ui: Add "About" window to display version, authors, license, etc.

This adds a new adw::AboutWindow containing information about version, authors, license, links etc.
It is opened via a new menu button in the toolbar, which opens a menu containing an "About Helvum" button.

The version and authors are pulled from the Cargo.toml file.

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "helvum"
 version = "0.4.1"
-authors = ["Tom A. Wagner <tom.a.wagner@protonmail.com>"]
+authors = ["Tom Wagner <tom.a.wagner@protonmail.com>"]
 edition = "2021"
 rust-version = "1.70"
 license = "GPL-3.0-only"
@@ -15,7 +15,7 @@ categories = ["gui", "multimedia"]
 
 [dependencies]
 pipewire = "0.7.1"
-adw = { version = "0.5", package = "libadwaita" }
+adw = { version = "0.5", package = "libadwaita", features = ["v1_2"] }
 glib = { version = "0.18", features = ["log"] }
 
 log = "0.4.11"

meson.build

@@ -12,7 +12,7 @@ base_id = 'org.pipewire.Helvum'
 
 dependency('glib-2.0',     version: '>= 2.66')
 dependency('gtk4',         version: '>= 4.4.0')
-dependency('libadwaita-1')
+dependency('libadwaita-1', version: '>= 1.2')
 dependency('libpipewire-0.3')
 
 desktop_file_validate = find_program('desktop-file-validate', required: false)

src/application.rs

@@ -26,6 +26,9 @@ use pipewire::channel::Sender;
 use crate::{graph_manager::GraphManager, ui, GtkMessage, PipewireMessage};
 
 static STYLE: &str = include_str!("style.css");
+static APP_ID: &str = "org.pipewire.Helvum";
+static VERSION: &str = env!("CARGO_PKG_VERSION");
+static AUTHORS: &str = env!("CARGO_PKG_AUTHORS");
 
 mod imp {
     use super::*;
@@ -81,10 +84,50 @@ mod imp {
                 &provider,
                 gtk::STYLE_PROVIDER_PRIORITY_APPLICATION,
             );
+
+            self.setup_actions();
         }
     }
     impl GtkApplicationImpl for Application {}
     impl AdwApplicationImpl for Application {}
+
+    impl Application {
+        fn setup_actions(&self) {
+            let obj = &*self.obj();
+
+            // Add <Control-Q> shortcut for quitting the application.
+            let quit = gtk::gio::SimpleAction::new("quit", None);
+            quit.connect_activate(clone!(@weak obj => move |_, _| {
+                obj.quit();
+            }));
+            obj.set_accels_for_action("app.quit", &["<Control>Q"]);
+            obj.add_action(&quit);
+
+            let action_about = gio::ActionEntry::builder("about")
+                .activate(|obj: &super::Application, _, _| {
+                    obj.imp().show_about_dialog();
+                })
+                .build();
+            obj.add_action_entries([action_about]);
+        }
+
+        fn show_about_dialog(&self) {
+            let authors: Vec<&str> = AUTHORS.split(':').collect();
+
+            let about_window = adw::AboutWindow::builder()
+                .application_icon(APP_ID)
+                .application_name("Helvum")
+                .developer_name("Tom Wagner")
+                .developers(authors)
+                .version(VERSION)
+                .website("https://gitlab.freedesktop.org/pipewire/helvum")
+                .issue_url("https://gitlab.freedesktop.org/pipewire/helvum/-/issues")
+                .license_type(gtk::License::Gpl30Only)
+                .build();
+
+            about_window.present();
+        }
+    }
 }
 
 glib::wrapper! {
@@ -101,7 +144,7 @@ impl Application {
         pw_sender: Sender<GtkMessage>,
     ) -> Self {
         let app: Application = glib::Object::builder()
-            .property("application-id", "org.pipewire.Helvum")
+            .property("application-id", APP_ID)
             .build();
 
         let imp = app.imp();
@@ -114,14 +157,6 @@ impl Application {
             ))
             .expect("Should be able to set graph manager");
 
-        // Add <Control-Q> shortcut for quitting the application.
-        let quit = gtk::gio::SimpleAction::new("quit", None);
-        quit.connect_activate(clone!(@weak app => move |_, _| {
-            app.quit();
-        }));
-        app.set_accels_for_action("app.quit", &["<Control>Q"]);
-        app.add_action(&quit);
-
         app
     }
 }

src/ui/window.ui

@@ -2,6 +2,14 @@
 <interface>
   <requires lib="gtk" version="4.0"/>
   <requires lib="Adw" version="1.0"/>
+  <menu id="primary_menu">
+    <section>
+      <item>
+        <attribute name="label">_About Helvum</attribute>
+        <attribute name="action">app.about</attribute>
+      </item>
+    </section>
+  </menu>
   <template class="HelvumWindow" parent="AdwApplicationWindow">
     <property name="default-width">1280</property>
     <property name="default-height">720</property>
@@ -12,10 +20,23 @@
         <child>
           <object class="AdwHeaderBar" id="header_bar">
             <child type="end">
+              <object class="GtkBox">
+                <style>
+                  <class name="toolbar"></class>
+                </style>
+                <child>
                   <object class="HelvumZoomEntry">
                     <property name="zoomed-widget">graph</property>
                   </object>
                 </child>
+                <child>
+                  <object class="GtkMenuButton">
+                    <property name="icon-name">open-menu-symbolic</property>
+                    <property name="menu-model">primary_menu</property>
+                  </object>
+                </child>
+              </object>
+            </child>
           </object>
         </child>
         <child>