source: branch/egtra-stream-without-en_dec/Classes/System/IO/StreamReader.ab@ 672

'Classes/System/IO/StreamReader.ab

Namespace System
Namespace IO

/*
@brief ストリームから読み取りを行うTextReaderの実装。
@date 2008/02/25
@auther Egtra
*/
Class StreamReader
    Inherits TextReader
Public
    /*
    @date 2008/02/25
    @auther Egtra
    */
    Sub StreamReader(path As String)
        init(New FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read))
    End Sub

    /*
    @date 2008/02/25
    @auther Egtra
    */
    Sub StreamReader(stream As Stream)
        init(stream)
    End Sub

Public
    /*
    @brief 基になるストリームを取得する
    @date 2008/09/02
    @auther NoWest
    */
    Function BaseStream () As Stream
        Return s
    End Function


Protected
    /*
    @date 2008/02/25
    @auther Egtra
    */
    Override Sub Dispose(disposing As Boolean)
        If disposing Then
            If Not ActiveBasic.IsNothing(s) Then
                s.Dispose(True)
            End If
        End If
        s = Nothing
    End Sub

    /*
    @date 2008/12/27
    @auther Egtra
    */
    Override Function Underflow() As Boolean
        Dim wcBuf[4095] As WCHAR
        Dim mbBuf[4095] As SByte
        Dim pNext = mbBuf As PSTR
        Dim mbBufSize = Len(buf)
        If leadByte <> 0 Then
            pNext[0] = leadByte
            leadByte = 0
            pNext++
            mbBufSize--
        End If
        Dim mbLen = s.Read(pNext As *Byte, 0, mbBufSize)
        If mbLen = 0 Then
            Underflow = False
            Exit Function
        End If
        Do
            Dim q = CharNextExA(cp, pNext, 0)
            If q = pNext Then
                Exit Do
            End If
            pNext = q As PSTR
        Loop
        If pNext <> mbBuf + mbLen Then
            leadByte = mbBuf[mbLen - 1]
        End If
        Dim wcLen = MultiByteToWideChar(cp, 0, mbBuf, (pNext - mbBuf) As Long, wcBuf, 4095)
        Dim s = New String(wcBuf, wcLen)
        Dim buf = Buffer
        buf.Append(s)
        Underflow = True
    End Function
Private

    /*
    @date 2008/02/25
    @auther Egtra
    */
    Sub init(str As Stream)
        s = str
        cp  = CP_ACP '暫定。
        leadByte = 0
    End Sub

    s As Stream
    cp As Word
    leadByte As Byte
End Class

End Namespace
End Namespace