// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
// 
// Description: Inline element. 
//
 
using MS.Internal;
 
namespace System.Windows.Documents 
{
    /// <summary>
    /// Inline element.
    /// </summary>
    [TextElementEditingBehaviorAttribute(IsMergeable = true, IsTypographicOnly = true)]
    public abstract class Inline : TextElement
    {
        //-------------------------------------------------------------------
        //
        // Constructors
        //
        //-------------------------------------------------------------------
 
        #region Constructors
 
        /// <summary>
        /// Public constructor.
        /// </summary>
        protected Inline() 
            : base()
        {
        }
 
        #endregion Constructors
 
        //-------------------------------------------------------------------
        //
        // Public Properties
        //
        //-------------------------------------------------------------------
 
        #region Public Properties
 
        /// <value>
        /// A collection of Inlines containing this one in its sequential tree.
        /// May return null if an element is not inserted into any tree.
        /// </value>
        public InlineCollection SiblingInlines
        {
            get
            {
                if (this.Parent == null)
                {
                    return null;
                }
 
                return new InlineCollection(this, /*isOwnerParent*/false);
            }
        }
 
        /// <summary>
        /// Returns an Inline immediately following this one
        /// on the same level of siblings
        /// </summary>
        public Inline NextInline
        {
            get
            {
                return this.NextElement as Inline;
            }
        }
 
        /// <summary>
        /// Returns an Inline immediately preceding this one
        /// on the same level of siblings
        /// </summary>
        public Inline PreviousInline
        {
            get
            {
                return this.PreviousElement as Inline;
            }
        }
 
        /// <summary>
        /// DependencyProperty for <see cref="BaselineAlignment" /> property.
        /// </summary>
        public static readonly DependencyProperty BaselineAlignmentProperty = 
                DependencyProperty.Register(
                        "BaselineAlignment", 
                        typeof(BaselineAlignment), 
                        typeof(Inline), 
                        new FrameworkPropertyMetadata(
                                BaselineAlignment.Baseline, 
                                FrameworkPropertyMetadataOptions.AffectsParentMeasure), 
                        new ValidateValueCallback(IsValidBaselineAlignment));
 
        /// <summary>
        /// 
        /// </summary>
        public BaselineAlignment BaselineAlignment
        {
            get { return (BaselineAlignment) GetValue(BaselineAlignmentProperty); }
            set { SetValue(BaselineAlignmentProperty, value); }
        }
 
        /// <summary>
        /// DependencyProperty for <see cref="TextDecorations" /> property.
        /// </summary>
        public static readonly DependencyProperty TextDecorationsProperty = 
                DependencyProperty.Register(
                        "TextDecorations", 
                        typeof(TextDecorationCollection), 
                        typeof(Inline),
                        new FrameworkPropertyMetadata(
                                new FreezableDefaultValueFactory(TextDecorationCollection.Empty), 
                                FrameworkPropertyMetadataOptions.AffectsRender 
                                ));
 
        /// <summary>
        /// The TextDecorations property specifies decorations that are added to the text of an element.
        /// </summary>
        public TextDecorationCollection TextDecorations
        {
            get { return (TextDecorationCollection) GetValue(TextDecorationsProperty); }
            set { SetValue(TextDecorationsProperty, value); }
        }
 
        /// <summary>
        /// DependencyProperty for <see cref="FlowDirection" /> property.
        /// </summary>
        public static readonly DependencyProperty FlowDirectionProperty =
                FrameworkElement.FlowDirectionProperty.AddOwner(typeof(Inline));
 
        /// <summary>
        /// The FlowDirection property specifies the flow direction of the element.
        /// </summary>
        public FlowDirection FlowDirection
        {
            get { return (FlowDirection)GetValue(FlowDirectionProperty); }
            set { SetValue(FlowDirectionProperty, value); }
        }
 
        #endregion Public Properties
 
        //-------------------------------------------------------------------
        //
        //  Internal Methods
        //
        //-------------------------------------------------------------------
 
        #region Internal Methods
 
        internal static Run CreateImplicitRun(DependencyObject parent)
        {
            return new Run();
        }
 
        internal static InlineUIContainer CreateImplicitInlineUIContainer(DependencyObject parent)
        {
            return new InlineUIContainer();
        }
 
        #endregion Internal Methods
 
        //-------------------------------------------------------------------
        //
        // Private Methods
        //
        //-------------------------------------------------------------------
 
        #region Private Methods
        private static bool IsValidBaselineAlignment(object o)
        {
            BaselineAlignment value = (BaselineAlignment)o;
            return value == BaselineAlignment.Baseline
                || value == BaselineAlignment.Bottom
                || value == BaselineAlignment.Center
                || value == BaselineAlignment.Subscript
                || value == BaselineAlignment.Superscript
                || value == BaselineAlignment.TextBottom
                || value == BaselineAlignment.TextTop
                || value == BaselineAlignment.Top;
        }
 
        #endregion Private Methods
    }
}