microsoft-visualbasic-runtime/Serialization/JSON/Formatter/JsonFormatterStrategyContext.vb

#Region "Microsoft.VisualBasic::60e9cc85d88a634488df990b70e6a31a, Serialization\JSON\Formatter\JsonFormatterStrategyContext.vb"

    ' Author:
    ' 
    '       asuka (amethyst.asuka@gcmodeller.org)
    '       xie (genetics@smrucc.org)
    '       xieguigang (xie.guigang@live.com)
    ' 
    ' Copyright (c) 2018 GPL3 Licensed
    ' 
    ' 
    ' GNU GENERAL PUBLIC LICENSE (GPL3)
    ' 
    ' 
    ' This program is free software: you can redistribute it and/or modify
    ' it under the terms of the GNU General Public License as published by
    ' the Free Software Foundation, either version 3 of the License, or
    ' (at your option) any later version.
    ' 
    ' This program is distributed in the hope that it will be useful,
    ' but WITHOUT ANY WARRANTY; without even the implied warranty of
    ' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ' GNU General Public License for more details.
    ' 
    ' You should have received a copy of the GNU General Public License
    ' along with this program. If not, see <http://www.gnu.org/licenses/>.



    ' /********************************************************************************/

    ' Summaries:

    '     Class JsonFormatterStrategyContext
    ' 
    '         Properties: Indent, IsInArrayScope, IsProcessingDoubleQuoteInitiatedString, IsProcessingSingleQuoteInitiatedString, IsProcessingString
    '                     IsStart, WasLastCharacterABackSlash
    ' 
    '         Sub: AddCharacterStrategy, AppendCurrentChar, AppendIndents, AppendNewLine, AppendSpace
    '              BuildContextIndents, ClearStrategies, CloseCurrentScope, EnterArrayScope, EnterObjectScope
    '              PrettyPrintCharacter
    ' 
    ' 
    ' /********************************************************************************/

#End Region

Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.VisualBasic.Language.Default
Imports Microsoft.VisualBasic.Serialization.JSON.Formatter.Internals.Strategies

Namespace Serialization.JSON.Formatter.Internals

    Friend NotInheritable Class JsonFormatterStrategyContext

        Const Space As String = " "
        Const SpacesPerIndent As Integer = 2

        Dim m_indent As String = String.Empty
        Dim currentCharacter As Char
        Dim previousChar As Char

        Dim outputBuilder As StringBuilder

        ReadOnly scopeState As New FormatterScopeState()
        ReadOnly strategies As New Dictionary(Of Char, ICharacterStrategy)()

        Public ReadOnly Property Indent() As String
            Get
                If Me.m_indent = String.Empty Then
                    Me.m_indent = New String(Space, SpacesPerIndent)
                End If

                Return Me.m_indent
            End Get
        End Property

        Public ReadOnly Property IsInArrayScope() As Boolean
            Get
                Return Me.scopeState.IsTopTypeArray
            End Get
        End Property

        Private Sub AppendIndents(indents As Integer)
            For i As Integer = 0 To indents - 1
                Me.outputBuilder.Append(Indent)
            Next
        End Sub

        Public IsProcessingVariableAssignment As Boolean

        Public Property IsProcessingDoubleQuoteInitiatedString As Boolean
        Public Property IsProcessingSingleQuoteInitiatedString As Boolean

        Public ReadOnly Property IsProcessingString() As Boolean
            Get
                Return Me.IsProcessingDoubleQuoteInitiatedString OrElse Me.IsProcessingSingleQuoteInitiatedString
            End Get
        End Property

        Public ReadOnly Property IsStart() As Boolean
            Get
                Return Me.outputBuilder.Length = 0
            End Get
        End Property

        Public ReadOnly Property WasLastCharacterABackSlash() As Boolean
            Get
                Return Me.previousChar = "\"c
            End Get
        End Property

        Public Sub PrettyPrintCharacter(curChar As Char, output As StringBuilder)
            Dim strategy As ICharacterStrategy

            If Not strategies.ContainsKey(curChar) Then
                strategy = New DefaultCharacterStrategy
            Else
                strategy = strategies(curChar)
            End If

            Me.currentCharacter = curChar
            Me.outputBuilder = output

            Call strategy.Execute(Me)

            Me.previousChar = curChar
        End Sub

        Public Sub AppendCurrentChar()
            Me.outputBuilder.Append(Me.currentCharacter)
        End Sub

        Public Sub AppendNewLine()
            Me.outputBuilder.Append(Environment.NewLine)
        End Sub

        Public Sub BuildContextIndents()
            Me.AppendNewLine()
            Me.AppendIndents(Me.scopeState.ScopeDepth)
        End Sub

        Public Sub EnterObjectScope()
            Me.scopeState.PushObjectContextOntoStack()
        End Sub

        Public Sub CloseCurrentScope()
            Me.scopeState.PopJsonType()
        End Sub

        Public Sub EnterArrayScope()
            Me.scopeState.PushJsonArrayType()
        End Sub

        Public Sub AppendSpace()
            Me.outputBuilder.Append(Space)
        End Sub

        Public Sub ClearStrategies()
            Me.strategies.Clear()
        End Sub

        Public Sub AddCharacterStrategy(strategy As ICharacterStrategy)
            Me.strategies(strategy.ForWhichCharacter) = strategy
        End Sub
    End Class
End Namespace