PDF example

Update https://skia.org/user/sample/pdf to use example.

https://fiddle.skia.org/c/0777df0419252e28d93c26fb5b789059

Change-Id: Ia828cd5d2ffd30d24a237ffaa3b007984d98a3ba
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/216345
Auto-Submit: Hal Canary <halcanary@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>

docs/examples/PDF.cpp

@@ -0,0 +1,64 @@
+// Copyright 2019 Google LLC.
+// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
+#include "tools/fiddle/examples.h"
+REG_FIDDLE(PDF, 256, 256, true, 0) {
+
+// Here is an example of using Skia’s PDF backend (SkPDF) via the SkDocument
+// and SkCanvas APIs.
+void WritePDF(SkWStream* outputStream,
+              const char* documentTitle,
+              void (*writePage)(SkCanvas*, int page),
+              int numberOfPages,
+              SkSize pageSize) {
+    SkPDF::Metadata metadata;
+    metadata.fTitle = documentTitle;
+    metadata.fCreator = "Example WritePDF() Function";
+    metadata.fCreation = {0, 2019, 1, 4, 31, 12, 34, 56};
+    metadata.fModified = {0, 2019, 1, 4, 31, 12, 34, 56};
+    auto pdfDocument = SkPDF::MakeDocument(outputStream, metadata);
+    SkASSERT(pdfDocument);
+    for (int page = 0; page < numberOfPages; ++page) {
+        SkCanvas* pageCanvas = pdfDocument->beginPage(pageSize.width(),
+                                                      pageSize.height());
+        writePage(pageCanvas, page);
+        pdfDocument->endPage();
+    }
+    pdfDocument->close();
+}
+
+// Print binary data to stdout as hex.
+void print_data(const SkData* data, const char* name) {
+    if (data) {
+        SkDebugf("\nxxd -r -p > %s << EOF", name);
+        size_t s = data->size();
+        const uint8_t* d = data->bytes();
+        for (size_t i = 0; i < s; ++i) {
+            if (i % 40 == 0) { SkDebugf("\n"); }
+            SkDebugf("%02x", d[i]);
+        }
+        SkDebugf("\nEOF\n\n");
+    }
+}
+
+// example function that draws on a SkCanvas.
+void write_page(SkCanvas* canvas, int) {
+    const SkScalar R = 115.2f, C = 128.0f;
+    SkPath path;
+    path.moveTo(C + R, C);
+    for (int i = 1; i < 8; ++i) {
+        SkScalar a = 2.6927937f * i;
+        path.lineTo(C + R * cos(a), C + R * sin(a));
+    }
+    SkPaint paint;
+    paint.setStyle(SkPaint::kStroke_Style);
+    canvas->drawPath(path, paint);
+}
+
+void draw(SkCanvas*) {
+    constexpr SkSize ansiLetterSize{8.5f * 72, 11.0f * 72};
+    SkDynamicMemoryWStream buffer;
+    WritePDF(&buffer, "SkPDF Example", &write_page, 1, ansiLetterSize);
+    sk_sp<SkData> pdfData = buffer.detachAsData();
+    print_data(pdfData.get(), "skpdf_example.pdf");
+}
+}  // END FIDDLE

site/user/sample/pdf.md

@@ -4,33 +4,8 @@ Using Skia's PDF Backend
 Here is an example of using Skia's PDF backend (SkPDF) via the
 SkDocument and SkCanvas APIs.
 
-<!--?prettify lang=cc?-->
-
-    #include "SkPDFDocument.h"
-
-    void WritePDF(SkWStream* outputStream,
-                  const char* documentTitle,
-                  void (*writePage)(SkCanvas*, int page),
-                  int numberOfPages,
-                  SkSize pageSize) {
-        SkPDF::Metadata metadata;
-        metadata.fTitle = documentTitle;
-        metadata.fCreator = "Example WritePDF() Function";
-        SkTime::DateTime now;
-        SkTime::GetDateTime(&now);
-        metadata.fCreation = now;
-        metadata.fModified = now;
-        auto pdfDocument = SkPDF::MakeDocument(outputStream, metadata);
-        assert(pdfDocument);
-
-        for (int page = 0; page < numberOfPages; ++page) {
-            SkCanvas* pageCanvas = pdfDocument->beginPage(pageSize.width(),
-                                                          pageSize.height());
-            writePage(pageCanvas, page);
-            pdfDocument->endPage();
-        }
-        pdfDocument->close();
-    }
+<fiddle-embed name='@PDF'></fiddle-embed>
+<!-- https://fiddle.skia.org/c/@PDF docs/examples/PDF.cpp -->
 
 * * *
 

tools/fiddle/all_examples.cpp

@@ -529,6 +529,7 @@
 #include "../../docs/examples/Modulate.cpp"
 #include "../../docs/examples/Multiply.cpp"
 #include "../../docs/examples/Overlay.cpp"
+#include "../../docs/examples/PDF.cpp"
 #include "../../docs/examples/Paint_053.cpp"
 #include "../../docs/examples/Paint_057.cpp"
 #include "../../docs/examples/Paint_containsText.cpp"