[FEATURE] Layer tree indicators for memory layers

[nyalldawson]

Shows a memory layer icon in the layer tree for all memory layers, with a tooltip warning that the contents of the layer will be lost when closing the project.

Should help avoid data loss by users who don't realise that certain layers are temporary only.

(No screenshots until @nirvn gives me a nice icon ;) )

[nyalldawson]

Now with a nice icon thanks to @nirvn:

[Gustry]

Thanks. Related to https://issues.qgis.org/issues/19038

[nyalldawson]

Now activates the "make permanent" action when clicking on the indicator!

[NathanW2]

Heck yeah!

…

On Mon, Aug 6, 2018 at 11:42 AM Nyall Dawson ***@***.***> wrote: Now activates the "make permanent" action when clicking on the indicator! — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#7516 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAXS3CcPUhIUxSyHxwrvyIImTVVz-_gxks5uN57-gaJpZM4Vrm7O> .

[nirvn]

Just tried this earlier today, fantastic UX improvement.

1+ to merge.

[nyalldawson]

Thanks for the review @nirvn!

[AlisterH]

Hi guys,
Maybe it isn't the done thing commenting here long after the merge, but I'm wondering - have you thought about whether the temporary files created by default by processing algorithms should be treated more like memory layers?

These nifty new features for memory layers are nice, but they seem inconsistent when a memory layer is alongside a processing-created temporary file - those still look like any other (permanent) layer, even though they aren't really any more permanent than a memory layer.

Should help avoid data loss by users who don't realise that certain layers are temporary only.

But doesn't the inconsistency actually encourage data loss with temporary files from processing?!

[AlisterH]

Sorry, I thought I'd better also point out that people may unintentionally create temporary output files when using processing tools.

e.g. some of those dialogs have a lot of complex options - it is easy enough to fill most of them in, then go away to check on an option or something, then come back and just run it without realising that you haven't specified an output file.

[AlisterH]

Thanks. Related to https://issues.qgis.org/issues/19038

Note this comment there, which you can say supports what I'm saying:

It's exactly the same behavior with QGIS Processing creating temporary layers.