Added TreeNode.GetLevel(). Resolves #502

README.md

@@ -1,6 +1,6 @@
 # Rich Interactive Widgets for Terminal UIs
 
-[![Godoc Reference](https://img.shields.io/badge/godoc-reference-blue.svg)](https://pkg.go.dev/github.com/rivo/tview)
+[![PkgGoDev](https://pkg.go.dev/badge/github.com/rivo/tview)](https://pkg.go.dev/github.com/rivo/tview)
 [![Go Report](https://img.shields.io/badge/go%20report-A%2B-brightgreen.svg)](https://goreportcard.com/report/github.com/rivo/tview)
 
 This Go package provides commonly needed components for terminal based user interfaces.

treeview.go

@@ -41,9 +41,13 @@ type TreeNode struct {
 	// An optional function which is called when the user selects this node.
 	selected func()
 
+	// The hierarchy level (0 for the root, 1 for its children, and so on). This
+	// is only up to date immediately after a call to process() (e.g. via
+	// Draw()).
+	level int
+
 	// Temporary member variables.
 	parent    *TreeNode // The parent node (nil for the root).
-	level     int       // The hierarchy level (0 for the root, 1 for its children, and so on).
 	graphicsX int       // The x-coordinate of the left-most graphics rune.
 	textX     int       // The x-coordinate of the first rune of the text.
 }
@@ -207,6 +211,14 @@ func (n *TreeNode) SetIndent(indent int) *TreeNode {
 	return n
 }
 
+// GetLevel returns the node's level within the hierarchy, where 0 corresponds
+// to the root node, 1 corresponds to its children, and so on. This is only
+// guaranteed to be up to date immediately after the tree that contains this
+// node is drawn.
+func (n *TreeNode) GetLevel() int {
+	return n.level
+}
+
 // TreeView displays tree structures. A tree consists of nodes (TreeNode
 // objects) where each node has zero or more child nodes and exactly one parent
 // node (except for the root node which has no parent node).