从 Quick PDF Library 和 PdfiumViewer 迁移到 sgcPDF

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ExtCtrls, ShellAPI,
  // sgc
  sgcPDF_Types, sgcPDF_Fonts, sgcPDF_Document, sgcPDF_Encryption,
  sgcPDF_Editor, sgcPDF_Renderer_GDI;

oDoc := TsgcPDFDocument.Create;
try
  // SetInformation(1, ...) / SetInformation(2, ...)
  oDoc.Info.Title := 'Created with sgcPDF';
  oDoc.Info.Author := 'Migration sample';
  // NewDocument creates page 1, sgcPDF adds every page explicitly
  oPage := oDoc.AddPage(CS_A4_WIDTH, CS_A4_HEIGHT);
  // AddStandardFont(4) + SelectFont + SetTextSize(28) + DrawText
  oPage.DrawText('Hello from sgcPDF', 72, 760, sfHelveticaBold, 28);
  // SetTextColor(r, g, b) + DrawText
  oPage.DrawTextColor('No DLL, pure Pascal.', 72, 725, sfHelvetica, 14,
    0.1, 0.3, 0.7);
  // SetLineColor + SetLineWidth + DrawBox(x, y, w, h, 0)
  oPage.DrawRectangle(72, 520, 260, 120, 1.5);
  // AddImageFromFile + SelectImage + DrawImage(x, y, w, h)
  vImage := oDoc.AddImage(OutFile('logo.bmp'));
  oPage.DrawImageFromIndex(vImage, 102, 540, 200, 80);
  oDoc.SaveToFile(OutFile('created.pdf'));
finally
  oDoc.Free;
end;

oDoc.LoadFromFile(OutFile('input_a.pdf'));
Log('Extract text: input_a.pdf has ' + IntToStr(oDoc.PageCount) +
  ' pages');
// SelectPage(2) + GetPageText(0): sgcPDF page indexes are 0-based
vText := string(oDoc.ExtractTextW(1));
Log(vText);

sgcPDFMergeFiles([OutFile('input_a.pdf'), OutFile('input_b.pdf')],
  OutFile('merged.pdf'));

// 1-based range string, the same syntax as Quick PDF Library
sgcPDFExtractPages(OutFile('merged.pdf'), OutFile('pages_2-3.pdf'), '2-3');
// one file per page: split
sgcPDFExtractPages(OutFile('merged.pdf'), OutFile('page_4.pdf'), '4');

oEditor.LoadFromFile(OutFile('input_a.pdf'));
vOptions.Text := 'CONFIDENTIAL';
vOptions.Font := sfHelveticaBold;
vOptions.FontSize := 72;
vOptions.Rotation := 45;
vOptions.Opacity := 0.3;
vOptions.R := 0.8;
vOptions.G := 0.1;
vOptions.B := 0.1;
oEditor.AddWatermarkAllPages(vOptions);
// a stamp in the top right corner of every page
for i := 0 to oEditor.Document.PageCount - 1 do
  oEditor.AddTextColor(i, 'APPROVED', 440, 800, sfHelveticaBold, 16,
    0.0, 0.5, 0.0);
oEditor.SaveToFile(OutFile('watermarked.pdf'));

oDoc.LoadFromFile(OutFile('created.pdf'));
oPage := oDoc.Pages[0];
// 96 DPI: points are 1/72 inch
vScale := 96 / 72;
vW := Round(oPage.Width * vScale);
vH := Round(oPage.Height * vScale);
oBitmap.PixelFormat := pf24bit;
oBitmap.Width := vW;
oBitmap.Height := vH;
oBitmap.Canvas.Brush.Color := clWhite;
oBitmap.Canvas.FillRect(Rect(0, 0, vW, vH));
oRenderer.RenderPage(oBitmap.Canvas.Handle, oDoc.Parser, oPage.PageDict,
  vW, vH);
GdiFlush;
oBitmap.SaveToFile(OutFile('created_page1.bmp'));

oDoc.LoadFromFile(OutFile('form.pdf'));
Log('Fill form: form.pdf has ' + IntToStr(oDoc.AcroForm.FieldCount) +
  ' fields');
oDoc.AcroForm.FillField('Customer', 'ACME Corporation');
oDoc.AcroForm.FillField('Amount', '1250.00');
oDoc.AcroForm.SetCheckBox('Paid', True);
oDoc.SaveToFile(OutFile('form_filled.pdf'));

oDoc.LoadFromFile(OutFile('input_a.pdf'));
oDoc.SetEncryption(emAES_256, CS_USER_PASSWORD, CS_OWNER_PASSWORD);
oDoc.SaveToFile(OutFile('encrypted.pdf'));

oDoc.SetPassword(CS_USER_PASSWORD);
oDoc.LoadFromFile(OutFile('encrypted.pdf'));
vText := string(oDoc.ExtractTextW(0));

oSource.LoadFromFile(OutFile('merged.pdf'));
vHalf := CS_A4_HEIGHT / 2;
oSheet := nil;
for i := 0 to oSource.PageCount - 1 do
begin
  // a landscape A4 sheet for every 2 source pages
  if i mod 2 = 0 then
    oSheet := oTarget.AddPage(CS_A4_HEIGHT, CS_A4_WIDTH);
  // CapturePage
  vForm := oTarget.AddPageAsForm(oSource, i);
  // DrawCapturedPage, scaled to fit the left or the right half
  oSheet.DrawFormInRect(vForm, sgcPDFRect((i mod 2) * vHalf, 0,
    (i mod 2) * vHalf + vHalf, CS_A4_WIDTH), True);
end;
oTarget.SaveToFile(OutFile('imposed_2up.pdf'));

// PdfiumViewer: PdfViewer (UserControl with toolbar) and its PdfRenderer (the page
// surface, PdfViewer.Renderer) -> one control, TsgcPDFViewerControl
private TsgcPDFViewerControl FViewer;

FViewer = new TsgcPDFViewerControl();
FViewer.Parent = pnlViewer;
FViewer.Dock = DockStyle.Fill;
// PdfiumViewer: PdfRenderer.DisplayRectangleChanged / polling PdfRenderer.Page -> OnPageChange
FViewer.OnPageChange = DoPageChange;
// PdfiumViewer: none, PdfiumViewer renders form fields but cannot edit them.
// sgcPDF: the user types into text fields and toggles check boxes in the viewer
FViewer.FormFilling = true;
FViewer.OnFieldChange = DoFieldChange;
// PdfiumViewer: none. sgcPDF: AnnotationTool adds notes, highlights, shapes, ink
// and stamps with the mouse; AnnotationEditing moves, resizes and deletes them
FViewer.AnnotationAuthor = "sgcPDF demo";

// PdfiumViewer: pdfViewer1.Document = PdfDocument.Load(AFileName)
// sgcPDF: the viewer loads and owns the document; to share a document you load
// yourself, assign it: FViewer.Document = vDoc (you dispose it)
FViewer.LoadFromFile(AFileName);
// PdfiumViewer: PdfViewer.ZoomMode = PdfViewerZoomMode.FitWidth
FViewer.ZoomMode = TsgcPDFViewerZoomMode.zmFitWidth;
// PdfiumViewer: PdfDocument.PageCount -> TsgcPDFViewerControl.PageCount
// (or TsgcPDFDocument.PageCount(), a method)
Log("Opened " + Path.GetFileName(AFileName) + ", " + sgcPDF_RTL.IntToStr(FViewer.PageCount) + " pages");

internal void FitWidth()
{
    // PdfiumViewer: PdfViewerZoomMode.FitWidth -> TsgcPDFViewerZoomMode.zmFitWidth
    FViewer.ZoomMode = TsgcPDFViewerZoomMode.zmFitWidth;
}

internal void FitPage()
{
    // PdfiumViewer: PdfViewerZoomMode.FitBest -> TsgcPDFViewerZoomMode.zmFitPage
    FViewer.ZoomMode = TsgcPDFViewerZoomMode.zmFitPage;
}

internal void FitHeight()
{
    // PdfiumViewer: PdfViewerZoomMode.FitHeight -> TsgcPDFViewerZoomMode.zmFitHeight
    FViewer.ZoomMode = TsgcPDFViewerZoomMode.zmFitHeight;
}

internal void RotateLeft()
{
    // PdfiumViewer: PdfRenderer.RotateLeft() -> TsgcPDFViewerControl.RotateLeft()
    // (ViewRotation turns the view only, the document is not changed)
    FViewer.RotateLeft();
}

internal void RotateRight()
{
    // PdfiumViewer: PdfRenderer.RotateRight() -> TsgcPDFViewerControl.RotateRight()
    FViewer.RotateRight();
}

internal void SetZoomPercent(double APercent)
{
    // PdfiumViewer: PdfRenderer.Zoom is a factor (1.0 = 100%);
    // TsgcPDFViewerControl.Zoom is a percentage (100 = 100%) and sets ZoomMode to zmCustom
    FViewer.Zoom = APercent;
}

// PdfiumViewer: PdfDocument.Search(text, matchCase, wholeWord) returns PdfMatches
// and the app adds PdfMarker objects to PdfRenderer.Markers to highlight them.
// sgcPDF: FindText highlights every match and scrolls to the first one,
// FindNext / FindPrevious move between them, GetSearchMatch(i) gives page and chars
if (!FViewer.FindText(AText, false, false))
{
    Log("Not found: " + AText);
    return 0;
}
for (int i = 0; i < FViewer.SearchResults; i++)
{
    TsgcPDFViewerSearchMatch vMatch = FViewer.GetSearchMatch(i);
    Log("Match " + sgcPDF_RTL.IntToStr(i + 1) + ": page " + sgcPDF_RTL.IntToStr(vMatch.PageIndex + 1) +
      ", char " + sgcPDF_RTL.IntToStr(vMatch.FirstChar));
}
return FViewer.SearchResults;

// PdfiumViewer: using (PrintDocument d = PdfDocument.CreatePrintDocument())
//   { PrintDialog dlg = new PrintDialog(); dlg.Document = d; if (dlg.ShowDialog() == OK) d.Print(); }
// sgcPDF: TsgcPDFViewerControl.CreatePrintDocument() returns the same kind of
// System.Drawing.Printing.PrintDocument, so the PdfiumViewer code stays as it is. It honours
// the page range (all, some pages, current page), copies and collate of its PrinterSettings.
// A shorter way: FViewer.PrintDialog(title) shows the dialog and prints in one call, and
// FViewer.Print(from, to, title) prints without a dialog (0-based pages, -1 = last page).
if (FViewer.PageCount == 0)
    return;
using (PrintDocument vDoc = FViewer.CreatePrintDocument())
using (PrintDialog vDialog = new PrintDialog())
{
    vDoc.DocumentName = "PdfiumViewer migration sample";
    vDialog.Document = vDoc;
    vDialog.AllowSomePages = true;
    vDialog.AllowCurrentPage = true;
    vDialog.UseEXDialog = true;
    vDoc.PrinterSettings.MinimumPage = 1;
    vDoc.PrinterSettings.MaximumPage = FViewer.PageCount;
    vDoc.PrinterSettings.FromPage = 1;
    vDoc.PrinterSettings.ToPage = FViewer.PageCount;
    if (vDialog.ShowDialog(this) == DialogResult.OK)
        vDoc.Print();
}

// PdfiumViewer: PrintPreviewDialog with PdfDocument.CreatePrintDocument()
// sgcPDF: the same with TsgcPDFViewerControl.CreatePrintDocument()
if (FViewer.PageCount == 0)
    return;
using (PrintDocument vDoc = FViewer.CreatePrintDocument())
using (PrintPreviewDialog vPreview = new PrintPreviewDialog())
{
    vPreview.Document = vDoc;
    vPreview.Width = 900;
    vPreview.Height = 700;
    vPreview.ShowDialog(this);
}

// PdfiumViewer: Image img = PdfDocument.Render(page, dpiX, dpiY, forPrinting)
// sgcPDF: RenderPageToBitmap(page, ref bitmap, zoomPercent, dpi); the bitmap passed
// in is disposed and replaced
Bitmap vBitmap = null;
FViewer.RenderPageToBitmap(APageIndex, ref vBitmap, 100, 150);
try
{
    vBitmap.Save(AFileName, ImageFormat.Png);
    Log("Page " + sgcPDF_RTL.IntToStr(APageIndex + 1) + " rendered at 150 dpi: " +
      sgcPDF_RTL.IntToStr(vBitmap.Width) + " x " + sgcPDF_RTL.IntToStr(vBitmap.Height) + " px, " +
      AFileName);
}
finally
{
    vBitmap.Dispose();
}
// without a viewer (server, batch): one call from file to image
sgcPDF_Export.sgcPDFPageToImage(FViewer.FileName, Path.ChangeExtension(AFileName, null) + "_file.png",
  APageIndex, 72);

// PdfiumViewer: PdfDocument.GetPdfText(page) returns the plain text of a page.
// sgcPDF: TsgcPDFDocument.ExtractTextW(page) is the same plain text, and
// TsgcPDFViewerControl.PageText(page) returns a TsgcPDFTextExtractor with the
// characters and their positions (GetTextWithPositions); the user can also select
// text with the mouse and copy it (SelectedText, CopyToClipboard)
string vText = FViewer.Document.ExtractTextW(APageIndex);
Log("Text of page " + sgcPDF_RTL.IntToStr(APageIndex + 1) + ": " + vText.Trim());
TsgcPDFTextExtractor vExtractor = FViewer.PageText(APageIndex);
if (vExtractor != null)
    Log("Characters with positions: " + sgcPDF_RTL.IntToStr(vExtractor.GetCharCount()));
return vText;

// PdfiumViewer: none (no AcroForm API). sgcPDF: AcroForm.FillField / SetCheckBox,
// then an incremental save keeps the original bytes and appends the change
TsgcPDFDocument vDoc = FViewer.Document;
if (vDoc.AcroForm.FindField("CustomerName") == null)
{
    Log("This document has no CustomerName field, open the generated sample");
    return;
}
vDoc.AcroForm.FillField("CustomerName", "ACME Ltd.");
vDoc.AcroForm.SetCheckBox("Approved", true);
FViewer.ClearCache();
FViewer.Invalidate();
vDoc.SaveIncremental(AFileName);
Log("Form filled and saved: " + AFileName);

// PdfiumViewer: none (annotations are only rendered). sgcPDF: the document's
// Annotations manager adds notes, free text, highlights, stamps, lines, shapes and
// ink; the viewer shows them after AnnotationsChanged
TsgcPDFDocument vDoc = FViewer.Document;
int vPage = FViewer.PageIndex;
TsgcPDFTextAnnotation vNote = vDoc.Annotations.AddText(vPage, 420, 760, 444, 784,
  "Migrated from PdfiumViewer to sgcPDF.");
vNote.Author = "sgcPDF demo";
vNote.SetColor(1.0, 0.9, 0.2);
vDoc.Annotations.AddHighlight(vPage, 72, 728, 330, 728, 72, 742, 330, 742);
FViewer.AnnotationsChanged();
vDoc.SaveIncremental(AFileName);
Log("Note and highlight added on page " + sgcPDF_RTL.IntToStr(vPage + 1) + ", saved: " + AFileName);