed to the issue, so please be as verbose as you can.

Thank you!

[github-actions]

🪟 Windows Qt6 builds

Download Windows Qt6 builds of this PR for testing.
(Built from commit 7f352f6)

🪟 Windows builds

Download Windows builds of this PR for testing.
Debug symbols for this build are available here.
(Built from commit 7f352f6)

[nirvn]

Nice, I love of these things are so easy to add now that the legend is using our text renderer classes.

[qgis-bot]

@nyalldawson
A documentation ticket has been opened at qgis/QGIS-Documentation#9772
It is your responsibility to visit this ticket and add as much detail as possible for the documentation team to correctly document this change.
Thank you!

[DelazJ]

@nyalldawson, Do you have an example of the use case of the data-defined "Assistant" entry, for this feature? Thanks

[nyalldawson]

@DelazJ this should be of use for atlases where you may want to tweak the legend appearance on different pages. Or for dynamic layouts which adjust legend sizes based on eg page orientation.

[DelazJ]

Thanks @nyalldawson for the reply. I see how this can be done using expression. My point refers mainly to the Assistant widget that generates values sequentially, not really foreseeable. I can't see what data it may be compatible with, in real life situations. If you have such data/case, I think it may be of great help we share in the docs. Thanks.

I saw the assistant widget on another option in the layout and got also surprised, but I'm currently away from QGIS for checking. Added to any numeric widget such as legend column number, rotation, opacity, map scale...

[nyalldawson]

@DelazJ assistant is just shown everywhere for these buttons. There's no use case I can see for it here, but it's just generic functionality from those buttons

[DelazJ]

Thanks @nyalldawson That clarifies.