Wetlands.vb
'' 
'' このコードは、DioDocs for PDF のサンプルの一部として提供されています。
'' © MESCIUS inc. All rights reserved.
'' 
Imports System.IO
Imports System.Drawing
Imports System.Collections.Generic
Imports GrapeCity.Documents.Pdf
Imports GrapeCity.Documents.Text
Imports GrapeCity.Documents.Drawing
Imports GCTEXT = GrapeCity.Documents.Text
Imports GCDRAW = GrapeCity.Documents.Drawing

'' このサンプルは、TextLayout クラスを使用してテキストと画像を配置することにより、
'' いくつかの画像とテキストのハイライトを含むテキストドキュメントを生成します。
Public Class Wetlands
    '' メインのサンプルドライバーです。
    Function CreatePDF(ByVal stream As Stream) As Integer
        Dim doc = New GcPdfDocument()

        '' これにより、画像のリストが保持され、ドキュメントを保存した後に破棄することができます。
        Dim disposables As New Generic.List(Of IDisposable)

        '' タイトルの色。
        Dim colorBlue = Color.FromArgb(&H3B, &H5C, &HAA)
        '' ハイライトの色。
        Dim colorRed = Color.Red
        '' テキストの描画に使用されるテキストレイアウトです。
        Dim tl = New TextLayout(72) With {
            .MaxWidth = doc.PageSize.Width,
            .MaxHeight = doc.PageSize.Height,
            .MarginLeft = 72,
            .MarginRight = 72,
            .MarginTop = 72,
            .MarginBottom = 72
        }
        tl.DefaultFormat.Font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "segoeui.ttf"))
        tl.DefaultFormat.FontSize = 11

        Dim page = doc.NewPage()

        Dim g = page.Graphics

        '' キャプション。
        tl.TextAlignment = TextAlignment.Center
        tl.Append("Introduction" + vbCrLf, New TextFormat() With {.FontSize = 16, .ForeColor = colorBlue})
        tl.Append("The Importance of Wetlands", New TextFormat() With {.FontSize = 13, .ForeColor = colorBlue})
        tl.PerformLayout(True)
        g.DrawTextLayout(tl, PointF.Empty)

        '' 最初の段落をキャプションの下に移動します。
        tl.MarginTop = tl.ContentHeight + 72 * 2
        tl.Clear()
        tl.TextAlignment = TextAlignment.Leading
        tl.ParagraphSpacing = 12

        Dim addPara As Action(Of String) =
            Sub(para)
                '' 赤色の部分を強調表示するためのプリミティブなマークアップを実装します。
                Dim txt = para.Split(New String() {"<red>", "</red>"}, StringSplitOptions.None)
                For i = 0 To txt.Length - 1
                    If i Mod 2 = 0 Then
                        tl.Append(txt(i))
                    Else
                        tl.Append(txt(i), New TextFormat(tl.DefaultFormat) With {.ForeColor = colorRed})
                    End If
                Next
                tl.AppendLine()
            End Sub

        '' 最初の段落の場合、より大きな最初の文字は必要ですが、最初の行は
        '' インデントしないので、テキストの残りの部分とは別に描画します。
        tl.Append(_paras(0).Substring(0, 1), New TextFormat(tl.DefaultFormat) With {.FontSize = 22})
        addPara(_paras(0).Substring(1))
        tl.PerformLayout(True)
        g.DrawTextLayout(tl, PointF.Empty)

        '' 最初の段落を考慮し、残りのテキストのテキストレイアウトを設定します
        '' (TextLayout では複数の段落を描画できますが、すべて同じ段落書式を
        '' 持つ必要があります)。
        tl.MarginTop = tl.ContentRectangle.Bottom
        tl.Clear()
        tl.FirstLineIndent = 36

        '' 残りの段落を追加します。
        For Each para In _paras.Skip(1)
            '' '::' で始まる段落は、ページ幅で描画される画像を示します。
            If (para.StartsWith("::")) Then
                Dim img = GCDRAW.Image.FromFile(Path.Combine("Resources", "ImagesBis", para.Substring(2)))
                disposables.Add(img)
                Dim w = tl.MaxWidth.Value - tl.MarginLeft - tl.MarginRight
                Dim h = img.Height / img.Width * w
                tl.AppendInlineObject(img, w, h)
                tl.AppendLine()
            Else
                addPara(para)
            End If
        Next
        '' 段落をレイアウトします。
        tl.PerformLayout(True)
        '' テキスト分割オプションを使用すると、widow/orphan 制御を実装できます。
        Dim tso = New TextSplitOptions(tl) With {
            .RestMarginTop = 72,
            .MinLinesInFirstParagraph = 2,
            .MinLinesInLastParagraph = 2
        }
        '' 画像の描画に使用される画像配置です。
        Dim ia = New ImageAlign(ImageAlignHorz.Left, ImageAlignVert.Top, True, True, True, False, False) With {.BestFit = True}
        '' ループ内で、テキストを分割して描画します。
        While (True)
            Dim rest As TextLayout = Nothing
            Dim splitResult = tl.Split(tso, rest)
            g = doc.Pages.Last.Graphics
            doc.Pages.Last.Graphics.DrawTextLayout(tl, PointF.Empty)
            '' このページで発生したすべての画像を描画します。
            For Each inlobj In tl.InlineObjects
                doc.Pages.Last.Graphics.DrawImage(DirectCast(inlobj.Object, GCDRAW.Image), inlobj.ObjectRect.ToRectangleF(), Nothing, ia)
            Next
            '' さらに描画する必要がなければ中断します。
            If splitResult <> SplitResult.Split Then
                Exit While
            End If
            '' 残りのテキストを 'main' TextLayout に割り当て、新しいページを追加して続行します。
            tl = rest
            doc.Pages.Add()
        End While

        '' PDF を保存します。
        doc.Save(stream)
        '' 画像を廃棄します(ドキュメントを保存した後にのみ行うことができます)。
        disposables.ForEach(Sub(d_) d_.Dispose())
        '' PDF ドキュメントを保存します。
        Return doc.Pages.Count
    End Function

    '' 描画するテキスト段落のリストです。
    '' 注意:
    '' - 段落が "::" で始まる場合、残りの文字列は挿入する画像ファイルの名前です。
    '' - <red>..</red> は、強調表示するテキストをマークアップします。
    Shared _paras() As String =
        {
            "Originally there were in excess of <red>two point three (2.3) million</red> hectares of wetlands in southern Ontario. Today there is a mere <red>twelve percent (12%)</red> remaining (Rowntree 1979). Yet, these same areas are vital to the continued existence of a whole host of wildlife species. Grebes,herons, bitterns, rails, shorebirds, gulls, terns, and numerous smaller birds, plus the waterfowl, nest in or use wetlands for feeding and resting. About <red>ninety-five percent (95%)</red> of all furbearers are taken in water (Rowntree 1979). Reptiles and amphibians must return there to breed. ",
            "::Birdswetland.jpg",
            "Several species of game fish live or spawn in wetlands. Hundreds, if not thousands, of invertebrates that form the food of birds also rely on water for most, if not all, phases of their existence. In fact, most all species of animals we have must spend at least part of the year in wetlands. To lose any more of these vital areas is almost unthinkable.",
            "Wetlands enhance and protect water quality in lakes and streams where additional species spend their time and from which we draw our water. Water from drainage may have five (5) times more phosphates or as much as fifty (50) times more nitrates than water from marshes. These nutrient loads act as fertilizers to aquatic plants whose growth may clog rivers, foul shorelines and deplete oxygen in the water making it unsuitable for fish. Wetlands handle as much as <red>fifty percent (50%)</red> of terrestrial denitrification whereby nitrogen is returned to the atmosphere. Wetlands act as settling and filtration basins collecting silt that might build up behind dams or clog navigation channels. Vegetation in wetlands protects shorelines from damage by tides and storms. Wetlands soak up tremendous amounts of rainwater, slowing runoff and decreasing flooding that will help to decrease erosion of streambanks and prevent property damage. Water maintained in wetlands also helps to maintain ground water levels.",
            "Wetlands provide valuable renewable resources of fur, wild rice, fish, bait, cranberries, game, etc. They are rich in plant and animal life and are, therefore, ideal for scientific studies and educational field trips. The recreational potential for wetlands is immense. About <red>eighty percent (80%)</red> of Canadians value wildlife conservation and spend some three (3) billion dollars annually on nonconsumptive wildlife related activities as well as another one (1) billion on consumptive pursuits. Photography, bird-watching, canoeing, nature study, hiking, fishing and hunting are all pursued in wetlands.",
            "::palo_verde.jpg",
            "The economic value of wetlands may far exceed the returns gained from converting them to other uses. In addition to recreational potential, the farming of wildlife for economic return has proven to be viable for many species (Smith et al. 1983). Wetlands may prove valuable to more than fur, rice or cranberries in future.",
            "The greatest threats to our remaining wetlands are from agricultural drainage and industrial or hoimports developments (Brynaert 1983). Vast sums are expended annually by federal and provincial government agencies to implement drainage programs with little or no consideration given to wildlife values. The extensive so-called stream improvements, channeling and ditching, are very much questionable. It is essential now to introduce measures that clearly place the onus on agricultural agencies to prove that drainage projects are economically viable and that they do not jeopardize our wetland habitats (Brynaert 1983).",
            "Wetlands are important to the productivity of the entire biosphere (Sanderson 1977). They are vital to effective management of many wildlife species that depend upon these habitats. Whether a hunter or a naturalist, the preservation of wetlands is an objective that should appeal to everyone (Brynaert 1983). The entire province, country and continent have suffered a great loss in natural resources because of wetland losses. If we cannot succeed in saving wetlands, we shall not be able to meet the greater challenge of safeguarding an environment that man can continue to inhabit (Rowntree 1979)."
        }
End Class