TileData not perfectly aligned to grid will be lost when exporting to .tbin format

[krisives]

When saving a map in the .tbin format you have to be very careful to have perfectly aligned objects called TileData otherwise they will be deleted upon export without any warning. This can be irritating if you don't notice they aren't perfectly aligned.

[krisives]

Appears this happens in this code:

https://github.com/bjorn/tiled/blob/31337ee0ff35c88dbb70c6a3a5e098f7c6e5704e/src/plugins/tbin/tbinplugin.cpp#L311-L314

It would be nice if either a.) it produced a warning or b.) saved to the closest aligned tile.

[bjorn]

Yeah, the manual makes an explicit warning about this, but I agree it is not ideal and I fully support your suggestions for improvement.

A warning could be shown using a modal QMessageBox, as is already done by some other plugins. Maybe a warning like "%n objects did not align with the tile grid, they have been automatically aligned to the nearest position".

[krisives]

@bjorn I tried to find another plugin using QMessageBox but couldn't find any. Is it safe to call from within the plugin code or do I need to get a reference to some other GUI object? Sorry, I'm not a Qt developer by trade.

[krisives]

I checked out how errorString() and various plugins use mError to propagate the error up to the user with QMessageBox and was able to modify the TbinMapFormat to show an error when TileData objects were automatically aligned. However, this stops the file from being marked as saved and tells the user an error has occurred, when in reality the file was saved and it's a warning.

I tried modifying the code to have a warningString() virtual method, but there are too many layers of abstraction to find and update since this behavior is from the FileFormat object which is used by a lot of pieces of the codebase. Waiting a few minutes for make to fail over and over isn't fun either, so I think I will give up on this and just use my hacked version for the time being since it solves my problem.

Feel free to close this issue.

[bjorn]

Sorry, it seems you're right that no QMessageBox was actually used yet by any plugins. It should be safe to call from plugin code though. And indeed raising an error instead is not an option in this case.

When adding a warningString() virtual method, you could have provided a default implementation returning an empty string, in which case you'd only have to adjust the tBIN plugin to use it. However, I'm not sure whether this is the best way to raise a warning. I'd probably rather find a convenient way to use the Debug Console for this, probably with something added to the status bar to make warnings more noticeable.

I'll keep this issue open since I'd still like to improve the behavior at least a bit before the Tiled 1.2 release.