This directory contains files related to Flatpak build of Evolution. Apart
of Evolution itself, it builds also evolution-data-server, and uses it,
the same as evolution-ews for Exchange Web Services accounts.

The build uses GNOME Flatpak SDK and runtime.

To build it, one can follow the below commands, which expect flatpak and
flatpak-builder installed. Refer to the Flatpak developer documentation
and command man pages for the meaning of respective arguments.

Note the actual versions of the GNOME SDK and Platform (below is used
version 3.26) can differ each release of Evolution. The exact expected
version can be seen (or changed) in the .json file, the runtime-version
key (line "runtime-version": "3.26",). Use the same version in the below
install commands as is written in the runtime-version key of the .json file.

To prepare Flatpak, add GNOME repository and install the SDK and Platform:

   $ flatpak remote-add --from gnome https://sdk.gnome.org/gnome.flatpakrepo
   $ flatpak install gnome org.gnome.Platform//3.26
   $ flatpak install gnome org.gnome.Sdk//3.26

After this, Evolution can be built. While the below commands build the git master
version of Evolution, it can be changed to the stable version, when all "-master"
occurrences are replaced with "-stable":

   $ flatpak-builder --force-clean org.gnome.Evolution-master org.gnome.Evolution-master.json

The above command can be repeated multiple times, for cases when the build fails
and any changes are required.

Once it's built, Flatpak requires the built application to be added as a repository,
which means to create, add and install it:

   $ flatpak build-export repo-master org.gnome.Evolution-master
   $ flatpak --user remote-add --no-gpg-verify --if-not-exists evolution-repo-master repo-master
   $ flatpak --user install evolution-repo-master org.gnome.Evolution

And it's basically it. The last thing is to run the flatpak version of Evolution:

   $ flatpak run org.gnome.Evolution

In some cases one might need to debug the build environment, which can be done
with the following command. It opens a bash terminal where can be examined
built data in the /app prefix:

   $ flatpak run --devel --command=bash org.gnome.Evolution

A short command to rebuild any changes, refresh the repository and update
installed Evolution from this repository can look like:

   $ flatpak-builder --force-clean org.gnome.Evolution-master org.gnome.Evolution-master.json && \
     flatpak build-export repo-master org.gnome.Evolution-master && \
     flatpak --user update org.gnome.Evolution

Note the above commands install the Evolution as a user repository, not
as a system repository, while the GNOME platform and SDK are installed
into the system repository (which requires root password). Add --user
argument to the first three commands at the top to avoid the root requirement.

Finally, to clean up installed Flatpak data, check what is installed:

   $ flatpak list

and remove Evolution from there:

   $ flatpak --user uninstall org.gnome.Evolution

Then also check what repositories are installed:

   $ flatpak remotes

and remove the custom Evolution repository with:

   $ flatpak --user remote-delete evolution-repo-master
