1375 lines
43 KiB
Rust
1375 lines
43 KiB
Rust
//! Navigate an endless amount of content with a scrollbar.
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use crate::event::{self, Event};
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use crate::layout;
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use crate::mouse;
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use crate::overlay;
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use crate::renderer;
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use crate::touch;
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use crate::widget;
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use crate::widget::operation::{self, Operation};
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use crate::widget::tree::{self, Tree};
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use crate::{
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Background, Clipboard, Color, Command, Element, Layout, Length, Point,
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Rectangle, Shell, Size, Vector, Widget,
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};
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pub use iced_style::scrollable::StyleSheet;
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pub mod style {
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//! The styles of a [`Scrollable`].
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//!
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//! [`Scrollable`]: crate::widget::Scrollable
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pub use iced_style::scrollable::{Scrollbar, Scroller};
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}
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/// A widget that can vertically display an infinite amount of content with a
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/// scrollbar.
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#[allow(missing_debug_implementations)]
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pub struct Scrollable<'a, Message, Renderer>
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where
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Renderer: crate::Renderer,
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Renderer::Theme: StyleSheet,
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{
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id: Option<Id>,
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height: Length,
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scrollbar_width: u16,
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scrollbar_margin: u16,
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scroller_width: u16,
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scroll_horizontal: Option<Horizontal>,
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content: Element<'a, Message, Renderer>,
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on_scroll: Option<Box<dyn Fn(Vector<f32>) -> Message + 'a>>,
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style: <Renderer::Theme as StyleSheet>::Style,
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}
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impl<'a, Message, Renderer> Scrollable<'a, Message, Renderer>
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where
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Renderer: crate::Renderer,
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Renderer::Theme: StyleSheet,
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{
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/// Creates a new [`Scrollable`].
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pub fn new(content: impl Into<Element<'a, Message, Renderer>>) -> Self {
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Scrollable {
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id: None,
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height: Length::Shrink,
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scrollbar_width: 10,
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scrollbar_margin: 0,
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scroller_width: 10,
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scroll_horizontal: None,
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content: content.into(),
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on_scroll: None,
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style: Default::default(),
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}
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}
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/// Sets the [`Id`] of the [`Scrollable`].
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pub fn id(mut self, id: Id) -> Self {
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self.id = Some(id);
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self
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}
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/// Sets the height of the [`Scrollable`].
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pub fn height(mut self, height: Length) -> Self {
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self.height = height;
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self
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}
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/// Sets the scrollbar width of the [`Scrollable`] .
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/// Silently enforces a minimum width of 1.
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pub fn scrollbar_width(mut self, scrollbar_width: u16) -> Self {
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self.scrollbar_width = scrollbar_width.max(1);
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self
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}
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/// Sets the scrollbar margin of the [`Scrollable`] .
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pub fn scrollbar_margin(mut self, scrollbar_margin: u16) -> Self {
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self.scrollbar_margin = scrollbar_margin;
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self
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}
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/// Sets the scroller width of the [`Scrollable`] .
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///
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/// It silently enforces a minimum width of 1.
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pub fn scroller_width(mut self, scroller_width: u16) -> Self {
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self.scroller_width = scroller_width.max(1);
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self
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}
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/// Allow scrolling in a horizontal direction within the [`Scrollable`] .
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pub fn horizontal_scroll(mut self, horizontal: Horizontal) -> Self {
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self.scroll_horizontal = Some(horizontal);
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self
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}
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/// Sets a function to call when the [`Scrollable`] is scrolled.
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///
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/// The function takes the new relative x & y offset of the [`Scrollable`]
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/// (e.g. `0` means beginning, while `1` means end).
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pub fn on_scroll(
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mut self,
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f: impl Fn(Vector<f32>) -> Message + 'a,
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) -> Self {
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self.on_scroll = Some(Box::new(f));
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self
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}
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/// Sets the style of the [`Scrollable`] .
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pub fn style(
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mut self,
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style: impl Into<<Renderer::Theme as StyleSheet>::Style>,
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) -> Self {
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self.style = style.into();
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self
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}
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}
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/// Properties of a horizontal scrollbar within a [`Scrollable`].
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#[derive(Debug)]
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pub struct Horizontal {
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scrollbar_height: u16,
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scrollbar_margin: u16,
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scroller_height: u16,
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}
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impl Default for Horizontal {
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fn default() -> Self {
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Self {
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scrollbar_height: 10,
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scrollbar_margin: 0,
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scroller_height: 10,
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}
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}
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}
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impl Horizontal {
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/// Creates a new [`Horizontal`] for use in a [`Scrollable`].
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pub fn new() -> Self {
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Self::default()
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}
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/// Sets the [`Horizontal`] scrollbar height of the [`Scrollable`] .
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/// Silently enforces a minimum height of 1.
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pub fn scrollbar_height(mut self, scrollbar_height: u16) -> Self {
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self.scrollbar_height = scrollbar_height.max(1);
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self
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}
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/// Sets the [`Horizontal`] scrollbar margin of the [`Scrollable`] .
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pub fn scrollbar_margin(mut self, scrollbar_margin: u16) -> Self {
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self.scrollbar_margin = scrollbar_margin;
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self
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}
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/// Sets the scroller height of the [`Horizontal`] scrollbar of the [`Scrollable`] .
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/// Silently enforces a minimum height of 1.
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pub fn scroller_height(mut self, scroller_height: u16) -> Self {
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self.scroller_height = scroller_height.max(1);
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self
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}
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}
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impl<'a, Message, Renderer> Widget<Message, Renderer>
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for Scrollable<'a, Message, Renderer>
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where
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Renderer: crate::Renderer,
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Renderer::Theme: StyleSheet,
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{
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fn width(&self) -> Length {
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self.content.as_widget().width()
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}
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fn height(&self) -> Length {
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self.height
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}
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fn layout(
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&self,
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renderer: &Renderer,
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limits: &layout::Limits,
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) -> layout::Node {
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layout(
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renderer,
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limits,
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Widget::<Message, Renderer>::width(self),
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self.height,
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self.scroll_horizontal.is_some(),
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|renderer, limits| {
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self.content.as_widget().layout(renderer, limits)
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},
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)
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}
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fn draw(
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&self,
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tree: &Tree,
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renderer: &mut Renderer,
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theme: &Renderer::Theme,
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style: &renderer::Style,
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layout: Layout<'_>,
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cursor_position: Point,
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_viewport: &Rectangle,
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) {
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draw(
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tree.state.downcast_ref::<State>(),
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renderer,
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theme,
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layout,
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cursor_position,
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&self.style,
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|renderer, layout, cursor_position, viewport| {
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self.content.as_widget().draw(
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&tree.children[0],
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renderer,
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theme,
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style,
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layout,
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cursor_position,
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viewport,
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)
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},
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)
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}
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fn tag(&self) -> tree::Tag {
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tree::Tag::of::<State>()
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}
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fn state(&self) -> tree::State {
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tree::State::new(State::new())
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}
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fn children(&self) -> Vec<Tree> {
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vec![Tree::new(&self.content)]
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}
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fn diff(&self, tree: &mut Tree) {
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tree.diff_children(std::slice::from_ref(&self.content))
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}
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fn operate(
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&self,
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tree: &mut Tree,
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layout: Layout<'_>,
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operation: &mut dyn Operation<Message>,
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) {
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let state = tree.state.downcast_mut::<State>();
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operation.scrollable(state, self.id.as_ref().map(|id| &id.0));
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operation.container(None, &mut |operation| {
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self.content.as_widget().operate(
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&mut tree.children[0],
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layout.children().next().unwrap(),
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operation,
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);
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});
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}
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fn on_event(
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&mut self,
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tree: &mut Tree,
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event: Event,
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layout: Layout<'_>,
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cursor_position: Point,
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renderer: &Renderer,
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clipboard: &mut dyn Clipboard,
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shell: &mut Shell<'_, Message>,
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) -> event::Status {
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update(
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tree.state.downcast_mut::<State>(),
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event,
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layout,
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cursor_position,
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clipboard,
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shell,
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self.scrollbar_width,
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self.scrollbar_margin,
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self.scroller_width,
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self.scroll_horizontal.as_ref(),
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&self.on_scroll,
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|event, layout, cursor_position, clipboard, shell| {
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self.content.as_widget_mut().on_event(
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&mut tree.children[0],
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event,
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layout,
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cursor_position,
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renderer,
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clipboard,
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shell,
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)
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},
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)
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}
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fn mouse_interaction(
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&self,
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tree: &Tree,
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layout: Layout<'_>,
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cursor_position: Point,
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_viewport: &Rectangle,
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renderer: &Renderer,
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) -> mouse::Interaction {
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mouse_interaction(
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tree.state.downcast_ref::<State>(),
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layout,
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cursor_position,
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|layout, cursor_position, viewport| {
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self.content.as_widget().mouse_interaction(
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&tree.children[0],
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layout,
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cursor_position,
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viewport,
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renderer,
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)
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},
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)
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}
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fn overlay<'b>(
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&'b self,
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tree: &'b mut Tree,
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layout: Layout<'_>,
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renderer: &Renderer,
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) -> Option<overlay::Element<'b, Message, Renderer>> {
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self.content
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.as_widget()
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.overlay(
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&mut tree.children[0],
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layout.children().next().unwrap(),
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renderer,
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)
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.map(|overlay| {
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let bounds = layout.bounds();
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let content_layout = layout.children().next().unwrap();
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let content_bounds = content_layout.bounds();
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let (offset_x, offset_y) = tree
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.state
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.downcast_ref::<State>()
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.offset(bounds, content_bounds);
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overlay.translate(Vector::new(
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-(offset_x as f32),
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-(offset_y as f32),
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))
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})
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}
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}
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impl<'a, Message, Renderer> From<Scrollable<'a, Message, Renderer>>
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for Element<'a, Message, Renderer>
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where
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Message: 'a,
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Renderer: 'a + crate::Renderer,
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Renderer::Theme: StyleSheet,
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{
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fn from(
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text_input: Scrollable<'a, Message, Renderer>,
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) -> Element<'a, Message, Renderer> {
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Element::new(text_input)
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}
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}
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/// The identifier of a [`Scrollable`].
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#[derive(Debug, Clone, PartialEq, Eq, Hash)]
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pub struct Id(widget::Id);
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impl Id {
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/// Creates a custom [`Id`].
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pub fn new(id: impl Into<std::borrow::Cow<'static, str>>) -> Self {
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Self(widget::Id::new(id))
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}
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/// Creates a unique [`Id`].
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///
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/// This function produces a different [`Id`] every time it is called.
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pub fn unique() -> Self {
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Self(widget::Id::unique())
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}
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}
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impl From<Id> for widget::Id {
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fn from(id: Id) -> Self {
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id.0
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}
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}
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/// Produces a [`Command`] that snaps the [`Scrollable`] with the given [`Id`]
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/// to the provided `percentage`.
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pub fn snap_to<Message: 'static>(
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id: Id,
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percentage: Vector<f32>,
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) -> Command<Message> {
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Command::widget(operation::scrollable::snap_to(id.0, percentage))
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}
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/// Computes the layout of a [`Scrollable`].
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pub fn layout<Renderer>(
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renderer: &Renderer,
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limits: &layout::Limits,
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width: Length,
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height: Length,
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horizontal_enabled: bool,
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layout_content: impl FnOnce(&Renderer, &layout::Limits) -> layout::Node,
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) -> layout::Node {
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let limits = limits
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.max_height(u32::MAX)
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.max_width(if horizontal_enabled {
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u32::MAX
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} else {
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limits.max().width as u32
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})
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.width(width)
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.height(height);
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let child_limits = layout::Limits::new(
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Size::new(limits.min().width, 0.0),
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Size::new(
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if horizontal_enabled {
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f32::INFINITY
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} else {
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limits.max().width
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},
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f32::MAX,
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),
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);
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let content = layout_content(renderer, &child_limits);
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let size = limits.resolve(content.size());
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layout::Node::with_children(size, vec![content])
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}
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|
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/// Processes an [`Event`] and updates the [`State`] of a [`Scrollable`]
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/// accordingly.
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pub fn update<Message>(
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state: &mut State,
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event: Event,
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layout: Layout<'_>,
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cursor_position: Point,
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clipboard: &mut dyn Clipboard,
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shell: &mut Shell<'_, Message>,
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scrollbar_width: u16,
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scrollbar_margin: u16,
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scroller_width: u16,
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horizontal: Option<&Horizontal>,
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on_scroll: &Option<Box<dyn Fn(Vector<f32>) -> Message + '_>>,
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update_content: impl FnOnce(
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Event,
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Layout<'_>,
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Point,
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&mut dyn Clipboard,
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&mut Shell<'_, Message>,
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) -> event::Status,
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) -> event::Status {
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let bounds = layout.bounds();
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let mouse_over_scrollable = bounds.contains(cursor_position);
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let content = layout.children().next().unwrap();
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let content_bounds = content.bounds();
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state.create_scrollbars_maybe(
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horizontal,
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scrollbar_width,
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scrollbar_margin,
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scroller_width,
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bounds,
|
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content_bounds,
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);
|
|
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let (mouse_over_x_scrollbar, mouse_over_y_scrollbar) =
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state.mouse_over_scrollbars(cursor_position);
|
|
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let event_status = {
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let cursor_position = if mouse_over_scrollable
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&& !(mouse_over_y_scrollbar || mouse_over_x_scrollbar)
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{
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let (offset_x, offset_y) = state.offset(bounds, content_bounds);
|
|
|
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Point::new(
|
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cursor_position.x + offset_x as f32,
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cursor_position.y + offset_y as f32,
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)
|
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} else {
|
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// TODO: Make `cursor_position` an `Option<Point>` so we can encode
|
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// cursor availability.
|
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// This will probably happen naturally once we add multi-window
|
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// support.
|
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Point::new(-1.0, -1.0)
|
|
};
|
|
|
|
update_content(
|
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event.clone(),
|
|
content,
|
|
cursor_position,
|
|
clipboard,
|
|
shell,
|
|
)
|
|
};
|
|
|
|
if let event::Status::Captured = event_status {
|
|
return event::Status::Captured;
|
|
}
|
|
|
|
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 (?)
|
|
Vector::new(x * 60.0, y * 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) => {
|
|
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 =
|
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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(scrollbar) = &mut state.scrollbar_y {
|
|
if let Some(scroller_grabbed_at) = scrollbar.scroller.grabbed_at {
|
|
match event {
|
|
Event::Mouse(mouse::Event::ButtonReleased(
|
|
mouse::Button::Left,
|
|
))
|
|
| Event::Touch(touch::Event::FingerLifted { .. })
|
|
| Event::Touch(touch::Event::FingerLost { .. }) => {
|
|
scrollbar.scroller.grabbed_at = None;
|
|
|
|
return event::Status::Captured;
|
|
}
|
|
Event::Mouse(mouse::Event::CursorMoved { .. })
|
|
| Event::Touch(touch::Event::FingerMoved { .. }) => {
|
|
scrollbar.scroll_to(
|
|
scrollbar.scroll_percentage(
|
|
scroller_grabbed_at,
|
|
cursor_position,
|
|
),
|
|
bounds,
|
|
content_bounds,
|
|
);
|
|
|
|
notify_on_scroll(
|
|
state,
|
|
on_scroll,
|
|
bounds,
|
|
content_bounds,
|
|
shell,
|
|
);
|
|
|
|
return event::Status::Captured;
|
|
}
|
|
_ => {}
|
|
}
|
|
} else if scrollbar.is_mouse_over(cursor_position) {
|
|
match event {
|
|
Event::Mouse(mouse::Event::ButtonPressed(
|
|
mouse::Button::Left,
|
|
))
|
|
| Event::Touch(touch::Event::FingerPressed { .. }) => {
|
|
if let Some(scroller_grabbed_at) =
|
|
scrollbar.grab_scroller(cursor_position)
|
|
{
|
|
scrollbar.scroll_to(
|
|
scrollbar.scroll_percentage(
|
|
scroller_grabbed_at,
|
|
cursor_position,
|
|
),
|
|
bounds,
|
|
content_bounds,
|
|
);
|
|
|
|
scrollbar.scroller.grabbed_at =
|
|
Some(scroller_grabbed_at);
|
|
|
|
notify_on_scroll(
|
|
state,
|
|
on_scroll,
|
|
bounds,
|
|
content_bounds,
|
|
shell,
|
|
);
|
|
}
|
|
|
|
return event::Status::Captured;
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
}
|
|
|
|
if let Some(scrollbar) = &mut state.scrollbar_x {
|
|
if let Some(scroller_grabbed_at) = scrollbar.scroller.grabbed_at {
|
|
match event {
|
|
Event::Mouse(mouse::Event::ButtonReleased(
|
|
mouse::Button::Left,
|
|
))
|
|
| Event::Touch(touch::Event::FingerLifted { .. })
|
|
| Event::Touch(touch::Event::FingerLost { .. }) => {
|
|
scrollbar.scroller.grabbed_at = None;
|
|
|
|
return event::Status::Captured;
|
|
}
|
|
Event::Mouse(mouse::Event::CursorMoved { .. })
|
|
| Event::Touch(touch::Event::FingerMoved { .. }) => {
|
|
scrollbar.scroll_to(
|
|
scrollbar.scroll_percentage(
|
|
scroller_grabbed_at,
|
|
cursor_position,
|
|
),
|
|
bounds,
|
|
content_bounds,
|
|
);
|
|
|
|
notify_on_scroll(
|
|
state,
|
|
on_scroll,
|
|
bounds,
|
|
content_bounds,
|
|
shell,
|
|
);
|
|
|
|
return event::Status::Captured;
|
|
}
|
|
_ => {}
|
|
}
|
|
} else if scrollbar.is_mouse_over(cursor_position) {
|
|
match event {
|
|
Event::Mouse(mouse::Event::ButtonPressed(
|
|
mouse::Button::Left,
|
|
))
|
|
| Event::Touch(touch::Event::FingerPressed { .. }) => {
|
|
if let Some(scroller_grabbed_at) =
|
|
scrollbar.grab_scroller(cursor_position)
|
|
{
|
|
scrollbar.scroll_to(
|
|
scrollbar.scroll_percentage(
|
|
scroller_grabbed_at,
|
|
cursor_position,
|
|
),
|
|
bounds,
|
|
content_bounds,
|
|
);
|
|
|
|
scrollbar.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,
|
|
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 (mouse_over_x_scrollbar, mouse_over_y_scrollbar) =
|
|
state.mouse_over_scrollbars(cursor_position);
|
|
|
|
if (mouse_over_x_scrollbar || mouse_over_y_scrollbar)
|
|
|| state.scrollers_grabbed()
|
|
{
|
|
mouse::Interaction::Idle
|
|
} else {
|
|
let (offset_x, offset_y) = state.offset(bounds, content_bounds);
|
|
|
|
let cursor_position = if mouse_over_scrollable
|
|
&& !(mouse_over_y_scrollbar || mouse_over_x_scrollbar)
|
|
{
|
|
Point::new(
|
|
cursor_position.x + offset_x as f32,
|
|
cursor_position.y + offset_y as f32,
|
|
)
|
|
} else {
|
|
Point::new(-1.0, -1.0)
|
|
};
|
|
|
|
content_interaction(
|
|
content_layout,
|
|
cursor_position,
|
|
&Rectangle {
|
|
y: bounds.y + offset_y as f32,
|
|
x: bounds.x + offset_x as f32,
|
|
..bounds
|
|
},
|
|
)
|
|
}
|
|
}
|
|
|
|
/// Draws a [`Scrollable`].
|
|
pub fn draw<Renderer>(
|
|
state: &State,
|
|
renderer: &mut Renderer,
|
|
theme: &Renderer::Theme,
|
|
layout: Layout<'_>,
|
|
cursor_position: Point,
|
|
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 (offset_x, offset_y) = state.offset(bounds, content_bounds);
|
|
|
|
let mouse_over_scrollable = bounds.contains(cursor_position);
|
|
|
|
let (mouse_over_x_scrollbar, mouse_over_y_scrollbar) =
|
|
state.mouse_over_scrollbars(cursor_position);
|
|
|
|
let cursor_position = if mouse_over_scrollable
|
|
&& !(mouse_over_x_scrollbar || mouse_over_y_scrollbar)
|
|
{
|
|
Point::new(
|
|
cursor_position.x + offset_x as f32,
|
|
cursor_position.y + offset_y as f32,
|
|
)
|
|
} else {
|
|
Point::new(-1.0, -1.0)
|
|
};
|
|
|
|
// Draw inner content
|
|
if state.scrollbar_y.is_some() || state.scrollbar_x.is_some() {
|
|
renderer.with_layer(bounds, |renderer| {
|
|
renderer.with_translation(
|
|
Vector::new(-(offset_x as f32), -(offset_y as f32)),
|
|
|renderer| {
|
|
draw_content(
|
|
renderer,
|
|
content_layout,
|
|
cursor_position,
|
|
&Rectangle {
|
|
y: bounds.y + offset_y as f32,
|
|
x: bounds.x + offset_x as f32,
|
|
..bounds
|
|
},
|
|
);
|
|
},
|
|
);
|
|
});
|
|
|
|
let draw_scrollbar =
|
|
|renderer: &mut Renderer, scrollbar: Option<&Scrollbar>| {
|
|
if let Some(scrollbar) = scrollbar {
|
|
let style = match scrollbar.direction {
|
|
Direction::Vertical => {
|
|
if scrollbar.scroller.grabbed_at.is_some() {
|
|
theme.dragging(style)
|
|
} else if mouse_over_y_scrollbar {
|
|
theme.hovered(style)
|
|
} else {
|
|
theme.active(style)
|
|
}
|
|
}
|
|
Direction::Horizontal => {
|
|
if scrollbar.scroller.grabbed_at.is_some() {
|
|
theme.dragging_horizontal(style)
|
|
} else if mouse_over_x_scrollbar {
|
|
theme.hovered_horizontal(style)
|
|
} else {
|
|
theme.active_horizontal(style)
|
|
}
|
|
}
|
|
};
|
|
|
|
//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,
|
|
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,
|
|
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_scrollbar(renderer, state.scrollbar_y.as_ref());
|
|
draw_scrollbar(renderer, state.scrollbar_x.as_ref());
|
|
},
|
|
);
|
|
} else {
|
|
draw_content(
|
|
renderer,
|
|
content_layout,
|
|
cursor_position,
|
|
&Rectangle {
|
|
x: bounds.x + offset_x as f32,
|
|
y: bounds.y + offset_y as f32,
|
|
..bounds
|
|
},
|
|
);
|
|
}
|
|
}
|
|
|
|
fn notify_on_scroll<Message>(
|
|
state: &State,
|
|
on_scroll: &Option<Box<dyn Fn(Vector<f32>) -> Message + '_>>,
|
|
bounds: Rectangle,
|
|
content_bounds: Rectangle,
|
|
shell: &mut Shell<'_, Message>,
|
|
) {
|
|
if let Some(on_scroll) = on_scroll {
|
|
let delta_x = if content_bounds.width <= bounds.width {
|
|
0.0
|
|
} else {
|
|
state.scrollbar_x.map_or(0.0, |scrollbar| {
|
|
scrollbar.offset.absolute(
|
|
Direction::Horizontal,
|
|
bounds,
|
|
content_bounds,
|
|
) / (content_bounds.width - bounds.width)
|
|
})
|
|
};
|
|
|
|
let delta_y = if content_bounds.height <= bounds.height {
|
|
0.0
|
|
} else {
|
|
state.scrollbar_y.map_or(0.0, |scrollbar| {
|
|
scrollbar.offset.absolute(
|
|
Direction::Vertical,
|
|
bounds,
|
|
content_bounds,
|
|
) / (content_bounds.height - bounds.height)
|
|
})
|
|
};
|
|
|
|
shell.publish(on_scroll(Vector::new(delta_x, delta_y)))
|
|
}
|
|
}
|
|
|
|
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
|
|
/// The direction of the [`Scrollable`].
|
|
pub enum Direction {
|
|
/// X or horizontal
|
|
Horizontal,
|
|
/// Y or vertical
|
|
Vertical,
|
|
}
|
|
|
|
/// The local state of a [`Scrollable`].
|
|
#[derive(Debug, Clone, Copy, Default)]
|
|
pub struct State {
|
|
scroll_area_touched_at: Option<Point>,
|
|
scrollbar_x: Option<Scrollbar>,
|
|
scrollbar_y: Option<Scrollbar>,
|
|
}
|
|
|
|
impl operation::Scrollable for State {
|
|
fn snap_to(&mut self, percentage: Vector<f32>) {
|
|
if let Some(scrollbar) = &mut self.scrollbar_y {
|
|
scrollbar.snap_to(percentage.y)
|
|
}
|
|
if let Some(scrollbar) = &mut self.scrollbar_x {
|
|
scrollbar.snap_to(percentage.x)
|
|
}
|
|
}
|
|
}
|
|
|
|
impl State {
|
|
/// Creates a new [`State`].
|
|
pub fn new() -> Self {
|
|
State::default()
|
|
}
|
|
|
|
/// Create y or x scrollbars if content is overflowing the [`Scrollable`] bounds.
|
|
pub fn create_scrollbars_maybe(
|
|
&mut self,
|
|
horizontal: Option<&Horizontal>,
|
|
scrollbar_width: u16,
|
|
scrollbar_margin: u16,
|
|
scroller_width: u16,
|
|
bounds: Rectangle,
|
|
content_bounds: Rectangle,
|
|
) {
|
|
let show_scrollbar_x = horizontal.and_then(|h| {
|
|
if content_bounds.width > bounds.width {
|
|
Some(h)
|
|
} else {
|
|
None
|
|
}
|
|
});
|
|
|
|
self.scrollbar_y = if content_bounds.height > bounds.height {
|
|
let (offset_y, scroller_grabbed) =
|
|
if let Some(scrollbar) = &self.scrollbar_y {
|
|
(
|
|
scrollbar.offset.absolute(
|
|
scrollbar.direction,
|
|
bounds,
|
|
content_bounds,
|
|
),
|
|
scrollbar.scroller.grabbed_at,
|
|
)
|
|
} else {
|
|
(0.0, None)
|
|
};
|
|
|
|
// Need to adjust the height of the vertical scrollbar if the horizontal scrollbar
|
|
// is present
|
|
let scrollbar_x_height = show_scrollbar_x.map_or(0.0, |h| {
|
|
(h.scrollbar_height.max(h.scroller_height) + h.scrollbar_margin)
|
|
as f32
|
|
});
|
|
|
|
let total_scrollbar_width =
|
|
scrollbar_width.max(scroller_width) + 2 * scrollbar_margin;
|
|
|
|
// Total bounds of the scrollbar + margin + scroller width
|
|
let total_scrollbar_bounds = Rectangle {
|
|
x: bounds.x + bounds.width - total_scrollbar_width as f32,
|
|
y: bounds.y,
|
|
width: total_scrollbar_width as f32,
|
|
height: (bounds.height - scrollbar_x_height).max(0.0),
|
|
};
|
|
|
|
// Bounds of just the scrollbar
|
|
let scrollbar_bounds = Rectangle {
|
|
x: bounds.x + bounds.width
|
|
- f32::from(
|
|
total_scrollbar_width / 2 + scrollbar_width / 2,
|
|
),
|
|
y: bounds.y,
|
|
width: scrollbar_width as f32,
|
|
height: (bounds.height - scrollbar_x_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 as f32 * ratio;
|
|
|
|
let scroller_bounds = Rectangle {
|
|
x: bounds.x + bounds.width
|
|
- f32::from(total_scrollbar_width / 2 + scroller_width / 2),
|
|
y: (scrollbar_bounds.y + scroller_offset - scrollbar_x_height)
|
|
.max(0.0),
|
|
width: scroller_width as f32,
|
|
height: scroller_height,
|
|
};
|
|
|
|
Some(Scrollbar {
|
|
total_bounds: total_scrollbar_bounds,
|
|
bounds: scrollbar_bounds,
|
|
direction: Direction::Vertical,
|
|
scroller: Scroller {
|
|
bounds: scroller_bounds,
|
|
grabbed_at: scroller_grabbed,
|
|
},
|
|
offset: Offset::Absolute(offset_y),
|
|
})
|
|
} else {
|
|
None
|
|
};
|
|
|
|
self.scrollbar_x = if let Some(horizontal) = show_scrollbar_x {
|
|
let (offset_x, scroller_grabbed) =
|
|
if let Some(scrollbar) = &self.scrollbar_x {
|
|
(
|
|
scrollbar.offset.absolute(
|
|
scrollbar.direction,
|
|
bounds,
|
|
content_bounds,
|
|
),
|
|
scrollbar.scroller.grabbed_at,
|
|
)
|
|
} else {
|
|
(0.0, None)
|
|
};
|
|
|
|
// Need to adjust the width of the horizontal scrollbar if the vertical scrollbar
|
|
// is present
|
|
let scrollbar_y_width = self.scrollbar_y.map_or(0.0, |_| {
|
|
(scrollbar_width.max(scroller_width) + scrollbar_margin) as f32
|
|
});
|
|
|
|
let total_scrollbar_height =
|
|
horizontal.scrollbar_height.max(horizontal.scroller_height)
|
|
+ 2 * horizontal.scrollbar_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 as f32,
|
|
width: (bounds.width - scrollbar_y_width).max(0.0),
|
|
height: total_scrollbar_height as f32,
|
|
};
|
|
|
|
// Bounds of just the scrollbar
|
|
let scrollbar_bounds = Rectangle {
|
|
x: bounds.x,
|
|
y: bounds.y + bounds.height
|
|
- f32::from(
|
|
total_scrollbar_height / 2
|
|
+ horizontal.scrollbar_height / 2,
|
|
),
|
|
width: (bounds.width - scrollbar_y_width).max(0.0),
|
|
height: horizontal.scrollbar_height as f32,
|
|
};
|
|
|
|
let ratio = bounds.width / content_bounds.width;
|
|
// min width for easier grabbing with extra wide content
|
|
let scroller_width = (bounds.width * ratio).max(2.0);
|
|
let scroller_offset = offset_x as f32 * ratio;
|
|
|
|
let scroller_bounds = Rectangle {
|
|
x: (scrollbar_bounds.x + scroller_offset - scrollbar_y_width)
|
|
.max(0.0),
|
|
y: bounds.y + bounds.height
|
|
- f32::from(
|
|
total_scrollbar_height / 2
|
|
+ horizontal.scroller_height / 2,
|
|
),
|
|
width: scroller_width,
|
|
height: horizontal.scroller_height as f32,
|
|
};
|
|
|
|
Some(Scrollbar {
|
|
total_bounds: total_scrollbar_bounds,
|
|
bounds: scrollbar_bounds,
|
|
direction: Direction::Horizontal,
|
|
scroller: Scroller {
|
|
bounds: scroller_bounds,
|
|
grabbed_at: scroller_grabbed,
|
|
},
|
|
offset: Offset::Absolute(offset_x),
|
|
})
|
|
} else {
|
|
None
|
|
};
|
|
}
|
|
|
|
/// Returns whether the mouse is within the bounds of each scrollbar.
|
|
fn mouse_over_scrollbars(&self, cursor_position: Point) -> (bool, bool) {
|
|
(
|
|
self.scrollbar_x.map_or(false, |scrollbar| {
|
|
scrollbar.is_mouse_over(cursor_position)
|
|
}),
|
|
self.scrollbar_y.map_or(false, |scrollbar| {
|
|
scrollbar.is_mouse_over(cursor_position)
|
|
}),
|
|
)
|
|
}
|
|
|
|
/// Returns whether the scroller for either scrollbar is currently grabbed.
|
|
fn scrollers_grabbed(&self) -> bool {
|
|
self.scrollbar_x
|
|
.map_or(false, |scrollbar| scrollbar.scroller.grabbed_at.is_some())
|
|
|| self.scrollbar_y.map_or(false, |scrollbar| {
|
|
scrollbar.scroller.grabbed_at.is_some()
|
|
})
|
|
}
|
|
|
|
/// 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 delta.x != 0.0 && bounds.width < content_bounds.width {
|
|
if let Some(scrollbar) = &mut self.scrollbar_x {
|
|
scrollbar.offset = Offset::Absolute(
|
|
(scrollbar.offset.absolute(
|
|
Direction::Horizontal,
|
|
bounds,
|
|
content_bounds,
|
|
) - delta.x)
|
|
.max(0.0)
|
|
.min((content_bounds.width - bounds.width) as f32),
|
|
);
|
|
}
|
|
}
|
|
|
|
if delta.y != 0.0 && bounds.height < content_bounds.height {
|
|
if let Some(scrollbar) = &mut self.scrollbar_y {
|
|
scrollbar.offset = Offset::Absolute(
|
|
(scrollbar.offset.absolute(
|
|
Direction::Vertical,
|
|
bounds,
|
|
content_bounds,
|
|
) - delta.y)
|
|
.max(0.0)
|
|
.min((content_bounds.height - bounds.height) as f32),
|
|
)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Returns the current x & y scrolling offset of the [`State`], given the bounds
|
|
/// of the [`Scrollable`] and its contents.
|
|
pub fn offset(
|
|
&self,
|
|
bounds: Rectangle,
|
|
content_bounds: Rectangle,
|
|
) -> (f32, f32) {
|
|
(
|
|
self.scrollbar_x.map_or(0.0, |scrollbar| {
|
|
scrollbar.offset.absolute(
|
|
Direction::Horizontal,
|
|
bounds,
|
|
content_bounds,
|
|
)
|
|
}),
|
|
self.scrollbar_y.map_or(0.0, |scrollbar| {
|
|
scrollbar.offset.absolute(
|
|
Direction::Vertical,
|
|
bounds,
|
|
content_bounds,
|
|
)
|
|
}),
|
|
)
|
|
}
|
|
}
|
|
|
|
/// 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 direction of the [`Scrollbar`].
|
|
direction: Direction,
|
|
|
|
/// The state of this scrollbar's [`Scroller`].
|
|
scroller: Scroller,
|
|
|
|
/// The current offset of the [`Scrollbar`].
|
|
offset: Offset,
|
|
}
|
|
|
|
impl Scrollbar {
|
|
/// Snaps the scroll position to a relative amount.
|
|
///
|
|
/// `0` represents scrollbar at the beginning, while `1` represents scrollbar at
|
|
/// the end.
|
|
pub fn snap_to(&mut self, percentage: f32) {
|
|
self.offset = Offset::Relative(percentage.max(0.0).min(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 = Offset::Absolute(self.offset.absolute(
|
|
self.direction,
|
|
bounds,
|
|
content_bounds,
|
|
));
|
|
}
|
|
|
|
/// Scrolls the [`Scrollbar`] to a certain percentage.
|
|
fn scroll_to(
|
|
&mut self,
|
|
percentage: f32,
|
|
bounds: Rectangle,
|
|
content_bounds: Rectangle,
|
|
) {
|
|
self.snap_to(percentage);
|
|
self.unsnap(bounds, content_bounds);
|
|
}
|
|
|
|
/// 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)
|
|
}
|
|
|
|
fn grab_scroller(&self, cursor_position: Point) -> Option<f32> {
|
|
if self.total_bounds.contains(cursor_position) {
|
|
Some(if self.scroller.bounds.contains(cursor_position) {
|
|
match self.direction {
|
|
Direction::Vertical => {
|
|
(cursor_position.y - self.scroller.bounds.y)
|
|
/ self.scroller.bounds.height
|
|
}
|
|
Direction::Horizontal => {
|
|
(cursor_position.x - self.scroller.bounds.x)
|
|
/ self.scroller.bounds.width
|
|
}
|
|
}
|
|
} else {
|
|
0.5
|
|
})
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
fn scroll_percentage(
|
|
&self,
|
|
grabbed_at: f32,
|
|
cursor_position: Point,
|
|
) -> f32 {
|
|
match self.direction {
|
|
Direction::Vertical => {
|
|
(cursor_position.y
|
|
- self.bounds.y
|
|
- self.scroller.bounds.height * grabbed_at)
|
|
/ (self.bounds.height - self.scroller.bounds.height)
|
|
}
|
|
Direction::Horizontal => {
|
|
(cursor_position.x
|
|
- self.bounds.x
|
|
- self.scroller.bounds.width * grabbed_at)
|
|
/ (self.bounds.width - self.scroller.bounds.width)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/// The directional offset of a [`Scrollable`].
|
|
#[derive(Debug, Clone, Copy)]
|
|
enum Offset {
|
|
Absolute(f32),
|
|
Relative(f32),
|
|
}
|
|
|
|
impl Offset {
|
|
fn absolute(
|
|
self,
|
|
direction: Direction,
|
|
bounds: Rectangle,
|
|
content_bounds: Rectangle,
|
|
) -> f32 {
|
|
match self {
|
|
Self::Absolute(absolute) => match direction {
|
|
Direction::Horizontal => {
|
|
absolute.min((content_bounds.width - bounds.width).max(0.0))
|
|
}
|
|
Direction::Vertical => absolute
|
|
.min((content_bounds.height - bounds.height).max(0.0)),
|
|
},
|
|
Self::Relative(percentage) => match direction {
|
|
Direction::Horizontal => {
|
|
((content_bounds.width - bounds.width) * percentage)
|
|
.max(0.0)
|
|
}
|
|
Direction::Vertical => {
|
|
((content_bounds.height - bounds.height) * percentage)
|
|
.max(0.0)
|
|
}
|
|
},
|
|
}
|
|
}
|
|
}
|
|
|
|
/// The handle of a [`Scrollbar`].
|
|
#[derive(Debug, Clone, Copy)]
|
|
struct Scroller {
|
|
/// The bounds of the [`Scroller`].
|
|
bounds: Rectangle,
|
|
|
|
/// Whether or not the scroller is currently grabbed.
|
|
grabbed_at: Option<f32>,
|
|
}
|