[libpeas] build: fix peas-demo installation

[Christian Hergert <chergert src gnome org>]

commit e93e274b34caef65fc0174b336b08d591c3432ca
Author: Christian Hergert <chergert redhat com>
Date:   Tue Aug 20 15:53:15 2019 +0200

    build: fix peas-demo installation
    
    This was fallout from the change to meson.
    
    Fixes #30

 peas-demo/meson.build                     | 8 +++++++-
 peas-demo/plugins/helloworld/meson.build  | 5 ++++-
 peas-demo/plugins/luahello/meson.build    | 2 ++
 peas-demo/plugins/pythonhello/meson.build | 2 ++
 peas-demo/plugins/secondtime/meson.build  | 5 ++++-
 5 files changed, 19 insertions(+), 3 deletions(-)
---
diff --git a/peas-demo/meson.build b/peas-demo/meson.build
index 8441999..b0cc133 100644
--- a/peas-demo/meson.build
+++ b/peas-demo/meson.build
@@ -1,5 +1,8 @@
+if get_option('demos')
+
 peas_demo_name = 'peas-demo'
 peas_demo_string = '@0@-@1@'.format(peas_demo_name, api_version)
+peas_demo_plugins_dir = join_paths(get_option('libdir'), 'peas-demo', 'plugins')
 
 peas_demo_c = [
   'peas-demo-window.c',
@@ -14,10 +17,13 @@ peas_demo_c_args = [
 ]
 
 executable(
-  peas_demo_string,
+  peas_demo_name,
   peas_demo_c,
   c_args: peas_demo_c_args,
   dependencies: [libpeas_gtk_dep],
+  install: true,
 )
 
 subdir('plugins')
+
+endif
diff --git a/peas-demo/plugins/helloworld/meson.build b/peas-demo/plugins/helloworld/meson.build
index 6d2ea95..0e325ce 100644
--- a/peas-demo/plugins/helloworld/meson.build
+++ b/peas-demo/plugins/helloworld/meson.build
@@ -19,7 +19,8 @@ libhelloworld_lib = shared_library(
   include_directories: rootdir,
   dependencies: [gtk_dep, libpeas_gtk_dep],
   c_args: libhelloworld_c_args,
-  install: false,
+  install_dir: join_paths(peas_demo_plugins_dir, 'helloworld'),
+  install: true,
 )
 
 custom_target(
@@ -28,4 +29,6 @@ custom_target(
   output: libhelloworld_plugin_data,
   command: ['cp', '@INPUT@', '@OUTDIR@'],
   build_by_default: true,
+  install_dir: join_paths(peas_demo_plugins_dir, 'helloworld'),
+  install: true,
 )
diff --git a/peas-demo/plugins/luahello/meson.build b/peas-demo/plugins/luahello/meson.build
index 72d90cc..90d0dae 100644
--- a/peas-demo/plugins/luahello/meson.build
+++ b/peas-demo/plugins/luahello/meson.build
@@ -11,4 +11,6 @@ custom_target(
   output: luahello_plugin_data,
   command: ['cp', '@INPUT@', '@OUTDIR@'],
   build_by_default: true,
+  install_dir: join_paths(peas_demo_plugins_dir, 'luahello'),
+  install: true,
 )
diff --git a/peas-demo/plugins/pythonhello/meson.build b/peas-demo/plugins/pythonhello/meson.build
index d3fbf1d..7ba4406 100644
--- a/peas-demo/plugins/pythonhello/meson.build
+++ b/peas-demo/plugins/pythonhello/meson.build
@@ -11,4 +11,6 @@ custom_target(
   output: pythonhello_plugin_data,
   command: ['cp', '@INPUT@', '@OUTDIR@'],
   build_by_default: true,
+  install_dir: join_paths(peas_demo_plugins_dir, 'pythonhello'),
+  install: true,
 )
diff --git a/peas-demo/plugins/secondtime/meson.build b/peas-demo/plugins/secondtime/meson.build
index 6d4716e..30c0dac 100644
--- a/peas-demo/plugins/secondtime/meson.build
+++ b/peas-demo/plugins/secondtime/meson.build
@@ -18,7 +18,8 @@ libsecondtime_lib = shared_library(
   include_directories: rootdir,
   dependencies: [gtk_dep, libpeas_dep],
   c_args: libsecondtime_c_args,
-  install: false,
+  install_dir: join_paths(peas_demo_plugins_dir, 'secondtime'),
+  install: true,
 )
 
 custom_target(
@@ -27,4 +28,6 @@ custom_target(
   output: libsecondtime_plugin_data,
   command: ['cp', '@INPUT@', '@OUTDIR@'],
   build_by_default: true,
+  install_dir: join_paths(peas_demo_plugins_dir, 'secondtime'),
+  install: true,
 )