feat(audio): scroll audio icon to apply volume changes

cosmic-applet-audio/src/lib.rs

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: GPL-3.0-only
 
 mod localize;
+mod mouse_area;
 
 use crate::localize::localize;
 use crate::pulse::DeviceInfo;
@@ -122,6 +123,7 @@ enum IsOpen {
 
 #[derive(Debug, Clone)]
 pub enum Message {
+    Ignore,
     SetOutputVolume(f64),
     SetInputVolume(f64),
     OutputToggle,
@@ -290,6 +292,7 @@ impl cosmic::Application for Audio {
     fn update(&mut self, message: Message) -> Command<Message> {
         match message {
             Message::Frame(now) => self.timeline.now(now),
+            Message::Ignore => {}
             Message::TogglePopup => {
                 if let Some(p) = self.popup.take() {
                     return destroy_popup(p);
@@ -577,6 +580,21 @@ impl cosmic::Application for Audio {
             .applet
             .icon_button(self.output_icon_name())
             .on_press(Message::TogglePopup);
+        let btn = crate::mouse_area::MouseArea::new(btn).on_mouse_wheel(|delta| {
+            let change = match delta {
+                iced::mouse::ScrollDelta::Lines { x, y } => (x + y) * 5.,
+                iced::mouse::ScrollDelta::Pixels { y, .. } => y / 40.3125,
+            };
+            if change.abs() < f32::EPSILON {
+                return Message::Ignore;
+            }
+            let new_volume = self
+                .current_output
+                .as_ref()
+                .map_or(0f64, |v| volume_to_percent(v.volume.avg()) + change as f64)
+                .clamp(0.0, 100.0);
+            Message::SetOutputVolume(new_volume)
+        });
         if let Some(playback_buttons) = self.playback_buttons() {
             match self.core.applet.anchor {
                 PanelAnchor::Left | PanelAnchor::Right => {

cosmic-applet-audio/src/mouse_area.rs

@@ -0,0 +1,418 @@
+//! A container for capturing mouse events.
+
+use cosmic::iced_renderer::core::widget::OperationOutputWrapper;
+use cosmic::iced_renderer::core::Point;
+
+use cosmic::iced_core::event::{self, Event};
+use cosmic::iced_core::layout;
+use cosmic::iced_core::mouse;
+use cosmic::iced_core::overlay;
+use cosmic::iced_core::renderer;
+use cosmic::iced_core::touch;
+use cosmic::iced_core::widget::{tree, Operation, Tree};
+use cosmic::iced_core::{Clipboard, Element, Layout, Length, Rectangle, Shell, Size, Widget};
+
+/// Emit messages on mouse events.
+#[allow(missing_debug_implementations)]
+pub struct MouseArea<'a, Message, Theme = crate::Theme, Renderer = crate::Renderer> {
+    content: Element<'a, Message, Theme, Renderer>,
+    on_drag: Option<Message>,
+    on_press: Option<Message>,
+    on_release: Option<Message>,
+    on_right_press: Option<Message>,
+    on_right_release: Option<Message>,
+    on_middle_press: Option<Message>,
+    on_middle_release: Option<Message>,
+    on_mouse_enter: Option<Message>,
+    on_mouse_exit: Option<Message>,
+    on_mouse_wheel: Option<Box<dyn Fn(mouse::ScrollDelta) -> Message + 'a>>,
+}
+
+impl<'a, Message, Theme, Renderer> MouseArea<'a, Message, Theme, Renderer> {
+    /// The message to emit when a drag is initiated.
+    #[must_use]
+    pub fn on_drag(mut self, message: Message) -> Self {
+        self.on_drag = Some(message);
+        self
+    }
+
+    /// The message to emit on a left button press.
+    #[must_use]
+    pub fn on_press(mut self, message: Message) -> Self {
+        self.on_press = Some(message);
+        self
+    }
+
+    /// The message to emit on a left button release.
+    #[must_use]
+    pub fn on_release(mut self, message: Message) -> Self {
+        self.on_release = Some(message);
+        self
+    }
+
+    /// The message to emit on a right button press.
+    #[must_use]
+    pub fn on_right_press(mut self, message: Message) -> Self {
+        self.on_right_press = Some(message);
+        self
+    }
+
+    /// The message to emit on a right button release.
+    #[must_use]
+    pub fn on_right_release(mut self, message: Message) -> Self {
+        self.on_right_release = Some(message);
+        self
+    }
+
+    /// The message to emit on a middle button press.
+    #[must_use]
+    pub fn on_middle_press(mut self, message: Message) -> Self {
+        self.on_middle_press = Some(message);
+        self
+    }
+
+    /// The message to emit on a middle button release.
+    #[must_use]
+    pub fn on_middle_release(mut self, message: Message) -> Self {
+        self.on_middle_release = Some(message);
+        self
+    }
+    #[must_use]
+    /// The message to emit on mouse enter.
+    pub fn on_mouse_enter(mut self, message: Message) -> Self {
+        self.on_mouse_enter = Some(message);
+        self
+    }
+    #[must_use]
+    /// The message to emit on mouse exit.
+    pub fn on_mouse_exit(mut self, message: Message) -> Self {
+        self.on_mouse_exit = Some(message);
+        self
+    }
+    #[must_use]
+    /// The message to emit when the mouse wheel is released.
+    pub fn on_mouse_wheel(mut self, message: impl Fn(mouse::ScrollDelta) -> Message + 'a) -> Self {
+        self.on_mouse_wheel = Some(Box::new(message));
+        self
+    }
+}
+
+/// Local state of the [`MouseArea`].
+struct State {
+    // TODO: Support on_mouse_enter and on_mouse_exit
+    drag_initiated: Option<Point>,
+    is_out_of_bounds: bool,
+}
+impl Default for State {
+    fn default() -> Self {
+        Self {
+            drag_initiated: Default::default(),
+            is_out_of_bounds: true,
+        }
+    }
+}
+
+impl<'a, Message, Theme, Renderer> MouseArea<'a, Message, Theme, Renderer> {
+    /// Creates a [`MouseArea`] with the given content.
+    pub fn new(content: impl Into<Element<'a, Message, Theme, Renderer>>) -> Self {
+        MouseArea {
+            content: content.into(),
+            on_drag: None,
+            on_press: None,
+            on_release: None,
+            on_right_press: None,
+            on_right_release: None,
+            on_middle_press: None,
+            on_middle_release: None,
+            on_mouse_enter: None,
+            on_mouse_exit: None,
+            on_mouse_wheel: None,
+        }
+    }
+}
+
+impl<'a, Message, Theme, Renderer> Widget<Message, Theme, Renderer>
+    for MouseArea<'a, Message, Theme, Renderer>
+where
+    Renderer: renderer::Renderer,
+    Message: Clone,
+{
+    fn tag(&self) -> tree::Tag {
+        tree::Tag::of::<State>()
+    }
+
+    fn state(&self) -> tree::State {
+        tree::State::new(State::default())
+    }
+
+    fn children(&self) -> Vec<Tree> {
+        vec![Tree::new(&self.content)]
+    }
+
+    fn diff(&mut self, tree: &mut Tree) {
+        tree.diff_children(std::slice::from_mut(&mut self.content));
+    }
+
+    fn size(&self) -> Size<Length> {
+        self.content.as_widget().size()
+    }
+
+    fn layout(
+        &self,
+        tree: &mut Tree,
+        renderer: &Renderer,
+        limits: &layout::Limits,
+    ) -> layout::Node {
+        self.content
+            .as_widget()
+            .layout(&mut tree.children[0], renderer, limits)
+    }
+
+    fn operate(
+        &self,
+        tree: &mut Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+        operation: &mut dyn Operation<OperationOutputWrapper<Message>>,
+    ) {
+        self.content
+            .as_widget()
+            .operate(&mut tree.children[0], layout, renderer, operation);
+    }
+
+    fn on_event(
+        &mut self,
+        tree: &mut Tree,
+        event: Event,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        renderer: &Renderer,
+        clipboard: &mut dyn Clipboard,
+        shell: &mut Shell<'_, Message>,
+        viewport: &Rectangle,
+    ) -> event::Status {
+        if let event::Status::Captured = self.content.as_widget_mut().on_event(
+            &mut tree.children[0],
+            event.clone(),
+            layout,
+            cursor,
+            renderer,
+            clipboard,
+            shell,
+            viewport,
+        ) {
+            return event::Status::Captured;
+        }
+
+        update(
+            self,
+            &event,
+            layout,
+            cursor,
+            shell,
+            tree.state.downcast_mut::<State>(),
+        )
+    }
+
+    fn mouse_interaction(
+        &self,
+        tree: &Tree,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+        renderer: &Renderer,
+    ) -> mouse::Interaction {
+        self.content.as_widget().mouse_interaction(
+            &tree.children[0],
+            layout,
+            cursor,
+            viewport,
+            renderer,
+        )
+    }
+
+    fn draw(
+        &self,
+        tree: &Tree,
+        renderer: &mut Renderer,
+        theme: &Theme,
+        renderer_style: &renderer::Style,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+    ) {
+        self.content.as_widget().draw(
+            &tree.children[0],
+            renderer,
+            theme,
+            renderer_style,
+            layout,
+            cursor,
+            viewport,
+        );
+    }
+    fn overlay<'b>(
+        &'b mut self,
+        tree: &'b mut Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+    ) -> Option<overlay::Element<'b, Message, Theme, Renderer>> {
+        self.content
+            .as_widget_mut()
+            .overlay(&mut tree.children[0], layout, renderer)
+    }
+    fn drag_destinations(
+        &self,
+        state: &Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+        dnd_rectangles: &mut cosmic::iced_style::core::clipboard::DndDestinationRectangles,
+    ) {
+        if let Some(state) = state.children.iter().next() {
+            self.content
+                .as_widget()
+                .drag_destinations(state, layout, renderer, dnd_rectangles);
+        }
+    }
+}
+
+impl<'a, Message, Theme, Renderer> From<MouseArea<'a, Message, Theme, Renderer>>
+    for Element<'a, Message, Theme, Renderer>
+where
+    Message: 'a + Clone,
+    Theme: 'a,
+    Renderer: 'a + renderer::Renderer,
+{
+    fn from(
+        area: MouseArea<'a, Message, Theme, Renderer>,
+    ) -> Element<'a, Message, Theme, Renderer> {
+        Element::new(area)
+    }
+}
+
+/// Processes the given [`Event`] and updates the [`State`] of an [`MouseArea`]
+/// accordingly.
+fn update<Message: Clone, Theme, Renderer>(
+    widget: &mut MouseArea<'_, Message, Theme, Renderer>,
+    event: &Event,
+    layout: Layout<'_>,
+    cursor: mouse::Cursor,
+    shell: &mut Shell<'_, Message>,
+    state: &mut State,
+) -> event::Status {
+    if !cursor.is_over(layout.bounds()) {
+        if !state.is_out_of_bounds {
+            if widget
+                .on_mouse_enter
+                .as_ref()
+                .or(widget.on_mouse_exit.as_ref())
+                .is_some()
+            {
+                if let Event::Mouse(mouse::Event::CursorMoved { .. }) = event {
+                    state.is_out_of_bounds = true;
+                    if let Some(message) = widget.on_mouse_exit.as_ref() {
+                        shell.publish(message.clone());
+                    }
+                    return event::Status::Captured;
+                }
+            }
+        }
+
+        return event::Status::Ignored;
+    }
+
+    if let Some(message) = widget.on_press.as_ref() {
+        if let Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
+        | Event::Touch(touch::Event::FingerPressed { .. }) = event
+        {
+            state.drag_initiated = cursor.position();
+            shell.publish(message.clone());
+
+            return event::Status::Captured;
+        }
+    }
+
+    if let Some(message) = widget.on_release.as_ref() {
+        if let Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Left))
+        | Event::Touch(touch::Event::FingerLifted { .. }) = event
+        {
+            state.drag_initiated = None;
+            shell.publish(message.clone());
+
+            return event::Status::Captured;
+        }
+    }
+
+    if let Some(message) = widget.on_right_press.as_ref() {
+        if let Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Right)) = event {
+            shell.publish(message.clone());
+
+            return event::Status::Captured;
+        }
+    }
+
+    if let Some(message) = widget.on_right_release.as_ref() {
+        if let Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Right)) = event {
+            shell.publish(message.clone());
+
+            return event::Status::Captured;
+        }
+    }
+
+    if let Some(message) = widget.on_middle_press.as_ref() {
+        if let Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Middle)) = event {
+            shell.publish(message.clone());
+
+            return event::Status::Captured;
+        }
+    }
+
+    if let Some(message) = widget.on_middle_release.as_ref() {
+        if let Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Middle)) = event {
+            shell.publish(message.clone());
+
+            return event::Status::Captured;
+        }
+    }
+    if let Some(message) = widget
+        .on_mouse_enter
+        .as_ref()
+        .or(widget.on_mouse_exit.as_ref())
+    {
+        if let Event::Mouse(mouse::Event::CursorMoved { .. }) = event {
+            if state.is_out_of_bounds {
+                state.is_out_of_bounds = false;
+                if widget.on_mouse_enter.is_some() {
+                    shell.publish(message.clone());
+                }
+                return event::Status::Captured;
+            }
+        }
+    }
+
+    if state.drag_initiated.is_none() && widget.on_drag.is_some() {
+        if let Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
+        | Event::Touch(touch::Event::FingerPressed { .. }) = event
+        {
+            state.drag_initiated = cursor.position();
+        }
+    } else if let Some((message, drag_source)) = widget.on_drag.as_ref().zip(state.drag_initiated) {
+        if let Some(position) = cursor.position() {
+            if position.distance(drag_source) > 1.0 {
+                state.drag_initiated = None;
+                shell.publish(message.clone());
+
+                return event::Status::Captured;
+            }
+        }
+    }
+
+    if let Some(message) = widget.on_mouse_wheel.as_ref() {
+        if let Event::Mouse(mouse::Event::WheelScrolled { delta }) = event {
+            shell.publish((message)(*delta));
+            return event::Status::Captured;
+        }
+    }
+
+    event::Status::Ignored
+}