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//---------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
// File: ContainerParagraph.cs
//
// Description: Text line formatter.
//
// History:
// 05/05/2003 : Microsoft - moving from Avalon branch.
//
//---------------------------------------------------------------------------
#pragma warning disable 1634, 1691 // avoid generating warnings about unknown
// message numbers and unknown pragmas for PRESharp contol
using System;
using System.Diagnostics;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.Security; // SecurityCritical
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Media;
using System.Windows.Media.TextFormatting;
using MS.Internal.Text;
using MS.Internal.Documents;
using MS.Internal.PtsHost.UnsafeNativeMethods;
namespace MS.Internal.PtsHost
{
/// <summary>
/// Text line formatter.
/// </summary>
/// <remarks>
/// NOTE: All DCPs used during line formatting are related to cpPara.
/// To get abosolute CP, add cpPara to a dcp value.
/// </remarks>
internal sealed class OptimalTextSource : LineBase
{
//-------------------------------------------------------------------
//
// Constructors
//
//-------------------------------------------------------------------
#region Constructors
/// <summary>
/// Constructor.
/// </summary>
/// <param name="host">
/// TextFormatter host
/// </param>
/// <param name="cpPara">
/// Character position of paragraph
/// </param>
/// <param name="durTrack">
/// Track width
/// </param>
/// <param name="paraClient">
/// Owner of the line
/// </param>
/// <param name="runCache">
/// Text run cache
/// </param>
internal OptimalTextSource(TextFormatterHost host, int cpPara, int durTrack, TextParaClient paraClient, TextRunCache runCache) : base(paraClient)
{
_host = host;
_durTrack = durTrack;
_runCache = runCache;
_cpPara = cpPara;
}
/// <summary>
/// Free all resources associated with the line. Prepare it for reuse.
/// </summary>
public override void Dispose()
{
base.Dispose();
}
#endregion Constructors
// ------------------------------------------------------------------
//
// TextSource Implementation
//
// ------------------------------------------------------------------
#region TextSource Implementation
/// <summary>
/// Get a text run at specified text source position and return it.
/// </summary>
/// <param name="dcp">
/// dcp of position relative to start of line
/// </param>
internal override TextRun GetTextRun(int dcp)
{
TextRun run = null;
ITextContainer textContainer = _paraClient.Paragraph.StructuralCache.TextContainer;
StaticTextPointer position = textContainer.CreateStaticPointerAtOffset(_cpPara + dcp);
switch (position.GetPointerContext(LogicalDirection.Forward))
{
case TextPointerContext.Text:
run = HandleText(position);
break;
case TextPointerContext.ElementStart:
run = HandleElementStartEdge(position);
break;
case TextPointerContext.ElementEnd:
run = HandleElementEndEdge(position);
break;
case TextPointerContext.EmbeddedElement:
run = HandleEmbeddedObject(dcp, position);
break;
case TextPointerContext.None:
run = new ParagraphBreakRun(_syntheticCharacterLength, PTS.FSFLRES.fsflrEndOfParagraph);
break;
}
Invariant.Assert(run != null, "TextRun has not been created.");
Invariant.Assert(run.Length > 0, "TextRun has to have positive length.");
return run;
}
/// <summary>
/// Get text immediately before specified text source position. Return CharacterBufferRange
/// containing this text.
/// </summary>
/// <param name="dcp">
/// dcp of position relative to start of line
/// </param>
internal override TextSpan<CultureSpecificCharacterBufferRange> GetPrecedingText(int dcp)
{
// Parameter validation
Invariant.Assert(dcp >= 0);
int nonTextLength = 0;
CharacterBufferRange precedingText = CharacterBufferRange.Empty;
CultureInfo culture = null;
if (dcp > 0)
{
// Create TextPointer at dcp, and pointer at paragraph start to compare
ITextPointer startPosition = TextContainerHelper.GetTextPointerFromCP(_paraClient.Paragraph.StructuralCache.TextContainer, _cpPara, LogicalDirection.Forward);
ITextPointer position = TextContainerHelper.GetTextPointerFromCP(_paraClient.Paragraph.StructuralCache.TextContainer, _cpPara + dcp, LogicalDirection.Forward);
// Move backward until we find a position at the end of a text run, or reach start of TextContainer
while (position.GetPointerContext(LogicalDirection.Backward) != TextPointerContext.Text &&
position.CompareTo(startPosition) != 0)
{
position.MoveByOffset(-1);
nonTextLength++;
}
// Return text in run. If it is at start of TextContainer this will return an empty string
string precedingTextString = position.GetTextInRun(LogicalDirection.Backward);
precedingText = new CharacterBufferRange(precedingTextString, 0, precedingTextString.Length);
StaticTextPointer pointer = position.CreateStaticPointer();
DependencyObject element = (pointer.Parent != null) ? pointer.Parent : _paraClient.Paragraph.Element;
culture = DynamicPropertyReader.GetCultureInfo(element);
}
return new TextSpan<CultureSpecificCharacterBufferRange>(
nonTextLength + precedingText.Length,
new CultureSpecificCharacterBufferRange(culture, precedingText)
);
}
/// <summary>
/// Get Text effect index from text source character index. Return int value of Text effect index.
/// </summary>
/// <param name="dcp">
/// dcp of CharacterHit relative to start of line
/// </param>
internal override int GetTextEffectCharacterIndexFromTextSourceCharacterIndex(int dcp)
{
// Text effect index is an index relative to the start of the Text Container.
// To convert a text source index to text effect index, we first convert the dcp into text pointer
// and call GetDistance() from the start of the text container.
ITextPointer position = TextContainerHelper.GetTextPointerFromCP(_paraClient.Paragraph.StructuralCache.TextContainer, _cpPara + dcp, LogicalDirection.Forward);
return position.TextContainer.Start.GetOffsetToPosition(position);
}
#endregion TextSource Implementation
internal PTS.FSFLRES GetFormatResultForBreakpoint(int dcp, TextBreakpoint textBreakpoint)
{
int dcpRun = 0;
PTS.FSFLRES formatResult = PTS.FSFLRES.fsflrOutOfSpace;
foreach (TextSpan<TextRun> textSpan in _runCache.GetTextRunSpans())
{
TextRun run = textSpan.Value;
if (run != null && ((dcpRun + run.Length) >= (dcp + textBreakpoint.Length)))
{
if (run is ParagraphBreakRun)
{
formatResult = ((ParagraphBreakRun)run).BreakReason;
}
else if (run is LineBreakRun)
{
formatResult = ((LineBreakRun)run).BreakReason;
}
break;
}
dcpRun += textSpan.Length;
}
return formatResult;
}
/// <summary>
/// Measure child UIElement.
/// </summary>
/// <param name="inlineObject">
/// Element whose size we are measuring
/// </param>
/// <returns>
/// Size of the child UIElement
/// </returns>
internal Size MeasureChild(InlineObjectRun inlineObject)
{
// Always measure at infinity for bottomless, consistent constraint.
double pageHeight = _paraClient.Paragraph.StructuralCache.CurrentFormatContext.DocumentPageSize.Height;
if (!_paraClient.Paragraph.StructuralCache.CurrentFormatContext.FinitePage)
{
pageHeight = Double.PositiveInfinity;
}
return inlineObject.UIElementIsland.DoLayout(new Size(TextDpi.FromTextDpi(_durTrack), pageHeight), true, true);
}
/// <summary>
/// TextFormatter host
/// </summary>
private readonly TextFormatterHost _host;
private TextRunCache _runCache;
private int _durTrack;
private int _cpPara;
}
}
#pragma warning enable 1634, 1691
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