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// 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: Block element.
// Block element - an abstract class, a base for elements allowed
// as siblings of Paragraphs.
//
using System.ComponentModel; // TypeConverter
using System.Windows.Media; // Brush
using MS.Internal.Text; // Text DPI restrictions
using MS.Internal.PtsHost.UnsafeNativeMethods; // PTS restrictions
namespace System.Windows.Documents
{
/// <summary>
/// Block element - an abstract class, a base for elements allowed
/// as siblings of Paragraphs.
/// Only Blocks are allowed on top level of FlowDocument
/// and other structural text elements like Section, ListItem, TableCell.
/// </summary>
public abstract class Block : TextElement
{
//-------------------------------------------------------------------
//
// Public Properties
//
//-------------------------------------------------------------------
#region Public Properties
/// <value>
/// A collection of Blocks containing this Block in its sequential tree.
/// May return null if this Block is not inserted into any tree.
/// </value>
public BlockCollection SiblingBlocks
{
get
{
if (this.Parent == null)
{
return null;
}
return new BlockCollection(this, /*isOwnerParent*/false);
}
}
/// <summary>
/// Returns a Block immediately following this one
/// on the same level of siblings
/// </summary>
public Block NextBlock
{
get
{
return this.NextElement as Block;
}
}
/// <summary>
/// Returns a block immediately preceding this one
/// on the same level of siblings
/// </summary>
public Block PreviousBlock
{
get
{
return this.PreviousElement as Block;
}
}
/// <summary>
/// DependencyProperty for hyphenation property.
/// </summary>
public static readonly DependencyProperty IsHyphenationEnabledProperty =
DependencyProperty.RegisterAttached(
"IsHyphenationEnabled",
typeof(bool),
typeof(Block),
new FrameworkPropertyMetadata(
false,
FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.Inherits));
/// <summary>
/// CLR property for hyphenation
/// </summary>
public bool IsHyphenationEnabled
{
get { return (bool)GetValue(IsHyphenationEnabledProperty); }
set { SetValue(IsHyphenationEnabledProperty, value); }
}
/// <summary>
/// DependencyProperty setter for <see cref="IsHyphenationEnabled" /> property.
/// </summary>
/// <param name="element">The element to which to write the attached property.</param>
/// <param name="value">The property value to set</param>
public static void SetIsHyphenationEnabled(DependencyObject element, bool value)
{
ArgumentNullException.ThrowIfNull(element);
element.SetValue(IsHyphenationEnabledProperty, value);
}
/// <summary>
/// DependencyProperty getter for <see cref="IsHyphenationEnabled" /> property.
/// </summary>
/// <param name="element">The element from which to read the attached property.</param>
public static bool GetIsHyphenationEnabled(DependencyObject element)
{
ArgumentNullException.ThrowIfNull(element);
return (bool)element.GetValue(IsHyphenationEnabledProperty);
}
/// <summary>
/// DependencyProperty for <see cref="Margin" /> property.
/// </summary>
public static readonly DependencyProperty MarginProperty =
DependencyProperty.Register(
"Margin",
typeof(Thickness),
typeof(Block),
new FrameworkPropertyMetadata(
new Thickness(),
FrameworkPropertyMetadataOptions.AffectsMeasure),
new ValidateValueCallback(IsValidMargin));
/// <summary>
/// The Margin property specifies the margin of the element.
/// </summary>
public Thickness Margin
{
get { return (Thickness)GetValue(MarginProperty); }
set { SetValue(MarginProperty, value); }
}
/// <summary>
/// DependencyProperty for <see cref="Padding" /> property.
/// </summary>
public static readonly DependencyProperty PaddingProperty =
DependencyProperty.Register(
"Padding",
typeof(Thickness),
typeof(Block),
new FrameworkPropertyMetadata(
new Thickness(),
FrameworkPropertyMetadataOptions.AffectsMeasure),
new ValidateValueCallback(IsValidPadding));
/// <summary>
/// The Padding property specifies the padding of the element.
/// </summary>
public Thickness Padding
{
get { return (Thickness)GetValue(PaddingProperty); }
set { SetValue(PaddingProperty, value); }
}
/// <summary>
/// DependencyProperty for <see cref="BorderThickness" /> property.
/// </summary>
public static readonly DependencyProperty BorderThicknessProperty =
DependencyProperty.Register(
"BorderThickness",
typeof(Thickness),
typeof(Block),
new FrameworkPropertyMetadata(
new Thickness(),
FrameworkPropertyMetadataOptions.AffectsMeasure),
new ValidateValueCallback(IsValidBorderThickness));
/// <summary>
/// The BorderThickness property specifies the border of the element.
/// </summary>
public Thickness BorderThickness
{
get { return (Thickness)GetValue(BorderThicknessProperty); }
set { SetValue(BorderThicknessProperty, value); }
}
/// <summary>
/// DependencyProperty for <see cref="BorderBrush" /> property.
/// </summary>
public static readonly DependencyProperty BorderBrushProperty =
DependencyProperty.Register(
"BorderBrush",
typeof(Brush),
typeof(Block),
new FrameworkPropertyMetadata(
null,
FrameworkPropertyMetadataOptions.AffectsRender));
/// <summary>
/// The BorderBrush property specifies the brush of the border.
/// </summary>
public Brush BorderBrush
{
get { return (Brush)GetValue(BorderBrushProperty); }
set { SetValue(BorderBrushProperty, value); }
}
/// <summary>
/// DependencyProperty for <see cref="TextAlignment" /> property.
/// </summary>
public static readonly DependencyProperty TextAlignmentProperty =
DependencyProperty.RegisterAttached(
"TextAlignment",
typeof(TextAlignment),
typeof(Block),
new FrameworkPropertyMetadata(
TextAlignment.Left,
FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.Inherits),
new ValidateValueCallback(IsValidTextAlignment));
/// <summary>
///
/// </summary>
public TextAlignment TextAlignment
{
get { return (TextAlignment)GetValue(TextAlignmentProperty); }
set { SetValue(TextAlignmentProperty, value); }
}
/// <summary>
/// DependencyProperty setter for <see cref="TextAlignment" /> property.
/// </summary>
/// <param name="element">The element to which to write the attached property.</param>
/// <param name="value">The property value to set</param>
public static void SetTextAlignment(DependencyObject element, TextAlignment value)
{
ArgumentNullException.ThrowIfNull(element);
element.SetValue(TextAlignmentProperty, value);
}
/// <summary>
/// DependencyProperty getter for <see cref="TextAlignment" /> property.
/// </summary>
/// <param name="element">The element from which to read the attached property.</param>
public static TextAlignment GetTextAlignment(DependencyObject element)
{
ArgumentNullException.ThrowIfNull(element);
return (TextAlignment)element.GetValue(TextAlignmentProperty);
}
/// <summary>
/// DependencyProperty for <see cref="FlowDirection" /> property.
/// </summary>
public static readonly DependencyProperty FlowDirectionProperty =
FrameworkElement.FlowDirectionProperty.AddOwner(typeof(Block));
/// <summary>
/// The FlowDirection property specifies the flow direction of the element.
/// </summary>
public FlowDirection FlowDirection
{
get { return (FlowDirection)GetValue(FlowDirectionProperty); }
set { SetValue(FlowDirectionProperty, value); }
}
/// <summary>
/// DependencyProperty for <see cref="LineHeight" /> property.
/// </summary>
public static readonly DependencyProperty LineHeightProperty =
DependencyProperty.RegisterAttached(
"LineHeight",
typeof(double),
typeof(Block),
new FrameworkPropertyMetadata(
double.NaN,
FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.Inherits),
new ValidateValueCallback(IsValidLineHeight));
/// <summary>
/// The LineHeight property specifies the height of each generated line box.
/// </summary>
[TypeConverter(typeof(LengthConverter))]
public double LineHeight
{
get { return (double)GetValue(LineHeightProperty); }
set { SetValue(LineHeightProperty, value); }
}
/// <summary>
/// DependencyProperty setter for <see cref="LineHeight" /> property.
/// </summary>
/// <param name="element">The element to which to write the attached property.</param>
/// <param name="value">The property value to set</param>
public static void SetLineHeight(DependencyObject element, double value)
{
ArgumentNullException.ThrowIfNull(element);
element.SetValue(LineHeightProperty, value);
}
/// <summary>
/// DependencyProperty getter for <see cref="LineHeight" /> property.
/// </summary>
/// <param name="element">The element from which to read the attached property.</param>
[TypeConverter(typeof(LengthConverter))]
public static double GetLineHeight(DependencyObject element)
{
ArgumentNullException.ThrowIfNull(element);
return (double)element.GetValue(LineHeightProperty);
}
/// <summary>
/// DependencyProperty for <see cref="LineStackingStrategy" /> property.
/// </summary>
public static readonly DependencyProperty LineStackingStrategyProperty =
DependencyProperty.RegisterAttached(
"LineStackingStrategy",
typeof(LineStackingStrategy),
typeof(Block),
new FrameworkPropertyMetadata(
LineStackingStrategy.MaxHeight,
FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender | FrameworkPropertyMetadataOptions.Inherits),
new ValidateValueCallback(IsValidLineStackingStrategy));
/// <summary>
/// The LineStackingStrategy property specifies how lines are placed
/// </summary>
public LineStackingStrategy LineStackingStrategy
{
get { return (LineStackingStrategy)GetValue(LineStackingStrategyProperty); }
set { SetValue(LineStackingStrategyProperty, value); }
}
/// <summary>
/// DependencyProperty setter for <see cref="LineStackingStrategy" /> property.
/// </summary>
/// <param name="element">The element to which to write the attached property.</param>
/// <param name="value">The property value to set</param>
public static void SetLineStackingStrategy(DependencyObject element, LineStackingStrategy value)
{
ArgumentNullException.ThrowIfNull(element);
element.SetValue(LineStackingStrategyProperty, value);
}
/// <summary>
/// DependencyProperty getter for <see cref="LineStackingStrategy" /> property.
/// </summary>
/// <param name="element">The element from which to read the attached property.</param>
public static LineStackingStrategy GetLineStackingStrategy(DependencyObject element)
{
ArgumentNullException.ThrowIfNull(element);
return (LineStackingStrategy)element.GetValue(LineStackingStrategyProperty);
}
/// <summary>
/// Page break property, replaces PageBreak element. Indicates that a break should occur before this page.
/// </summary>
public static readonly DependencyProperty BreakPageBeforeProperty =
DependencyProperty.Register(
"BreakPageBefore",
typeof(bool),
typeof(Block),
new FrameworkPropertyMetadata(
false,
FrameworkPropertyMetadataOptions.AffectsParentMeasure));
/// <summary>
/// The BreakPageBefore property indicates that a break should occur before this page
/// </summary>
public bool BreakPageBefore
{
get { return (bool)GetValue(BreakPageBeforeProperty); }
set { SetValue(BreakPageBeforeProperty, value); }
}
/// <summary>
/// Column break property, replaces ColumnBreak element. Indicates that a break should occur before this column.
/// </summary>
public static readonly DependencyProperty BreakColumnBeforeProperty =
DependencyProperty.Register(
"BreakColumnBefore",
typeof(bool),
typeof(Block),
new FrameworkPropertyMetadata(
false,
FrameworkPropertyMetadataOptions.AffectsParentMeasure));
/// <summary>
/// The BreakColumnBefore property indicates that a break should occur before this column
/// </summary>
public bool BreakColumnBefore
{
get { return (bool)GetValue(BreakColumnBeforeProperty); }
set { SetValue(BreakColumnBeforeProperty, value); }
}
/// <summary>
/// ClearFloaters property, replaces FloaterClear element. Clears floater in specified WrapDirection
/// </summary>
public static readonly DependencyProperty ClearFloatersProperty =
DependencyProperty.Register(
"ClearFloaters",
typeof(WrapDirection),
typeof(Block),
new FrameworkPropertyMetadata(
WrapDirection.None,
FrameworkPropertyMetadataOptions.AffectsParentMeasure),
new ValidateValueCallback(IsValidWrapDirection));
/// <summary>
/// ClearFloaters property, replaces FloaterClear element. Clears floater in specified WrapDirection
/// </summary>
public WrapDirection ClearFloaters
{
get { return (WrapDirection)GetValue(ClearFloatersProperty); }
set { SetValue(ClearFloatersProperty, value); }
}
#endregion Public Properties
//-------------------------------------------------------------------
//
// Internal Methods
//
//-------------------------------------------------------------------
#region Internal Methods
internal static bool IsValidMargin(object o)
{
Thickness t = (Thickness)o;
return IsValidThickness(t, /*allow NaN*/true);
}
internal static bool IsValidPadding(object o)
{
Thickness t = (Thickness)o;
return IsValidThickness(t, /*allow NaN*/true);
}
internal static bool IsValidBorderThickness(object o)
{
Thickness t = (Thickness)o;
return IsValidThickness(t, /*allow NaN*/false);
}
#endregion Internal Methods
//------------------------------------------------------
//
// Internal Properties
//
//------------------------------------------------------
#region Internal Properties
/// <summary>
/// Marks this element's left edge as visible to IMEs.
/// This means element boundaries will act as word breaks.
/// </summary>
internal override bool IsIMEStructuralElement
{
get
{
return true;
}
}
#endregion Internal Properties
//-------------------------------------------------------------------
//
// Private Methods
//
//-------------------------------------------------------------------
#region Private Methods
private static bool IsValidLineHeight(object o)
{
double lineHeight = (double)o;
double minLineHeight = TextDpi.MinWidth;
double maxLineHeight = Math.Min(1000000, PTS.MaxFontSize);
if (Double.IsNaN(lineHeight))
{
return true;
}
if (lineHeight < minLineHeight)
{
return false;
}
if (lineHeight > maxLineHeight)
{
return false;
}
return true;
}
private static bool IsValidLineStackingStrategy(object o)
{
LineStackingStrategy value = (LineStackingStrategy)o;
return (value == LineStackingStrategy.MaxHeight
|| value == LineStackingStrategy.BlockLineHeight);
}
private static bool IsValidTextAlignment(object o)
{
TextAlignment value = (TextAlignment)o;
return value == TextAlignment.Center
|| value == TextAlignment.Justify
|| value == TextAlignment.Left
|| value == TextAlignment.Right;
}
private static bool IsValidWrapDirection(object o)
{
WrapDirection value = (WrapDirection)o;
return value == WrapDirection.None
|| value == WrapDirection.Left
|| value == WrapDirection.Right
|| value == WrapDirection.Both;
}
internal static bool IsValidThickness(Thickness t, bool allowNaN)
{
double maxThickness = Math.Min(1000000, PTS.MaxPageSize);
if (!allowNaN)
{
if (Double.IsNaN(t.Left) || Double.IsNaN(t.Right) || Double.IsNaN(t.Top) || Double.IsNaN(t.Bottom))
{
return false;
}
}
if (!Double.IsNaN(t.Left) && (t.Left < 0 || t.Left > maxThickness))
{
return false;
}
if (!Double.IsNaN(t.Right) && (t.Right < 0 || t.Right > maxThickness))
{
return false;
}
if (!Double.IsNaN(t.Top) && (t.Top < 0 || t.Top > maxThickness))
{
return false;
}
if (!Double.IsNaN(t.Bottom) && (t.Bottom < 0 || t.Bottom > maxThickness))
{
return false;
}
return true;
}
#endregion Private Methods
}
}
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