treeview

type ConnectorState struct {
	// RowBounds is the full row bounding rectangle.
	RowBounds geometry.Rect

	// Depth is the nesting level of this row.
	Depth int

	// IndentWidth is the pixel offset per nesting level.
	IndentWidth float32

	// IsLastChild is true if this node is the last child of its parent.
	IsLastChild bool

	// HasChildren is true if this node has children (branch node).
	HasChildren bool

	// ParentHasMore indicates which ancestor levels still have more
	// siblings below. Index 0 = depth 1, index 1 = depth 2, etc.
	// Used to draw vertical continuation lines.
	ParentHasMore []bool

	// ColorScheme provides theme-derived colors.
	ColorScheme TreeColorScheme
}

type DefaultPainter struct{}

type ExpandIconState struct {
	// Bounds is the bounding rectangle for the expand icon.
	Bounds geometry.Rect

	// Expanded is true if the node is currently expanded.
	Expanded bool

	// Hovered is true if the mouse cursor is over this row.
	Hovered bool

	// ColorScheme provides theme-derived colors.
	ColorScheme TreeColorScheme
}

type LabelState struct {
	// Bounds is the bounding rectangle for the label text.
	Bounds geometry.Rect

	// Text is the label text.
	Text string

	// Selected is true if this row is selected.
	Selected bool

	// Disabled is true if the tree is disabled.
	Disabled bool

	// ColorScheme provides theme-derived colors.
	ColorScheme TreeColorScheme
}

type Option func(*config)

type Painter interface {
	// PaintRowBackground draws the background for a tree row.
	// Called before the row label is drawn.
	PaintRowBackground(canvas widget.Canvas, state RowPaintState)

	// PaintSelection draws the selection highlight for a selected row.
	// Called before the row label is drawn.
	PaintSelection(canvas widget.Canvas, state RowPaintState)

	// PaintExpandIcon draws the expand/collapse indicator for branch nodes.
	PaintExpandIcon(canvas widget.Canvas, state ExpandIconState)

	// PaintConnectorLines draws the tree connector lines (if enabled).
	PaintConnectorLines(canvas widget.Canvas, state ConnectorState)

	// PaintLabel draws the node label text.
	PaintLabel(canvas widget.Canvas, state LabelState)

	// PaintEmptyState draws placeholder content when the tree has no root.
	PaintEmptyState(canvas widget.Canvas, bounds geometry.Rect)
}

type RowPaintState struct {
	// Bounds is the full row bounding rectangle.
	Bounds geometry.Rect

	// Node is the tree node for this row.
	Node *TreeNode

	// Depth is the nesting level (0 = root).
	Depth int

	// Selected is true if this row is the currently selected node.
	Selected bool

	// Focused is true if the tree has keyboard focus and this row is selected.
	Focused bool

	// Hovered is true if the mouse cursor is over this row.
	Hovered bool

	// Disabled is true if the tree is disabled.
	Disabled bool

	// ColorScheme provides theme-derived colors.
	ColorScheme TreeColorScheme
}

type SelectionMode uint8

type TreeColorScheme struct {
	SelectionColor widget.Color // selected row background
	HoverColor     widget.Color // hovered row background
	FocusColor     widget.Color // focused row border/background
	LabelColor     widget.Color // default label text color
	LineColor      widget.Color // connector line color
	IconColor      widget.Color // expand/collapse icon color
	EmptyTextColor widget.Color // empty state text color
}

type TreeNode struct {
	// ID uniquely identifies this node within the tree.
	// Must be unique across all nodes.
	ID string

	// Label is the display text for this node.
	Label string

	// Children are this node's child nodes. Nil or empty means leaf.
	Children []*TreeNode

	// Expanded controls whether this node's children are visible.
	// Only meaningful for branch nodes (len(Children) > 0).
	Expanded bool

	// Data carries an arbitrary user payload.
	Data interface{}
}

type Widget struct {
	widget.WidgetBase
	// contains filtered or unexported fields
}