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//---------------------------------------------------------------------------
//
// File: XamlGridLengthSerializer.cs
//
// Description:
// XamlSerializer used to persist GridLength structures in Baml
//
// Copyright (C) 2004 by Microsoft Corporation. All rights reserved.
//
//---------------------------------------------------------------------------
using System;
using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.ComponentModel.Design.Serialization;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Xml;
using System.Windows;
using System.Windows.Markup;
using MS.Utility;
using MS.Internal;
#if PBTCOMPILER
namespace MS.Internal.Markup
#else
namespace System.Windows.Markup
#endif
{
/// <summary>
/// XamlGridLengthSerializer is used to persist a GridLength structure in Baml files
/// </summary>
internal class XamlGridLengthSerializer : XamlSerializer
{
#region Construction
/// <summary>
/// Constructor for XamlGridLengthSerializer
/// </summary>
/// <remarks>
/// This constructor will be used under
/// the following two scenarios
/// 1. Convert a string to a custom binary representation stored in BAML
/// 2. Convert a custom binary representation back into a GridLength
/// </remarks>
private XamlGridLengthSerializer()
{
}
#endregion Construction
#region Conversions
///<summary>
/// Serializes this object using the passed writer.
///</summary>
/// <remarks>
/// This is called ONLY from the Parser and is not a general public method.
/// </remarks>
//
// Format of serialized data:
// first byte other bytes format
// 0AAAAAAA none Amount [0 - 127] in AAAAAAA, Pixel GridUnitType
// 100XXUUU one byte Amount in byte [0 - 255], GridUnitType in UUU
// 110XXUUU two bytes Amount in int16 , GridUnitType in UUU
// 101XXUUU four bytes Amount in int32 , GridUnitType in UUU
// 111XXUUU eight bytes Amount in double, GridUnitType in UUU
//
public override bool ConvertStringToCustomBinary (
BinaryWriter writer, // Writer into the baml stream
string stringValue) // String to convert
{
if (writer == null)
{
throw new ArgumentNullException( "writer" );
}
GridUnitType gridUnitType;
double value;
FromString(stringValue, TypeConverterHelper.InvariantEnglishUS,
out value, out gridUnitType);
byte unitAndFlags = (byte)gridUnitType;
int intAmount = (int)value;
if ((double)intAmount == value)
{
//
// 0 - 127 and Pixel
//
if ( intAmount <= 127
&& intAmount >= 0
&& gridUnitType == GridUnitType.Pixel )
{
writer.Write((byte)intAmount);
}
//
// unsigned byte
//
else if ( intAmount <= 255
&& intAmount >= 0 )
{
writer.Write((byte)(0x80 | unitAndFlags));
writer.Write((byte)intAmount);
}
//
// signed short integer
//
else if ( intAmount <= 32767
&& intAmount >= -32768 )
{
writer.Write((byte)(0xC0 | unitAndFlags));
writer.Write((Int16)intAmount);
}
//
// signed integer
//
else
{
writer.Write((byte)(0xA0 | unitAndFlags));
writer.Write(intAmount);
}
}
//
// double
//
else
{
writer.Write((byte)(0xE0 | unitAndFlags));
writer.Write(value);
}
return true;
}
/// <summary>
/// Convert a compact binary representation of a GridLength into and instance
/// of GridLength. The reader must be left pointing immediately after the object
/// data in the underlying stream.
/// </summary>
/// <remarks>
/// This is called ONLY from the Parser and is not a general public method.
/// </remarks>
public override object ConvertCustomBinaryToObject(
BinaryReader reader)
{
if (reader == null)
{
throw new ArgumentNullException( "reader" );
}
GridUnitType unitType;
double unitValue;
byte unitAndFlags = reader.ReadByte();
if ((unitAndFlags & 0x80) == 0)
{
unitType = GridUnitType.Pixel;
unitValue = (double)unitAndFlags;
}
else
{
unitType = (GridUnitType)(unitAndFlags & 0x1F);
byte flags = (byte)(unitAndFlags & 0xE0);
if (flags == 0x80)
{
unitValue = (double)reader.ReadByte();
}
else if (flags == 0xC0)
{
unitValue = (double)reader.ReadInt16();
}
else if (flags == 0xA0)
{
unitValue = (double)reader.ReadInt32();
}
else
{
unitValue = (double)reader.ReadDouble();
}
}
return new GridLength(unitValue, unitType);
}
// Parse a GridLength from a string given the CultureInfo.
static internal void FromString(
string s,
CultureInfo cultureInfo,
out double value,
out GridUnitType unit)
{
string goodString = s.Trim().ToLowerInvariant();
value = 0.0;
unit = GridUnitType.Pixel;
int i;
int strLen = goodString.Length;
int strLenUnit = 0;
double unitFactor = 1.0;
// this is where we would handle trailing whitespace on the input string.
// peel [unit] off the end of the string
i = 0;
if (goodString == UnitStrings[i])
{
strLenUnit = UnitStrings[i].Length;
unit = (GridUnitType)i;
}
else
{
for (i = 1; i < UnitStrings.Length; ++i)
{
// Note: this is NOT a culture specific comparison.
// this is by design: we want the same unit string table to work across all cultures.
if (goodString.EndsWith(UnitStrings[i], StringComparison.Ordinal))
{
strLenUnit = UnitStrings[i].Length;
unit = (GridUnitType)i;
break;
}
}
}
// we couldn't match a real unit from GridUnitTypes.
// try again with a converter-only unit (a pixel equivalent).
if (i >= UnitStrings.Length)
{
for (i = 0; i < PixelUnitStrings.Length; ++i)
{
// Note: this is NOT a culture specific comparison.
// this is by design: we want the same unit string table to work across all cultures.
if (goodString.EndsWith(PixelUnitStrings[i], StringComparison.Ordinal))
{
strLenUnit = PixelUnitStrings[i].Length;
unitFactor = PixelUnitFactors[i];
break;
}
}
}
// this is where we would handle leading whitespace on the input string.
// this is also where we would handle whitespace between [value] and [unit].
// check if we don't have a [value]. This is acceptable for certain UnitTypes.
if ( strLen == strLenUnit
&& ( unit == GridUnitType.Auto
|| unit == GridUnitType.Star ) )
{
value = 1;
}
// we have a value to parse.
else
{
Debug.Assert( unit == GridUnitType.Pixel
|| DoubleUtil.AreClose(unitFactor, 1.0) );
string valueString = goodString.Substring(0, strLen - strLenUnit);
value = Convert.ToDouble(valueString, cultureInfo) * unitFactor;
}
}
#endregion Conversions
#region Fields
// Note: keep this array in sync with the GridUnitType enum
static private string[] UnitStrings = { "auto", "px", "*" };
// this array contains strings for unit types that are not present in the GridUnitType enum
static private string[] PixelUnitStrings = { "in", "cm", "pt" };
static private double[] PixelUnitFactors =
{
96.0, // Pixels per Inch
96.0 / 2.54, // Pixels per Centimeter
96.0 / 72.0, // Pixels per Point
};
#endregion Fields
}
}
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