Avalonia/src/Avalonia.Styling/LogicalTree/ILogical.cs

// Copyright (c) The Avalonia Project. All rights reserved.
// Licensed under the MIT license. See licence.md file in the project root for full license information.

using System;
using Avalonia.Collections;

namespace Avalonia.LogicalTree
{
    /// <summary>
    /// Represents a node in the logical tree.
    /// </summary>
    public interface ILogical
    {
        /// <summary>
        /// Raised when the control is attached to a rooted logical tree.
        /// </summary>
        event EventHandler<LogicalTreeAttachmentEventArgs> AttachedToLogicalTree;

        /// <summary>
        /// Raised when the control is detached from a rooted logical tree.
        /// </summary>
        event EventHandler<LogicalTreeAttachmentEventArgs> DetachedFromLogicalTree;

        /// <summary>
        /// Gets a value indicating whether the element is attached to a rooted logical tree.
        /// </summary>
        bool IsAttachedToLogicalTree { get; }

        /// <summary>
        /// Gets the logical parent.
        /// </summary>
        ILogical LogicalParent { get; }

        /// <summary>
        /// Gets the logical children.
        /// </summary>
        IAvaloniaReadOnlyList<ILogical> LogicalChildren { get; }

        /// <summary>
        /// Notifies the control that it is being attached to a rooted logical tree.
        /// </summary>
        /// <param name="e">The event args.</param>
        /// <remarks>
        /// This method will be called automatically by the framework, you should not need to call
        /// this method yourself.
        /// </remarks>
        void NotifyAttachedToLogicalTree(LogicalTreeAttachmentEventArgs e);

        /// <summary>
        /// Notifies the control that it is being detached from a rooted logical tree.
        /// </summary>
        /// <param name="e">The event args.</param>
        /// <remarks>
        /// This method will be called automatically by the framework, you should not need to call
        /// this method yourself.
        /// </remarks>
        void NotifyDetachedFromLogicalTree(LogicalTreeAttachmentEventArgs e);
    }
}