[devhelp] meson: add option for Flatpak build mode

[Sébastien Wilmet <swilmet src gnome org>]

commit 1dba392ac96d5a7da2c2cfb5b4707cf5e6b7530f
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Wed Mar 14 14:49:41 2018 +0100

    meson: add option for Flatpak build mode

 meson.build       |   13 +++++++++----
 meson_options.txt |    1 +
 2 files changed, 10 insertions(+), 4 deletions(-)
---
diff --git a/meson.build b/meson.build
index e85d5f8..3713380 100644
--- a/meson.build
+++ b/meson.build
@@ -69,10 +69,8 @@ config_data.set_quoted(
         'LOCALEDIR',
         join_paths(get_option('prefix'), get_option('localedir'))
 )
-config_data.set_quoted(
-        'PACKAGE_VERSION',
-        meson.project_version()
-)
+config_data.set_quoted('PACKAGE_VERSION', meson.project_version())
+config_data.set('FLATPAK_BUILD', get_option('flatpak_build'))
 
 configure_file(
         output : 'config.h',
@@ -153,3 +151,10 @@ subdir('help')
 subdir('devhelp')
 subdir('src')
 subdir('unit-tests')
+
+# Print a summary of the configuration
+output = 'Configuration:\n\n'
+output += '        Devhelp version ' + meson.project_version() + '\n\n'
+output += '        Prefix:             ' + get_option('prefix') + '\n'
+output += '        Flatpak build mode: ' + get_option('flatpak_build').to_string()
+message(output)
diff --git a/meson_options.txt b/meson_options.txt
new file mode 100644
index 0000000..489dc20
--- /dev/null
+++ b/meson_options.txt
@@ -0,0 +1 @@
+option('flatpak_build', type : 'boolean', value : false, description : 'Flatpak build mode')