iced-yoda/widget/src/button.rs
2026-01-21 14:12:38 -05:00

992 lines
28 KiB
Rust

//! Buttons allow your users to perform actions by pressing them.
//!
//! # Example
//! ```no_run
//! # mod iced { pub mod widget { pub use iced_widget::*; } }
//! # pub type State = ();
//! # pub type Element<'a, Message> = iced_widget::core::Element<'a, Message, iced_widget::Theme, iced_widget::Renderer>;
//! use iced::widget::button;
//!
//! #[derive(Clone)]
//! enum Message {
//! ButtonPressed,
//! }
//!
//! fn view(state: &State) -> Element<'_, Message> {
//! button("Press me!").on_press(Message::ButtonPressed).into()
//! }
//! ```
//! Allow your users to perform actions by pressing a button.
use iced_runtime::core::border::Radius;
use iced_runtime::core::widget::Id;
use iced_runtime::{Task, keyboard, task};
#[cfg(feature = "a11y")]
use std::borrow::Cow;
use crate::core::border::{self, Border};
use crate::core::layout;
use crate::core::mouse;
use crate::core::overlay;
use crate::core::renderer;
use crate::core::theme::palette;
use crate::core::touch;
use crate::core::widget::Operation;
use crate::core::widget::tree::{self, Tree};
use crate::core::window;
use crate::core::{
Background, Clipboard, Color, Element, Event, Layout, Length, Padding,
Rectangle, Shadow, Shell, Size, Theme, Vector, Widget,
};
use iced_renderer::core::widget::operation;
/// A generic widget that produces a message when pressed.
///
/// # Example
/// ```no_run
/// # mod iced { pub mod widget { pub use iced_widget::*; } }
/// # pub type State = ();
/// # pub type Element<'a, Message> = iced_widget::core::Element<'a, Message, iced_widget::Theme, iced_widget::Renderer>;
/// use iced::widget::button;
///
/// #[derive(Clone)]
/// enum Message {
/// ButtonPressed,
/// }
///
/// fn view(state: &State) -> Element<'_, Message> {
/// button("Press me!").on_press(Message::ButtonPressed).into()
/// }
/// ```
///
/// If a [`Button::on_press`] handler is not set, the resulting [`Button`] will
/// be disabled:
///
/// ```no_run
/// # mod iced { pub mod widget { pub use iced_widget::*; } }
/// # pub type State = ();
/// # pub type Element<'a, Message> = iced_widget::core::Element<'a, Message, iced_widget::Theme, iced_widget::Renderer>;
/// use iced::widget::button;
///
/// #[derive(Clone)]
/// enum Message {
/// ButtonPressed,
/// }
///
/// fn view(state: &State) -> Element<'_, Message> {
/// button("I am disabled!").into()
/// }
/// ```
pub struct Button<'a, Message, Theme = crate::Theme, Renderer = crate::Renderer>
where
Renderer: crate::core::Renderer,
Theme: Catalog,
{
content: Element<'a, Message, Theme, Renderer>,
on_press: Option<OnPress<'a, Message>>,
id: Id,
#[cfg(feature = "a11y")]
name: Option<Cow<'a, str>>,
#[cfg(feature = "a11y")]
description: Option<iced_accessibility::Description<'a>>,
#[cfg(feature = "a11y")]
label: Option<Vec<iced_accessibility::accesskit::NodeId>>,
width: Length,
height: Length,
padding: Padding,
clip: bool,
class: Theme::Class<'a>,
status: Option<Status>,
}
enum OnPress<'a, Message> {
Direct(Message),
Closure(Box<dyn Fn() -> Message + 'a>),
}
impl<Message: Clone> OnPress<'_, Message> {
fn get(&self) -> Message {
match self {
OnPress::Direct(message) => message.clone(),
OnPress::Closure(f) => f(),
}
}
}
impl<'a, Message, Theme, Renderer> Button<'a, Message, Theme, Renderer>
where
Renderer: crate::core::Renderer,
Theme: Catalog,
{
/// Creates a new [`Button`] with the given content.
pub fn new(
content: impl Into<Element<'a, Message, Theme, Renderer>>,
) -> Self {
let content = content.into();
let size = content.as_widget().size_hint();
Button {
content,
id: Id::unique(),
#[cfg(feature = "a11y")]
name: None,
#[cfg(feature = "a11y")]
description: None,
#[cfg(feature = "a11y")]
label: None,
on_press: None,
width: size.width.fluid(),
height: size.height.fluid(),
padding: DEFAULT_PADDING,
clip: false,
class: Theme::default(),
status: None,
}
}
/// Sets the width of the [`Button`].
pub fn width(mut self, width: impl Into<Length>) -> Self {
self.width = width.into();
self
}
/// Sets the height of the [`Button`].
pub fn height(mut self, height: impl Into<Length>) -> Self {
self.height = height.into();
self
}
/// Sets the [`Padding`] of the [`Button`].
pub fn padding<P: Into<Padding>>(mut self, padding: P) -> Self {
self.padding = padding.into();
self
}
/// Sets the message that will be produced when the [`Button`] is pressed.
///
/// Unless `on_press` is called, the [`Button`] will be disabled.
pub fn on_press(mut self, on_press: Message) -> Self {
self.on_press = Some(OnPress::Direct(on_press));
self
}
/// Sets the message that will be produced when the [`Button`] is pressed.
///
/// This is analogous to [`Button::on_press`], but using a closure to produce
/// the message.
///
/// This closure will only be called when the [`Button`] is actually pressed and,
/// therefore, this method is useful to reduce overhead if creating the resulting
/// message is slow.
pub fn on_press_with(
mut self,
on_press: impl Fn() -> Message + 'a,
) -> Self {
self.on_press = Some(OnPress::Closure(Box::new(on_press)));
self
}
/// Sets the message that will be produced when the [`Button`] is pressed,
/// if `Some`.
///
/// If `None`, the [`Button`] will be disabled.
pub fn on_press_maybe(mut self, on_press: Option<Message>) -> Self {
self.on_press = on_press.map(OnPress::Direct);
self
}
/// Sets whether the contents of the [`Button`] should be clipped on
/// overflow.
pub fn clip(mut self, clip: bool) -> Self {
self.clip = clip;
self
}
/// Sets the style of the [`Button`].
#[must_use]
pub fn style(mut self, style: impl Fn(&Theme, Status) -> Style + 'a) -> Self
where
Theme::Class<'a>: From<StyleFn<'a, Theme>>,
{
self.class = (Box::new(style) as StyleFn<'a, Theme>).into();
self
}
/// Sets the style class of the [`Button`].
#[cfg(feature = "advanced")]
#[must_use]
pub fn class(mut self, class: impl Into<Theme::Class<'a>>) -> Self {
self.class = class.into();
self
}
/// Sets the [`Id`] of the [`Button`].
pub fn id(mut self, id: Id) -> Self {
self.id = id;
self
}
#[cfg(feature = "a11y")]
/// Sets the name of the [`Button`].
pub fn name(mut self, name: impl Into<Cow<'a, str>>) -> Self {
self.name = Some(name.into());
self
}
#[cfg(feature = "a11y")]
/// Sets the description of the [`Button`].
pub fn description_widget<T: iced_accessibility::Describes>(
mut self,
description: &T,
) -> Self {
self.description = Some(iced_accessibility::Description::Id(
description.description(),
));
self
}
#[cfg(feature = "a11y")]
/// Sets the description of the [`Button`].
pub fn description(mut self, description: impl Into<Cow<'a, str>>) -> Self {
self.description =
Some(iced_accessibility::Description::Text(description.into()));
self
}
#[cfg(feature = "a11y")]
/// Sets the label of the [`Button`].
pub fn label(mut self, label: &dyn iced_accessibility::Labels) -> Self {
self.label =
Some(label.label().into_iter().map(|l| l.into()).collect());
self
}
}
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
struct State {
is_hovered: bool,
is_pressed: bool,
is_focused: bool,
}
impl<'a, Message, Theme, Renderer> Widget<Message, Theme, Renderer>
for Button<'a, Message, Theme, Renderer>
where
Message: 'a + Clone,
Renderer: 'a + crate::core::Renderer,
Theme: Catalog,
{
fn tag(&self) -> tree::Tag {
tree::Tag::of::<State>()
}
fn state(&self) -> tree::State {
tree::State::new(State::default())
}
fn children(&self) -> Vec<Tree> {
vec![Tree::new(&self.content)]
}
fn diff(&mut self, tree: &mut Tree) {
tree.diff_children(std::slice::from_mut(&mut self.content));
}
fn size(&self) -> Size<Length> {
Size {
width: self.width,
height: self.height,
}
}
fn layout(
&mut self,
tree: &mut Tree,
renderer: &Renderer,
limits: &layout::Limits,
) -> layout::Node {
layout::padded(
limits,
self.width,
self.height,
self.padding,
|limits| {
self.content.as_widget_mut().layout(
&mut tree.children[0],
renderer,
limits,
)
},
)
}
fn operate(
&mut self,
tree: &mut Tree,
layout: Layout<'_>,
renderer: &Renderer,
operation: &mut dyn Operation,
) {
operation.container(None, layout.bounds());
operation.traverse(&mut |operation| {
self.content.as_widget_mut().operate(
&mut tree.children[0],
layout.children().next().unwrap(),
renderer,
operation,
);
});
}
fn update(
&mut self,
tree: &mut Tree,
event: &Event,
layout: Layout<'_>,
cursor: mouse::Cursor,
renderer: &Renderer,
clipboard: &mut dyn Clipboard,
shell: &mut Shell<'_, Message>,
viewport: &Rectangle,
) {
self.content.as_widget_mut().update(
&mut tree.children[0],
event,
layout.children().next().unwrap(),
cursor,
renderer,
clipboard,
shell,
viewport,
);
if shell.is_event_captured() {
return;
}
match event {
Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left))
| Event::Touch(touch::Event::FingerPressed { .. }) => {
if self.on_press.is_some() {
let bounds = layout.bounds();
if cursor.is_over(bounds) {
let state = tree.state.downcast_mut::<State>();
state.is_pressed = true;
shell.capture_event();
}
}
}
Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Left))
| Event::Touch(touch::Event::FingerLifted { .. }) => {
if let Some(on_press) = &self.on_press {
let state = tree.state.downcast_mut::<State>();
if state.is_pressed {
state.is_pressed = false;
let bounds = layout.bounds();
if cursor.is_over(bounds) {
shell.publish(on_press.get());
}
shell.capture_event();
}
}
}
#[cfg(feature = "a11y")]
Event::A11y(
event_id,
iced_accessibility::accesskit::ActionRequest { action, .. },
) => {
let state = tree.state.downcast_mut::<State>();
if let Some(Some(on_press)) = (self.id == *event_id
&& matches!(
action,
iced_accessibility::accesskit::Action::Click
))
.then(|| self.on_press.as_ref())
{
state.is_pressed = false;
shell.publish(on_press.get());
}
return;
}
Event::Keyboard(keyboard::Event::KeyPressed { key, .. }) => {
if let Some(on_press) = self.on_press.as_ref() {
let state = tree.state.downcast_mut::<State>();
if state.is_focused
&& matches!(
key,
keyboard::Key::Named(keyboard::key::Named::Enter)
)
{
state.is_pressed = true;
shell.publish(on_press.get());
shell.capture_event();
return;
}
}
}
Event::Touch(touch::Event::FingerLost { .. })
| Event::Mouse(mouse::Event::CursorLeft) => {
let state = tree.state.downcast_mut::<State>();
state.is_hovered = false;
state.is_pressed = false;
}
_ => {}
}
let current_status = if self.on_press.is_none() {
Status::Disabled
} else if cursor.is_over(layout.bounds()) {
let state = tree.state.downcast_ref::<State>();
if state.is_pressed {
Status::Pressed
} else {
Status::Hovered
}
} else {
Status::Active
};
if let Event::Window(window::Event::RedrawRequested(_now)) = event {
self.status = Some(current_status);
} else if self.status.is_some_and(|status| status != current_status) {
shell.request_redraw();
}
}
fn draw(
&self,
tree: &Tree,
renderer: &mut Renderer,
theme: &Theme,
renderer_style: &renderer::Style,
layout: Layout<'_>,
cursor: mouse::Cursor,
viewport: &Rectangle,
) {
let bounds = layout.bounds();
let content_layout = layout.children().next().unwrap();
let style =
theme.style(&self.class, self.status.unwrap_or(Status::Disabled));
if style.background.is_some()
|| style.border.width > 0.0
|| style.shadow.color.a > 0.0
{
renderer.fill_quad(
renderer::Quad {
bounds,
border: style.border,
shadow: style.shadow,
snap: style.snap,
},
style
.background
.unwrap_or(Background::Color(Color::TRANSPARENT)),
);
}
let viewport = if self.clip {
bounds.intersection(viewport).unwrap_or(*viewport)
} else {
*viewport
};
self.content.as_widget().draw(
&tree.children[0],
renderer,
theme,
&renderer::Style {
text_color: style.text_color,
icon_color: style
.icon_color
.unwrap_or(renderer_style.icon_color),
scale_factor: renderer_style.scale_factor,
},
content_layout,
cursor,
&viewport,
);
}
fn mouse_interaction(
&self,
_tree: &Tree,
layout: Layout<'_>,
cursor: mouse::Cursor,
_viewport: &Rectangle,
_renderer: &Renderer,
) -> mouse::Interaction {
let is_mouse_over = cursor.is_over(layout.bounds());
if is_mouse_over && self.on_press.is_some() {
mouse::Interaction::Pointer
} else {
mouse::Interaction::default()
}
}
fn overlay<'b>(
&'b mut self,
tree: &'b mut Tree,
layout: Layout<'b>,
renderer: &Renderer,
viewport: &Rectangle,
translation: Vector,
) -> Option<overlay::Element<'b, Message, Theme, Renderer>> {
self.content.as_widget_mut().overlay(
&mut tree.children[0],
layout.children().next().unwrap(),
renderer,
viewport,
translation,
)
}
#[cfg(feature = "a11y")]
/// get the a11y nodes for the widget
fn a11y_nodes(
&self,
layout: Layout<'_>,
state: &Tree,
p: mouse::Cursor,
) -> iced_accessibility::A11yTree {
use iced_accessibility::{
A11yNode, A11yTree,
accesskit::{Action, Node, NodeId, Rect, Role},
};
let child_layout = layout.children().next().unwrap();
let child_tree = &state.children[0];
let child_tree =
self.content
.as_widget()
.a11y_nodes(child_layout, child_tree, p);
let Rectangle {
x,
y,
width,
height,
} = layout.bounds();
let bounds = Rect::new(
x as f64,
y as f64,
(x + width) as f64,
(y + height) as f64,
);
let is_hovered = state.state.downcast_ref::<State>().is_hovered;
let mut node = Node::new(Role::Button);
node.add_action(Action::Focus);
node.add_action(Action::Click);
node.set_bounds(bounds);
if let Some(name) = self.name.as_ref()
&& self.label.as_ref().is_none_or(|l| l.is_empty())
{
node.set_label(name.clone());
}
match self.description.as_ref() {
Some(iced_accessibility::Description::Id(id)) => {
node.set_described_by(
id.iter()
.cloned()
.map(|id| NodeId::from(id))
.collect::<Vec<_>>(),
);
}
Some(iced_accessibility::Description::Text(text)) => {
node.set_description(text.clone());
}
None => {}
}
if let Some(label) = self.label.as_ref() {
node.set_labelled_by(label.clone());
}
if self.on_press.is_none() {
node.set_disabled()
}
// TODO hover
// if is_hovered {
// node.set_busy()
// }
A11yTree::node_with_child_tree(
A11yNode::new(node, self.id.clone()),
child_tree,
)
}
fn id(&self) -> Option<Id> {
Some(self.id.clone())
}
fn set_id(&mut self, id: Id) {
self.id = id;
}
}
impl<'a, Message, Theme, Renderer> From<Button<'a, Message, Theme, Renderer>>
for Element<'a, Message, Theme, Renderer>
where
Message: Clone + 'a,
Theme: Catalog + 'a,
Renderer: crate::core::Renderer + 'a,
{
fn from(button: Button<'a, Message, Theme, Renderer>) -> Self {
Self::new(button)
}
}
/// The default [`Padding`] of a [`Button`].
pub const DEFAULT_PADDING: Padding = Padding {
top: 5.0,
bottom: 5.0,
right: 10.0,
left: 10.0,
};
/// The possible status of a [`Button`].
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Status {
/// The [`Button`] can be pressed.
Active,
/// The [`Button`] can be pressed and it is being hovered.
Hovered,
/// The [`Button`] is being pressed.
Pressed,
/// The [`Button`] cannot be pressed.
Disabled,
}
/// The style of a button.
///
/// If not specified with [`Button::style`]
/// the theme will provide the style.
#[derive(Debug, Clone, Copy, PartialEq)]
pub struct Style {
/// The [`Background`] of the button.
pub background: Option<Background>,
/// The border radius of the button.
pub border_radius: Radius,
/// The border width of the button.
pub border_width: f32,
/// The border [`Color`] of the button.
pub border_color: Color,
/// The icon [`Color`] of the button.
pub icon_color: Option<Color>,
/// The text [`Color`] of the button.
pub text_color: Color,
/// The [`Border`] of the button.
pub border: Border,
/// The [`Shadow`] of the button.
pub shadow: Shadow,
/// Whether the button should be snapped to the pixel grid.
pub snap: bool,
}
impl Style {
/// Updates the [`Style`] with the given [`Background`].
pub fn with_background(self, background: impl Into<Background>) -> Self {
Self {
background: Some(background.into()),
..self
}
}
// /// Returns whether the [`Button`] is currently focused or not.
// pub fn is_focused(&self) -> bool {
// self.is_focused
// }
// /// Returns whether the [`Button`] is currently hovered or not.
// pub fn is_hovered(&self) -> bool {
// self.is_hovered
// }
// /// Focuses the [`Button`].
// pub fn focus(&mut self) {
// self.is_focused = true;
// }
// /// Unfocuses the [`Button`].
// pub fn unfocus(&mut self) {
// self.is_focused = false;
// }
}
impl Default for Style {
fn default() -> Self {
Self {
background: None,
border_radius: 0.0.into(),
border_width: 0.0,
border_color: Color::TRANSPARENT,
icon_color: None,
text_color: Color::BLACK,
border: Border::default(),
shadow: Shadow::default(),
snap: cfg!(feature = "crisp"),
}
}
}
/// The theme catalog of a [`Button`].
///
/// All themes that can be used with [`Button`]
/// must implement this trait.
///
/// # Example
/// ```no_run
/// # use iced_widget::core::{Color, Background};
/// # use iced_widget::button::{Catalog, Status, Style};
/// # struct MyTheme;
/// #[derive(Debug, Default)]
/// pub enum ButtonClass {
/// #[default]
/// Primary,
/// Secondary,
/// Danger
/// }
///
/// impl Catalog for MyTheme {
/// type Class<'a> = ButtonClass;
///
/// fn default<'a>() -> Self::Class<'a> {
/// ButtonClass::default()
/// }
///
///
/// fn style(&self, class: &Self::Class<'_>, status: Status) -> Style {
/// let mut style = Style::default();
///
/// match class {
/// ButtonClass::Primary => {
/// style.background = Some(Background::Color(Color::from_rgb(0.529, 0.808, 0.921)));
/// },
/// ButtonClass::Secondary => {
/// style.background = Some(Background::Color(Color::WHITE));
/// },
/// ButtonClass::Danger => {
/// style.background = Some(Background::Color(Color::from_rgb(0.941, 0.502, 0.502)));
/// },
/// }
///
/// style
/// }
/// }
/// ```
///
/// Although, in order to use [`Button::style`]
/// with `MyTheme`, [`Catalog::Class`] must implement
/// `From<StyleFn<'_, MyTheme>>`.
pub trait Catalog {
/// The item class of the [`Catalog`].
type Class<'a>;
/// The default class produced by the [`Catalog`].
fn default<'a>() -> Self::Class<'a>;
/// The [`Style`] of a class with the given status.
fn style(&self, class: &Self::Class<'_>, status: Status) -> Style;
}
/// A styling function for a [`Button`].
pub type StyleFn<'a, Theme> = Box<dyn Fn(&Theme, Status) -> Style + 'a>;
impl Catalog for Theme {
type Class<'a> = StyleFn<'a, Self>;
fn default<'a>() -> Self::Class<'a> {
Box::new(primary)
}
fn style(&self, class: &Self::Class<'_>, status: Status) -> Style {
class(self, status)
}
}
/// A primary button; denoting a main action.
pub fn primary(theme: &Theme, status: Status) -> Style {
let palette = theme.extended_palette();
let base = styled(palette.primary.base);
match status {
Status::Active | Status::Pressed => base,
Status::Hovered => Style {
background: Some(Background::Color(palette.primary.strong.color)),
..base
},
Status::Disabled => disabled(base),
}
}
/// A secondary button; denoting a complementary action.
pub fn secondary(theme: &Theme, status: Status) -> Style {
let palette = theme.extended_palette();
let base = styled(palette.secondary.base);
match status {
Status::Active | Status::Pressed => base,
Status::Hovered => Style {
background: Some(Background::Color(palette.secondary.strong.color)),
..base
},
Status::Disabled => disabled(base),
}
}
/// A success button; denoting a good outcome.
pub fn success(theme: &Theme, status: Status) -> Style {
let palette = theme.extended_palette();
let base = styled(palette.success.base);
match status {
Status::Active | Status::Pressed => base,
Status::Hovered => Style {
background: Some(Background::Color(palette.success.strong.color)),
..base
},
Status::Disabled => disabled(base),
}
}
/// A warning button; denoting a risky action.
pub fn warning(theme: &Theme, status: Status) -> Style {
let palette = theme.extended_palette();
let base = styled(palette.warning.base);
match status {
Status::Active | Status::Pressed => base,
Status::Hovered => Style {
background: Some(Background::Color(palette.warning.strong.color)),
..base
},
Status::Disabled => disabled(base),
}
}
/// A danger button; denoting a destructive action.
pub fn danger(theme: &Theme, status: Status) -> Style {
let palette = theme.extended_palette();
let base = styled(palette.danger.base);
match status {
Status::Active | Status::Pressed => base,
Status::Hovered => Style {
background: Some(Background::Color(palette.danger.strong.color)),
..base
},
Status::Disabled => disabled(base),
}
}
/// A text button; useful for links.
pub fn text(theme: &Theme, status: Status) -> Style {
let palette = theme.extended_palette();
let base = Style {
text_color: palette.background.base.text,
..Style::default()
};
match status {
Status::Active | Status::Pressed => base,
Status::Hovered => Style {
text_color: palette.background.base.text.scale_alpha(0.8),
..base
},
Status::Disabled => disabled(base),
}
}
/// A button using background shades.
pub fn background(theme: &Theme, status: Status) -> Style {
let palette = theme.extended_palette();
let base = styled(palette.background.base);
match status {
Status::Active => base,
Status::Pressed => Style {
background: Some(Background::Color(
palette.background.strong.color,
)),
..base
},
Status::Hovered => Style {
background: Some(Background::Color(palette.background.weak.color)),
..base
},
Status::Disabled => disabled(base),
}
}
/// A subtle button using weak background shades.
pub fn subtle(theme: &Theme, status: Status) -> Style {
let palette = theme.extended_palette();
let base = styled(palette.background.weakest);
match status {
Status::Active => base,
Status::Pressed => Style {
background: Some(Background::Color(
palette.background.strong.color,
)),
..base
},
Status::Hovered => Style {
background: Some(Background::Color(
palette.background.weaker.color,
)),
..base
},
Status::Disabled => disabled(base),
}
}
fn styled(pair: palette::Pair) -> Style {
Style {
background: Some(Background::Color(pair.color)),
text_color: pair.text,
border: border::rounded(2),
..Style::default()
}
}
fn disabled(style: Style) -> Style {
Style {
background: style
.background
.map(|background| background.scale_alpha(0.5)),
text_color: style.text_color.scale_alpha(0.5),
..style
}
}
/// Produces a [`Task`] that focuses the [`Button`] with the given [`Id`].
pub fn focus<Message: 'static + Send>(id: Id) -> Task<Message> {
task::widget(operation::focusable::focus(id))
}
impl operation::Focusable for State {
fn is_focused(&self) -> bool {
self.is_focused
}
fn focus(&mut self) {
self.is_focused = true;
}
fn unfocus(&mut self) {
self.is_focused = false;
}
}