PDF: add support for named destinations.

gm/internal_links.cpp

Index: gm/internal_links.cpp
===================================================================
--- gm/internal_links.cpp	(revision 0)
+++ gm/internal_links.cpp	(revision 0)
@@ -0,0 +1,77 @@
+
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "gm.h"
+
+#include "SkAnnotation.h"
+#include "SkData.h"
+
+namespace skiagm {
+
+/** Draws two rectangles. In output formats that support internal links (PDF),
+ *  clicking the one labeled "Link to A" should take you to the one labeled
+ *  "Target A". Note that you'll need to zoom your PDF viewer in a fair bit in
+ *  order for the scrolling to not be blocked by the edge of the document.
+ */
+class InternalLinksGM : public GM {
+public:
+    InternalLinksGM() {
+        this->setBGColor(0xFFDDDDDD);
+    }
+
+protected:
+    virtual SkString onShortName() {
+        return SkString("internal_links");
+    }
+
+    virtual SkISize onISize() {
+        return make_isize(700, 500);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        SkAutoTUnref<SkData> name(SkData::NewWithCString("target-a"));
+
+        canvas->save();
+        canvas->translate(SkIntToScalar(100), SkIntToScalar(100));
+        drawLabeledRect(canvas, "Link to A", 0, 0);
+        SkRect rect = SkRect::MakeXYWH(0, 0, SkIntToScalar(50), SkIntToScalar(20));
+        SkAnnotateLinkToDestination(canvas, rect, name.get());
+        canvas->restore();
+
+        canvas->save();
+        canvas->translate(SkIntToScalar(200), SkIntToScalar(200));
+        SkPoint point = SkPoint::Make(SkIntToScalar(100), SkIntToScalar(50));
+        drawLabeledRect(canvas, "Target A", point.x(), point.y());
+        SkAnnotateNamedDestination(canvas, point, name.get());
+        canvas->restore();
+    }
+
+private:
+    /** Draw an arbitrary rectangle at a given location and label it with some
+     *  text. */
+    void drawLabeledRect(SkCanvas* canvas, const char* text, SkScalar x, SkScalar y) {
+        SkPaint paint;
+        paint.setColor(SK_ColorBLUE);
+        SkRect rect = SkRect::MakeXYWH(x, y,
+                                       SkIntToScalar(50), SkIntToScalar(20));
+        canvas->drawRect(rect, paint);
+
+        paint.setAntiAlias(true);
+        paint.setTextSize(SkIntToScalar(25));
+        paint.setColor(SK_ColorBLACK);
+        canvas->drawText(text, strlen(text), x, y, paint);
+    }
+
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static GM* MyFactory(void*) { return SkNEW(InternalLinksGM); }
+static GMRegistry reg(MyFactory);
+
+}