1343 lines
41 KiB
Rust
1343 lines
41 KiB
Rust
//! Navigate an endless amount of content with a scrollbar.
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use crate::core::event::{self, Event};
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use crate::core::keyboard;
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use crate::core::layout;
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use crate::core::mouse;
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use crate::core::overlay;
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use crate::core::renderer;
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use crate::core::touch;
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use crate::core::widget;
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use crate::core::widget::operation::{self, Operation};
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use crate::core::widget::tree::{self, Tree};
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use crate::core::{
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Background, Clipboard, Color, Element, Layout, Length, Pixels, Point,
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Rectangle, Shell, Size, Vector, Widget,
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};
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use crate::runtime::Command;
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pub use crate::style::scrollable::{Scrollbar, Scroller, StyleSheet};
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pub use operation::scrollable::RelativeOffset;
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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 = crate::Renderer>
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where
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Renderer: crate::core::Renderer,
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Renderer::Theme: StyleSheet,
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{
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id: Option<Id>,
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width: Length,
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height: Length,
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vertical: Properties,
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horizontal: Option<Properties>,
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content: Element<'a, Message, Renderer>,
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on_scroll: Option<Box<dyn Fn(RelativeOffset) -> 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::core::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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width: Length::Shrink,
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height: Length::Shrink,
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vertical: Properties::default(),
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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 width of the [`Scrollable`].
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pub fn width(mut self, width: impl Into<Length>) -> Self {
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self.width = width.into();
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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: impl Into<Length>) -> Self {
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self.height = height.into();
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self
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}
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/// Configures the vertical scrollbar of the [`Scrollable`] .
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pub fn vertical_scroll(mut self, properties: Properties) -> Self {
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self.vertical = properties;
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self
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}
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/// Configures the horizontal scrollbar of the [`Scrollable`] .
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pub fn horizontal_scroll(mut self, properties: Properties) -> Self {
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self.horizontal = Some(properties);
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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(RelativeOffset) -> 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 scrollbar within a [`Scrollable`].
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#[derive(Debug)]
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pub struct Properties {
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width: f32,
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margin: f32,
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scroller_width: f32,
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}
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impl Default for Properties {
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fn default() -> Self {
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Self {
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width: 10.0,
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margin: 0.0,
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scroller_width: 10.0,
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}
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}
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}
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impl Properties {
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/// Creates new [`Properties`] 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 scrollbar width of the [`Scrollable`] .
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/// Silently enforces a minimum width of 1.
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pub fn width(mut self, width: impl Into<Pixels>) -> Self {
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self.width = width.into().0.max(1.0);
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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 margin(mut self, margin: impl Into<Pixels>) -> Self {
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self.margin = margin.into().0;
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self
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}
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/// Sets the scroller width of the [`Scrollable`] .
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/// Silently enforces a minimum width of 1.
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pub fn scroller_width(mut self, scroller_width: impl Into<Pixels>) -> Self {
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self.scroller_width = scroller_width.into().0.max(1.0);
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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::core::Renderer,
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Renderer::Theme: StyleSheet,
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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 width(&self) -> Length {
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self.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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self.width,
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self.height,
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self.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 operate(
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&self,
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tree: &mut Tree,
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layout: Layout<'_>,
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renderer: &Renderer,
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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(
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self.id.as_ref().map(|id| &id.0),
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&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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renderer,
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operation,
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);
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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.vertical,
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self.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 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.vertical,
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self.horizontal.as_ref(),
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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 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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&self.vertical,
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self.horizontal.as_ref(),
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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 mut 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_mut()
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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 = 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(-offset.x, -offset.y))
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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::core::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` along the x & y axis.
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pub fn snap_to<Message: 'static>(
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id: Id,
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offset: RelativeOffset,
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) -> Command<Message> {
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Command::widget(operation::scrollable::snap_to(id.0, offset))
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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.width(width).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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/// 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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vertical: &Properties,
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horizontal: Option<&Properties>,
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on_scroll: &Option<Box<dyn Fn(RelativeOffset) -> 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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let scrollbars =
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Scrollbars::new(state, vertical, horizontal, bounds, content_bounds);
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let (mouse_over_y_scrollbar, mouse_over_x_scrollbar) =
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scrollbars.is_mouse_over(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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cursor_position + state.offset(bounds, content_bounds)
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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)
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};
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update_content(
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event.clone(),
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content,
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cursor_position,
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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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if let event::Status::Captured = event_status {
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return event::Status::Captured;
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}
|
|
|
|
if let Event::Keyboard(keyboard::Event::ModifiersChanged(modifiers)) = event
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{
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state.keyboard_modifiers = modifiers;
|
|
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return event::Status::Ignored;
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}
|
|
|
|
if mouse_over_scrollable {
|
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match event {
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Event::Mouse(mouse::Event::WheelScrolled { delta }) => {
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let delta = match delta {
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mouse::ScrollDelta::Lines { x, y } => {
|
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// TODO: Configurable speed/friction (?)
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let movement = if state.keyboard_modifiers.shift() {
|
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Vector::new(y, x)
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|
} else {
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Vector::new(x, y)
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};
|
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|
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movement * 60.0
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}
|
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mouse::ScrollDelta::Pixels { x, y } => Vector::new(x, y),
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};
|
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|
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state.scroll(delta, bounds, content_bounds);
|
|
|
|
notify_on_scroll(
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state,
|
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on_scroll,
|
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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 =>
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{
|
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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);
|
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|
|
notify_on_scroll(
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|
state,
|
|
on_scroll,
|
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bounds,
|
|
content_bounds,
|
|
shell,
|
|
);
|
|
}
|
|
}
|
|
touch::Event::FingerLifted { .. }
|
|
| touch::Event::FingerLost { .. } => {
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|
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::core::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: Scrollbar,
|
|
scrollbar: &internals::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_scrollable {
|
|
theme.hovered(style, mouse_over_y_scrollbar)
|
|
} 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_scrollable {
|
|
theme.hovered_horizontal(style, mouse_over_x_scrollbar)
|
|
} 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: &mut 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);
|
|
|
|
let new_offset = RelativeOffset { x, y };
|
|
|
|
// Don't publish redundant offsets to shell
|
|
if let Some(prev_offset) = state.last_notified {
|
|
let unchanged = |a: f32, b: f32| {
|
|
(a - b).abs() <= f32::EPSILON || (a.is_nan() && b.is_nan())
|
|
};
|
|
|
|
if unchanged(prev_offset.x, new_offset.x)
|
|
&& unchanged(prev_offset.y, new_offset.y)
|
|
{
|
|
return;
|
|
}
|
|
}
|
|
|
|
shell.publish(on_scroll(new_offset));
|
|
state.last_notified = Some(new_offset);
|
|
}
|
|
}
|
|
|
|
/// 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,
|
|
last_notified: Option<RelativeOffset>,
|
|
}
|
|
|
|
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(),
|
|
last_notified: None,
|
|
}
|
|
}
|
|
}
|
|
|
|
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<internals::Scrollbar>,
|
|
x: Option<internals::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(internals::Scrollbar {
|
|
total_bounds: total_scrollbar_bounds,
|
|
bounds: scrollbar_bounds,
|
|
scroller: internals::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(internals::Scrollbar {
|
|
total_bounds: total_scrollbar_bounds,
|
|
bounds: scrollbar_bounds,
|
|
scroller: internals::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()
|
|
}
|
|
}
|
|
|
|
pub(super) mod internals {
|
|
use crate::core::{Point, Rectangle};
|
|
|
|
/// The scrollbar of a [`Scrollable`].
|
|
#[derive(Debug, Copy, Clone)]
|
|
pub struct Scrollbar {
|
|
/// The total bounds of the [`Scrollbar`], including the scrollbar, the scroller,
|
|
/// and the scrollbar margin.
|
|
pub total_bounds: Rectangle,
|
|
|
|
/// The bounds of just the [`Scrollbar`].
|
|
pub bounds: Rectangle,
|
|
|
|
/// The state of this scrollbar's [`Scroller`].
|
|
pub scroller: Scroller,
|
|
}
|
|
|
|
impl Scrollbar {
|
|
/// Returns whether the mouse is over the scrollbar or not.
|
|
pub 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.
|
|
pub 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.
|
|
pub 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)]
|
|
pub struct Scroller {
|
|
/// The bounds of the [`Scroller`].
|
|
pub bounds: Rectangle,
|
|
}
|
|
}
|