Gumby.TextBuffer

0.0.1.0

Gumby.TextBuffer.psm1

using module Gumby.Log
using module Gumby.String

class TextBuffer {
    TextBuffer(
        [System.ConsoleColor] $defaultForegroundColor = $Global:Host.UI.RawUI.ForegroundColor,
        [System.ConsoleColor] $defaultBackgroundColor = $Global:Host.UI.RawUI.BackgroundColor) {
        $this.DefaultForegroundColor = $defaultForegroundColor
        $this.DefaultBackgroundColor = $defaultBackgroundColor
    }

    [void] SetScreenBuffer(
        [System.Management.Automation.Host.Rectangle] $targetArea,
        [System.Management.Automation.Host.Coordinates] $sourceOrigin) {

        $stripes = $this.GetStripes($targetArea, $sourceOrigin)
        foreach ($stripe in $stripes) {
            $Global:Host.UI.RawUI.SetBufferContents($stripe.Coordinates, $stripe.BufferCells)
        }
    }

    # The implementation below is an attempt to allocate a BufferCell array with a single allocation.
    # It results in about the same performance as the original implementation.
    <#
    [void] SetScreenBuffer(
        [System.Management.Automation.Host.Rectangle] $targetArea,
        [System.Management.Automation.Host.Coordinates] $sourceOrigin) {
 
        $targetAreaStringList = [System.Collections.ArrayList]::new()
 
        $targetWidth = $targetArea.Right - $targetArea.Left + 1
        $targetHeight = $targetArea.Bottom - $targetArea.Top + 1
 
        for ($i = 0; $i -lt $targetHeight; ++$i) {
 
            if (($sourceOrigin.Y + $i -lt 0) </# above the text #/> -or
                ($sourceOrigin.Y + $i -ge $this._lines.Count) </# below the text #/> -or
                ($sourceOrigin.X + $targetWidth -lt 0) </# to the left of the text #/> -or
                ($sourceOrigin.X -gt $this._lines[$sourceOrigin.Y + $i].Text.Length) </# to the right of the right #/>) {
                $targetAreaString = ' ' * $targetWidth
            } else {
 
                $line = $this._lines[$sourceOrigin.Y + $i]
 
                $targetAreaString = if ($sourceOrigin.X -lt 0) {
                    EnsureStringLength ((" " * -$sourceOrigin.X) + $line.Text) $targetWidth
                } else {
                    EnsureStringLength $line.Text.Substring($sourceOrigin.X) $targetWidth
                }
            }
            $targetAreaStringList.Add($targetAreaString) | Out-Null
        }
 
        $targetAreaStringArray = $targetAreaStringList.ToArray()
 
        [System.Management.Automation.Host.BufferCell[,]] $bufferCells = $Global:Host.UI.RawUI.NewBufferCellArray($targetAreaStringArray, $this.DefaultForegroundColor, $this.DefaultBackgroundColor)
 
        # correct colors
        for ($i = 0; $i -lt $targetHeight; ++$i) {
            [Log]::Trace("TB.SetScreenBuffer.CorrectColors: i=$i")
            if ($sourceOrigin.Y + $i -lt 0) { </# above the text #/> continue }
            if ($sourceOrigin.Y + $i -ge $this._lines.Count) {</# below the text #/> break }
            $line = $this._lines[$sourceOrigin.Y + $i]
            [Log]::Trace("TB.SetScreenBuffer.CorrectColors: FC=$($line.ForegroundColor); BC=$($line.BackgroundColor)")
            for ($j = 0; $j -lt $targetWidth; ++$j) {
                #[Log]::Trace("TB.SetScreenBuffer.CorrectColors: [$i, $j].FC=$($bufferCells[$i, $j].ForegroundColor); line.FC=$($line.ForegroundColor)")
     
                # Work around the fact that calling the 'ForegroundColor' and 'BackgroundColor'
                # setters on an array element seem to have no effect.
 
                $temp = $bufferCells[$i, $j]
                $temp.ForegroundColor = $line.ForegroundColor
                $temp.BackgroundColor = $line.BackgroundColor
                $bufferCells[$i, $j] = $temp
 
                #[Log]::Trace("TB.SetScreenBuffer.CorrectColors: [$i, $j].FC=$($bufferCells[$i, $j].ForegroundColor)")
            }
        }
 
        $targetOrigin = [System.Management.Automation.Host.Coordinates]::new($targetArea.Left, $targetArea.Top)
        $Global:Host.UI.RawUI.SetBufferContents($targetOrigin, $bufferCells)
    }
    #>

    # The implementation below is an attempt to allocate a BufferCell array with a single allocation.
    # It results in about the same performance as the original implementation.
    <#
    [void] SetScreenBuffer(
        [System.Management.Automation.Host.Rectangle] $targetArea,
        [System.Management.Automation.Host.Coordinates] $sourceOrigin) {
 
        # The structure of the code below is based on the fact the BufferCell.ForegroundColor and
        # BufferCell.BackgroundColor properties appear to be read-only.
 
        $targetAreaStringList = [System.Collections.ArrayList]::new()
 
        $targetWidth = $targetArea.Right - $targetArea.Left + 1
        $targetHeight = $targetArea.Bottom - $targetArea.Top + 1
 
        for ($i = 0; $i -lt $targetHeight; ++$i) {
            if (($sourceOrigin.Y + $i -lt 0) <!# above the text #!> -or
                ($sourceOrigin.Y + $i -ge $this._lines.Count) <!# below the text #!> -or
                ($sourceOrigin.X + $targetWidth -lt 0) <!# to the left of the text #!> -or
                ($sourceOrigin.X -gt $this._lines[$sourceOrigin.Y + $i].Text.Length) <!# to the right of the right #!>) {
 
                $targetAreaString = ' ' * $targetWidth
 
            } else {
 
                $line = $this._lines[$sourceOrigin.Y + $i]
 
                $targetAreaString = if ($sourceOrigin.X -lt 0) {
                    EnsureStringLength ((" " * -$sourceOrigin.X) + $line.Text) $targetWidth
                } else {
                    EnsureStringLength $line.Text.Substring($sourceOrigin.X) $targetWidth
                }
            }
            $targetAreaStringList.Add($targetAreaString) | Out-Null
        }
 
        $targetAreaStringArray = $targetAreaStringList.ToArray()
        $targetOrigin = [System.Management.Automation.Host.Coordinates]::new($targetArea.Left, $targetArea.Top)
        [System.Management.Automation.Host.BufferCell[,]] $bufferCells =
            $Global:Host.UI.RawUI.NewBufferCellArray(
                $targetAreaStringArray,
                $this.DefaultForegroundColor,
                $this.DefaultBackgroundColor)
        $Global:Host.UI.RawUI.SetBufferContents($targetOrigin, $bufferCells)
 
        # correct colors
        for ($i = 0; $i -lt $targetHeight; ++$i) {
            if ($sourceOrigin.Y + $i -lt 0 <!# above the text #!>) { continue }
            if ($sourceOrigin.Y + $i -ge $this._lines.Count <!# below the text #!>) { break }
 
            $line = $this._lines[$sourceOrigin.Y + $i]
 
            if ($line.ForegroundColor -ne $this.DefaultForegroundColor -or
                $line.BackgroundColor -ne $this.DefaultBackgroundColor) {
 
                $targetOrigin = [System.Management.Automation.Host.Coordinates]::new($targetArea.Left, $targetArea.Top + $i)
 
                [System.Management.Automation.Host.BufferCell[,]] $bufferCells =
                    $Global:Host.UI.RawUI.NewBufferCellArray(
                        @($targetAreaStringArray[$i]),
                        $line.ForegroundColor,
                        $line.BackgroundColor)
 
                $Global:Host.UI.RawUI.SetBufferContents($targetOrigin, $bufferCells)
            }
        }
    }
    #>

    # for unit testing

    [object] GetStripes(
        [System.Management.Automation.Host.Rectangle] $targetArea,
        [System.Management.Automation.Host.Coordinates] $sourceOrigin) {

        $stripes = [System.Collections.ArrayList]::new()

        $targetWidth = $targetArea.Right - $targetArea.Left + 1
        $targetHeight = $targetArea.Bottom - $targetArea.Top + 1

        for ($i = 0; $i -lt $targetHeight; ++$i) {
            $stripe = @{Coordinates = [System.Management.Automation.Host.Coordinates]::new($targetArea.Left, $targetArea.Top + $i)}

            if (($sourceOrigin.Y + $i -lt 0) <# above the text #> -or
                ($sourceOrigin.Y + $i -ge $this._lines.Count) <# below the text #>) {
                $stripe.BufferCells = $Global:Host.UI.RawUI.NewBufferCellArray( @(' ' * $targetWidth), $this.DefaultForegroundColor, $this.DefaultBackgroundColor)
            } else {
                $line = $this._lines[$sourceOrigin.Y + $i]

                if (($sourceOrigin.X + $targetWidth -lt 0) <# to the left of the text #> -or
                    ($sourceOrigin.X -gt $line.Text.Length) <# to the right of the right#>) {
                    $stripe.BufferCells = $Global:Host.UI.RawUI.NewBufferCellArray( @(' ' * $targetWidth), $line.ForegroundColor, $line.BackgroundColor)
                } else {
                    $text = if ($sourceOrigin.X -lt 0) {
                        EnsureStringLength ((" " * -$sourceOrigin.X) + $line.Text) $targetWidth
                    } else {
                        EnsureStringLength $line.Text.Substring($sourceOrigin.X) $targetWidth
                    }

                    $stripe.BufferCells = $Global:Host.UI.RawUI.NewBufferCellArray(@($text), $line.ForegroundColor, $line.BackgroundColor)
                }
            }
            [void] $stripes.Add($stripe)
        }

        return $stripes
    }

    [int] LineCount() { return $this._lines.Count }
    [int] ColumnCount() { return $this._lines[$this._maxLengthLineNumber].Text.Length }

    [void] AddLine([string] $text, [ConsoleColor] $foregroundColor, [ConsoleColor] $backgroundColor) {
        $i = $this._lines.Add(@{Text = $text; ForegroundColor = $foregroundColor; BackgroundColor = $backgroundColor})

        if (($this._maxLengthLineNumber -eq -1) -or ($text.Length -gt $this._lines[$this._maxLengthLineNumber].Text.Length)) {
            $this._maxLengthLineNumber = $i
        }
    }

    [void] InsertLine([int] $lineNumber, [string] $text, [ConsoleColor] $foregroundColor, [ConsoleColor] $backgroundColor) {
        if (($this._maxLengthLineNumber -eq -1) -or ($text.Length -gt $this._lines[$this._maxLengthLineNumber].Text.Length)) {
            $this._maxLengthLineNumber = $lineNumber
        }

        $this._lines.Insert($lineNumber, @{Text = $text; ForegroundColor = $foregroundColor; BackgroundColor = $backgroundColor})
    }

    [object] GetLine([int] $lineNumber) { return $this._lines[$lineNumber] }

    [void] RemoveLine([int] $lineNumber) {
        $this._lines.RemoveAt($lineNumber)
        if ($lineNumber -eq $this._maxLengthLineNumber) { $this.DetermineMaxLengthLineNumber() }
    }

    [void] ClearLines() {
        $this._lines.Clear()
        $this._maxLengthLineNumber = -1
    }

    [ConsoleColor] $DefaultForegroundColor = $Global:Host.UI.RawUI.ForegroundColor
    [ConsoleColor] $DefaultBackgroundColor = $Global:Host.UI.RawUI.BackgroundColor

    hidden [void] DetermineMaxLengthLineNumber() {
        $this._maxLengthLineNumber = -1
        $maxLength = -1
        for ($i = 0; $i -lt $this._lines.Count; ++$i) {
            if ($this._lines[$i].Text.Length -gt $maxLength) {
                $maxLength = $this._lines[$i].Text.Length
                $this._maxLengthLineNumber = $i
            }
        }
    }

    hidden [System.Collections.ArrayList] $_lines = [System.Collections.ArrayList]::new()
    hidden [int] $_maxLengthLineNumber = -1
}