1 // Copyright 2019 Google LLC.
2 // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3 #include "tools/fiddle/examples.h"
4 REG_FIDDLE(PDF, 256, 256, true, 0) {
5
6 // Here is an example of using Skia’s PDF backend (SkPDF) via the SkDocument
7 // and SkCanvas APIs.
WritePDF(SkWStream * outputStream,const char * documentTitle,void (* writePage)(SkCanvas *,int page),int numberOfPages,SkSize pageSize)8 void WritePDF(SkWStream* outputStream,
9 const char* documentTitle,
10 void (*writePage)(SkCanvas*, int page),
11 int numberOfPages,
12 SkSize pageSize) {
13 SkPDF::Metadata metadata;
14 metadata.fTitle = documentTitle;
15 metadata.fCreator = "Example WritePDF() Function";
16 metadata.fCreation = {0, 2019, 1, 4, 31, 12, 34, 56};
17 metadata.fModified = {0, 2019, 1, 4, 31, 12, 34, 56};
18 auto pdfDocument = SkPDF::MakeDocument(outputStream, metadata);
19 SkASSERT(pdfDocument);
20 for (int page = 0; page < numberOfPages; ++page) {
21 SkCanvas* pageCanvas = pdfDocument->beginPage(pageSize.width(),
22 pageSize.height());
23 writePage(pageCanvas, page);
24 pdfDocument->endPage();
25 }
26 pdfDocument->close();
27 }
28
29 // Print binary data to stdout as hex.
print_data(const SkData * data,const char * name)30 void print_data(const SkData* data, const char* name) {
31 if (data) {
32 SkDebugf("\nxxd -r -p > %s << EOF", name);
33 size_t s = data->size();
34 const uint8_t* d = data->bytes();
35 for (size_t i = 0; i < s; ++i) {
36 if (i % 40 == 0) { SkDebugf("\n"); }
37 SkDebugf("%02x", d[i]);
38 }
39 SkDebugf("\nEOF\n\n");
40 }
41 }
42
43 // example function that draws on a SkCanvas.
write_page(SkCanvas * canvas,int)44 void write_page(SkCanvas* canvas, int) {
45 const SkScalar R = 115.2f, C = 128.0f;
46 SkPath path;
47 path.moveTo(C + R, C);
48 for (int i = 1; i < 8; ++i) {
49 SkScalar a = 2.6927937f * i;
50 path.lineTo(C + R * cos(a), C + R * sin(a));
51 }
52 SkPaint paint;
53 paint.setStyle(SkPaint::kStroke_Style);
54 canvas->drawPath(path, paint);
55 }
56
draw(SkCanvas *)57 void draw(SkCanvas*) {
58 constexpr SkSize ansiLetterSize{8.5f * 72, 11.0f * 72};
59 SkDynamicMemoryWStream buffer;
60 WritePDF(&buffer, "SkPDF Example", &write_page, 1, ansiLetterSize);
61 sk_sp<SkData> pdfData = buffer.detachAsData();
62 print_data(pdfData.get(), "skpdf_example.pdf");
63 }
64 } // END FIDDLE
65