diff options
Diffstat (limited to 'native/src/widget/scrollable.rs')
| -rw-r--r-- | native/src/widget/scrollable.rs | 373 |
1 files changed, 266 insertions, 107 deletions
diff --git a/native/src/widget/scrollable.rs b/native/src/widget/scrollable.rs index 75e97027..68da2e67 100644 --- a/native/src/widget/scrollable.rs +++ b/native/src/widget/scrollable.rs @@ -1,7 +1,13 @@ //! Navigate an endless amount of content with a scrollbar. +use crate::column; +use crate::event::{self, Event}; +use crate::layout; +use crate::mouse; +use crate::overlay; +use crate::touch; use crate::{ - column, layout, mouse, overlay, Align, Clipboard, Column, Element, Event, - Hasher, Layout, Length, Point, Rectangle, Size, Vector, Widget, + Align, Clipboard, Column, Element, Hasher, Layout, Length, Padding, Point, + Rectangle, Size, Vector, Widget, }; use std::{f32, hash::Hash, u32}; @@ -13,21 +19,26 @@ pub struct Scrollable<'a, Message, Renderer: self::Renderer> { state: &'a mut State, height: Length, max_height: u32, + scrollbar_width: u16, + scrollbar_margin: u16, + scroller_width: u16, content: Column<'a, Message, Renderer>, + on_scroll: Option<Box<dyn Fn(f32) -> Message>>, style: Renderer::Style, } impl<'a, Message, Renderer: self::Renderer> Scrollable<'a, Message, Renderer> { /// Creates a new [`Scrollable`] with the given [`State`]. - /// - /// [`Scrollable`]: struct.Scrollable.html - /// [`State`]: struct.State.html pub fn new(state: &'a mut State) -> Self { Scrollable { state, height: Length::Shrink, max_height: u32::MAX, + scrollbar_width: 10, + scrollbar_margin: 0, + scroller_width: 10, content: Column::new(), + on_scroll: None, style: Renderer::Style::default(), } } @@ -42,65 +53,79 @@ impl<'a, Message, Renderer: self::Renderer> Scrollable<'a, Message, Renderer> { self } - /// Sets the padding of the [`Scrollable`]. - /// - /// [`Scrollable`]: struct.Scrollable.html - pub fn padding(mut self, units: u16) -> Self { - self.content = self.content.padding(units); + /// Sets the [`Padding`] of the [`Scrollable`]. + pub fn padding<P: Into<Padding>>(mut self, padding: P) -> Self { + self.content = self.content.padding(padding); self } /// Sets the width of the [`Scrollable`]. - /// - /// [`Scrollable`]: struct.Scrollable.html pub fn width(mut self, width: Length) -> Self { self.content = self.content.width(width); self } /// Sets the height of the [`Scrollable`]. - /// - /// [`Scrollable`]: struct.Scrollable.html pub fn height(mut self, height: Length) -> Self { self.height = height; self } /// Sets the maximum width of the [`Scrollable`]. - /// - /// [`Scrollable`]: struct.Scrollable.html pub fn max_width(mut self, max_width: u32) -> Self { self.content = self.content.max_width(max_width); self } /// Sets the maximum height of the [`Scrollable`] in pixels. - /// - /// [`Scrollable`]: struct.Scrollable.html pub fn max_height(mut self, max_height: u32) -> Self { self.max_height = max_height; self } /// Sets the horizontal alignment of the contents of the [`Scrollable`] . - /// - /// [`Scrollable`]: struct.Scrollable.html pub fn align_items(mut self, align_items: Align) -> Self { self.content = self.content.align_items(align_items); self } - /// Sets the style of the [`Scrollable`] . + /// Sets the scrollbar width of the [`Scrollable`] . + /// Silently enforces a minimum value of 1. + pub fn scrollbar_width(mut self, scrollbar_width: u16) -> Self { + self.scrollbar_width = scrollbar_width.max(1); + self + } + + /// Sets the scrollbar margin of the [`Scrollable`] . + pub fn scrollbar_margin(mut self, scrollbar_margin: u16) -> Self { + self.scrollbar_margin = scrollbar_margin; + self + } + + /// Sets the scroller width of the [`Scrollable`] . /// - /// [`Scrollable`]: struct.Scrollable.html + /// It silently enforces a minimum value of 1. + pub fn scroller_width(mut self, scroller_width: u16) -> Self { + self.scroller_width = scroller_width.max(1); + self + } + + /// Sets a function to call when the [`Scrollable`] is scrolled. + /// + /// The function takes the new relative offset of the [`Scrollable`] + /// (e.g. `0` means top, while `1` means bottom). + pub fn on_scroll(mut self, f: impl Fn(f32) -> Message + 'static) -> Self { + self.on_scroll = Some(Box::new(f)); + self + } + + /// Sets the style of the [`Scrollable`] . pub fn style(mut self, style: impl Into<Renderer::Style>) -> Self { self.style = style.into(); self } /// Adds an element to the [`Scrollable`]. - /// - /// [`Scrollable`]: struct.Scrollable.html pub fn push<E>(mut self, child: E) -> Self where E: Into<Element<'a, Message, Renderer>>, @@ -108,6 +133,24 @@ impl<'a, Message, Renderer: self::Renderer> Scrollable<'a, Message, Renderer> { self.content = self.content.push(child); self } + + fn notify_on_scroll( + &self, + bounds: Rectangle, + content_bounds: Rectangle, + messages: &mut Vec<Message>, + ) { + if content_bounds.height <= bounds.height { + return; + } + + if let Some(on_scroll) = &self.on_scroll { + messages.push(on_scroll( + self.state.offset.absolute(bounds, content_bounds) + / (content_bounds.height - bounds.height), + )); + } + } } impl<'a, Message, Renderer> Widget<Message, Renderer> @@ -149,17 +192,59 @@ where event: Event, layout: Layout<'_>, cursor_position: Point, - messages: &mut Vec<Message>, renderer: &Renderer, - clipboard: Option<&dyn Clipboard>, - ) { + clipboard: &mut dyn Clipboard, + messages: &mut Vec<Message>, + ) -> event::Status { let bounds = layout.bounds(); let is_mouse_over = bounds.contains(cursor_position); let content = layout.children().next().unwrap(); let content_bounds = content.bounds(); - // TODO: Event capture. Nested scrollables should capture scroll events. + let offset = self.state.offset(bounds, content_bounds); + let scrollbar = renderer.scrollbar( + bounds, + content_bounds, + offset, + self.scrollbar_width, + self.scrollbar_margin, + self.scroller_width, + ); + let is_mouse_over_scrollbar = scrollbar + .as_ref() + .map(|scrollbar| scrollbar.is_mouse_over(cursor_position)) + .unwrap_or(false); + + let event_status = { + let cursor_position = if is_mouse_over && !is_mouse_over_scrollbar { + Point::new( + cursor_position.x, + cursor_position.y + + self.state.offset(bounds, content_bounds) as f32, + ) + } else { + // TODO: Make `cursor_position` an `Option<Point>` so we can encode + // cursor availability. + // This will probably happen naturally once we add multi-window + // support. + Point::new(cursor_position.x, -1.0) + }; + + self.content.on_event( + event.clone(), + content, + cursor_position, + renderer, + clipboard, + messages, + ) + }; + + if let event::Status::Captured = event_status { + return event::Status::Captured; + } + if is_mouse_over { match event { Event::Mouse(mouse::Event::WheelScrolled { delta }) => { @@ -172,26 +257,65 @@ where self.state.scroll(y, bounds, content_bounds); } } + + self.notify_on_scroll(bounds, content_bounds, messages); + + return event::Status::Captured; + } + Event::Touch(event) => { + match event { + touch::Event::FingerPressed { .. } => { + self.state.scroll_box_touched_at = + Some(cursor_position); + } + touch::Event::FingerMoved { .. } => { + if let Some(scroll_box_touched_at) = + self.state.scroll_box_touched_at + { + let delta = + cursor_position.y - scroll_box_touched_at.y; + + self.state.scroll( + delta, + bounds, + content_bounds, + ); + + self.state.scroll_box_touched_at = + Some(cursor_position); + + self.notify_on_scroll( + bounds, + content_bounds, + messages, + ); + } + } + touch::Event::FingerLifted { .. } + | touch::Event::FingerLost { .. } => { + self.state.scroll_box_touched_at = None; + } + } + + return event::Status::Captured; } _ => {} } } - let offset = self.state.offset(bounds, content_bounds); - let scrollbar = renderer.scrollbar(bounds, content_bounds, offset); - let is_mouse_over_scrollbar = scrollbar - .as_ref() - .map(|scrollbar| scrollbar.is_mouse_over(cursor_position)) - .unwrap_or(false); - if self.state.is_scroller_grabbed() { match event { Event::Mouse(mouse::Event::ButtonReleased( mouse::Button::Left, - )) => { + )) + | Event::Touch(touch::Event::FingerLifted { .. }) + | Event::Touch(touch::Event::FingerLost { .. }) => { self.state.scroller_grabbed_at = None; + + return event::Status::Captured; } - Event::Mouse(mouse::Event::CursorMoved { .. }) => { + Event::Mouse(mouse::Event::CursorMoved { .. }) + | Event::Touch(touch::Event::FingerMoved { .. }) => { if let (Some(scrollbar), Some(scroller_grabbed_at)) = (scrollbar, self.state.scroller_grabbed_at) { @@ -203,6 +327,10 @@ where bounds, content_bounds, ); + + self.notify_on_scroll(bounds, content_bounds, messages); + + return event::Status::Captured; } } _ => {} @@ -211,7 +339,8 @@ where match event { Event::Mouse(mouse::Event::ButtonPressed( mouse::Button::Left, - )) => { + )) + | Event::Touch(touch::Event::FingerPressed { .. }) => { if let Some(scrollbar) = scrollbar { if let Some(scroller_grabbed_at) = scrollbar.grab_scroller(cursor_position) @@ -227,6 +356,14 @@ where self.state.scroller_grabbed_at = Some(scroller_grabbed_at); + + self.notify_on_scroll( + bounds, + content_bounds, + messages, + ); + + return event::Status::Captured; } } } @@ -234,28 +371,7 @@ where } } - let cursor_position = if is_mouse_over && !is_mouse_over_scrollbar { - Point::new( - cursor_position.x, - cursor_position.y - + self.state.offset(bounds, content_bounds) as f32, - ) - } else { - // TODO: Make `cursor_position` an `Option<Point>` so we can encode - // cursor availability. - // This will probably happen naturally once we add multi-window - // support. - Point::new(cursor_position.x, -1.0) - }; - - self.content.on_event( - event, - content, - cursor_position, - messages, - renderer, - clipboard, - ) + event::Status::Ignored } fn draw( @@ -264,12 +380,20 @@ where defaults: &Renderer::Defaults, layout: Layout<'_>, cursor_position: Point, + _viewport: &Rectangle, ) -> Renderer::Output { let bounds = layout.bounds(); let content_layout = layout.children().next().unwrap(); let content_bounds = content_layout.bounds(); let offset = self.state.offset(bounds, content_bounds); - let scrollbar = renderer.scrollbar(bounds, content_bounds, offset); + let scrollbar = renderer.scrollbar( + bounds, + content_bounds, + offset, + self.scrollbar_width, + self.scrollbar_margin, + self.scroller_width, + ); let is_mouse_over = bounds.contains(cursor_position); let is_mouse_over_scrollbar = scrollbar @@ -289,6 +413,10 @@ where defaults, content_layout, cursor_position, + &Rectangle { + y: bounds.y + offset as f32, + ..bounds + }, ) }; @@ -336,27 +464,54 @@ where } /// The local state of a [`Scrollable`]. -/// -/// [`Scrollable`]: struct.Scrollable.html -#[derive(Debug, Clone, Copy, Default)] +#[derive(Debug, Clone, Copy)] pub struct State { scroller_grabbed_at: Option<f32>, - offset: f32, + scroll_box_touched_at: Option<Point>, + offset: Offset, +} + +impl Default for State { + fn default() -> Self { + Self { + scroller_grabbed_at: None, + scroll_box_touched_at: None, + offset: Offset::Absolute(0.0), + } + } +} + +/// The local state of a [`Scrollable`]. +#[derive(Debug, Clone, Copy)] +enum Offset { + Absolute(f32), + Relative(f32), +} + +impl Offset { + fn absolute(self, bounds: Rectangle, content_bounds: Rectangle) -> f32 { + match self { + Self::Absolute(absolute) => { + let hidden_content = + (content_bounds.height - bounds.height).max(0.0); + + absolute.min(hidden_content) + } + Self::Relative(percentage) => { + ((content_bounds.height - bounds.height) * percentage).max(0.0) + } + } + } } impl State { /// Creates a new [`State`] with the scrollbar located at the top. - /// - /// [`State`]: struct.State.html pub fn new() -> Self { State::default() } /// Apply a scrolling offset to the current [`State`], given the bounds of /// the [`Scrollable`] and its contents. - /// - /// [`Scrollable`]: struct.Scrollable.html - /// [`State`]: struct.State.html pub fn scroll( &mut self, delta_y: f32, @@ -367,70 +522,83 @@ impl State { return; } - self.offset = (self.offset - delta_y) - .max(0.0) - .min((content_bounds.height - bounds.height) as f32); + self.offset = Offset::Absolute( + (self.offset.absolute(bounds, content_bounds) - delta_y) + .max(0.0) + .min((content_bounds.height - bounds.height) as f32), + ); } - /// Moves the scroll position to a relative amount, given the bounds of - /// the [`Scrollable`] and its contents. + /// Scrolls the [`Scrollable`] to a relative amount. /// /// `0` represents scrollbar at the top, while `1` represents scrollbar at /// the bottom. - /// - /// [`Scrollable`]: struct.Scrollable.html - /// [`State`]: struct.State.html pub fn scroll_to( &mut self, percentage: f32, bounds: Rectangle, content_bounds: Rectangle, ) { + self.snap_to(percentage); + self.unsnap(bounds, content_bounds); + } + + /// Snaps the scroll position to a relative amount. + /// + /// `0` represents scrollbar at the top, while `1` represents scrollbar at + /// the bottom. + 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 = - ((content_bounds.height - bounds.height) * percentage).max(0.0); + Offset::Absolute(self.offset.absolute(bounds, content_bounds)); } /// Returns the current scrolling offset of the [`State`], given the bounds /// of the [`Scrollable`] and its contents. - /// - /// [`Scrollable`]: struct.Scrollable.html - /// [`State`]: struct.State.html pub fn offset(&self, bounds: Rectangle, content_bounds: Rectangle) -> u32 { - let hidden_content = - (content_bounds.height - bounds.height).max(0.0).round() as u32; - - self.offset.min(hidden_content as f32) as u32 + self.offset.absolute(bounds, content_bounds) as u32 } /// Returns whether the scroller is currently grabbed or not. pub fn is_scroller_grabbed(&self) -> bool { self.scroller_grabbed_at.is_some() } + + /// Returns whether the scroll box is currently touched or not. + pub fn is_scroll_box_touched(&self) -> bool { + self.scroll_box_touched_at.is_some() + } } /// The scrollbar of a [`Scrollable`]. -/// -/// [`Scrollable`]: struct.Scrollable.html #[derive(Debug)] pub struct Scrollbar { + /// The outer bounds of the scrollable, including the [`Scrollbar`] and + /// [`Scroller`]. + pub outer_bounds: Rectangle, + /// The bounds of the [`Scrollbar`]. - /// - /// [`Scrollbar`]: struct.Scrollbar.html pub bounds: Rectangle, + /// The margin within the [`Scrollbar`]. + pub margin: u16, + /// The bounds of the [`Scroller`]. - /// - /// [`Scroller`]: struct.Scroller.html pub scroller: Scroller, } impl Scrollbar { fn is_mouse_over(&self, cursor_position: Point) -> bool { - self.bounds.contains(cursor_position) + self.outer_bounds.contains(cursor_position) } fn grab_scroller(&self, cursor_position: Point) -> Option<f32> { - if self.bounds.contains(cursor_position) { + if self.outer_bounds.contains(cursor_position) { Some(if self.scroller.bounds.contains(cursor_position) { (cursor_position.y - self.scroller.bounds.y) / self.scroller.bounds.height @@ -455,13 +623,9 @@ impl Scrollbar { } /// The handle of a [`Scrollbar`]. -/// -/// [`Scrollbar`]: struct.Scrollbar.html #[derive(Debug, Clone, Copy)] pub struct Scroller { /// The bounds of the [`Scroller`]. - /// - /// [`Scroller`]: struct.Scrollbar.html pub bounds: Rectangle, } @@ -470,22 +634,21 @@ pub struct Scroller { /// Your [renderer] will need to implement this trait before being /// able to use a [`Scrollable`] in your user interface. /// -/// [`Scrollable`]: struct.Scrollable.html -/// [renderer]: ../../renderer/index.html +/// [renderer]: crate::renderer pub trait Renderer: column::Renderer + Sized { /// The style supported by this renderer. type Style: Default; /// Returns the [`Scrollbar`] given the bounds and content bounds of a /// [`Scrollable`]. - /// - /// [`Scrollbar`]: struct.Scrollbar.html - /// [`Scrollable`]: struct.Scrollable.html fn scrollbar( &self, bounds: Rectangle, content_bounds: Rectangle, offset: u32, + scrollbar_width: u16, + scrollbar_margin: u16, + scroller_width: u16, ) -> Option<Scrollbar>; /// Draws the [`Scrollable`]. @@ -499,10 +662,6 @@ pub trait Renderer: column::Renderer + Sized { /// - a optional [`Scrollbar`] to be rendered /// - the scrolling offset /// - the drawn content - /// - /// [`Scrollbar`]: struct.Scrollbar.html - /// [`Scrollable`]: struct.Scrollable.html - /// [`State`]: struct.State.html fn draw( &mut self, scrollable: &State, |