Struct TreeItem

pub struct TreeItem<'text, Identifier> { /* private fields */ }

One item inside a Tree.

Can have zero or more children.

Identifier

The generic argument Identifier is used to keep the state like the currently selected or opened TreeItems in the TreeState.

It needs to be unique among its siblings but can be used again on parent or child TreeItems. A common example would be a filename which has to be unique in its directory while it can exist in another.

The text can be different from its identifier. To repeat the filename analogy: File browsers sometimes hide file extensions. The filename main.rs is the identifier while its shown as main. Two files main.rs and main.toml can exist in the same directory and can both be displayed as main but their identifier is different.

Just like every file in a file system can be uniquely identified with its file and directory names each TreeItem in a Tree can be with these identifiers. As an example the following two identifiers describe the main file in a Rust cargo project: vec!["src", "main.rs"].

The identifier does not need to be a String and is therefore generic. Until version 0.14 this crate used usize and indices. This might still be perfect for your use case.

Example

let a = TreeItem::new_leaf("l", "Leaf");
let b = TreeItem::new("r", "Root", vec![a])?;

Implementations

impl<'text, Identifier> TreeItem<'text, Identifier>

where Identifier: Clone + PartialEq + Eq + Hash,

pub fn new_leaf<T>(identifier: Identifier, text: T) -> Self

where T: Into<Text<'text>>,

Create a new TreeItem without children.

pub fn new<T>( identifier: Identifier, text: T, children: Vec<Self>, ) -> Result<Self>

where T: Into<Text<'text>>,

Create a new TreeItem with children.

Errors

Errors when there are duplicate identifiers in the children.

pub const fn identifier(&self) -> &Identifier

Get a reference to the identifier.

pub fn children(&self) -> &[Self]

pub fn child(&self, index: usize) -> Option<&Self>

Get a reference to a child by index.

pub fn child_mut(&mut self, index: usize) -> Option<&mut Self>

Get a mutable reference to a child by index.

When you choose to change the identifier the TreeState might not work as expected afterwards.

pub fn height(&self) -> usize

pub fn add_child(&mut self, child: Self) -> Result<()>

Add a child to the TreeItem.

Errors

Errors when the identifier of the child already exists in the children.

Trait Implementations

impl<'text, Identifier: Clone> Clone for TreeItem<'text, Identifier>

fn clone(&self) -> TreeItem<'text, Identifier>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'text, Identifier: Debug> Debug for TreeItem<'text, Identifier>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.