libcosmic/src/widget/menu/menu_tree.rs
2025-07-21 22:59:30 +02:00

359 lines
13 KiB
Rust

// From iced_aw, license MIT
//! A tree structure for constructing a hierarchical menu
use std::borrow::Cow;
use std::collections::HashMap;
use std::rc::Rc;
use iced::advanced::widget::text::Style as TextStyle;
use iced_widget::core::{Element, renderer};
use crate::iced_core::{Alignment, Length};
use crate::widget::menu::action::MenuAction;
use crate::widget::menu::key_bind::KeyBind;
use crate::widget::{Button, RcElementWrapper, icon};
use crate::{theme, widget};
/// Nested menu is essentially a tree of items, a menu is a collection of items
/// a menu itself can also be an item of another menu.
///
/// A `MenuTree` represents a node in the tree, it holds a widget as a menu item
/// for its parent, and a list of menu tree as child nodes.
/// Conceptually a node is either a menu(inner node) or an item(leaf node),
/// but there's no need to explicitly distinguish them here, if a menu tree
/// has children, it's a menu, otherwise it's an item
#[allow(missing_debug_implementations)]
#[derive(Clone)]
pub struct MenuTree<Message> {
/// The menu tree will be flatten into a vector to build a linear widget tree,
/// the `index` field is the index of the item in that vector
pub(crate) index: usize,
/// The item of the menu tree
pub(crate) item: RcElementWrapper<Message>,
/// The children of the menu tree
pub(crate) children: Vec<MenuTree<Message>>,
/// The width of the menu tree
pub(crate) width: Option<u16>,
/// The height of the menu tree
pub(crate) height: Option<u16>,
}
impl<Message: Clone + 'static> MenuTree<Message> {
/// Create a new menu tree from a widget
pub fn new(item: impl Into<RcElementWrapper<Message>>) -> Self {
Self {
index: 0,
item: item.into(),
children: Vec::new(),
width: None,
height: None,
}
}
/// Create a menu tree from a widget and a vector of sub trees
pub fn with_children(
item: impl Into<RcElementWrapper<Message>>,
children: Vec<impl Into<MenuTree<Message>>>,
) -> Self {
Self {
index: 0,
item: item.into(),
children: children.into_iter().map(Into::into).collect(),
width: None,
height: None,
}
}
/// Sets the width of the menu tree.
/// See [`ItemWidth`]
///
/// [`ItemWidth`]:`super::ItemWidth`
#[must_use]
pub fn width(mut self, width: u16) -> Self {
self.width = Some(width);
self
}
/// Sets the height of the menu tree.
/// See [`ItemHeight`]
///
/// [`ItemHeight`]: `super::ItemHeight`
#[must_use]
pub fn height(mut self, height: u16) -> Self {
self.height = Some(height);
self
}
/* Keep `set_index()` and `flattern()` recurse in the same order */
/// Set the index of each item
pub(crate) fn set_index(&mut self) {
/// inner counting function.
fn rec<Message: Clone + 'static>(mt: &mut MenuTree<Message>, count: &mut usize) {
// keep items under the same menu line up
mt.children.iter_mut().for_each(|c| {
c.index = *count;
*count += 1;
});
mt.children.iter_mut().for_each(|c| rec(c, count));
}
let mut count = 0;
self.index = count;
count += 1;
rec(self, &mut count);
}
/// Flatten the menu tree
pub(crate) fn flattern(&self) -> Vec<&Self> {
/// Inner flattening function
fn rec<'a, Message: Clone + 'static>(
mt: &'a MenuTree<Message>,
flat: &mut Vec<&'a MenuTree<Message>>,
) {
mt.children.iter().for_each(|c| {
flat.push(c);
});
mt.children.iter().for_each(|c| {
rec(&c, flat);
});
}
let mut flat = Vec::new();
flat.push(self);
rec(self, &mut flat);
flat
}
}
impl<Message: Clone + 'static> From<crate::Element<'static, Message>> for MenuTree<Message> {
fn from(value: crate::Element<'static, Message>) -> Self {
Self::new(RcElementWrapper::new(value))
}
}
pub fn menu_button<'a, Message>(
children: Vec<crate::Element<'a, Message>>,
) -> crate::widget::Button<'a, Message>
where
Message: std::clone::Clone + 'a,
{
widget::button::custom(
widget::Row::with_children(children)
.align_y(Alignment::Center)
.height(Length::Fill)
.width(Length::Fill),
)
.height(Length::Fixed(36.0))
.padding([4, 16])
.width(Length::Fill)
.class(theme::Button::MenuItem)
}
#[derive(Clone)]
/// Represents a menu item that performs an action when selected or a separator between menu items.
///
/// - `Action` - Represents a menu item that performs an action when selected.
/// - `L` - The label of the menu item.
/// - `A` - The action to perform when the menu item is selected, the action must implement the `MenuAction` trait.
/// - `CheckBox` - Represents a checkbox menu item.
/// - `L` - The label of the menu item.
/// - `bool` - The state of the checkbox.
/// - `A` - The action to perform when the menu item is selected, the action must implement the `MenuAction` trait.
/// - `Folder` - Represents a folder menu item.
/// - `L` - The label of the menu item.
/// - `Vec<MenuItem<A, L>>` - A vector of menu items.
/// - `Divider` - Represents a divider between menu items.
pub enum MenuItem<A: MenuAction, L: Into<Cow<'static, str>>> {
/// Represents a button menu item.
Button(L, Option<icon::Handle>, A),
/// Represents a button menu item that is disabled.
ButtonDisabled(L, Option<icon::Handle>, A),
/// Represents a checkbox menu item.
CheckBox(L, Option<icon::Handle>, bool, A),
/// Represents a folder menu item.
Folder(L, Vec<MenuItem<A, L>>),
/// Represents a divider between menu items.
Divider,
}
/// Create a root menu item.
///
/// # Arguments
/// - `label` - The label of the menu item.
///
/// # Returns
/// - A button for the root menu item.
pub fn menu_root<'a, Message, Renderer: renderer::Renderer>(
label: impl Into<Cow<'a, str>> + 'a,
) -> Button<'a, Message>
where
Element<'a, Message, crate::Theme, Renderer>: From<widget::Button<'a, Message>>,
Message: std::clone::Clone + 'a,
{
widget::button::custom(widget::text(label))
.padding([4, 12])
.class(theme::Button::MenuRoot)
}
/// Create a list of menu items from a vector of `MenuItem`.
///
/// The `MenuItem` can be either an action or a separator.
///
/// # Arguments
/// - `key_binds` - A reference to a `HashMap` that maps `KeyBind` to `A`.
/// - `children` - A vector of `MenuItem`.
///
/// # Returns
/// - A vector of `MenuTree`.
#[must_use]
pub fn menu_items<
A: MenuAction<Message = Message>,
L: Into<Cow<'static, str>> + 'static,
Message: 'static + std::clone::Clone,
>(
key_binds: &HashMap<KeyBind, A>,
children: Vec<MenuItem<A, L>>,
) -> Vec<MenuTree<Message>> {
fn find_key<A: MenuAction>(action: &A, key_binds: &HashMap<KeyBind, A>) -> String {
for (key_bind, key_action) in key_binds {
if action == key_action {
return key_bind.to_string();
}
}
String::new()
}
fn key_style(theme: &crate::Theme) -> TextStyle {
let mut color = theme.cosmic().background.component.on;
color.alpha *= 0.75;
TextStyle {
color: Some(color.into()),
}
}
let key_class = theme::Text::Custom(key_style);
let size = children.len();
children
.into_iter()
.enumerate()
.flat_map(|(i, item)| {
let mut trees = vec![];
let spacing = crate::theme::spacing();
match item {
MenuItem::Button(label, icon, action) => {
let l: Cow<'static, str> = label.into();
let key = find_key(&action, key_binds);
let mut items = vec![
widget::text(l.clone()).into(),
widget::horizontal_space().into(),
widget::text(key).class(key_class).into(),
];
if let Some(icon) = icon {
items.insert(0, widget::icon::icon(icon).size(14).into());
items.insert(1, widget::Space::with_width(spacing.space_xxs).into());
}
let menu_button = menu_button(items).on_press(action.message());
trees.push(MenuTree::<Message>::from(Element::from(menu_button)));
}
MenuItem::ButtonDisabled(label, icon, action) => {
let l: Cow<'static, str> = label.into();
let key = find_key(&action, key_binds);
let mut items = vec![
widget::text(l.clone()).into(),
widget::horizontal_space().into(),
widget::text(key).class(key_class).into(),
];
if let Some(icon) = icon {
items.insert(0, widget::icon::icon(icon).size(14).into());
items.insert(1, widget::Space::with_width(spacing.space_xxs).into());
}
let menu_button = menu_button(items);
trees.push(MenuTree::<Message>::from(Element::from(menu_button)));
}
MenuItem::CheckBox(label, icon, value, action) => {
let key = find_key(&action, key_binds);
let mut items = vec![
if value {
widget::icon::from_name("object-select-symbolic")
.size(16)
.icon()
.class(theme::Svg::Custom(Rc::new(|theme| {
iced_widget::svg::Style {
color: Some(theme.cosmic().accent_text_color().into()),
}
})))
.width(Length::Fixed(16.0))
.into()
} else {
widget::Space::with_width(Length::Fixed(16.0)).into()
},
widget::Space::with_width(spacing.space_xxs).into(),
widget::text(label).align_x(iced::Alignment::Start).into(),
widget::horizontal_space().into(),
widget::text(key).class(key_class).into(),
];
if let Some(icon) = icon {
items.insert(1, widget::Space::with_width(spacing.space_xxs).into());
items.insert(2, widget::icon::icon(icon).size(14).into());
}
trees.push(MenuTree::from(Element::from(
menu_button(items).on_press(action.message()),
)));
}
MenuItem::Folder(label, children) => {
let l: Cow<'static, str> = label.into();
trees.push(MenuTree::<Message>::with_children(
RcElementWrapper::new(crate::Element::from(
menu_button::<'static, _>(vec![
widget::text(l.clone()).into(),
widget::horizontal_space().into(),
widget::icon::from_name("pan-end-symbolic")
.size(16)
.icon()
.into(),
])
.class(
// Menu folders have no on_press so they take on the disabled style by default
if children.is_empty() {
// This will make the folder use the disabled style if it has no children
theme::Button::MenuItem
} else {
// This will make the folder use the enabled style if it has children
theme::Button::MenuFolder
},
),
)),
menu_items(key_binds, children),
));
}
MenuItem::Divider => {
if i != size - 1 {
trees.push(MenuTree::<Message>::from(Element::from(
widget::divider::horizontal::light(),
)));
}
}
}
trees
})
.collect()
}