[Bugfix] North arrow / image should account for item rotation too.

[roya0045]

Description

This is my proposal to fix #33482 .

The changes implemented are the following:

Override the rotateitem method in qgslayoutitemmap to add the rotation signal.

Change the mapRotationChanged signals by adding the rotation value of the item.

Backport for 3.10 is suggested.

Checklist

• Commit messages are descriptive and explain the rationale for changes
• Commits which fix bugs include Fixes #11111 at the bottom of the commit message
• I have read the QGIS Coding Standards and this PR complies with them
• New unit tests have been added for core changes
• I have run the scripts/prepare-commit.sh script before each commit
• I have evaluated whether it is appropriate for this PR to be backported, backport requests are left as label or comment

[roya0045]

PR might not be ready for review, haven't tested, just made it so I don't forget when I get back to work.

[nyalldawson]

Thanks for working on this one!

[nyalldawson]

The mapRotationChanged signal is used quite heavily in other areas of code outside of the north arrow, so I'm reluctant to change it's current behavior here. I'd suggest instead hooking into the existing QgsLayoutItem::rotationChanged signal, i.e. by making the picture item listen out for both the mapRotationChanged AND rotationChanged signals (i.e. adding new connections to rotationChanged wherever QgsLayoutItemPicture currently uses mapRotationChanged )

Also note that you'll need to update QgsLayoutItemPicture::updateMapRotation() -- it doesn't use the rotation value from the mapRotationChanged signal in any case, so it needs to be updated to base the picture orientation on mRotationMap->mapRotation() + mRotationMap->rotation().

[roya0045]

I'm confused as to why the value provided was useless, I saw the function and thought it was overloaded somewhere else to accept the given value and couldn't find that overloaded method. + the holiday lack of sleep doesn't help. I was debating simply changing the function at first but didn't want to alter some core component if it could be prevented.

[nyalldawson]

It's not useless, it's just not used by the north arrow code. Check the QgsLayoutItemPicture::updateMapRotation() slot, it doesn't have an argument accepting the rotation value used in the signal.

[nyalldawson]

Nearly there!

[nyalldawson]

There's also one connection missed in QgsLayoutItemPicture::finalizeRestoreFromXml()