Struct tui_tree_widget::TreeState

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pub struct TreeState<Identifier> { /* private fields */ }

Expand description

Keeps the state of what is currently selected and what was opened in a Tree.

The generic argument Identifier is used to keep the state like the currently selected or opened TreeItems in the TreeState. For more information see TreeItem.

§Example

type Identifier = usize;

let mut state = TreeState::<Identifier>::default();

Implementations§

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impl<Identifier> State<Identifier>
where Identifier: Clone + PartialEq + Eq + Hash,

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pub const fn get_offset(&self) -> usize

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pub fn get_all_opened(&self) -> Vec<Vec<Identifier>>

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pub fn flatten<'a>( &self, items: &'a [Item<'a, Identifier>] ) -> Vec<Flattened<'a, Identifier>>

Get a flat list of all visible (= below open) TreeItems with this TreeState.

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pub fn selected(&self) -> Vec<Identifier>

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pub fn select(&mut self, identifier: Vec<Identifier>) -> bool

Selects the given identifier.

Returns true when the selection changed.

Clear the selection by passing an empty identifier vector:

state.select(Vec::new());

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pub fn open(&mut self, identifier: Vec<Identifier>) -> bool

Open a tree node. Returns true if the node was closed and has been opened. Returns false if the node was already open.

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pub fn close(&mut self, identifier: &[Identifier]) -> bool

Close a tree node. Returns true if the node was open and has been closed. Returns false if the node was already closed.

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pub fn toggle(&mut self, identifier: Vec<Identifier>) -> bool

Toggles a tree node. If the node is in opened then it calls close. Otherwise it calls open.

Returns true when a node is opened / closed. As toggle always changes something, this only returns false when an empty identifier is given.

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pub fn toggle_selected(&mut self) -> bool

Toggles the currently selected tree node. See also toggle

Returns true when a node is opened / closed. As toggle always changes something, this only returns false when nothing is selected.

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pub fn close_all(&mut self) -> bool

Closes all open nodes.

Returns true when any node was closed.

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pub fn select_first(&mut self, items: &[Item<'_, Identifier>]) -> bool

Select the first node.

Returns true when the selection changed.

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pub fn select_last(&mut self, items: &[Item<'_, Identifier>]) -> bool

Select the last visible node.

Returns true when the selection changed.

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pub fn select_visible_index( &mut self, items: &[Item<'_, Identifier>], new_index: usize ) -> bool

Select the node visible on the given index.

Returns true when the selection changed.

This can be useful for mouse clicks.

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pub fn select_visible_relative<F>( &mut self, items: &[Item<'_, Identifier>], change_function: F ) -> bool
where F: FnOnce(Option<usize>) -> usize,

Move the current selection with the direction/amount by the given function.

Returns true when the selection changed.

§Example

// Move the selection one down
state.select_visible_relative(&items, |current| {
    current.map_or(0, |current| current.saturating_add(1))
});

For more examples take a look into the source code of key_up or key_down. They are implemented with this method.

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pub fn scroll_selected_into_view(&mut self)

Ensure the selected TreeItem is visible on next render

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pub fn scroll_up(&mut self, lines: usize) -> bool

Scroll the specified amount of lines up

Returns true when the scroll position changed. Returns false when the scrolling has reached the top.

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pub fn scroll_down(&mut self, lines: usize) -> bool

Scroll the specified amount of lines down

In contrast to scroll_up() this can not return whether the view position changed or not as the actual change is determined on render. Always returns true.

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