diff options
Diffstat (limited to 'native/src/widget/combo_box.rs')
| -rw-r--r-- | native/src/widget/combo_box.rs | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/native/src/widget/combo_box.rs b/native/src/widget/combo_box.rs new file mode 100644 index 00000000..0b25b836 --- /dev/null +++ b/native/src/widget/combo_box.rs @@ -0,0 +1,256 @@ +use crate::{ + layer::{self, menu}, + layout, mouse, scrollable, text, Clipboard, Element, Event, Hasher, Layout, + Length, Overlay, Point, Rectangle, Size, Vector, Widget, +}; +use std::borrow::Cow; + +pub struct ComboBox<'a, T, Message> +where + [T]: ToOwned<Owned = Vec<T>>, +{ + internal: Option<Internal<'a, T, Message>>, + options: Cow<'a, [T]>, + selected: Option<T>, + width: Length, + padding: u16, + text_size: Option<u16>, +} + +#[derive(Default)] +pub struct State { + menu: menu::State, +} + +pub struct Internal<'a, T, Message> { + menu: &'a mut menu::State, + on_selected: Box<dyn Fn(T) -> Message>, +} + +impl<'a, T: 'a, Message> ComboBox<'a, T, Message> +where + T: ToString, + [T]: ToOwned<Owned = Vec<T>>, +{ + pub fn new( + state: &'a mut State, + options: impl Into<Cow<'a, [T]>>, + selected: Option<T>, + on_selected: impl Fn(T) -> Message + 'static, + ) -> Self { + Self { + internal: Some(Internal { + menu: &mut state.menu, + on_selected: Box::new(on_selected), + }), + options: options.into(), + selected, + width: Length::Shrink, + text_size: None, + padding: 5, + } + } + + /// Sets the width of the [`ComboBox`]. + /// + /// [`ComboBox`]: struct.Button.html + pub fn width(mut self, width: Length) -> Self { + self.width = width; + self + } + + /// Sets the padding of the [`ComboBox`]. + /// + /// [`ComboBox`]: struct.Button.html + pub fn padding(mut self, padding: u16) -> Self { + self.padding = padding; + self + } + + pub fn text_size(mut self, size: u16) -> Self { + self.text_size = Some(size); + self + } +} + +impl<'a, T: 'a, Message, Renderer> Widget<'a, Message, Renderer> + for ComboBox<'a, T, Message> +where + T: Clone + ToString + Eq, + [T]: ToOwned<Owned = Vec<T>>, + Message: 'static, + Renderer: self::Renderer + scrollable::Renderer + 'a, +{ + fn width(&self) -> Length { + Length::Shrink + } + + fn height(&self) -> Length { + Length::Shrink + } + + fn layout( + &self, + renderer: &Renderer, + limits: &layout::Limits, + ) -> layout::Node { + use std::f32; + + let limits = limits + .width(self.width) + .height(Length::Shrink) + .pad(f32::from(self.padding)); + + let text_size = self.text_size.unwrap_or(renderer.default_size()); + + let max_width = match self.width { + Length::Shrink => { + let labels = self.options.iter().map(ToString::to_string); + + labels + .map(|label| { + let (width, _) = renderer.measure( + &label, + text_size, + Renderer::Font::default(), + Size::new(f32::INFINITY, f32::INFINITY), + ); + + width.round() as u32 + }) + .max() + .unwrap_or(100) + } + _ => 0, + }; + + let size = { + let intrinsic = Size::new( + max_width as f32 + f32::from(text_size), + f32::from(text_size), + ); + + limits.resolve(intrinsic).pad(f32::from(self.padding)) + }; + + layout::Node::new(size) + } + + fn hash_layout(&self, state: &mut Hasher) { + use std::hash::Hash as _; + + match self.width { + Length::Shrink => { + self.options + .iter() + .map(ToString::to_string) + .for_each(|label| label.hash(state)); + } + _ => { + self.width.hash(state); + } + } + } + + fn on_event( + &mut self, + event: Event, + layout: Layout<'_>, + cursor_position: Point, + _messages: &mut Vec<Message>, + _renderer: &Renderer, + _clipboard: Option<&dyn Clipboard>, + ) { + match event { + Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left)) => { + if let Some(internal) = &mut self.internal { + if layout.bounds().contains(cursor_position) { + let selected = self.selected.as_ref(); + + internal.menu.open( + self.options + .iter() + .position(|option| Some(option) == selected), + ); + } + } + } + _ => {} + } + } + + fn draw( + &self, + renderer: &mut Renderer, + _defaults: &Renderer::Defaults, + layout: Layout<'_>, + cursor_position: Point, + ) -> Renderer::Output { + self::Renderer::draw( + renderer, + layout.bounds(), + cursor_position, + self.selected.as_ref().map(ToString::to_string), + self.text_size.unwrap_or(renderer.default_size()), + self.padding, + ) + } + + fn overlay( + &mut self, + layout: Layout<'_>, + ) -> Option<Overlay<'a, Message, Renderer>> { + let is_open = self + .internal + .as_ref() + .map(|internal| internal.menu.is_open()) + .unwrap_or(false); + + if is_open { + if let Some(Internal { menu, on_selected }) = self.internal.take() { + Some(Overlay::new( + layout.position() + + Vector::new(0.0, layout.bounds().height), + Box::new(layer::Menu::new( + menu, + self.options.clone(), + on_selected, + layout.bounds().width.round() as u16, + self.text_size.unwrap_or(20), + self.padding, + )), + )) + } else { + None + } + } else { + None + } + } +} + +pub trait Renderer: text::Renderer + menu::Renderer { + const DEFAULT_PADDING: u16; + + fn draw( + &mut self, + bounds: Rectangle, + cursor_position: Point, + selected: Option<String>, + text_size: u16, + padding: u16, + ) -> Self::Output; +} + +impl<'a, T: 'a, Message, Renderer> Into<Element<'a, Message, Renderer>> + for ComboBox<'a, T, Message> +where + T: Clone + ToString + Eq, + [T]: ToOwned<Owned = Vec<T>>, + Renderer: self::Renderer + 'a, + Message: 'static, +{ + fn into(self) -> Element<'a, Message, Renderer> { + Element::new(self) + } +} |