Inline helper functions in widget modules

widget/src/combo_box.rs

@@ -717,8 +717,7 @@ where
     }
 }
 
-/// Search list of options for a given query.
+fn search<'a, T, A>(
-pub fn search<'a, T, A>(
     options: impl IntoIterator<Item = T> + 'a,
     option_matchers: impl IntoIterator<Item = &'a A> + 'a,
     query: &'a str,
@@ -745,8 +744,7 @@ where
         })
 }
 
-/// Build matchers from given list of options.
+fn build_matchers<'a, T>(
-pub fn build_matchers<'a, T>(
     options: impl IntoIterator<Item = T> + 'a,
 ) -> Vec<String>
 where
@@ -769,6 +767,8 @@ pub struct Style<Theme> {
     pub text_input: fn(&Theme, text_input::Status) -> text_input::Appearance,
 
     /// The style of the [`Menu`] of the [`ComboBox`].
+    ///
+    /// [`Menu`]: menu::Menu
     pub menu: menu::Style<Theme>,
 }
 

widget/src/lib.rs

@@ -18,6 +18,7 @@ pub use iced_runtime::core;
 mod column;
 mod mouse_area;
 mod row;
+mod space;
 mod themer;
 
 pub mod button;
@@ -33,7 +34,6 @@ pub mod radio;
 pub mod rule;
 pub mod scrollable;
 pub mod slider;
-pub mod space;
 pub mod text;
 pub mod text_editor;
 pub mod text_input;

widget/src/pick_list.rs

@@ -16,6 +16,7 @@ use crate::core::{
 use crate::overlay::menu::{self, Menu};
 
 use std::borrow::Borrow;
+use std::f32;
 
 /// A widget for selecting a single value from a list of options.
 #[allow(missing_debug_implementations)]
@@ -186,19 +187,77 @@ where
         renderer: &Renderer,
         limits: &layout::Limits,
     ) -> layout::Node {
-        layout(
+        let state = tree.state.downcast_mut::<State<Renderer::Paragraph>>();
-            tree.state.downcast_mut::<State<Renderer::Paragraph>>(),
+
-            renderer,
+        let font = self.font.unwrap_or_else(|| renderer.default_font());
-            limits,
+        let text_size =
-            self.width,
+            self.text_size.unwrap_or_else(|| renderer.default_size());
-            self.padding,
+        let options = self.options.borrow();
-            self.text_size,
+
-            self.text_line_height,
+        state.options.resize_with(options.len(), Default::default);
-            self.text_shaping,
+
-            self.font,
+        let option_text = Text {
-            self.placeholder.as_deref(),
+            content: "",
-            self.options.borrow(),
+            bounds: Size::new(
-        )
+                f32::INFINITY,
+                self.text_line_height.to_absolute(text_size).into(),
+            ),
+            size: text_size,
+            line_height: self.text_line_height,
+            font,
+            horizontal_alignment: alignment::Horizontal::Left,
+            vertical_alignment: alignment::Vertical::Center,
+            shaping: self.text_shaping,
+        };
+
+        for (option, paragraph) in options.iter().zip(state.options.iter_mut())
+        {
+            let label = option.to_string();
+
+            paragraph.update(Text {
+                content: &label,
+                ..option_text
+            });
+        }
+
+        if let Some(placeholder) = &self.placeholder {
+            state.placeholder.update(Text {
+                content: placeholder,
+                ..option_text
+            });
+        }
+
+        let max_width = match self.width {
+            Length::Shrink => {
+                let labels_width =
+                    state.options.iter().fold(0.0, |width, paragraph| {
+                        f32::max(width, paragraph.min_width())
+                    });
+
+                labels_width.max(
+                    self.placeholder
+                        .as_ref()
+                        .map(|_| state.placeholder.min_width())
+                        .unwrap_or(0.0),
+                )
+            }
+            _ => 0.0,
+        };
+
+        let size = {
+            let intrinsic = Size::new(
+                max_width + text_size.0 + self.padding.left,
+                f32::from(self.text_line_height.to_absolute(text_size)),
+            );
+
+            limits
+                .width(self.width)
+                .shrink(self.padding)
+                .resolve(self.width, Length::Shrink, intrinsic)
+                .expand(self.padding)
+        };
+
+        layout::Node::new(size)
     }
 
     fn on_event(
@@ -212,18 +271,98 @@ where
         shell: &mut Shell<'_, Message>,
         _viewport: &Rectangle,
     ) -> event::Status {
-        update(
+        match event {
-            event,
+            Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
-            layout,
+            | Event::Touch(touch::Event::FingerPressed { .. }) => {
-            cursor,
+                let state =
-            shell,
+                    tree.state.downcast_mut::<State<Renderer::Paragraph>>();
-            self.on_select.as_ref(),
+
-            self.on_open.as_ref(),
+                if state.is_open {
-            self.on_close.as_ref(),
+                    // Event wasn't processed by overlay, so cursor was clicked either outside its
-            self.selected.as_ref().map(Borrow::borrow),
+                    // bounds or on the drop-down, either way we close the overlay.
-            self.options.borrow(),
+                    state.is_open = false;
-            || tree.state.downcast_mut::<State<Renderer::Paragraph>>(),
+
-        )
+                    if let Some(on_close) = &self.on_close {
+                        shell.publish(on_close.clone());
+                    }
+
+                    event::Status::Captured
+                } else if cursor.is_over(layout.bounds()) {
+                    let selected = self.selected.as_ref().map(Borrow::borrow);
+
+                    state.is_open = true;
+                    state.hovered_option = self
+                        .options
+                        .borrow()
+                        .iter()
+                        .position(|option| Some(option) == selected);
+
+                    if let Some(on_open) = &self.on_open {
+                        shell.publish(on_open.clone());
+                    }
+
+                    event::Status::Captured
+                } else {
+                    event::Status::Ignored
+                }
+            }
+            Event::Mouse(mouse::Event::WheelScrolled {
+                delta: mouse::ScrollDelta::Lines { y, .. },
+            }) => {
+                let state =
+                    tree.state.downcast_mut::<State<Renderer::Paragraph>>();
+
+                if state.keyboard_modifiers.command()
+                    && cursor.is_over(layout.bounds())
+                    && !state.is_open
+                {
+                    fn find_next<'a, T: PartialEq>(
+                        selected: &'a T,
+                        mut options: impl Iterator<Item = &'a T>,
+                    ) -> Option<&'a T> {
+                        let _ = options.find(|&option| option == selected);
+
+                        options.next()
+                    }
+
+                    let options = self.options.borrow();
+                    let selected = self.selected.as_ref().map(Borrow::borrow);
+
+                    let next_option = if y < 0.0 {
+                        if let Some(selected) = selected {
+                            find_next(selected, options.iter())
+                        } else {
+                            options.first()
+                        }
+                    } else if y > 0.0 {
+                        if let Some(selected) = selected {
+                            find_next(selected, options.iter().rev())
+                        } else {
+                            options.last()
+                        }
+                    } else {
+                        None
+                    };
+
+                    if let Some(next_option) = next_option {
+                        shell.publish((self.on_select)(next_option.clone()));
+                    }
+
+                    event::Status::Captured
+                } else {
+                    event::Status::Ignored
+                }
+            }
+            Event::Keyboard(keyboard::Event::ModifiersChanged(modifiers)) => {
+                let state =
+                    tree.state.downcast_mut::<State<Renderer::Paragraph>>();
+
+                state.keyboard_modifiers = modifiers;
+
+                event::Status::Ignored
+            }
+            _ => event::Status::Ignored,
+        }
     }
 
     fn mouse_interaction(
@@ -234,7 +373,14 @@ where
         _viewport: &Rectangle,
         _renderer: &Renderer,
     ) -> mouse::Interaction {
-        mouse_interaction(layout, cursor)
+        let bounds = layout.bounds();
+        let is_mouse_over = cursor.is_over(bounds);
+
+        if is_mouse_over {
+            mouse::Interaction::Pointer
+        } else {
+            mouse::Interaction::default()
+        }
     }
 
     fn draw(
@@ -429,9 +575,8 @@ where
     }
 }
 
-/// The state of a [`PickList`].
 #[derive(Debug)]
-pub struct State<P: text::Paragraph> {
+struct State<P: text::Paragraph> {
     menu: menu::State,
     keyboard_modifiers: keyboard::Modifiers,
     is_open: bool,
@@ -504,210 +649,6 @@ pub struct Icon<Font> {
     pub shaping: text::Shaping,
 }
 
-/// Computes the layout of a [`PickList`].
-pub fn layout<Renderer, T>(
-    state: &mut State<Renderer::Paragraph>,
-    renderer: &Renderer,
-    limits: &layout::Limits,
-    width: Length,
-    padding: Padding,
-    text_size: Option<Pixels>,
-    text_line_height: text::LineHeight,
-    text_shaping: text::Shaping,
-    font: Option<Renderer::Font>,
-    placeholder: Option<&str>,
-    options: &[T],
-) -> layout::Node
-where
-    Renderer: text::Renderer,
-    T: ToString,
-{
-    use std::f32;
-
-    let font = font.unwrap_or_else(|| renderer.default_font());
-    let text_size = text_size.unwrap_or_else(|| renderer.default_size());
-
-    state.options.resize_with(options.len(), Default::default);
-
-    let option_text = Text {
-        content: "",
-        bounds: Size::new(
-            f32::INFINITY,
-            text_line_height.to_absolute(text_size).into(),
-        ),
-        size: text_size,
-        line_height: text_line_height,
-        font,
-        horizontal_alignment: alignment::Horizontal::Left,
-        vertical_alignment: alignment::Vertical::Center,
-        shaping: text_shaping,
-    };
-
-    for (option, paragraph) in options.iter().zip(state.options.iter_mut()) {
-        let label = option.to_string();
-
-        paragraph.update(Text {
-            content: &label,
-            ..option_text
-        });
-    }
-
-    if let Some(placeholder) = placeholder {
-        state.placeholder.update(Text {
-            content: placeholder,
-            ..option_text
-        });
-    }
-
-    let max_width = match width {
-        Length::Shrink => {
-            let labels_width =
-                state.options.iter().fold(0.0, |width, paragraph| {
-                    f32::max(width, paragraph.min_width())
-                });
-
-            labels_width.max(
-                placeholder
-                    .map(|_| state.placeholder.min_width())
-                    .unwrap_or(0.0),
-            )
-        }
-        _ => 0.0,
-    };
-
-    let size = {
-        let intrinsic = Size::new(
-            max_width + text_size.0 + padding.left,
-            f32::from(text_line_height.to_absolute(text_size)),
-        );
-
-        limits
-            .width(width)
-            .shrink(padding)
-            .resolve(width, Length::Shrink, intrinsic)
-            .expand(padding)
-    };
-
-    layout::Node::new(size)
-}
-
-/// Processes an [`Event`] and updates the [`State`] of a [`PickList`]
-/// accordingly.
-pub fn update<'a, T, P, Message>(
-    event: Event,
-    layout: Layout<'_>,
-    cursor: mouse::Cursor,
-    shell: &mut Shell<'_, Message>,
-    on_select: &dyn Fn(T) -> Message,
-    on_open: Option<&Message>,
-    on_close: Option<&Message>,
-    selected: Option<&T>,
-    options: &[T],
-    state: impl FnOnce() -> &'a mut State<P>,
-) -> event::Status
-where
-    T: PartialEq + Clone + 'a,
-    P: text::Paragraph + 'a,
-    Message: Clone,
-{
-    match event {
-        Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
-        | Event::Touch(touch::Event::FingerPressed { .. }) => {
-            let state = state();
-
-            if state.is_open {
-                // Event wasn't processed by overlay, so cursor was clicked either outside it's
-                // bounds or on the drop-down, either way we close the overlay.
-                state.is_open = false;
-
-                if let Some(on_close) = on_close {
-                    shell.publish(on_close.clone());
-                }
-
-                event::Status::Captured
-            } else if cursor.is_over(layout.bounds()) {
-                state.is_open = true;
-                state.hovered_option =
-                    options.iter().position(|option| Some(option) == selected);
-
-                if let Some(on_open) = on_open {
-                    shell.publish(on_open.clone());
-                }
-
-                event::Status::Captured
-            } else {
-                event::Status::Ignored
-            }
-        }
-        Event::Mouse(mouse::Event::WheelScrolled {
-            delta: mouse::ScrollDelta::Lines { y, .. },
-        }) => {
-            let state = state();
-
-            if state.keyboard_modifiers.command()
-                && cursor.is_over(layout.bounds())
-                && !state.is_open
-            {
-                fn find_next<'a, T: PartialEq>(
-                    selected: &'a T,
-                    mut options: impl Iterator<Item = &'a T>,
-                ) -> Option<&'a T> {
-                    let _ = options.find(|&option| option == selected);
-
-                    options.next()
-                }
-
-                let next_option = if y < 0.0 {
-                    if let Some(selected) = selected {
-                        find_next(selected, options.iter())
-                    } else {
-                        options.first()
-                    }
-                } else if y > 0.0 {
-                    if let Some(selected) = selected {
-                        find_next(selected, options.iter().rev())
-                    } else {
-                        options.last()
-                    }
-                } else {
-                    None
-                };
-
-                if let Some(next_option) = next_option {
-                    shell.publish((on_select)(next_option.clone()));
-                }
-
-                event::Status::Captured
-            } else {
-                event::Status::Ignored
-            }
-        }
-        Event::Keyboard(keyboard::Event::ModifiersChanged(modifiers)) => {
-            let state = state();
-
-            state.keyboard_modifiers = modifiers;
-
-            event::Status::Ignored
-        }
-        _ => event::Status::Ignored,
-    }
-}
-
-/// Returns the current [`mouse::Interaction`] of a [`PickList`].
-pub fn mouse_interaction(
-    layout: Layout<'_>,
-    cursor: mouse::Cursor,
-) -> mouse::Interaction {
-    let bounds = layout.bounds();
-    let is_mouse_over = cursor.is_over(bounds);
-
-    if is_mouse_over {
-        mouse::Interaction::Pointer
-    } else {
-        mouse::Interaction::default()
-    }
-}
-
 /// The possible status of a [`PickList`].
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum Status {

widget/src/scrollable.rs

@@ -269,20 +269,29 @@ where
         renderer: &Renderer,
         limits: &layout::Limits,
     ) -> layout::Node {
-        layout(
+        layout::contained(limits, self.width, self.height, |limits| {
-            renderer,
+            let child_limits = layout::Limits::new(
-            limits,
+                Size::new(limits.min().width, limits.min().height),
-            self.width,
+                Size::new(
-            self.height,
+                    if self.direction.horizontal().is_some() {
-            &self.direction,
+                        f32::INFINITY
-            |renderer, limits| {
+                    } else {
-                self.content.as_widget().layout(
+                        limits.max().width
-                    &mut tree.children[0],
+                    },
-                    renderer,
+                    if self.direction.vertical().is_some() {
-                    limits,
+                        f32::MAX
-                )
+                    } else {
-            },
+                        limits.max().height
-        )
+                    },
+                ),
+            );
+
+            self.content.as_widget().layout(
+                &mut tree.children[0],
+                renderer,
+                &child_limits,
+            )
+        })
     }
 
     fn operate(
@@ -332,28 +341,316 @@ where
         shell: &mut Shell<'_, Message>,
         _viewport: &Rectangle,
     ) -> event::Status {
-        update(
+        let state = tree.state.downcast_mut::<State>();
-            tree.state.downcast_mut::<State>(),
+        let bounds = layout.bounds();
-            event,
+        let cursor_over_scrollable = cursor.position_over(bounds);
-            layout,
+
-            cursor,
+        let content = layout.children().next().unwrap();
-            clipboard,
+        let content_bounds = content.bounds();
-            shell,
+
-            self.direction,
+        let scrollbars =
-            &self.on_scroll,
+            Scrollbars::new(state, self.direction, bounds, content_bounds);
-            |event, layout, cursor, clipboard, shell, viewport| {
+
-                self.content.as_widget_mut().on_event(
+        let (mouse_over_y_scrollbar, mouse_over_x_scrollbar) =
-                    &mut tree.children[0],
+            scrollbars.is_mouse_over(cursor);
-                    event,
+
-                    layout,
+        let mut event_status = {
-                    cursor,
+            let cursor = match cursor_over_scrollable {
-                    renderer,
+                Some(cursor_position)
-                    clipboard,
+                    if !(mouse_over_x_scrollbar || mouse_over_y_scrollbar) =>
+                {
+                    mouse::Cursor::Available(
+                        cursor_position
+                            + state.translation(
+                                self.direction,
+                                bounds,
+                                content_bounds,
+                            ),
+                    )
+                }
+                _ => mouse::Cursor::Unavailable,
+            };
+
+            let translation =
+                state.translation(self.direction, bounds, content_bounds);
+
+            self.content.as_widget_mut().on_event(
+                &mut tree.children[0],
+                event.clone(),
+                layout,
+                cursor,
+                renderer,
+                clipboard,
+                shell,
+                &Rectangle {
+                    y: bounds.y + translation.y,
+                    x: bounds.x + translation.x,
+                    ..bounds
+                },
+            )
+        };
+
+        if let event::Status::Captured = event_status {
+            return event::Status::Captured;
+        }
+
+        if let Event::Keyboard(keyboard::Event::ModifiersChanged(modifiers)) =
+            event
+        {
+            state.keyboard_modifiers = modifiers;
+
+            return event::Status::Ignored;
+        }
+
+        match event {
+            Event::Mouse(mouse::Event::WheelScrolled { delta }) => {
+                if cursor_over_scrollable.is_none() {
+                    return event::Status::Ignored;
+                }
+
+                let delta = match delta {
+                    mouse::ScrollDelta::Lines { x, y } => {
+                        // TODO: Configurable speed/friction (?)
+                        let movement = if state.keyboard_modifiers.shift() {
+                            Vector::new(y, x)
+                        } else {
+                            Vector::new(x, y)
+                        };
+
+                        movement * 60.0
+                    }
+                    mouse::ScrollDelta::Pixels { x, y } => Vector::new(x, y),
+                };
+
+                state.scroll(delta, self.direction, bounds, content_bounds);
+
+                notify_on_scroll(
+                    state,
+                    &self.on_scroll,
+                    bounds,
+                    content_bounds,
                     shell,
-                    viewport,
+                );
-                )
+
-            },
+                event_status = event::Status::Captured;
-        )
+            }
+            Event::Touch(event)
+                if state.scroll_area_touched_at.is_some()
+                    || !mouse_over_y_scrollbar && !mouse_over_x_scrollbar =>
+            {
+                match event {
+                    touch::Event::FingerPressed { .. } => {
+                        let Some(cursor_position) = cursor.position() else {
+                            return event::Status::Ignored;
+                        };
+
+                        state.scroll_area_touched_at = Some(cursor_position);
+                    }
+                    touch::Event::FingerMoved { .. } => {
+                        if let Some(scroll_box_touched_at) =
+                            state.scroll_area_touched_at
+                        {
+                            let Some(cursor_position) = cursor.position()
+                            else {
+                                return event::Status::Ignored;
+                            };
+
+                            let delta = Vector::new(
+                                cursor_position.x - scroll_box_touched_at.x,
+                                cursor_position.y - scroll_box_touched_at.y,
+                            );
+
+                            state.scroll(
+                                delta,
+                                self.direction,
+                                bounds,
+                                content_bounds,
+                            );
+
+                            state.scroll_area_touched_at =
+                                Some(cursor_position);
+
+                            notify_on_scroll(
+                                state,
+                                &self.on_scroll,
+                                bounds,
+                                content_bounds,
+                                shell,
+                            );
+                        }
+                    }
+                    touch::Event::FingerLifted { .. }
+                    | touch::Event::FingerLost { .. } => {
+                        state.scroll_area_touched_at = None;
+                    }
+                }
+
+                event_status = event::Status::Captured;
+            }
+            _ => {}
+        }
+
+        if let Some(scroller_grabbed_at) = state.y_scroller_grabbed_at {
+            match event {
+                Event::Mouse(mouse::Event::ButtonReleased(
+                    mouse::Button::Left,
+                ))
+                | Event::Touch(touch::Event::FingerLifted { .. })
+                | Event::Touch(touch::Event::FingerLost { .. }) => {
+                    state.y_scroller_grabbed_at = None;
+
+                    event_status = event::Status::Captured;
+                }
+                Event::Mouse(mouse::Event::CursorMoved { .. })
+                | Event::Touch(touch::Event::FingerMoved { .. }) => {
+                    if let Some(scrollbar) = scrollbars.y {
+                        let Some(cursor_position) = cursor.position() else {
+                            return event::Status::Ignored;
+                        };
+
+                        state.scroll_y_to(
+                            scrollbar.scroll_percentage_y(
+                                scroller_grabbed_at,
+                                cursor_position,
+                            ),
+                            bounds,
+                            content_bounds,
+                        );
+
+                        notify_on_scroll(
+                            state,
+                            &self.on_scroll,
+                            bounds,
+                            content_bounds,
+                            shell,
+                        );
+
+                        event_status = event::Status::Captured;
+                    }
+                }
+                _ => {}
+            }
+        } else if mouse_over_y_scrollbar {
+            match event {
+                Event::Mouse(mouse::Event::ButtonPressed(
+                    mouse::Button::Left,
+                ))
+                | Event::Touch(touch::Event::FingerPressed { .. }) => {
+                    let Some(cursor_position) = cursor.position() else {
+                        return event::Status::Ignored;
+                    };
+
+                    if let (Some(scroller_grabbed_at), Some(scrollbar)) = (
+                        scrollbars.grab_y_scroller(cursor_position),
+                        scrollbars.y,
+                    ) {
+                        state.scroll_y_to(
+                            scrollbar.scroll_percentage_y(
+                                scroller_grabbed_at,
+                                cursor_position,
+                            ),
+                            bounds,
+                            content_bounds,
+                        );
+
+                        state.y_scroller_grabbed_at = Some(scroller_grabbed_at);
+
+                        notify_on_scroll(
+                            state,
+                            &self.on_scroll,
+                            bounds,
+                            content_bounds,
+                            shell,
+                        );
+                    }
+
+                    event_status = event::Status::Captured;
+                }
+                _ => {}
+            }
+        }
+
+        if let Some(scroller_grabbed_at) = state.x_scroller_grabbed_at {
+            match event {
+                Event::Mouse(mouse::Event::ButtonReleased(
+                    mouse::Button::Left,
+                ))
+                | Event::Touch(touch::Event::FingerLifted { .. })
+                | Event::Touch(touch::Event::FingerLost { .. }) => {
+                    state.x_scroller_grabbed_at = None;
+
+                    event_status = event::Status::Captured;
+                }
+                Event::Mouse(mouse::Event::CursorMoved { .. })
+                | Event::Touch(touch::Event::FingerMoved { .. }) => {
+                    let Some(cursor_position) = cursor.position() else {
+                        return event::Status::Ignored;
+                    };
+
+                    if let Some(scrollbar) = scrollbars.x {
+                        state.scroll_x_to(
+                            scrollbar.scroll_percentage_x(
+                                scroller_grabbed_at,
+                                cursor_position,
+                            ),
+                            bounds,
+                            content_bounds,
+                        );
+
+                        notify_on_scroll(
+                            state,
+                            &self.on_scroll,
+                            bounds,
+                            content_bounds,
+                            shell,
+                        );
+                    }
+
+                    event_status = event::Status::Captured;
+                }
+                _ => {}
+            }
+        } else if mouse_over_x_scrollbar {
+            match event {
+                Event::Mouse(mouse::Event::ButtonPressed(
+                    mouse::Button::Left,
+                ))
+                | Event::Touch(touch::Event::FingerPressed { .. }) => {
+                    let Some(cursor_position) = cursor.position() else {
+                        return event::Status::Ignored;
+                    };
+
+                    if let (Some(scroller_grabbed_at), Some(scrollbar)) = (
+                        scrollbars.grab_x_scroller(cursor_position),
+                        scrollbars.x,
+                    ) {
+                        state.scroll_x_to(
+                            scrollbar.scroll_percentage_x(
+                                scroller_grabbed_at,
+                                cursor_position,
+                            ),
+                            bounds,
+                            content_bounds,
+                        );
+
+                        state.x_scroller_grabbed_at = Some(scroller_grabbed_at);
+
+                        notify_on_scroll(
+                            state,
+                            &self.on_scroll,
+                            bounds,
+                            content_bounds,
+                            shell,
+                        );
+
+                        event_status = event::Status::Captured;
+                    }
+                }
+                _ => {}
+            }
+        }
+
+        event_status
     }
 
     fn draw(
@@ -551,21 +848,48 @@ where
         _viewport: &Rectangle,
         renderer: &Renderer,
     ) -> mouse::Interaction {
-        mouse_interaction(
+        let state = tree.state.downcast_ref::<State>();
-            tree.state.downcast_ref::<State>(),
+        let bounds = layout.bounds();
-            layout,
+        let cursor_over_scrollable = cursor.position_over(bounds);
-            cursor,
+
-            self.direction,
+        let content_layout = layout.children().next().unwrap();
-            |layout, cursor, viewport| {
+        let content_bounds = content_layout.bounds();
-                self.content.as_widget().mouse_interaction(
+
-                    &tree.children[0],
+        let scrollbars =
-                    layout,
+            Scrollbars::new(state, self.direction, bounds, content_bounds);
-                    cursor,
+
-                    viewport,
+        let (mouse_over_y_scrollbar, mouse_over_x_scrollbar) =
-                    renderer,
+            scrollbars.is_mouse_over(cursor);
-                )
+
-            },
+        if (mouse_over_x_scrollbar || mouse_over_y_scrollbar)
-        )
+            || state.scrollers_grabbed()
+        {
+            mouse::Interaction::Idle
+        } else {
+            let translation =
+                state.translation(self.direction, bounds, content_bounds);
+
+            let cursor = match cursor_over_scrollable {
+                Some(cursor_position)
+                    if !(mouse_over_x_scrollbar || mouse_over_y_scrollbar) =>
+                {
+                    mouse::Cursor::Available(cursor_position + translation)
+                }
+                _ => mouse::Cursor::Unavailable,
+            };
+
+            self.content.as_widget().mouse_interaction(
+                &tree.children[0],
+                layout,
+                cursor,
+                &Rectangle {
+                    y: bounds.y + translation.y,
+                    x: bounds.x + translation.x,
+                    ..bounds
+                },
+                renderer,
+            )
+        }
     }
 
     fn overlay<'b>(
@@ -651,386 +975,6 @@ pub fn scroll_to<Message: 'static>(
     Command::widget(operation::scrollable::scroll_to(id.0, offset))
 }
 
-/// Computes the layout of a [`Scrollable`].
-pub fn layout<Renderer>(
-    renderer: &Renderer,
-    limits: &layout::Limits,
-    width: Length,
-    height: Length,
-    direction: &Direction,
-    layout_content: impl FnOnce(&Renderer, &layout::Limits) -> layout::Node,
-) -> layout::Node {
-    layout::contained(limits, width, height, |limits| {
-        let child_limits = layout::Limits::new(
-            Size::new(limits.min().width, limits.min().height),
-            Size::new(
-                if direction.horizontal().is_some() {
-                    f32::INFINITY
-                } else {
-                    limits.max().width
-                },
-                if direction.vertical().is_some() {
-                    f32::MAX
-                } else {
-                    limits.max().height
-                },
-            ),
-        );
-
-        layout_content(renderer, &child_limits)
-    })
-}
-
-/// Processes an [`Event`] and updates the [`State`] of a [`Scrollable`]
-/// accordingly.
-pub fn update<Message>(
-    state: &mut State,
-    event: Event,
-    layout: Layout<'_>,
-    cursor: mouse::Cursor,
-    clipboard: &mut dyn Clipboard,
-    shell: &mut Shell<'_, Message>,
-    direction: Direction,
-    on_scroll: &Option<Box<dyn Fn(Viewport) -> Message + '_>>,
-    update_content: impl FnOnce(
-        Event,
-        Layout<'_>,
-        mouse::Cursor,
-        &mut dyn Clipboard,
-        &mut Shell<'_, Message>,
-        &Rectangle,
-    ) -> event::Status,
-) -> event::Status {
-    let bounds = layout.bounds();
-    let cursor_over_scrollable = cursor.position_over(bounds);
-
-    let content = layout.children().next().unwrap();
-    let content_bounds = content.bounds();
-
-    let scrollbars = Scrollbars::new(state, direction, bounds, content_bounds);
-
-    let (mouse_over_y_scrollbar, mouse_over_x_scrollbar) =
-        scrollbars.is_mouse_over(cursor);
-
-    let mut event_status = {
-        let cursor = match cursor_over_scrollable {
-            Some(cursor_position)
-                if !(mouse_over_x_scrollbar || mouse_over_y_scrollbar) =>
-            {
-                mouse::Cursor::Available(
-                    cursor_position
-                        + state.translation(direction, bounds, content_bounds),
-                )
-            }
-            _ => mouse::Cursor::Unavailable,
-        };
-
-        let translation = state.translation(direction, bounds, content_bounds);
-
-        update_content(
-            event.clone(),
-            content,
-            cursor,
-            clipboard,
-            shell,
-            &Rectangle {
-                y: bounds.y + translation.y,
-                x: bounds.x + translation.x,
-                ..bounds
-            },
-        )
-    };
-
-    if let event::Status::Captured = event_status {
-        return event::Status::Captured;
-    }
-
-    if let Event::Keyboard(keyboard::Event::ModifiersChanged(modifiers)) = event
-    {
-        state.keyboard_modifiers = modifiers;
-
-        return event::Status::Ignored;
-    }
-
-    match event {
-        Event::Mouse(mouse::Event::WheelScrolled { delta }) => {
-            if cursor_over_scrollable.is_none() {
-                return event::Status::Ignored;
-            }
-
-            let delta = match delta {
-                mouse::ScrollDelta::Lines { x, y } => {
-                    // TODO: Configurable speed/friction (?)
-                    let movement = if state.keyboard_modifiers.shift() {
-                        Vector::new(y, x)
-                    } else {
-                        Vector::new(x, y)
-                    };
-
-                    movement * 60.0
-                }
-                mouse::ScrollDelta::Pixels { x, y } => Vector::new(x, y),
-            };
-
-            state.scroll(delta, direction, bounds, content_bounds);
-
-            notify_on_scroll(state, on_scroll, bounds, content_bounds, shell);
-
-            event_status = event::Status::Captured;
-        }
-        Event::Touch(event)
-            if state.scroll_area_touched_at.is_some()
-                || !mouse_over_y_scrollbar && !mouse_over_x_scrollbar =>
-        {
-            match event {
-                touch::Event::FingerPressed { .. } => {
-                    let Some(cursor_position) = cursor.position() else {
-                        return event::Status::Ignored;
-                    };
-
-                    state.scroll_area_touched_at = Some(cursor_position);
-                }
-                touch::Event::FingerMoved { .. } => {
-                    if let Some(scroll_box_touched_at) =
-                        state.scroll_area_touched_at
-                    {
-                        let Some(cursor_position) = cursor.position() else {
-                            return event::Status::Ignored;
-                        };
-
-                        let delta = Vector::new(
-                            cursor_position.x - scroll_box_touched_at.x,
-                            cursor_position.y - scroll_box_touched_at.y,
-                        );
-
-                        state.scroll(delta, direction, bounds, content_bounds);
-
-                        state.scroll_area_touched_at = Some(cursor_position);
-
-                        notify_on_scroll(
-                            state,
-                            on_scroll,
-                            bounds,
-                            content_bounds,
-                            shell,
-                        );
-                    }
-                }
-                touch::Event::FingerLifted { .. }
-                | touch::Event::FingerLost { .. } => {
-                    state.scroll_area_touched_at = None;
-                }
-            }
-
-            event_status = event::Status::Captured;
-        }
-        _ => {}
-    }
-
-    if let Some(scroller_grabbed_at) = state.y_scroller_grabbed_at {
-        match event {
-            Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Left))
-            | Event::Touch(touch::Event::FingerLifted { .. })
-            | Event::Touch(touch::Event::FingerLost { .. }) => {
-                state.y_scroller_grabbed_at = None;
-
-                event_status = event::Status::Captured;
-            }
-            Event::Mouse(mouse::Event::CursorMoved { .. })
-            | Event::Touch(touch::Event::FingerMoved { .. }) => {
-                if let Some(scrollbar) = scrollbars.y {
-                    let Some(cursor_position) = cursor.position() else {
-                        return event::Status::Ignored;
-                    };
-
-                    state.scroll_y_to(
-                        scrollbar.scroll_percentage_y(
-                            scroller_grabbed_at,
-                            cursor_position,
-                        ),
-                        bounds,
-                        content_bounds,
-                    );
-
-                    notify_on_scroll(
-                        state,
-                        on_scroll,
-                        bounds,
-                        content_bounds,
-                        shell,
-                    );
-
-                    event_status = event::Status::Captured;
-                }
-            }
-            _ => {}
-        }
-    } else if mouse_over_y_scrollbar {
-        match event {
-            Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
-            | Event::Touch(touch::Event::FingerPressed { .. }) => {
-                let Some(cursor_position) = cursor.position() else {
-                    return event::Status::Ignored;
-                };
-
-                if let (Some(scroller_grabbed_at), Some(scrollbar)) =
-                    (scrollbars.grab_y_scroller(cursor_position), scrollbars.y)
-                {
-                    state.scroll_y_to(
-                        scrollbar.scroll_percentage_y(
-                            scroller_grabbed_at,
-                            cursor_position,
-                        ),
-                        bounds,
-                        content_bounds,
-                    );
-
-                    state.y_scroller_grabbed_at = Some(scroller_grabbed_at);
-
-                    notify_on_scroll(
-                        state,
-                        on_scroll,
-                        bounds,
-                        content_bounds,
-                        shell,
-                    );
-                }
-
-                event_status = event::Status::Captured;
-            }
-            _ => {}
-        }
-    }
-
-    if let Some(scroller_grabbed_at) = state.x_scroller_grabbed_at {
-        match event {
-            Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Left))
-            | Event::Touch(touch::Event::FingerLifted { .. })
-            | Event::Touch(touch::Event::FingerLost { .. }) => {
-                state.x_scroller_grabbed_at = None;
-
-                event_status = event::Status::Captured;
-            }
-            Event::Mouse(mouse::Event::CursorMoved { .. })
-            | Event::Touch(touch::Event::FingerMoved { .. }) => {
-                let Some(cursor_position) = cursor.position() else {
-                    return event::Status::Ignored;
-                };
-
-                if let Some(scrollbar) = scrollbars.x {
-                    state.scroll_x_to(
-                        scrollbar.scroll_percentage_x(
-                            scroller_grabbed_at,
-                            cursor_position,
-                        ),
-                        bounds,
-                        content_bounds,
-                    );
-
-                    notify_on_scroll(
-                        state,
-                        on_scroll,
-                        bounds,
-                        content_bounds,
-                        shell,
-                    );
-                }
-
-                event_status = event::Status::Captured;
-            }
-            _ => {}
-        }
-    } else if mouse_over_x_scrollbar {
-        match event {
-            Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
-            | Event::Touch(touch::Event::FingerPressed { .. }) => {
-                let Some(cursor_position) = cursor.position() else {
-                    return event::Status::Ignored;
-                };
-
-                if let (Some(scroller_grabbed_at), Some(scrollbar)) =
-                    (scrollbars.grab_x_scroller(cursor_position), scrollbars.x)
-                {
-                    state.scroll_x_to(
-                        scrollbar.scroll_percentage_x(
-                            scroller_grabbed_at,
-                            cursor_position,
-                        ),
-                        bounds,
-                        content_bounds,
-                    );
-
-                    state.x_scroller_grabbed_at = Some(scroller_grabbed_at);
-
-                    notify_on_scroll(
-                        state,
-                        on_scroll,
-                        bounds,
-                        content_bounds,
-                        shell,
-                    );
-
-                    event_status = event::Status::Captured;
-                }
-            }
-            _ => {}
-        }
-    }
-
-    event_status
-}
-
-/// Computes the current [`mouse::Interaction`] of a [`Scrollable`].
-pub fn mouse_interaction(
-    state: &State,
-    layout: Layout<'_>,
-    cursor: mouse::Cursor,
-    direction: Direction,
-    content_interaction: impl FnOnce(
-        Layout<'_>,
-        mouse::Cursor,
-        &Rectangle,
-    ) -> mouse::Interaction,
-) -> mouse::Interaction {
-    let bounds = layout.bounds();
-    let cursor_over_scrollable = cursor.position_over(bounds);
-
-    let content_layout = layout.children().next().unwrap();
-    let content_bounds = content_layout.bounds();
-
-    let scrollbars = Scrollbars::new(state, direction, bounds, content_bounds);
-
-    let (mouse_over_y_scrollbar, mouse_over_x_scrollbar) =
-        scrollbars.is_mouse_over(cursor);
-
-    if (mouse_over_x_scrollbar || mouse_over_y_scrollbar)
-        || state.scrollers_grabbed()
-    {
-        mouse::Interaction::Idle
-    } else {
-        let translation = state.translation(direction, bounds, content_bounds);
-
-        let cursor = match cursor_over_scrollable {
-            Some(cursor_position)
-                if !(mouse_over_x_scrollbar || mouse_over_y_scrollbar) =>
-            {
-                mouse::Cursor::Available(cursor_position + translation)
-            }
-            _ => mouse::Cursor::Unavailable,
-        };
-
-        content_interaction(
-            content_layout,
-            cursor,
-            &Rectangle {
-                y: bounds.y + translation.y,
-                x: bounds.x + translation.x,
-                ..bounds
-            },
-        )
-    }
-}
-
 fn notify_on_scroll<Message>(
     state: &mut State,
     on_scroll: &Option<Box<dyn Fn(Viewport) -> Message + '_>>,
@@ -1078,9 +1022,8 @@ fn notify_on_scroll<Message>(
     }
 }
 
-/// The local state of a [`Scrollable`].
 #[derive(Debug, Clone, Copy)]
-pub struct State {
+struct State {
     scroll_area_touched_at: Option<Point>,
     offset_y: Offset,
     y_scroller_grabbed_at: Option<f32>,