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Diffstat (limited to 'native/src/widget/scrollable.rs')
| -rw-r--r-- | native/src/widget/scrollable.rs | 1327 |
1 files changed, 0 insertions, 1327 deletions
diff --git a/native/src/widget/scrollable.rs b/native/src/widget/scrollable.rs deleted file mode 100644 index c1df8c39..00000000 --- a/native/src/widget/scrollable.rs +++ /dev/null @@ -1,1327 +0,0 @@ -//! Navigate an endless amount of content with a scrollbar. -use crate::event::{self, Event}; -use crate::keyboard; -use crate::layout; -use crate::mouse; -use crate::overlay; -use crate::renderer; -use crate::touch; -use crate::widget; -use crate::widget::operation::{self, Operation}; -use crate::widget::tree::{self, Tree}; -use crate::{ - Background, Clipboard, Color, Command, Element, Layout, Length, Pixels, - Point, Rectangle, Shell, Size, Vector, Widget, -}; - -pub use iced_style::scrollable::StyleSheet; -pub use operation::scrollable::RelativeOffset; - -pub mod style { - //! The styles of a [`Scrollable`]. - //! - //! [`Scrollable`]: crate::widget::Scrollable - pub use iced_style::scrollable::{Scrollbar, Scroller}; -} - -/// A widget that can vertically display an infinite amount of content with a -/// scrollbar. -#[allow(missing_debug_implementations)] -pub struct Scrollable<'a, Message, Renderer> -where - Renderer: crate::Renderer, - Renderer::Theme: StyleSheet, -{ - id: Option<Id>, - height: Length, - vertical: Properties, - horizontal: Option<Properties>, - content: Element<'a, Message, Renderer>, - on_scroll: Option<Box<dyn Fn(RelativeOffset) -> Message + 'a>>, - style: <Renderer::Theme as StyleSheet>::Style, -} - -impl<'a, Message, Renderer> Scrollable<'a, Message, Renderer> -where - Renderer: crate::Renderer, - Renderer::Theme: StyleSheet, -{ - /// Creates a new [`Scrollable`]. - pub fn new(content: impl Into<Element<'a, Message, Renderer>>) -> Self { - Scrollable { - id: None, - height: Length::Shrink, - vertical: Properties::default(), - horizontal: None, - content: content.into(), - on_scroll: None, - style: Default::default(), - } - } - - /// Sets the [`Id`] of the [`Scrollable`]. - pub fn id(mut self, id: Id) -> Self { - self.id = Some(id); - self - } - - /// Sets the height of the [`Scrollable`]. - pub fn height(mut self, height: impl Into<Length>) -> Self { - self.height = height.into(); - self - } - - /// Configures the vertical scrollbar of the [`Scrollable`] . - pub fn vertical_scroll(mut self, properties: Properties) -> Self { - self.vertical = properties; - self - } - - /// Configures the horizontal scrollbar of the [`Scrollable`] . - pub fn horizontal_scroll(mut self, properties: Properties) -> Self { - self.horizontal = Some(properties); - self - } - - /// Sets a function to call when the [`Scrollable`] is scrolled. - /// - /// The function takes the new relative x & y offset of the [`Scrollable`] - /// (e.g. `0` means beginning, while `1` means end). - pub fn on_scroll( - mut self, - f: impl Fn(RelativeOffset) -> Message + 'a, - ) -> Self { - self.on_scroll = Some(Box::new(f)); - self - } - - /// Sets the style of the [`Scrollable`] . - pub fn style( - mut self, - style: impl Into<<Renderer::Theme as StyleSheet>::Style>, - ) -> Self { - self.style = style.into(); - self - } -} - -/// Properties of a scrollbar within a [`Scrollable`]. -#[derive(Debug)] -pub struct Properties { - width: f32, - margin: f32, - scroller_width: f32, -} - -impl Default for Properties { - fn default() -> Self { - Self { - width: 10.0, - margin: 0.0, - scroller_width: 10.0, - } - } -} - -impl Properties { - /// Creates new [`Properties`] for use in a [`Scrollable`]. - pub fn new() -> Self { - Self::default() - } - - /// Sets the scrollbar width of the [`Scrollable`] . - /// Silently enforces a minimum width of 1. - pub fn width(mut self, width: impl Into<Pixels>) -> Self { - self.width = width.into().0.max(1.0); - self - } - - /// Sets the scrollbar margin of the [`Scrollable`] . - pub fn margin(mut self, margin: impl Into<Pixels>) -> Self { - self.margin = margin.into().0; - self - } - - /// Sets the scroller width of the [`Scrollable`] . - /// Silently enforces a minimum width of 1. - pub fn scroller_width(mut self, scroller_width: impl Into<Pixels>) -> Self { - self.scroller_width = scroller_width.into().0.max(1.0); - self - } -} - -impl<'a, Message, Renderer> Widget<Message, Renderer> - for Scrollable<'a, Message, Renderer> -where - Renderer: crate::Renderer, - Renderer::Theme: StyleSheet, -{ - fn tag(&self) -> tree::Tag { - tree::Tag::of::<State>() - } - - fn state(&self) -> tree::State { - tree::State::new(State::new()) - } - - fn children(&self) -> Vec<Tree> { - vec![Tree::new(&self.content)] - } - - fn diff(&self, tree: &mut Tree) { - tree.diff_children(std::slice::from_ref(&self.content)) - } - - fn width(&self) -> Length { - self.content.as_widget().width() - } - - fn height(&self) -> Length { - self.height - } - - fn layout( - &self, - renderer: &Renderer, - limits: &layout::Limits, - ) -> layout::Node { - layout( - renderer, - limits, - Widget::<Message, Renderer>::width(self), - self.height, - self.horizontal.is_some(), - |renderer, limits| { - self.content.as_widget().layout(renderer, limits) - }, - ) - } - - fn operate( - &self, - tree: &mut Tree, - layout: Layout<'_>, - renderer: &Renderer, - operation: &mut dyn Operation<Message>, - ) { - let state = tree.state.downcast_mut::<State>(); - - operation.scrollable(state, self.id.as_ref().map(|id| &id.0)); - - operation.container( - self.id.as_ref().map(|id| &id.0), - &mut |operation| { - self.content.as_widget().operate( - &mut tree.children[0], - layout.children().next().unwrap(), - renderer, - operation, - ); - }, - ); - } - - fn on_event( - &mut self, - tree: &mut Tree, - event: Event, - layout: Layout<'_>, - cursor_position: Point, - renderer: &Renderer, - clipboard: &mut dyn Clipboard, - shell: &mut Shell<'_, Message>, - ) -> event::Status { - update( - tree.state.downcast_mut::<State>(), - event, - layout, - cursor_position, - clipboard, - shell, - &self.vertical, - self.horizontal.as_ref(), - &self.on_scroll, - |event, layout, cursor_position, clipboard, shell| { - self.content.as_widget_mut().on_event( - &mut tree.children[0], - event, - layout, - cursor_position, - renderer, - clipboard, - shell, - ) - }, - ) - } - - fn draw( - &self, - tree: &Tree, - renderer: &mut Renderer, - theme: &Renderer::Theme, - style: &renderer::Style, - layout: Layout<'_>, - cursor_position: Point, - _viewport: &Rectangle, - ) { - draw( - tree.state.downcast_ref::<State>(), - renderer, - theme, - layout, - cursor_position, - &self.vertical, - self.horizontal.as_ref(), - &self.style, - |renderer, layout, cursor_position, viewport| { - self.content.as_widget().draw( - &tree.children[0], - renderer, - theme, - style, - layout, - cursor_position, - viewport, - ) - }, - ) - } - - fn mouse_interaction( - &self, - tree: &Tree, - layout: Layout<'_>, - cursor_position: Point, - _viewport: &Rectangle, - renderer: &Renderer, - ) -> mouse::Interaction { - mouse_interaction( - tree.state.downcast_ref::<State>(), - layout, - cursor_position, - &self.vertical, - self.horizontal.as_ref(), - |layout, cursor_position, viewport| { - self.content.as_widget().mouse_interaction( - &tree.children[0], - layout, - cursor_position, - viewport, - renderer, - ) - }, - ) - } - - fn overlay<'b>( - &'b mut self, - tree: &'b mut Tree, - layout: Layout<'_>, - renderer: &Renderer, - ) -> Option<overlay::Element<'b, Message, Renderer>> { - self.content - .as_widget_mut() - .overlay( - &mut tree.children[0], - layout.children().next().unwrap(), - renderer, - ) - .map(|overlay| { - let bounds = layout.bounds(); - let content_layout = layout.children().next().unwrap(); - let content_bounds = content_layout.bounds(); - let offset = tree - .state - .downcast_ref::<State>() - .offset(bounds, content_bounds); - - overlay.translate(Vector::new(-offset.x, -offset.y)) - }) - } -} - -impl<'a, Message, Renderer> From<Scrollable<'a, Message, Renderer>> - for Element<'a, Message, Renderer> -where - Message: 'a, - Renderer: 'a + crate::Renderer, - Renderer::Theme: StyleSheet, -{ - fn from( - text_input: Scrollable<'a, Message, Renderer>, - ) -> Element<'a, Message, Renderer> { - Element::new(text_input) - } -} - -/// The identifier of a [`Scrollable`]. -#[derive(Debug, Clone, PartialEq, Eq, Hash)] -pub struct Id(widget::Id); - -impl Id { - /// Creates a custom [`Id`]. - pub fn new(id: impl Into<std::borrow::Cow<'static, str>>) -> Self { - Self(widget::Id::new(id)) - } - - /// Creates a unique [`Id`]. - /// - /// This function produces a different [`Id`] every time it is called. - pub fn unique() -> Self { - Self(widget::Id::unique()) - } -} - -impl From<Id> for widget::Id { - fn from(id: Id) -> Self { - id.0 - } -} - -/// Produces a [`Command`] that snaps the [`Scrollable`] with the given [`Id`] -/// to the provided `percentage` along the x & y axis. -pub fn snap_to<Message: 'static>( - id: Id, - offset: RelativeOffset, -) -> Command<Message> { - Command::widget(operation::scrollable::snap_to(id.0, offset)) -} - -/// Computes the layout of a [`Scrollable`]. -pub fn layout<Renderer>( - renderer: &Renderer, - limits: &layout::Limits, - width: Length, - height: Length, - horizontal_enabled: bool, - layout_content: impl FnOnce(&Renderer, &layout::Limits) -> layout::Node, -) -> layout::Node { - let limits = limits - .max_height(f32::INFINITY) - .max_width(if horizontal_enabled { - f32::INFINITY - } else { - limits.max().width - }) - .width(width) - .height(height); - - let child_limits = layout::Limits::new( - Size::new(limits.min().width, 0.0), - Size::new( - if horizontal_enabled { - f32::INFINITY - } else { - limits.max().width - }, - f32::MAX, - ), - ); - - let content = layout_content(renderer, &child_limits); - let size = limits.resolve(content.size()); - - layout::Node::with_children(size, vec![content]) -} - -/// Processes an [`Event`] and updates the [`State`] of a [`Scrollable`] -/// accordingly. -pub fn update<Message>( - state: &mut State, - event: Event, - layout: Layout<'_>, - cursor_position: Point, - clipboard: &mut dyn Clipboard, - shell: &mut Shell<'_, Message>, - vertical: &Properties, - horizontal: Option<&Properties>, - on_scroll: &Option<Box<dyn Fn(RelativeOffset) -> Message + '_>>, - update_content: impl FnOnce( - Event, - Layout<'_>, - Point, - &mut dyn Clipboard, - &mut Shell<'_, Message>, - ) -> event::Status, -) -> event::Status { - let bounds = layout.bounds(); - let mouse_over_scrollable = bounds.contains(cursor_position); - - let content = layout.children().next().unwrap(); - let content_bounds = content.bounds(); - - let scrollbars = - Scrollbars::new(state, vertical, horizontal, bounds, content_bounds); - - let (mouse_over_y_scrollbar, mouse_over_x_scrollbar) = - scrollbars.is_mouse_over(cursor_position); - - let event_status = { - let cursor_position = if mouse_over_scrollable - && !(mouse_over_y_scrollbar || mouse_over_x_scrollbar) - { - cursor_position + state.offset(bounds, content_bounds) - } else { - // TODO: Make `cursor_position` an `Option<Point>` so we can encode - // cursor availability. - // This will probably happen naturally once we add multi-window - // support. - Point::new(-1.0, -1.0) - }; - - update_content( - event.clone(), - content, - cursor_position, - clipboard, - shell, - ) - }; - - 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; - } - - if mouse_over_scrollable { - match event { - Event::Mouse(mouse::Event::WheelScrolled { delta }) => { - 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, bounds, content_bounds); - - notify_on_scroll( - state, - on_scroll, - bounds, - content_bounds, - shell, - ); - - return 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 { .. } => { - state.scroll_area_touched_at = Some(cursor_position); - } - touch::Event::FingerMoved { .. } => { - if let Some(scroll_box_touched_at) = - state.scroll_area_touched_at - { - let delta = Vector::new( - cursor_position.x - scroll_box_touched_at.x, - cursor_position.y - scroll_box_touched_at.y, - ); - - state.scroll(delta, 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; - } - } - - return 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; - - return event::Status::Captured; - } - Event::Mouse(mouse::Event::CursorMoved { .. }) - | Event::Touch(touch::Event::FingerMoved { .. }) => { - if let Some(scrollbar) = scrollbars.y { - 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, - ); - - return event::Status::Captured; - } - } - _ => {} - } - } else if mouse_over_y_scrollbar { - match event { - Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left)) - | Event::Touch(touch::Event::FingerPressed { .. }) => { - 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, - ); - } - - return 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; - - return event::Status::Captured; - } - Event::Mouse(mouse::Event::CursorMoved { .. }) - | Event::Touch(touch::Event::FingerMoved { .. }) => { - 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, - ); - } - - return event::Status::Captured; - } - _ => {} - } - } else if mouse_over_x_scrollbar { - match event { - Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left)) - | Event::Touch(touch::Event::FingerPressed { .. }) => { - 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, - ); - - return event::Status::Captured; - } - } - _ => {} - } - } - - event::Status::Ignored -} - -/// Computes the current [`mouse::Interaction`] of a [`Scrollable`]. -pub fn mouse_interaction( - state: &State, - layout: Layout<'_>, - cursor_position: Point, - vertical: &Properties, - horizontal: Option<&Properties>, - content_interaction: impl FnOnce( - Layout<'_>, - Point, - &Rectangle, - ) -> mouse::Interaction, -) -> mouse::Interaction { - let bounds = layout.bounds(); - let mouse_over_scrollable = bounds.contains(cursor_position); - - let content_layout = layout.children().next().unwrap(); - let content_bounds = content_layout.bounds(); - - let scrollbars = - Scrollbars::new(state, vertical, horizontal, bounds, content_bounds); - - let (mouse_over_y_scrollbar, mouse_over_x_scrollbar) = - scrollbars.is_mouse_over(cursor_position); - - if (mouse_over_x_scrollbar || mouse_over_y_scrollbar) - || state.scrollers_grabbed() - { - mouse::Interaction::Idle - } else { - let offset = state.offset(bounds, content_bounds); - - let cursor_position = if mouse_over_scrollable - && !(mouse_over_y_scrollbar || mouse_over_x_scrollbar) - { - cursor_position + offset - } else { - Point::new(-1.0, -1.0) - }; - - content_interaction( - content_layout, - cursor_position, - &Rectangle { - y: bounds.y + offset.y, - x: bounds.x + offset.x, - ..bounds - }, - ) - } -} - -/// Draws a [`Scrollable`]. -pub fn draw<Renderer>( - state: &State, - renderer: &mut Renderer, - theme: &Renderer::Theme, - layout: Layout<'_>, - cursor_position: Point, - vertical: &Properties, - horizontal: Option<&Properties>, - style: &<Renderer::Theme as StyleSheet>::Style, - draw_content: impl FnOnce(&mut Renderer, Layout<'_>, Point, &Rectangle), -) where - Renderer: crate::Renderer, - Renderer::Theme: StyleSheet, -{ - let bounds = layout.bounds(); - let content_layout = layout.children().next().unwrap(); - let content_bounds = content_layout.bounds(); - - let scrollbars = - Scrollbars::new(state, vertical, horizontal, bounds, content_bounds); - - let mouse_over_scrollable = bounds.contains(cursor_position); - let (mouse_over_y_scrollbar, mouse_over_x_scrollbar) = - scrollbars.is_mouse_over(cursor_position); - - let offset = state.offset(bounds, content_bounds); - - let cursor_position = if mouse_over_scrollable - && !(mouse_over_x_scrollbar || mouse_over_y_scrollbar) - { - cursor_position + offset - } else { - Point::new(-1.0, -1.0) - }; - - // Draw inner content - if scrollbars.active() { - renderer.with_layer(bounds, |renderer| { - renderer.with_translation( - Vector::new(-offset.x, -offset.y), - |renderer| { - draw_content( - renderer, - content_layout, - cursor_position, - &Rectangle { - y: bounds.y + offset.y, - x: bounds.x + offset.x, - ..bounds - }, - ); - }, - ); - }); - - let draw_scrollbar = - |renderer: &mut Renderer, - style: style::Scrollbar, - scrollbar: &Scrollbar| { - //track - if style.background.is_some() - || (style.border_color != Color::TRANSPARENT - && style.border_width > 0.0) - { - renderer.fill_quad( - renderer::Quad { - bounds: scrollbar.bounds, - border_radius: style.border_radius.into(), - border_width: style.border_width, - border_color: style.border_color, - }, - style - .background - .unwrap_or(Background::Color(Color::TRANSPARENT)), - ); - } - - //thumb - if style.scroller.color != Color::TRANSPARENT - || (style.scroller.border_color != Color::TRANSPARENT - && style.scroller.border_width > 0.0) - { - renderer.fill_quad( - renderer::Quad { - bounds: scrollbar.scroller.bounds, - border_radius: style.scroller.border_radius.into(), - border_width: style.scroller.border_width, - border_color: style.scroller.border_color, - }, - style.scroller.color, - ); - } - }; - - renderer.with_layer( - Rectangle { - width: bounds.width + 2.0, - height: bounds.height + 2.0, - ..bounds - }, - |renderer| { - //draw y scrollbar - if let Some(scrollbar) = scrollbars.y { - let style = if state.y_scroller_grabbed_at.is_some() { - theme.dragging(style) - } else if mouse_over_y_scrollbar { - theme.hovered(style) - } else { - theme.active(style) - }; - - draw_scrollbar(renderer, style, &scrollbar); - } - - //draw x scrollbar - if let Some(scrollbar) = scrollbars.x { - let style = if state.x_scroller_grabbed_at.is_some() { - theme.dragging_horizontal(style) - } else if mouse_over_x_scrollbar { - theme.hovered_horizontal(style) - } else { - theme.active_horizontal(style) - }; - - draw_scrollbar(renderer, style, &scrollbar); - } - }, - ); - } else { - draw_content( - renderer, - content_layout, - cursor_position, - &Rectangle { - x: bounds.x + offset.x, - y: bounds.y + offset.y, - ..bounds - }, - ); - } -} - -fn notify_on_scroll<Message>( - state: &State, - on_scroll: &Option<Box<dyn Fn(RelativeOffset) -> Message + '_>>, - bounds: Rectangle, - content_bounds: Rectangle, - shell: &mut Shell<'_, Message>, -) { - if let Some(on_scroll) = on_scroll { - if content_bounds.width <= bounds.width - && content_bounds.height <= bounds.height - { - return; - } - - let x = state.offset_x.absolute(bounds.width, content_bounds.width) - / (content_bounds.width - bounds.width); - - let y = state - .offset_y - .absolute(bounds.height, content_bounds.height) - / (content_bounds.height - bounds.height); - - shell.publish(on_scroll(RelativeOffset { x, y })) - } -} - -/// The local state of a [`Scrollable`]. -#[derive(Debug, Clone, Copy)] -pub struct State { - scroll_area_touched_at: Option<Point>, - offset_y: Offset, - y_scroller_grabbed_at: Option<f32>, - offset_x: Offset, - x_scroller_grabbed_at: Option<f32>, - keyboard_modifiers: keyboard::Modifiers, -} - -impl Default for State { - fn default() -> Self { - Self { - scroll_area_touched_at: None, - offset_y: Offset::Absolute(0.0), - y_scroller_grabbed_at: None, - offset_x: Offset::Absolute(0.0), - x_scroller_grabbed_at: None, - keyboard_modifiers: keyboard::Modifiers::default(), - } - } -} - -impl operation::Scrollable for State { - fn snap_to(&mut self, offset: RelativeOffset) { - State::snap_to(self, offset); - } -} - -#[derive(Debug, Clone, Copy)] -enum Offset { - Absolute(f32), - Relative(f32), -} - -impl Offset { - fn absolute(self, window: f32, content: f32) -> f32 { - match self { - Offset::Absolute(absolute) => { - absolute.min((content - window).max(0.0)) - } - Offset::Relative(percentage) => { - ((content - window) * percentage).max(0.0) - } - } - } -} - -impl State { - /// Creates a new [`State`] with the scrollbar(s) at the beginning. - pub fn new() -> Self { - State::default() - } - - /// Apply a scrolling offset to the current [`State`], given the bounds of - /// the [`Scrollable`] and its contents. - pub fn scroll( - &mut self, - delta: Vector<f32>, - bounds: Rectangle, - content_bounds: Rectangle, - ) { - if bounds.height < content_bounds.height { - self.offset_y = Offset::Absolute( - (self.offset_y.absolute(bounds.height, content_bounds.height) - - delta.y) - .clamp(0.0, content_bounds.height - bounds.height), - ) - } - - if bounds.width < content_bounds.width { - self.offset_x = Offset::Absolute( - (self.offset_x.absolute(bounds.width, content_bounds.width) - - delta.x) - .clamp(0.0, content_bounds.width - bounds.width), - ); - } - } - - /// Scrolls the [`Scrollable`] to a relative amount along the y axis. - /// - /// `0` represents scrollbar at the beginning, while `1` represents scrollbar at - /// the end. - pub fn scroll_y_to( - &mut self, - percentage: f32, - bounds: Rectangle, - content_bounds: Rectangle, - ) { - self.offset_y = Offset::Relative(percentage.clamp(0.0, 1.0)); - self.unsnap(bounds, content_bounds); - } - - /// Scrolls the [`Scrollable`] to a relative amount along the x axis. - /// - /// `0` represents scrollbar at the beginning, while `1` represents scrollbar at - /// the end. - pub fn scroll_x_to( - &mut self, - percentage: f32, - bounds: Rectangle, - content_bounds: Rectangle, - ) { - self.offset_x = Offset::Relative(percentage.clamp(0.0, 1.0)); - self.unsnap(bounds, content_bounds); - } - - /// Snaps the scroll position to a [`RelativeOffset`]. - pub fn snap_to(&mut self, offset: RelativeOffset) { - self.offset_x = Offset::Relative(offset.x.clamp(0.0, 1.0)); - self.offset_y = Offset::Relative(offset.y.clamp(0.0, 1.0)); - } - - /// Unsnaps the current scroll position, if snapped, given the bounds of the - /// [`Scrollable`] and its contents. - pub fn unsnap(&mut self, bounds: Rectangle, content_bounds: Rectangle) { - self.offset_x = Offset::Absolute( - self.offset_x.absolute(bounds.width, content_bounds.width), - ); - self.offset_y = Offset::Absolute( - self.offset_y.absolute(bounds.height, content_bounds.height), - ); - } - - /// Returns the scrolling offset of the [`State`], given the bounds of the - /// [`Scrollable`] and its contents. - pub fn offset( - &self, - bounds: Rectangle, - content_bounds: Rectangle, - ) -> Vector { - Vector::new( - self.offset_x.absolute(bounds.width, content_bounds.width), - self.offset_y.absolute(bounds.height, content_bounds.height), - ) - } - - /// Returns whether any scroller is currently grabbed or not. - pub fn scrollers_grabbed(&self) -> bool { - self.x_scroller_grabbed_at.is_some() - || self.y_scroller_grabbed_at.is_some() - } -} - -#[derive(Debug)] -/// State of both [`Scrollbar`]s. -struct Scrollbars { - y: Option<Scrollbar>, - x: Option<Scrollbar>, -} - -impl Scrollbars { - /// Create y and/or x scrollbar(s) if content is overflowing the [`Scrollable`] bounds. - fn new( - state: &State, - vertical: &Properties, - horizontal: Option<&Properties>, - bounds: Rectangle, - content_bounds: Rectangle, - ) -> Self { - let offset = state.offset(bounds, content_bounds); - - let show_scrollbar_x = horizontal.and_then(|h| { - if content_bounds.width > bounds.width { - Some(h) - } else { - None - } - }); - - let y_scrollbar = if content_bounds.height > bounds.height { - let Properties { - width, - margin, - scroller_width, - } = *vertical; - - // Adjust the height of the vertical scrollbar if the horizontal scrollbar - // is present - let x_scrollbar_height = show_scrollbar_x - .map_or(0.0, |h| h.width.max(h.scroller_width) + h.margin); - - let total_scrollbar_width = - width.max(scroller_width) + 2.0 * margin; - - // Total bounds of the scrollbar + margin + scroller width - let total_scrollbar_bounds = Rectangle { - x: bounds.x + bounds.width - total_scrollbar_width, - y: bounds.y, - width: total_scrollbar_width, - height: (bounds.height - x_scrollbar_height).max(0.0), - }; - - // Bounds of just the scrollbar - let scrollbar_bounds = Rectangle { - x: bounds.x + bounds.width - - total_scrollbar_width / 2.0 - - width / 2.0, - y: bounds.y, - width, - height: (bounds.height - x_scrollbar_height).max(0.0), - }; - - let ratio = bounds.height / content_bounds.height; - // min height for easier grabbing with super tall content - let scroller_height = (bounds.height * ratio).max(2.0); - let scroller_offset = offset.y * ratio; - - let scroller_bounds = Rectangle { - x: bounds.x + bounds.width - - total_scrollbar_width / 2.0 - - scroller_width / 2.0, - y: (scrollbar_bounds.y + scroller_offset - x_scrollbar_height) - .max(0.0), - width: scroller_width, - height: scroller_height, - }; - - Some(Scrollbar { - total_bounds: total_scrollbar_bounds, - bounds: scrollbar_bounds, - scroller: Scroller { - bounds: scroller_bounds, - }, - }) - } else { - None - }; - - let x_scrollbar = if let Some(horizontal) = show_scrollbar_x { - let Properties { - width, - margin, - scroller_width, - } = *horizontal; - - // Need to adjust the width of the horizontal scrollbar if the vertical scrollbar - // is present - let scrollbar_y_width = y_scrollbar.map_or(0.0, |_| { - vertical.width.max(vertical.scroller_width) + vertical.margin - }); - - let total_scrollbar_height = - width.max(scroller_width) + 2.0 * margin; - - // Total bounds of the scrollbar + margin + scroller width - let total_scrollbar_bounds = Rectangle { - x: bounds.x, - y: bounds.y + bounds.height - total_scrollbar_height, - width: (bounds.width - scrollbar_y_width).max(0.0), - height: total_scrollbar_height, - }; - - // Bounds of just the scrollbar - let scrollbar_bounds = Rectangle { - x: bounds.x, - y: bounds.y + bounds.height - - total_scrollbar_height / 2.0 - - width / 2.0, - width: (bounds.width - scrollbar_y_width).max(0.0), - height: width, - }; - - let ratio = bounds.width / content_bounds.width; - // min width for easier grabbing with extra wide content - let scroller_length = (bounds.width * ratio).max(2.0); - let scroller_offset = offset.x * ratio; - - let scroller_bounds = Rectangle { - x: (scrollbar_bounds.x + scroller_offset - scrollbar_y_width) - .max(0.0), - y: bounds.y + bounds.height - - total_scrollbar_height / 2.0 - - scroller_width / 2.0, - width: scroller_length, - height: scroller_width, - }; - - Some(Scrollbar { - total_bounds: total_scrollbar_bounds, - bounds: scrollbar_bounds, - scroller: Scroller { - bounds: scroller_bounds, - }, - }) - } else { - None - }; - - Self { - y: y_scrollbar, - x: x_scrollbar, - } - } - - fn is_mouse_over(&self, cursor_position: Point) -> (bool, bool) { - ( - self.y - .as_ref() - .map(|scrollbar| scrollbar.is_mouse_over(cursor_position)) - .unwrap_or(false), - self.x - .as_ref() - .map(|scrollbar| scrollbar.is_mouse_over(cursor_position)) - .unwrap_or(false), - ) - } - - fn grab_y_scroller(&self, cursor_position: Point) -> Option<f32> { - self.y.and_then(|scrollbar| { - if scrollbar.total_bounds.contains(cursor_position) { - Some(if scrollbar.scroller.bounds.contains(cursor_position) { - (cursor_position.y - scrollbar.scroller.bounds.y) - / scrollbar.scroller.bounds.height - } else { - 0.5 - }) - } else { - None - } - }) - } - - fn grab_x_scroller(&self, cursor_position: Point) -> Option<f32> { - self.x.and_then(|scrollbar| { - if scrollbar.total_bounds.contains(cursor_position) { - Some(if scrollbar.scroller.bounds.contains(cursor_position) { - (cursor_position.x - scrollbar.scroller.bounds.x) - / scrollbar.scroller.bounds.width - } else { - 0.5 - }) - } else { - None - } - }) - } - - fn active(&self) -> bool { - self.y.is_some() || self.x.is_some() - } -} - -/// The scrollbar of a [`Scrollable`]. -#[derive(Debug, Copy, Clone)] -struct Scrollbar { - /// The total bounds of the [`Scrollbar`], including the scrollbar, the scroller, - /// and the scrollbar margin. - total_bounds: Rectangle, - - /// The bounds of just the [`Scrollbar`]. - bounds: Rectangle, - - /// The state of this scrollbar's [`Scroller`]. - scroller: Scroller, -} - -impl Scrollbar { - /// Returns whether the mouse is over the scrollbar or not. - fn is_mouse_over(&self, cursor_position: Point) -> bool { - self.total_bounds.contains(cursor_position) - } - - /// Returns the y-axis scrolled percentage from the cursor position. - fn scroll_percentage_y( - &self, - grabbed_at: f32, - cursor_position: Point, - ) -> f32 { - if cursor_position.x < 0.0 && cursor_position.y < 0.0 { - // cursor position is unavailable! Set to either end or beginning of scrollbar depending - // on where the thumb currently is in the track - (self.scroller.bounds.y / self.total_bounds.height).round() - } else { - (cursor_position.y - - self.bounds.y - - self.scroller.bounds.height * grabbed_at) - / (self.bounds.height - self.scroller.bounds.height) - } - } - - /// Returns the x-axis scrolled percentage from the cursor position. - fn scroll_percentage_x( - &self, - grabbed_at: f32, - cursor_position: Point, - ) -> f32 { - if cursor_position.x < 0.0 && cursor_position.y < 0.0 { - (self.scroller.bounds.x / self.total_bounds.width).round() - } else { - (cursor_position.x - - self.bounds.x - - self.scroller.bounds.width * grabbed_at) - / (self.bounds.width - self.scroller.bounds.width) - } - } -} - -/// The handle of a [`Scrollbar`]. -#[derive(Debug, Clone, Copy)] -struct Scroller { - /// The bounds of the [`Scroller`]. - bounds: Rectangle, -} |