feat(lib, daemon, cli, gui): add volume multiplier (#175)

* initial implementation

* rename DaemonConfig.volume_multiplier to default_volume_multiplier

* add volume_multiplier to the FullState

* add pwsp-gui integration

pwsp-gui/locales/app.toml

@@ -217,6 +217,28 @@ kz = "Әрқашан дыбыс деңгейін есте сақтау"
 he = "זכור תמיד עוצמת קול"
 pt-BR = "Lembrar volume"
 
+[gui.settings.remember_volume_multiplier]
+en = "Always remember volume multiplier"
+ru = "Всегда запоминать множитель громкости"
+es = "Recordar siempre el multiplicador de volumen"
+fr = "Toujours se souvenir du multiplicateur de volume"
+zh = "始终记住音量乘数"
+ar = "تذكر ضرب الصوت دائمًا"
+kz = "Әрқашан дыбыс деңгейін есте сақтау"
+he = "זכור תמיד עוצמת קול"
+pt-BR = "Lembrar volume"
+
+[gui.settings.volume_multiplier]
+en = "Volume multiplier"
+ru = "Множитель громкости"
+es = "Multiplicador de volumen"
+fr = "Multiplicateur de volume"
+zh = "音量乘数"
+ar = "ضرب الصوت"
+kz = "Дыбыс деңгейі"
+he = "עוצמת קול"
+pt-BR = "Volume"
+
 [gui.settings.remember_mic]
 en = "Always remember microphone"
 ru = "Всегда запоминать микрофон"

pwsp-gui/src/gui/update.rs

@@ -93,6 +93,24 @@ impl App for SoundpadGui {
             }
         }
 
+        if self.app_state.volume_multiplier_dragged {
+            make_request_async(Request::set_volume_multiplier(
+                self.app_state.volume_multiplier_slider_value,
+            ));
+
+            self.app_state.volume_multiplier_dragged = false;
+            self.app_state.ignore_volume_multiplier_update_until =
+                Some(Instant::now() + Duration::from_millis(300));
+
+            if self.config.save_volume_multiplier
+                && let Ok(mut daemon_config) = get_daemon_config()
+            {
+                daemon_config.default_volume_multiplier =
+                    Some(self.app_state.volume_multiplier_slider_value);
+                update_daemon_config(&daemon_config).ok();
+            }
+        }
+
         // Sync audio player state
         {
             let mut guard = self

pwsp-gui/src/gui/views/settings.rs

@@ -1,5 +1,5 @@
 use crate::gui::SoundpadGui;
-use egui::{Align, Button, Color32, ComboBox, Layout, RichText, Ui};
+use egui::{Align, Button, Color32, ComboBox, Layout, RichText, Slider, Ui};
 use egui_material_icons::icons::ICON_ARROW_BACK;
 use pwsp_lib::types::config::PreferredTheme;
 use rust_i18n::t;
@@ -34,6 +34,10 @@ impl SoundpadGui {
                 &mut self.config.save_volume,
                 t!("gui.settings.remember_volume"),
             );
+            let save_volume_multiplier_response = ui.checkbox(
+                &mut self.config.save_volume_multiplier,
+                t!("gui.settings.remember_volume_multiplier"),
+            );
             let save_input_response =
                 ui.checkbox(&mut self.config.save_input, t!("gui.settings.remember_mic"));
             let save_scale_response = ui.checkbox(
@@ -46,6 +50,7 @@ impl SoundpadGui {
             );
 
             if save_volume_response.changed()
+                || save_volume_multiplier_response.changed()
                 || save_input_response.changed()
                 || save_scale_response.changed()
                 || pause_on_exit_response.changed()
@@ -88,6 +93,39 @@ impl SoundpadGui {
             }
             // --------------------------------
 
+            ui.separator();
+
+            // ----------- Sliders ------------
+            // Volume multiplier
+            let should_update_multiplier = !self.app_state.volume_multiplier_dragged
+                && self
+                    .app_state
+                    .ignore_volume_multiplier_update_until
+                    .map(|t| std::time::Instant::now() > t)
+                    .unwrap_or(true);
+
+            if should_update_multiplier {
+                self.app_state.volume_multiplier_slider_value =
+                    self.audio_player_state.volume_multiplier;
+            }
+
+            ui.horizontal(|ui| {
+                let slider = Slider::new(
+                    &mut self.app_state.volume_multiplier_slider_value,
+                    0.01..=3.0,
+                );
+                let response = ui.add(slider);
+                ui.label(t!("gui.settings.volume_multiplier"));
+
+                if response.changed() {
+                    // This condition is required to avoid spamming requests while dragging, but to allow changing the value via TextEdit
+                    if !response.dragged() || (response.dragged() && response.drag_stopped()) {
+                        self.app_state.volume_multiplier_dragged = true;
+                    }
+                }
+            });
+            // --------------------------------
+
             ui.with_layout(Layout::bottom_up(Align::Min), |ui| {
                 ui.label(t!(
                     "gui.settings.version",