Add HTTP client and login support

Cargo.toml

@@ -18,6 +18,10 @@ gtk = { version = "0.9.2", features = ["v3_24"] }
 gtk-macros = "0.2.0"
 gstreamer = "0.16.4"
 gstreamer-player = "0.16.3"
+isahc = "0.9.12"
 libhandy = "0.7.0"
 pango = "0.9.1"
 rand = "0.7.3"
+secret-service = "1.1.1"
+serde = { version = "1.0.117", features = ["derive"] }
+serde_json = "1.0.59"

data/de.johrpan.musicus.gschema.xml

@@ -5,5 +5,9 @@
 			<default>""</default>
 			<summary>Path to the music library folder</summary>
 		</key>
+		<key name="server-url" type="s">
+			<default>"https://musicus.johrpan.de"</default>
+			<summary>URL of the Musicus server to use</summary>
+		</key>
 	</schema>
 </schemalist>

meson.build

@@ -4,10 +4,12 @@ project('musicus', 'rust',
     license: 'AGPLv3+',
 )
 
+dependency('dbus-1', version: '>= 1.3')
 dependency('glib-2.0', version: '>= 2.56')
 dependency('gio-2.0', version: '>= 2.56')
 dependency('gstreamer-1.0', version: '>= 1.12')
 dependency('gtk+-3.0', version: '>= 3.24.7')
+dependency('libcurl', version: '>= 7.24.0')
 dependency('libhandy-1', version: '>= 1.0.0')
 dependency('pango', version: '>= 1.0')
 dependency('sqlite3', version: '>= 3.20')

res/musicus.gresource.xml

@@ -6,6 +6,7 @@
         <file preprocess="xml-stripblanks">ui/ensemble_screen.ui</file>
         <file preprocess="xml-stripblanks">ui/instrument_editor.ui</file>
         <file preprocess="xml-stripblanks">ui/instrument_selector.ui</file>
+        <file preprocess="xml-stripblanks">ui/login_dialog.ui</file>
         <file preprocess="xml-stripblanks">ui/part_editor.ui</file>
         <file preprocess="xml-stripblanks">ui/performance_editor.ui</file>
         <file preprocess="xml-stripblanks">ui/person_editor.ui</file>
@@ -21,6 +22,7 @@
         <file preprocess="xml-stripblanks">ui/recording_selector.ui</file>
         <file preprocess="xml-stripblanks">ui/recording_selector_screen.ui</file>
         <file preprocess="xml-stripblanks">ui/section_editor.ui</file>
+        <file preprocess="xml-stripblanks">ui/server_dialog.ui</file>
         <file preprocess="xml-stripblanks">ui/tracks_editor.ui</file>
         <file preprocess="xml-stripblanks">ui/track_editor.ui</file>
         <file preprocess="xml-stripblanks">ui/window.ui</file>

res/ui/login_dialog.ui

@@ -0,0 +1,219 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Generated with glade 3.38.1 -->
+<interface>
+  <requires lib="gtk+" version="3.24"/>
+  <requires lib="libhandy" version="0.0"/>
+  <object class="HdyWindow" id="window">
+    <property name="can-focus">False</property>
+    <property name="modal">True</property>
+    <property name="default-width">350</property>
+    <property name="type-hint">dialog</property>
+    <child>
+      <object class="GtkStack" id="stack">
+        <property name="visible">True</property>
+        <property name="can-focus">False</property>
+        <property name="transition-type">crossfade</property>
+        <child>
+          <object class="GtkBox">
+            <property name="visible">True</property>
+            <property name="can-focus">False</property>
+            <property name="orientation">vertical</property>
+            <child>
+              <object class="HdyHeaderBar">
+                <property name="visible">True</property>
+                <property name="can-focus">False</property>
+                <property name="title" translatable="yes">Login</property>
+                <child>
+                  <object class="GtkButton" id="cancel_button">
+                    <property name="label" translatable="yes">Cancel</property>
+                    <property name="visible">True</property>
+                    <property name="can-focus">True</property>
+                    <property name="receives-default">True</property>
+                  </object>
+                </child>
+                <child>
+                  <object class="GtkButton" id="login_button">
+                    <property name="label" translatable="yes">Login</property>
+                    <property name="visible">True</property>
+                    <property name="can-focus">True</property>
+                    <property name="can-default">True</property>
+                    <property name="has-default">True</property>
+                    <property name="receives-default">False</property>
+                    <style>
+                      <class name="suggested-action"/>
+                    </style>
+                  </object>
+                  <packing>
+                    <property name="pack-type">end</property>
+                    <property name="position">1</property>
+                  </packing>
+                </child>
+              </object>
+              <packing>
+                <property name="expand">False</property>
+                <property name="fill">True</property>
+                <property name="position">0</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkInfoBar" id="info_bar">
+                <property name="visible">True</property>
+                <property name="can-focus">False</property>
+                <property name="message-type">error</property>
+                <property name="revealed">False</property>
+                <child internal-child="action_area">
+                  <object class="GtkButtonBox">
+                    <property name="can-focus">False</property>
+                    <property name="spacing">6</property>
+                    <property name="layout-style">end</property>
+                    <child>
+                      <placeholder/>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">False</property>
+                    <property name="position">0</property>
+                  </packing>
+                </child>
+                <child internal-child="content_area">
+                  <object class="GtkBox">
+                    <property name="can-focus">False</property>
+                    <property name="spacing">16</property>
+                    <child>
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can-focus">False</property>
+                        <property name="label" translatable="yes">The login credentials were wrong!</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">0</property>
+                      </packing>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">False</property>
+                    <property name="position">0</property>
+                  </packing>
+                </child>
+              </object>
+              <packing>
+                <property name="expand">False</property>
+                <property name="fill">True</property>
+                <property name="position">1</property>
+              </packing>
+            </child>
+            <child>
+              <!-- n-columns=2 n-rows=2 -->
+              <object class="GtkGrid">
+                <property name="visible">True</property>
+                <property name="can-focus">False</property>
+                <property name="border-width">18</property>
+                <property name="row-spacing">12</property>
+                <property name="column-spacing">6</property>
+                <child>
+                  <object class="GtkLabel">
+                    <property name="visible">True</property>
+                    <property name="can-focus">False</property>
+                    <property name="halign">end</property>
+                    <property name="label" translatable="yes">Username</property>
+                  </object>
+                  <packing>
+                    <property name="left-attach">0</property>
+                    <property name="top-attach">0</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkLabel">
+                    <property name="visible">True</property>
+                    <property name="can-focus">False</property>
+                    <property name="halign">end</property>
+                    <property name="label" translatable="yes">Password</property>
+                  </object>
+                  <packing>
+                    <property name="left-attach">0</property>
+                    <property name="top-attach">1</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkEntry" id="username_entry">
+                    <property name="visible">True</property>
+                    <property name="can-focus">True</property>
+                    <property name="has-focus">True</property>
+                    <property name="hexpand">True</property>
+                  </object>
+                  <packing>
+                    <property name="left-attach">1</property>
+                    <property name="top-attach">0</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkEntry" id="password_entry">
+                    <property name="visible">True</property>
+                    <property name="can-focus">True</property>
+                    <property name="visibility">False</property>
+                    <property name="activates-default">True</property>
+                    <property name="input-purpose">password</property>
+                  </object>
+                  <packing>
+                    <property name="left-attach">1</property>
+                    <property name="top-attach">1</property>
+                  </packing>
+                </child>
+              </object>
+              <packing>
+                <property name="expand">False</property>
+                <property name="fill">True</property>
+                <property name="position">2</property>
+              </packing>
+            </child>
+          </object>
+          <packing>
+            <property name="name">content</property>
+          </packing>
+        </child>
+        <child>
+          <object class="GtkBox">
+            <property name="visible">True</property>
+            <property name="can-focus">False</property>
+            <property name="orientation">vertical</property>
+            <child>
+              <object class="HdyHeaderBar">
+                <property name="visible">True</property>
+                <property name="can-focus">False</property>
+                <property name="title" translatable="yes">Login</property>
+              </object>
+              <packing>
+                <property name="expand">False</property>
+                <property name="fill">True</property>
+                <property name="position">0</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkSpinner">
+                <property name="visible">True</property>
+                <property name="can-focus">False</property>
+                <property name="active">True</property>
+              </object>
+              <packing>
+                <property name="expand">True</property>
+                <property name="fill">True</property>
+                <property name="position">1</property>
+              </packing>
+            </child>
+          </object>
+          <packing>
+            <property name="name">loading</property>
+            <property name="position">1</property>
+          </packing>
+        </child>
+        <child>
+          <placeholder/>
+        </child>
+      </object>
+    </child>
+  </object>
+</interface>

res/ui/preferences.ui

@@ -40,7 +40,59 @@
             </child>
           </object>
         </child>
+        <child>
+          <object class="HdyPreferencesGroup">
+            <property name="visible">True</property>
+            <property name="can-focus">False</property>
+            <property name="title" translatable="yes">Server connection</property>
+            <child>
+              <object class="HdyActionRow" id="url_row">
+                <property name="visible">True</property>
+                <property name="can-focus">True</property>
+                <property name="selectable">False</property>
+                <property name="title" translatable="yes">Server URL</property>
+                <property name="activatable-widget">url_button</property>
+                <property name="subtitle" translatable="yes">Not set</property>
+                <child>
+                  <object class="GtkButton" id="url_button">
+                    <property name="label" translatable="yes">Change</property>
+                    <property name="visible">True</property>
+                    <property name="can-focus">True</property>
+                    <property name="receives-default">True</property>
+                    <property name="valign">center</property>
+                  </object>
+                </child>
+              </object>
+            </child>
+            <child>
+              <object class="HdyActionRow" id="login_row">
+                <property name="visible">True</property>
+                <property name="can-focus">True</property>
+                <property name="selectable">False</property>
+                <property name="title" translatable="yes">Login credentials</property>
+                <property name="activatable-widget">login_button</property>
+                <property name="subtitle" translatable="yes">Not logged in</property>
+                <child>
+                  <object class="GtkButton" id="login_button">
+                    <property name="label" translatable="yes">Change</property>
+                    <property name="visible">True</property>
+                    <property name="can-focus">True</property>
+                    <property name="receives-default">True</property>
+                    <property name="valign">center</property>
+                  </object>
+                </child>
+              </object>
+            </child>
+          </object>
+        </child>
       </object>
     </child>
   </object>
+  <object class="GtkSizeGroup">
+    <widgets>
+      <widget name="select_music_library_path_button"/>
+      <widget name="url_button"/>
+      <widget name="login_button"/>
+    </widgets>
+  </object>
 </interface>

res/ui/server_dialog.ui

@@ -0,0 +1,96 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Generated with glade 3.38.1 -->
+<interface>
+  <requires lib="gtk+" version="3.24"/>
+  <requires lib="libhandy" version="0.0"/>
+  <object class="HdyWindow" id="window">
+    <property name="can-focus">False</property>
+    <property name="modal">True</property>
+    <property name="destroy-with-parent">True</property>
+    <property name="type-hint">dialog</property>
+    <child>
+      <object class="GtkBox">
+        <property name="visible">True</property>
+        <property name="can-focus">False</property>
+        <property name="orientation">vertical</property>
+        <child>
+          <object class="HdyHeaderBar">
+            <property name="visible">True</property>
+            <property name="can-focus">False</property>
+            <property name="title" translatable="yes">Server</property>
+            <child>
+              <object class="GtkButton" id="cancel_button">
+                <property name="label" translatable="yes">Cancel</property>
+                <property name="visible">True</property>
+                <property name="can-focus">True</property>
+                <property name="receives-default">True</property>
+              </object>
+            </child>
+            <child>
+              <object class="GtkButton" id="set_button">
+                <property name="label" translatable="yes">Set</property>
+                <property name="visible">True</property>
+                <property name="can-focus">True</property>
+                <property name="can-default">True</property>
+                <property name="has-default">True</property>
+                <property name="receives-default">True</property>
+                <style>
+                  <class name="suggested-action"/>
+                </style>
+              </object>
+              <packing>
+                <property name="pack-type">end</property>
+                <property name="position">1</property>
+              </packing>
+            </child>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">True</property>
+            <property name="position">0</property>
+          </packing>
+        </child>
+        <child>
+          <!-- n-columns=2 n-rows=1 -->
+          <object class="GtkGrid">
+            <property name="visible">True</property>
+            <property name="can-focus">False</property>
+            <property name="border-width">18</property>
+            <property name="row-spacing">12</property>
+            <property name="column-spacing">6</property>
+            <child>
+              <object class="GtkLabel">
+                <property name="visible">True</property>
+                <property name="can-focus">False</property>
+                <property name="halign">end</property>
+                <property name="label" translatable="yes">URL</property>
+              </object>
+              <packing>
+                <property name="left-attach">0</property>
+                <property name="top-attach">0</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkEntry" id="url_entry">
+                <property name="visible">True</property>
+                <property name="can-focus">True</property>
+                <property name="has-focus">True</property>
+                <property name="hexpand">True</property>
+                <property name="activates-default">True</property>
+              </object>
+              <packing>
+                <property name="left-attach">1</property>
+                <property name="top-attach">0</property>
+              </packing>
+            </child>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">True</property>
+            <property name="position">1</property>
+          </packing>
+        </child>
+      </object>
+    </child>
+  </object>
+</interface>

src/backend/backend.rs

@@ -1,13 +1,23 @@
-use super::database::*;
+use super::secure;
+use crate::database::*;
 use crate::player::*;
 use anyhow::{anyhow, Result};
 use futures_channel::oneshot::Sender;
 use futures_channel::{mpsc, oneshot};
 use gio::prelude::*;
+use serde::Serialize;
 use std::cell::RefCell;
 use std::path::PathBuf;
 use std::rc::Rc;
 
+/// Credentials used for login.
+#[derive(Serialize, Debug, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct LoginData {
+    pub username: String,
+    pub password: String,
+}
+
 pub enum BackendState {
     NoMusicLibrary,
     Loading,
@@ -50,6 +60,10 @@ pub struct Backend {
     state_sender: RefCell<mpsc::Sender<BackendState>>,
     action_sender: RefCell<Option<std::sync::mpsc::Sender<BackendAction>>>,
     settings: gio::Settings,
+    secrets: secret_service::SecretService,
+    server_url: RefCell<Option<String>>,
+    login_data: RefCell<Option<LoginData>>,
+    token: RefCell<Option<String>>,
     music_library_path: RefCell<Option<PathBuf>>,
     player: RefCell<Option<Rc<Player>>>,
 }
@@ -57,13 +71,19 @@ pub struct Backend {
 impl Backend {
     pub fn new() -> Self {
         let (state_sender, state_stream) = mpsc::channel(1024);
+        let secrets = secret_service::SecretService::new(secret_service::EncryptionType::Dh)
+            .expect("Failed to connect to SecretsService!");
 
         Backend {
             state_stream: RefCell::new(state_stream),
             state_sender: RefCell::new(state_sender),
             action_sender: RefCell::new(None),
             settings: gio::Settings::new("de.johrpan.musicus"),
+            secrets,
             music_library_path: RefCell::new(None),
+            server_url: RefCell::new(None),
+            login_data: RefCell::new(None),
+            token: RefCell::new(None),
             player: RefCell::new(None),
         }
     }
@@ -72,13 +92,25 @@ impl Backend {
         if let Some(path) = self.settings.get_string("music-library-path") {
             if !path.is_empty() {
                 let context = glib::MainContext::default();
+                let clone = self.clone();
                 context.spawn_local(async move {
-                    self.set_music_library_path_priv(PathBuf::from(path.to_string()))
+                    clone
+                        .set_music_library_path_priv(PathBuf::from(path.to_string()))
                         .await
                         .unwrap();
                 });
             }
         }
+
+        if let Some(data) = secure::load_login_data().unwrap() {
+            self.login_data.replace(Some(data));
+        }
+
+        if let Some(url) = self.settings.get_string("server-url") {
+            if !url.is_empty() {
+                self.server_url.replace(Some(url.to_string()));
+            }
+        }
     }
 
     pub async fn update_person(&self, person: Person) -> Result<()> {
@@ -270,6 +302,40 @@ impl Backend {
         self.music_library_path.borrow().clone()
     }
 
+    /// Get the currently stored login credentials.
+    pub fn get_login_data(&self) -> Option<LoginData> {
+        self.login_data.borrow().clone()
+    }
+
+    /// Set the URL of the Musicus server to connect to.
+    pub fn set_server_url(&self, url: &str) -> Result<()> {
+        self.settings.set_string("server-url", url)?;
+        self.server_url.replace(Some(url.to_string()));
+        Ok(())
+    }
+
+    /// Get the currently used login token.
+    pub fn get_token(&self) -> Option<String> {
+        self.token.borrow().clone()
+    }
+
+    /// Set the login token to use. This will be done automatically by the login method.
+    pub fn set_token(&self, token: &str) {
+        self.token.replace(Some(token.to_string()));
+    }
+
+    /// Get the currently set server URL.
+    pub fn get_server_url(&self) -> Option<String> {
+        self.server_url.borrow().clone()
+    }
+
+    /// Set the user credentials to use.
+    pub async fn set_login_data(&self, data: LoginData) -> Result<()> {
+        secure::store_login_data(data.clone()).await?;
+        self.login_data.replace(Some(data));
+        Ok(())
+    }
+
     pub fn get_player(&self) -> Option<Rc<Player>> {
         self.player.borrow().clone()
     }

src/backend/client.rs

@@ -0,0 +1,31 @@
+use super::Backend;
+use anyhow::{anyhow, bail, Result};
+use isahc::http::StatusCode;
+use isahc::prelude::*;
+
+impl Backend {
+    /// Try to login a user with the provided credentials and return, wether the login suceeded.
+    pub async fn login(&self) -> Result<bool> {
+        let server_url = self.get_server_url().ok_or(anyhow!("No server URL set!"))?;
+        let data = self.get_login_data().ok_or(anyhow!("No login data set!"))?;
+
+        let request = Request::post(format!("{}/login", server_url))
+            .header("Content-Type", "application/json")
+            .body(serde_json::to_string(&data)?)?;
+
+        let mut response = isahc::send_async(request).await?;
+
+        let success = match response.status() {
+            StatusCode::OK => {
+                let token = response.text_async().await?;
+                self.set_token(&token);
+                println!("{}", &token);
+                true
+            }
+            StatusCode::UNAUTHORIZED => false,
+            _ => bail!("Unexpected response status!"),
+        };
+
+        Ok(success)
+    }
+}

src/backend/mod.rs

@@ -0,0 +1,7 @@
+pub mod backend;
+pub use backend::*;
+
+pub mod client;
+pub use client::*;
+
+mod secure;

src/backend/secure.rs

@@ -0,0 +1,108 @@
+use super::LoginData;
+use anyhow::{anyhow, Result};
+use futures_channel::oneshot;
+use secret_service::{Collection, EncryptionType, SecretService};
+
+/// Savely store the user's current login credentials.
+pub async fn store_login_data(data: LoginData) -> Result<()> {
+    let (sender, receiver) = oneshot::channel::<Result<()>>();
+    std::thread::spawn(move || sender.send(store_login_data_priv(data)));
+    receiver.await?
+}
+
+/// Savely store the user's current login credentials.
+fn store_login_data_priv(data: LoginData) -> Result<()> {
+    let ss = get_ss()?;
+    let collection = get_collection(&ss)?;
+
+    let key = "musicus-login-data";
+    delete_secrets(&collection, key)?;
+
+    collection
+        .create_item(
+            key,
+            vec![("username", &data.username)],
+            data.password.as_bytes(),
+            true,
+            "text/plain",
+        )
+        .or(Err(anyhow!(
+            "Failed to save login data using SecretService!"
+        )))?;
+
+    Ok(())
+}
+
+/// Get the login credentials from secret storage.
+pub fn load_login_data() -> Result<Option<LoginData>> {
+    let ss = get_ss()?;
+    let collection = get_collection(&ss)?;
+
+    let items = collection.get_all_items().or(Err(anyhow!(
+        "Failed to get items from SecretService collection!"
+    )))?;
+
+    let key = "musicus-login-data";
+    let item = items
+        .iter()
+        .find(|item| item.get_label().unwrap_or_default() == key);
+
+    Ok(match item {
+        Some(item) => {
+            let attrs = item.get_attributes().or(Err(anyhow!(
+                "Failed to get attributes for ScretService item!"
+            )))?;
+
+            let username = attrs
+                .iter()
+                .find(|attr| attr.0 == "username")
+                .ok_or(anyhow!("No username in login data!"))?
+                .1
+                .clone();
+
+            let password = std::str::from_utf8(
+                &item
+                    .get_secret()
+                    .or(Err(anyhow!("Failed to get secret from SecretService!")))?,
+            )?
+            .to_string();
+
+            Some(LoginData { username, password })
+        }
+        None => None,
+    })
+}
+
+/// Delete all stored secrets for the provided key.
+fn delete_secrets(collection: &Collection, key: &str) -> Result<()> {
+    let items = collection.get_all_items().or(Err(anyhow!(
+        "Failed to get items from SecretService collection!"
+    )))?;
+
+    for item in items {
+        if item.get_label().unwrap_or_default() == key {
+            item.delete()
+                .or(Err(anyhow!("Failed to delete SecretService item!")))?;
+        }
+    }
+
+    Ok(())
+}
+
+/// Get the SecretService interface.
+fn get_ss() -> Result<SecretService> {
+    SecretService::new(EncryptionType::Dh).or(Err(anyhow!("Failed to get SecretService!")))
+}
+
+/// Get the default SecretService collection and unlock it.
+fn get_collection(ss: &SecretService) -> Result<Collection> {
+    let collection = ss
+        .get_default_collection()
+        .or(Err(anyhow!("Failed to get SecretService connection!")))?;
+
+    collection
+        .unlock()
+        .or(Err(anyhow!("Failed to unclock SecretService collection!")))?;
+
+    Ok(collection)
+}

src/dialogs/login_dialog.rs

@@ -0,0 +1,88 @@
+use crate::backend::{Backend, LoginData};
+use glib::clone;
+use gtk::prelude::*;
+use gtk_macros::get_widget;
+use std::cell::RefCell;
+use std::rc::Rc;
+
+/// A dialog for entering login credentials.
+pub struct LoginDialog {
+    backend: Rc<Backend>,
+    window: libhandy::Window,
+    stack: gtk::Stack,
+    info_bar: gtk::InfoBar,
+    username_entry: gtk::Entry,
+    password_entry: gtk::Entry,
+    selected_cb: RefCell<Option<Box<dyn Fn(LoginData) -> ()>>>,
+}
+
+impl LoginDialog {
+    /// Create a new login dialog.
+    pub fn new<P: IsA<gtk::Window>>(backend: Rc<Backend>, parent: &P) -> Rc<Self> {
+        // Create UI
+        let builder = gtk::Builder::from_resource("/de/johrpan/musicus/ui/login_dialog.ui");
+
+        get_widget!(builder, libhandy::Window, window);
+        get_widget!(builder, gtk::Stack, stack);
+        get_widget!(builder, gtk::InfoBar, info_bar);
+        get_widget!(builder, gtk::Button, cancel_button);
+        get_widget!(builder, gtk::Button, login_button);
+        get_widget!(builder, gtk::Entry, username_entry);
+        get_widget!(builder, gtk::Entry, password_entry);
+
+        window.set_transient_for(Some(parent));
+
+        let this = Rc::new(Self {
+            backend,
+            window,
+            stack,
+            info_bar,
+            username_entry,
+            password_entry,
+            selected_cb: RefCell::new(None),
+        });
+
+        // Connect signals and callbacks
+
+        cancel_button.connect_clicked(clone!(@strong this => move |_| {
+            this.window.close();
+        }));
+
+        login_button.connect_clicked(clone!(@strong this => move |_| {
+            this.stack.set_visible_child_name("loading");
+
+            let data = LoginData {
+                username: this.username_entry.get_text().to_string(),
+                password: this.password_entry.get_text().to_string(),
+            };
+
+            let c = glib::MainContext::default();
+            let clone = this.clone();
+            c.spawn_local(async move {
+                clone.backend.set_login_data(data.clone()).await.unwrap();
+                if clone.backend.login().await.unwrap() {
+                    if let Some(cb) = &*clone.selected_cb.borrow() {
+                        cb(data);
+                    }
+
+                    clone.window.close();
+                } else {
+                    clone.stack.set_visible_child_name("content");
+                    clone.info_bar.set_revealed(true);
+                }
+            });
+        }));
+
+        this
+    }
+
+    /// The closure to call when the login succeded.
+    pub fn set_selected_cb<F: Fn(LoginData) -> () + 'static>(&self, cb: F) {
+        self.selected_cb.replace(Some(Box::new(cb)));
+    }
+
+    /// Show the login dialog.
+    pub fn show(&self) {
+        self.window.show();
+    }
+}

src/dialogs/mod.rs

@@ -13,6 +13,9 @@ pub use instrument_editor::*;
 pub mod instrument_selector;
 pub use instrument_selector::*;
 
+pub mod login_dialog;
+pub use login_dialog::*;
+
 pub mod person_editor;
 pub use person_editor::*;
 
@@ -22,6 +25,9 @@ pub use person_selector::*;
 pub mod preferences;
 pub use preferences::*;
 
+pub mod server_dialog;
+pub use server_dialog::*;
+
 pub mod recording;
 pub use recording::*;
 

src/dialogs/preferences.rs

@@ -1,3 +1,4 @@
+use super::{LoginDialog, ServerDialog};
 use crate::backend::Backend;
 use gettextrs::gettext;
 use glib::clone;
@@ -6,47 +7,98 @@ use gtk_macros::get_widget;
 use libhandy::prelude::*;
 use std::rc::Rc;
 
+/// A dialog for configuring the app.
 pub struct Preferences {
+    backend: Rc<Backend>,
     window: libhandy::Window,
+    music_library_path_row: libhandy::ActionRow,
+    url_row: libhandy::ActionRow,
+    login_row: libhandy::ActionRow,
 }
 
 impl Preferences {
-    pub fn new<P: IsA<gtk::Window>>(backend: Rc<Backend>, parent: &P) -> Self {
+    /// Create a new preferences dialog.
+    pub fn new<P: IsA<gtk::Window>>(backend: Rc<Backend>, parent: &P) -> Rc<Self> {
+        // Create UI
         let builder = gtk::Builder::from_resource("/de/johrpan/musicus/ui/preferences.ui");
 
         get_widget!(builder, libhandy::Window, window);
         get_widget!(builder, libhandy::ActionRow, music_library_path_row);
         get_widget!(builder, gtk::Button, select_music_library_path_button);
+        get_widget!(builder, libhandy::ActionRow, url_row);
+        get_widget!(builder, gtk::Button, url_button);
+        get_widget!(builder, libhandy::ActionRow, login_row);
+        get_widget!(builder, gtk::Button, login_button);
 
         window.set_transient_for(Some(parent));
 
-        if let Some(path) = backend.get_music_library_path() {
+        let this = Rc::new(Self {
-            music_library_path_row.set_subtitle(Some(path.to_str().unwrap()));
+            backend,
+            window,
+            music_library_path_row,
+            url_row,
+            login_row,
+        });
+
+        // Connect signals and callbacks
+
+        select_music_library_path_button.connect_clicked(clone!(@strong this => move |_| {
+            let dialog = gtk::FileChooserNative::new(
+                Some(&gettext("Select music library folder")),
+                Some(&this.window), gtk::FileChooserAction::SelectFolder,None, None);
+
+            if let gtk::ResponseType::Accept = dialog.run() {
+                if let Some(path) = dialog.get_filename() {
+                    this.music_library_path_row.set_subtitle(Some(path.to_str().unwrap()));
+
+                    let context = glib::MainContext::default();
+                    let backend = this.backend.clone();
+                    context.spawn_local(async move {
+                        backend.set_music_library_path(path).await.unwrap();
+                    });
+                }
+            }
+        }));
+
+        url_button.connect_clicked(clone!(@strong this => move |_| {
+            let dialog = ServerDialog::new(this.backend.clone(), &this.window);
+
+            dialog.set_selected_cb(clone!(@strong this => move |url| {
+                this.url_row.set_subtitle(Some(&url));
+            }));
+
+            dialog.show();
+        }));
+
+        login_button.connect_clicked(clone!(@strong this => move |_| {
+            let dialog = LoginDialog::new(this.backend.clone(), &this.window);
+
+            dialog.set_selected_cb(clone!(@strong this => move |data| {
+                this.login_row.set_subtitle(Some(&data.username));
+            }));
+
+            dialog.show();
+        }));
+
+        // Initialize
+
+        if let Some(path) = this.backend.get_music_library_path() {
+            this.music_library_path_row
+                .set_subtitle(Some(path.to_str().unwrap()));
         }
 
-        select_music_library_path_button.connect_clicked(
+        if let Some(url) = this.backend.get_server_url() {
-            clone!(@strong window, @strong backend, @strong music_library_path_row => move |_| {
+            this.url_row.set_subtitle(Some(&url));
-                let dialog = gtk::FileChooserNative::new(
+        }
-                    Some(&gettext("Select music library folder")),
-                    Some(&window), gtk::FileChooserAction::SelectFolder,None, None);
 
-                if let gtk::ResponseType::Accept = dialog.run() {
+        if let Some(data) = this.backend.get_login_data() {
-                    if let Some(path) = dialog.get_filename() {
+            this.login_row.set_subtitle(Some(&data.username));
-                        music_library_path_row.set_subtitle(Some(path.to_str().unwrap()));
+        }
 
-                        let context = glib::MainContext::default();
+        this
-                        let backend = backend.clone();
-                        context.spawn_local(async move {
-                            backend.set_music_library_path(path).await.unwrap();
-                        });
-                    }
-                }
-            }),
-        );
-
-        Self { window }
     }
 
+    /// Show the preferences dialog.
     pub fn show(&self) {
         self.window.show();
     }

src/dialogs/server_dialog.rs

@@ -0,0 +1,65 @@
+use crate::backend::Backend;
+use glib::clone;
+use gtk::prelude::*;
+use gtk_macros::get_widget;
+use std::cell::RefCell;
+use std::rc::Rc;
+
+/// A dialog for setting up the server.
+pub struct ServerDialog {
+    backend: Rc<Backend>,
+    window: libhandy::Window,
+    url_entry: gtk::Entry,
+    selected_cb: RefCell<Option<Box<dyn Fn(String) -> ()>>>,
+}
+
+impl ServerDialog {
+    /// Create a new server dialog.
+    pub fn new<P: IsA<gtk::Window>>(backend: Rc<Backend>, parent: &P) -> Rc<Self> {
+        // Create UI
+        let builder = gtk::Builder::from_resource("/de/johrpan/musicus/ui/server_dialog.ui");
+
+        get_widget!(builder, libhandy::Window, window);
+        get_widget!(builder, gtk::Button, cancel_button);
+        get_widget!(builder, gtk::Button, set_button);
+        get_widget!(builder, gtk::Entry, url_entry);
+
+        window.set_transient_for(Some(parent));
+
+        let this = Rc::new(Self {
+            backend,
+            window,
+            url_entry,
+            selected_cb: RefCell::new(None),
+        });
+
+        // Connect signals and callbacks
+
+        cancel_button.connect_clicked(clone!(@strong this => move |_| {
+            this.window.close();
+        }));
+
+        set_button.connect_clicked(clone!(@strong this => move |_| {
+            let url = this.url_entry.get_text().to_string();
+            this.backend.set_server_url(&url).unwrap();
+
+            if let Some(cb) = &*this.selected_cb.borrow() {
+                cb(url);
+            }
+
+            this.window.close();
+        }));
+
+        this
+    }
+
+    /// The closure to call when the server was set.
+    pub fn set_selected_cb<F: Fn(String) -> () + 'static>(&self, cb: F) {
+        self.selected_cb.replace(Some(Box::new(cb)));
+    }
+
+    /// Show the server dialog.
+    pub fn show(&self) {
+        self.window.show();
+    }
+}

src/meson.build

@@ -33,6 +33,10 @@ run_command(
 )
 
 sources = files(
+  'backend/backend.rs',
+  'backend/client.rs',
+  'backend/mod.rs',
+  'backend/secure.rs',
   'database/database.rs',
   'database/mod.rs',
   'database/models.rs',
@@ -43,10 +47,12 @@ sources = files(
   'dialogs/ensemble_selector.rs',
   'dialogs/instrument_editor.rs',
   'dialogs/instrument_selector.rs',
+  'dialogs/login_dialog.rs',
   'dialogs/mod.rs',
   'dialogs/person_editor.rs',
   'dialogs/person_selector.rs',
   'dialogs/preferences.rs',
+  'dialogs/server_dialog.rs',
   'dialogs/recording/mod.rs',
   'dialogs/recording/performance_editor.rs',
   'dialogs/recording/recording_dialog.rs',
@@ -78,7 +84,6 @@ sources = files(
   'widgets/player_bar.rs',
   'widgets/poe_list.rs',
   'widgets/selector_row.rs',
-  'backend.rs',
   'config.rs',
   'config.rs.in',
   'main.rs',