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Diffstat (limited to 'widget/src/tooltip.rs')
| -rw-r--r-- | widget/src/tooltip.rs | 446 |
1 files changed, 446 insertions, 0 deletions
diff --git a/widget/src/tooltip.rs b/widget/src/tooltip.rs new file mode 100644 index 00000000..2dc3da01 --- /dev/null +++ b/widget/src/tooltip.rs @@ -0,0 +1,446 @@ +//! Display a widget over another. +use crate::container; +use crate::core::event::{self, Event}; +use crate::core::layout::{self, Layout}; +use crate::core::mouse; +use crate::core::overlay; +use crate::core::renderer; +use crate::core::text; +use crate::core::widget::{self, Widget}; +use crate::core::{ + Clipboard, Element, Length, Padding, Pixels, Point, Rectangle, Shell, Size, + Vector, +}; +use crate::Text; + +use std::borrow::Cow; + +/// An element to display a widget over another. +#[allow(missing_debug_implementations)] +pub struct Tooltip<'a, Message, Renderer = crate::Renderer> +where + Renderer: text::Renderer, + Renderer::Theme: container::StyleSheet + crate::text::StyleSheet, +{ + content: Element<'a, Message, Renderer>, + tooltip: Text<'a, Renderer>, + position: Position, + gap: f32, + padding: f32, + snap_within_viewport: bool, + style: <Renderer::Theme as container::StyleSheet>::Style, +} + +impl<'a, Message, Renderer> Tooltip<'a, Message, Renderer> +where + Renderer: text::Renderer, + Renderer::Theme: container::StyleSheet + crate::text::StyleSheet, +{ + /// The default padding of a [`Tooltip`] drawn by this renderer. + const DEFAULT_PADDING: f32 = 5.0; + + /// Creates a new [`Tooltip`]. + /// + /// [`Tooltip`]: struct.Tooltip.html + pub fn new( + content: impl Into<Element<'a, Message, Renderer>>, + tooltip: impl Into<Cow<'a, str>>, + position: Position, + ) -> Self { + Tooltip { + content: content.into(), + tooltip: Text::new(tooltip), + position, + gap: 0.0, + padding: Self::DEFAULT_PADDING, + snap_within_viewport: true, + style: Default::default(), + } + } + + /// Sets the size of the text of the [`Tooltip`]. + pub fn size(mut self, size: impl Into<Pixels>) -> Self { + self.tooltip = self.tooltip.size(size); + self + } + + /// Sets the font of the [`Tooltip`]. + /// + /// [`Font`]: Renderer::Font + pub fn font(mut self, font: impl Into<Renderer::Font>) -> Self { + self.tooltip = self.tooltip.font(font); + self + } + + /// Sets the gap between the content and its [`Tooltip`]. + pub fn gap(mut self, gap: impl Into<Pixels>) -> Self { + self.gap = gap.into().0; + self + } + + /// Sets the padding of the [`Tooltip`]. + pub fn padding(mut self, padding: impl Into<Pixels>) -> Self { + self.padding = padding.into().0; + self + } + + /// Sets whether the [`Tooltip`] is snapped within the viewport. + pub fn snap_within_viewport(mut self, snap: bool) -> Self { + self.snap_within_viewport = snap; + self + } + + /// Sets the style of the [`Tooltip`]. + pub fn style( + mut self, + style: impl Into<<Renderer::Theme as container::StyleSheet>::Style>, + ) -> Self { + self.style = style.into(); + self + } +} + +impl<'a, Message, Renderer> Widget<Message, Renderer> + for Tooltip<'a, Message, Renderer> +where + Renderer: text::Renderer, + Renderer::Theme: container::StyleSheet + crate::text::StyleSheet, +{ + fn children(&self) -> Vec<widget::Tree> { + vec![widget::Tree::new(&self.content)] + } + + fn diff(&self, tree: &mut widget::Tree) { + tree.diff_children(std::slice::from_ref(&self.content)) + } + + fn state(&self) -> widget::tree::State { + widget::tree::State::new(State::default()) + } + + fn tag(&self) -> widget::tree::Tag { + widget::tree::Tag::of::<State>() + } + + fn width(&self) -> Length { + self.content.as_widget().width() + } + + fn height(&self) -> Length { + self.content.as_widget().height() + } + + fn layout( + &self, + renderer: &Renderer, + limits: &layout::Limits, + ) -> layout::Node { + self.content.as_widget().layout(renderer, limits) + } + + fn on_event( + &mut self, + tree: &mut widget::Tree, + event: Event, + layout: Layout<'_>, + cursor: mouse::Cursor, + renderer: &Renderer, + clipboard: &mut dyn Clipboard, + shell: &mut Shell<'_, Message>, + ) -> event::Status { + let state = tree.state.downcast_mut::<State>(); + + *state = cursor + .position_over(layout.bounds()) + .map(|cursor_position| State::Hovered { cursor_position }) + .unwrap_or_default(); + + self.content.as_widget_mut().on_event( + &mut tree.children[0], + event, + layout, + cursor, + renderer, + clipboard, + shell, + ) + } + + fn mouse_interaction( + &self, + tree: &widget::Tree, + layout: Layout<'_>, + cursor: mouse::Cursor, + viewport: &Rectangle, + renderer: &Renderer, + ) -> mouse::Interaction { + self.content.as_widget().mouse_interaction( + &tree.children[0], + layout, + cursor, + viewport, + renderer, + ) + } + + fn draw( + &self, + tree: &widget::Tree, + renderer: &mut Renderer, + theme: &Renderer::Theme, + inherited_style: &renderer::Style, + layout: Layout<'_>, + cursor: mouse::Cursor, + viewport: &Rectangle, + ) { + self.content.as_widget().draw( + &tree.children[0], + renderer, + theme, + inherited_style, + layout, + cursor, + viewport, + ); + } + + fn overlay<'b>( + &'b mut self, + tree: &'b mut widget::Tree, + layout: Layout<'_>, + renderer: &Renderer, + ) -> Option<overlay::Element<'b, Message, Renderer>> { + let state = tree.state.downcast_ref::<State>(); + + let content = self.content.as_widget_mut().overlay( + &mut tree.children[0], + layout, + renderer, + ); + + let tooltip = if let State::Hovered { cursor_position } = *state { + Some(overlay::Element::new( + layout.position(), + Box::new(Overlay { + tooltip: &self.tooltip, + cursor_position, + content_bounds: layout.bounds(), + snap_within_viewport: self.snap_within_viewport, + position: self.position, + gap: self.gap, + padding: self.padding, + style: &self.style, + }), + )) + } else { + None + }; + + if content.is_some() || tooltip.is_some() { + Some( + overlay::Group::with_children( + content.into_iter().chain(tooltip).collect(), + ) + .overlay(), + ) + } else { + None + } + } +} + +impl<'a, Message, Renderer> From<Tooltip<'a, Message, Renderer>> + for Element<'a, Message, Renderer> +where + Message: 'a, + Renderer: 'a + text::Renderer, + Renderer::Theme: container::StyleSheet + crate::text::StyleSheet, +{ + fn from( + tooltip: Tooltip<'a, Message, Renderer>, + ) -> Element<'a, Message, Renderer> { + Element::new(tooltip) + } +} + +/// The position of the tooltip. Defaults to following the cursor. +#[derive(Debug, Clone, Copy, PartialEq, Eq)] +pub enum Position { + /// The tooltip will follow the cursor. + FollowCursor, + /// The tooltip will appear on the top of the widget. + Top, + /// The tooltip will appear on the bottom of the widget. + Bottom, + /// The tooltip will appear on the left of the widget. + Left, + /// The tooltip will appear on the right of the widget. + Right, +} + +#[derive(Debug, Clone, Copy, Default)] +enum State { + #[default] + Idle, + Hovered { + cursor_position: Point, + }, +} + +struct Overlay<'a, 'b, Renderer> +where + Renderer: text::Renderer, + Renderer::Theme: container::StyleSheet + widget::text::StyleSheet, +{ + tooltip: &'b Text<'a, Renderer>, + cursor_position: Point, + content_bounds: Rectangle, + snap_within_viewport: bool, + position: Position, + gap: f32, + padding: f32, + style: &'b <Renderer::Theme as container::StyleSheet>::Style, +} + +impl<'a, 'b, Message, Renderer> overlay::Overlay<Message, Renderer> + for Overlay<'a, 'b, Renderer> +where + Renderer: text::Renderer, + Renderer::Theme: container::StyleSheet + widget::text::StyleSheet, +{ + fn layout( + &self, + renderer: &Renderer, + bounds: Size, + _position: Point, + ) -> layout::Node { + let viewport = Rectangle::with_size(bounds); + + let text_layout = Widget::<(), Renderer>::layout( + self.tooltip, + renderer, + &layout::Limits::new( + Size::ZERO, + self.snap_within_viewport + .then(|| viewport.size()) + .unwrap_or(Size::INFINITY), + ) + .pad(Padding::new(self.padding)), + ); + + let text_bounds = text_layout.bounds(); + let x_center = self.content_bounds.x + + (self.content_bounds.width - text_bounds.width) / 2.0; + let y_center = self.content_bounds.y + + (self.content_bounds.height - text_bounds.height) / 2.0; + + let mut tooltip_bounds = { + let offset = match self.position { + Position::Top => Vector::new( + x_center, + self.content_bounds.y + - text_bounds.height + - self.gap + - self.padding, + ), + Position::Bottom => Vector::new( + x_center, + self.content_bounds.y + + self.content_bounds.height + + self.gap + + self.padding, + ), + Position::Left => Vector::new( + self.content_bounds.x + - text_bounds.width + - self.gap + - self.padding, + y_center, + ), + Position::Right => Vector::new( + self.content_bounds.x + + self.content_bounds.width + + self.gap + + self.padding, + y_center, + ), + Position::FollowCursor => Vector::new( + self.cursor_position.x, + self.cursor_position.y - text_bounds.height, + ), + }; + + Rectangle { + x: offset.x - self.padding, + y: offset.y - self.padding, + width: text_bounds.width + self.padding * 2.0, + height: text_bounds.height + self.padding * 2.0, + } + }; + + if self.snap_within_viewport { + if tooltip_bounds.x < viewport.x { + tooltip_bounds.x = viewport.x; + } else if viewport.x + viewport.width + < tooltip_bounds.x + tooltip_bounds.width + { + tooltip_bounds.x = + viewport.x + viewport.width - tooltip_bounds.width; + } + + if tooltip_bounds.y < viewport.y { + tooltip_bounds.y = viewport.y; + } else if viewport.y + viewport.height + < tooltip_bounds.y + tooltip_bounds.height + { + tooltip_bounds.y = + viewport.y + viewport.height - tooltip_bounds.height; + } + } + + layout::Node::with_children( + tooltip_bounds.size(), + vec![text_layout.translate(Vector::new(self.padding, self.padding))], + ) + .translate(Vector::new(tooltip_bounds.x, tooltip_bounds.y)) + } + + fn draw( + &self, + renderer: &mut Renderer, + theme: &<Renderer as renderer::Renderer>::Theme, + inherited_style: &renderer::Style, + layout: Layout<'_>, + cursor_position: mouse::Cursor, + ) { + let style = <Renderer::Theme as container::StyleSheet>::appearance( + theme, self.style, + ); + + container::draw_background(renderer, &style, layout.bounds()); + + let defaults = renderer::Style { + text_color: style.text_color.unwrap_or(inherited_style.text_color), + }; + + Widget::<(), Renderer>::draw( + self.tooltip, + &widget::Tree::empty(), + renderer, + theme, + &defaults, + layout.children().next().unwrap(), + cursor_position, + &Rectangle::with_size(Size::INFINITY), + ); + } + + fn is_over( + &self, + _layout: Layout<'_>, + _renderer: &Renderer, + _cursor_position: Point, + ) -> bool { + false + } +} |