Add D-Bus activation to book (#2229)

Author: Hofer-Julian

Cargo.lock

@@ -1,23 +1,38 @@
-subdir('icons')
 subdir('resources')
 
-desktop_conf = configuration_data()
-desktop_conf.set('APP_ID', application_id)
-configure_file(
-    input: '@0@.desktop.in'.format(base_id),
-    output: '@0@.desktop'.format(application_id),
-    configuration: desktop_conf,
-    install: true,
-    install_dir: datadir / 'applications',
-)
+# Linux-specific: desktop file, GSettings schema, and icons
+if host_machine.system() == 'linux'
+    subdir('icons')
 
-gschema_conf = configuration_data()
-gschema_conf.set('APP_ID', application_id)
-configure_file(
-    input: '@0@.gschema.xml.in'.format(base_id),
-    output: '@0@.gschema.xml'.format(application_id),
-    configuration: gschema_conf,
-    install: true,
-    install_dir: datadir / 'glib-2.0' / 'schemas',
-)
+    desktop_conf = configuration_data()
+    desktop_conf.set('APP_ID', application_id)
+    configure_file(
+        input: '@0@.desktop.in'.format(base_id),
+        output: '@0@.desktop'.format(application_id),
+        configuration: desktop_conf,
+        install: true,
+        install_dir: datadir / 'applications',
+    )
+
+    gschema_conf = configuration_data()
+    gschema_conf.set('APP_ID', application_id)
+    configure_file(
+        input: '@0@.gschema.xml.in'.format(base_id),
+        output: '@0@.gschema.xml'.format(application_id),
+        configuration: gschema_conf,
+        install: true,
+        install_dir: datadir / 'glib-2.0' / 'schemas',
+    )
+
+    service_conf = configuration_data()
+    service_conf.set('APP_ID', application_id)
+    service_conf.set('BINDIR', bindir)
+    configure_file(
+        input: '@0@.service.in'.format(base_id),
+        output: '@0@.service'.format(application_id),
+        configuration: service_conf,
+        install: true,
+        install_dir: datadir / 'dbus-1' / 'services',
+    )
+endif
 

book/listings/todo/9/data/meson.build

@@ -4,4 +4,5 @@ Exec=todo
 Icon=@APP_ID@
 Terminal=false
 Type=Application
+DBusActivatable=true
 Categories=GNOME;GTK;Utility;

book/listings/todo/9/data/org.gtk_rs.Todo9.desktop.in

@@ -0,0 +1,3 @@
+[D-BUS Service]
+Name=@APP_ID@
+Exec=@BINDIR@/todo --gapplication-service

book/listings/todo/9/data/org.gtk_rs.Todo9.service.in

@@ -26,7 +26,7 @@ fn print_help() {
     eprintln!(
         "Tasks:
 install          install everything needed to run the listings
-configure        configure meson projects (generates config.rs, for CI)
+configure        configure meson projects
 "
     )
 }

book/listings/xtask/main.rs

@@ -9,17 +9,17 @@ To do this, execute the command belonging to the distribution you are using.
 Fedora and derivatives:
 
 ```
-sudo dnf install gtk4-devel libadwaita-devel meson desktop-file-utils gcc
+sudo dnf install gtk4-devel libadwaita-devel meson desktop-file-utils gcc glib-compile-resources gtk4-update-icon-cache update-desktop-database
 ```
 
 Debian and derivatives:
 
 ```
-sudo apt install libgtk-4-dev libadwaita-1-dev meson desktop-file-utils build-essential
+sudo apt install libgtk-4-dev libadwaita-1-dev meson desktop-file-utils gcc gtk-update-icon-cache
 ```
 
 Arch and derivatives:
 
 ```
-sudo pacman -S gtk4 libadwaita meson desktop-file-utils base-devel
+sudo pacman -S gtk4 libadwaita meson desktop-file-utils gcc
 ```

book/src/installation_linux.md

@@ -107,11 +107,15 @@ That means that we can change images and `.ui` files without triggering Rust com
 
 We also use `config::app_id()` instead of a hardcoded constant.
 
-## System Integration
+## Linux/GNOME Integration
+
+The following sections cover integration with Linux desktop environments, particularly GNOME.
+These are optional if you're targeting other platforms, but essential for a polished Linux experience.
 
 ### Data meson.build
 
-This file sets subdirs where `meson.build` files will be executed, and declares that a desktop and GSettings schema file will be templated and installed.
+This file compiles GResources (cross-platform) and handles Linux-specific installation.
+The desktop file, GSettings schema, and icon installation are wrapped in a `host_machine.system() == 'linux'` check, so they're skipped on other platforms.
 
 Filename: <a class=file-link href="https://github.com/gtk-rs/gtk4-rs/blob/main/book/listings/todo/9/data/meson.build">listings/todo/9/data/meson.build</a>
 
@@ -130,7 +134,24 @@ Filename: <a class=file-link href="https://github.com/gtk-rs/gtk4-rs/blob/main/b
 ```
 
 The `@APP_ID@` placeholder is substituted during the build.
-This way, we can install the app in default and development, without the two installations clashing with each other. 
+This way, we can install the app in default and development, without the two installations clashing with each other.
+
+The `DBusActivatable=true` entry enables [D-Bus activation](https://developer.gnome.org/documentation/guidelines/maintainer/integrating.html#d-bus-activation).
+Instead of launching your app directly, GNOME can send a D-Bus message to your application's well-known name.
+If the app is already running, it can respond by raising its existing window instead of spawning a duplicate instance.
+D-Bus activation is also a prerequisite for persistent notifications.
+
+### D-Bus Service File
+
+For D-Bus activation to work, we also need a service file that tells D-Bus how to start our application:
+
+Filename: <a class=file-link href="https://github.com/gtk-rs/gtk4-rs/blob/main/book/listings/todo/9/data/org.gtk_rs.Todo9.service.in">listings/todo/9/data/org.gtk_rs.Todo9.service.in</a>
+
+```ini
+{{#include ../listings/todo/9/data/org.gtk_rs.Todo9.service.in}}
+```
+
+The `--gapplication-service` flag tells GApplication to run as a D-Bus service rather than a standalone application.
 
 
 ### GSettings Schema