Meson: fix deprecation warnings (#362)

Author: danirabbit

data/meson.build

@@ -1,15 +1,15 @@
 i18n.merge_file(
     input: 'network.metainfo.xml.in',
     output: 'io.elementary.wingpanel.network.metainfo.xml',
-    po_dir: join_paths(meson.source_root(), 'po', 'extra'),
+    po_dir: meson.project_source_root() / 'po' / 'extra',
     type: 'xml',
     install: true,
-    install_dir: join_paths(get_option('datadir'), 'metainfo'),
+    install_dir: get_option('datadir') / 'metainfo',
 )
 
 configure_file(
     input: 'network.policy.in',
     output: 'io.elementary.wingpanel.network.policy',
     configuration: config_data,
-    install_dir: polkit_dep.get_pkgconfig_variable('policydir', define_variable: ['prefix', prefix])
+    install_dir: polkit_dep.get_variable('policydir', pkgconfig_define: ['prefix', prefix])
 )

meson.build

@@ -1,7 +1,8 @@
 project(
     'network',
     'vala', 'c',
-    version: '8.0.1'
+    version: '8.0.1',
+    meson_version: '>=0.58.0'
 )
 
 gettext_name = meson.project_name() + '-indicator'
@@ -21,7 +22,7 @@ add_project_arguments(
 add_project_arguments('-DG_LOG_DOMAIN="io.elementary.wingpanel.network"', language:'c')
 
 wingpanel_dep = dependency('wingpanel')
-wingpanel_indicatorsdir = wingpanel_dep.get_pkgconfig_variable('indicatorsdir', define_variable: ['libdir', libdir])
+wingpanel_indicatorsdir = wingpanel_dep.get_variable('indicatorsdir', pkgconfig_define: ['libdir', libdir])
 
 config_data = configuration_data()
 config_data.set_quoted('LOCALEDIR', join_paths(get_option('prefix'), get_option('localedir')))

po/extra/meson.build

@@ -1,5 +1,5 @@
 i18n.gettext('extra',
-    args: '--directory=' + meson.source_root(),
+    args: '--directory=' + meson.project_source_root(),
     preset: 'glib',
     install: false,
 )

po/meson.build

@@ -1,5 +1,5 @@
 i18n.gettext(gettext_name,
-    args: '--directory=' + meson.source_root(),
+    args: '--directory=' + meson.project_source_root(),
     preset: 'glib'
 )
 

vapi/meson.build

@@ -1,4 +1,4 @@
-gir_dir = g_ir_dep.get_pkgconfig_variable('girdir')
+gir_dir = g_ir_dep.get_variable('girdir', pkgconfig_define: ['prefix', prefix])
 
 libnm_target = custom_target('libnm',
     command: [