Allow running the demo from the build dir

[whot]

This sits on top of #150 so it builds on my machine but can be split out if need be.

Unless there's a trick I'm missing, we can't easily run the demo from the meson build dir because it looks in /usr/local/share/ for the gresources file. This could (possibly?) be worked around by setting the datadir in meson but another hack is to build the same binary with a .devel suffix, check for that suffix in argv0 and load the gresources from the builddir instead. Not overly pretty but for this use-case it's probably good enough.

[bilelmoussaoui]

Could use a rebase

[whot]

Rebased but switched back to draft. I tried running this on a new machine and luckily caught the error: the current branch still requires that the schemas are installed. Simply adding to XDG_DATA_DIRS isn't enough, we need to also compile the schemas in the builddir but that's where I ran into a bit of a rabbit hole. I'm not sure when I'll find time to complete this :(

[bilelmoussaoui]

Rebased but switched back to draft. I tried running this on a new machine and luckily caught the error: the current branch still requires that the schemas are installed. Simply adding to XDG_DATA_DIRS isn't enough, we need to also compile the schemas in the builddir but that's where I ran into a bit of a rabbit hole. I'm not sure when I'll find time to complete this :(

For the schemas, you can use GSETTINGS_SCHEMA_DIR

[bilelmoussaoui]

I am not particularly happy with this approach of checking the binary name. I think a viable path forward is to have a separate meson build option that would influence from where we load the gresource file making the changes to config.rs/main.rs not needed at all. The other option is to embed the gresource into the final binary but nobody took the time to figure out a nice way to do it that integrates well with the hackish meson/cargo thing we are doing

[whot]

For the schemas, you can use GSETTINGS_SCHEMA_DIR

So from what I've gathered so far

• gio::Resource::load() apparently requires a full path to the file, so we need to hack around that anyway
• gio::Settings::new() requires compiled schemas but meson's gnome.compile_schemas() can only compile in the source directory. We generate the gschema.xml files so they are in the build directory. That seems like a strangely missing part of the meson gnome module and needs to be fixed there. Manually compiling in the builddir and setting GSETTINGS_SCHEMA_DIR works.

If I hack around the two above, I get a segfault somewhere deep inside GTK4's gdk_wayland_toplevel_focus() which I'm assuming is not ashpd's fault :)

But I agree, the hackish way right now is not nice and since it doesn't work anyway, let's close this PR - I'm not sure when I'll have time to look at this again in the near future.

[eli-schwartz]

• gio::Settings::new() requires compiled schemas but meson's gnome.compile_schemas() can only compile in the source directory. We generate the gschema.xml files so they are in the build directory. That seems like a strangely missing part of the meson gnome module and needs to be fixed there. Manually compiling in the builddir and setting GSETTINGS_SCHEMA_DIR works.

It feels a bit awkward, mostly because glib-compile-schemas only compiles a single directory, and we hacked it up with --target to place the compiled version in a different tree hierarchy. I don't know that it's feasible to merge the two together, so we'd either need to pick one, or generate another directory as an internal implementation detail and append to the GSETTINGS_SCHEMA_DIR directory.

Of course this is all nothing users can't do manually, the main value of the module is to guarantee it is correct...

[whot]

Thanks for the explanation! From what I can tell from a quick browse glib-compile-schemas does take a srcdir argument (argv[1]), and I suspect during autotools builds srcdir == builddir in most cases anyway (also given the need for --target to be added), so my random guess is that passing an optional srcdir to the module to be passed through would probably work? but that's just that, a random guess :)