Table of Contents

Class TreeView

Namespace
Myra.Graphics2D.UI
Assembly
Myra.dll

A hierarchical tree view widget that displays nodes in an expandable/collapsible tree structure.

public class TreeView : Widget, IItemWithId, INotifyAttachedPropertyChanged, ITreeViewNode
Inheritance
TreeView
Implements
Inherited Members

Constructors

TreeView(Stylesheet, string)

Initializes a new instance of the TreeView class with the specified stylesheet and style.

public TreeView(Stylesheet stylesheet, string styleName = "")

Parameters

stylesheet Stylesheet

The stylesheet to use for applying the style.

styleName string

The name of the style to apply. Defaults to the default stylesheet style.

TreeView(string)

Initializes a new instance of the TreeView class with the specified style.

public TreeView(string styleName = "")

Parameters

styleName string

The name of the style to apply. Defaults to the default stylesheet style.

Properties

ChildNodesCount

Gets the number of top-level child nodes.

[Obsolete("Use SubNodesCount")]
public int ChildNodesCount { get; }

Property Value

int

SelectedNode

Gets or sets the currently selected node.

[Browsable(false)]
public TreeViewNode SelectedNode { get; set; }

Property Value

TreeViewNode

SelectionBackground

Gets or sets the brush used to draw the background of selected nodes.

public IBrush SelectionBackground { get; set; }

Property Value

IBrush

SelectionHoverBackground

Gets or sets the brush used to draw the background of hovered nodes.

public IBrush SelectionHoverBackground { get; set; }

Property Value

IBrush

SubNodesCount

Gets the number of child nodes directly under this tree view.

public int SubNodesCount { get; }

Property Value

int

TotalNodesCount

Gets the total number of nodes in the tree (including all nested nodes).

public int TotalNodesCount { get; }

Property Value

int

Methods

AddSubNode(Widget)

Adds a new top-level node to the tree with the specified content.

public TreeViewNode AddSubNode(Widget content)

Parameters

content Widget

The widget to display as the node's content.

Returns

TreeViewNode

The newly created tree node.

ApplyStyle(WidgetStyle)

Applies the specified widget style to this tree view.

protected override void ApplyStyle(WidgetStyle style)

Parameters

style WidgetStyle

The widget style to apply.

CopyFrom(Widget)

Copies the properties and child nodes from another tree view widget.

protected override void CopyFrom(Widget w)

Parameters

w Widget

The source tree view widget to copy from.

ExpandPath(TreeViewNode)

Expands path to the node

public void ExpandPath(TreeViewNode node)

Parameters

node TreeViewNode

FindNode(Func<TreeViewNode, bool>)

Finds the first node that matches the specified predicate.

public TreeViewNode FindNode(Func<TreeViewNode, bool> predicate)

Parameters

predicate Func<TreeViewNode, bool>

A function to test each node; returns true if the node matches.

Returns

TreeViewNode

The first matching node, or null if no nodes match.

GetNodeByAbsoluteIndex(int)

Gets a node by its absolute index (across all levels of the tree).

public TreeViewNode GetNodeByAbsoluteIndex(int index)

Parameters

index int

The zero-based absolute index.

Returns

TreeViewNode

The tree node at the specified absolute index.

GetSubNode(int)

Gets a top-level node by its index.

public TreeViewNode GetSubNode(int index)

Parameters

index int

The zero-based index of the node.

Returns

TreeViewNode

The tree node at the specified index.

InternalArrange()

Arranges the tree view and marks row information as needing update.

protected override void InternalArrange()

InternalRender(RenderContext)

Renders the tree view including selection and hover backgrounds for rows.

public override void InternalRender(RenderContext context)

Parameters

context RenderContext

The render context used for drawing.

Iterate(Func<TreeViewNode, bool>)

Iterates through all nodes

public void Iterate(Func<TreeViewNode, bool> action)

Parameters

action Func<TreeViewNode, bool>

Called for each node, returning false breaks iteration

OnKeyDown(Keys)

Handles keyboard input for tree navigation (Up, Down, and Enter keys).

public override void OnKeyDown(Keys k)

Parameters

k Keys

The key being pressed.

OnMouseLeft()

Handles mouse leaving the tree view and clears the hover state.

public override void OnMouseLeft()

OnMouseMoved()

Handles mouse movement and updates the hover state of nodes.

public override void OnMouseMoved()

OnTouchDoubleClick()

Handles touch double-click events and toggles node expansion if clicked on the mark.

public override void OnTouchDoubleClick()

OnTouchDown()

Handles touch down events and selects the node at the touch position.

public override void OnTouchDown()

RemoveAllSubNodes()

Removes all nodes from the tree.

public void RemoveAllSubNodes()

Events

SelectionChanged

Occurs when the selected node changes.

public event MyraEventHandler SelectionChanged

Event Type

MyraEventHandler
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