tree

Types

TreeGlyphs

Visual symbols for tree lines and expansion indicators.

pub type TreeGlyphs {
  TreeGlyphs(
    collapsed: String,
    expanded: String,
    leaf: String,
    indent: String,
  )
}

Constructors

```
TreeGlyphs(
  collapsed: String,
  expanded: String,
  leaf: String,
  indent: String,
)
```
Arguments

collapsed

Prefix for collapsed node with children.

expanded

Prefix for expanded node with children.

leaf

Prefix for leaf node.

indent

Indent per depth level (repeated).

TreeNode

</>

A tree node, either a leaf or an internal node with children. count shows a right-aligned number after the label (e.g. unread count, children count). Error(Nil) hides it.

pub type TreeNode {
  TreeNode(
    id: String,
    label: String,
    children: List(TreeNode),
    count: Result(Int, Nil),
  )
}

Constructors

TreeNode(
  id: String,
  label: String,
  children: List(TreeNode),
  count: Result(Int, Nil),
)

TreeState

</>

State: which nodes are expanded, which is selected.

pub type TreeState {
  TreeState(expanded: List(String), selected: String)
}

Constructors

```
TreeState(expanded: List(String), selected: String)
```
Arguments

expanded

IDs of expanded nodes.

selected

ID of currently selected node.

TreeWidget

</>

Tree widget configuration.

pub type TreeWidget {
  TreeWidget(
    roots: List(TreeNode),
    fg: style.Color,
    bg: style.Color,
    highlight_style: style.Style,
    glyphs: TreeGlyphs,
  )
}

Constructors

TreeWidget(
  roots: List(TreeNode),
  fg: style.Color,
  bg: style.Color,
  highlight_style: style.Style,
  glyphs: TreeGlyphs,
)

Arguments

glyphs: Characters used to render the tree structure.

Values

ascii_glyphs

</>

pub fn ascii_glyphs() -> TreeGlyphs

ASCII-safe glyphs for terminals without Unicode support.

collapse

</>

pub fn collapse(id: String, state: TreeState) -> TreeState

Collapse a node (hide children).

default_glyphs

</>

pub fn default_glyphs() -> TreeGlyphs

Default Unicode glyphs (▶ ▼ and box-drawing indent).

effective_offset

</>

pub fn effective_offset(
  state: TreeState,
  t: TreeWidget,
  height: Int,
) -> Int

Effective scroll offset for a viewport of height rows. Use as offset when building a scrollbar.

expand

</>

pub fn expand(id: String, state: TreeState) -> TreeState

Expand a node (show children).

is_expanded

</>

pub fn is_expanded(state: TreeState, id: String) -> Bool

True if the node with the given id is expanded.

leaf

</>

pub fn leaf(id: String, label: String) -> TreeNode

Create a leaf node (no children).

leaf_with_count

</>

pub fn leaf_with_count(
  id: String,
  label: String,
  count: Int,
) -> TreeNode

Leaf with a right-aligned count.

node

</>

pub fn node(
  id: String,
  label: String,
  children: List(TreeNode),
) -> TreeNode

Create an internal node with children.

node_with_count

</>

pub fn node_with_count(
  id: String,
  label: String,
  count: Int,
  children: List(TreeNode),
) -> TreeNode

Internal node with a right-aligned count.

render

</>

pub fn render(
  buf: buffer.Buffer,
  area: geometry.Rect,
  t: TreeWidget,
  state: TreeState,
) -> buffer.Buffer

Render the tree, scrolling so the selected node is visible.

select_next

</>

pub fn select_next(state: TreeState, t: TreeWidget) -> TreeState

Move selection to the next visible node.

select_prev

</>

pub fn select_prev(state: TreeState, t: TreeWidget) -> TreeState

Move selection to the previous visible node.

selected

</>

pub fn selected(state: TreeState) -> Result(String, Nil)

ID of the currently selected node. Error(Nil) if nothing selected.

state_from_tree

</>

pub fn state_from_tree(t: TreeWidget) -> TreeState

Initial state with first root pre-selected.

state_new

</>

pub fn state_new() -> TreeState

Initial state: first root node selected, all nodes collapsed.

toggle_selected

</>

pub fn toggle_selected(
  state: TreeState,
  t: TreeWidget,
) -> TreeState

Toggle expand/collapse on the currently selected node.

tree_new

</>

pub fn tree_new(roots: List(TreeNode)) -> TreeWidget

New tree widget. The first root node is selected initially.

visible_row_count

</>

pub fn visible_row_count(state: TreeState, t: TreeWidget) -> Int

Number of visible rows (respects expand/collapse state). Use as total when building a scrollbar.

with_colors

</>

pub fn with_colors(
  t: TreeWidget,
  fg: style.Color,
  bg: style.Color,
) -> TreeWidget

with_count

</>

pub fn with_count(n: TreeNode, count: Int) -> TreeNode

Attach a count to an existing node.

with_glyphs

</>

pub fn with_glyphs(t: TreeWidget, g: TreeGlyphs) -> TreeWidget

with_highlight_style

</>

pub fn with_highlight_style(
  t: TreeWidget,
  s: style.Style,
) -> TreeWidget

with_style

</>

pub fn with_style(t: TreeWidget, s: style.Style) -> TreeWidget