Update PDF backend to support fallback fonts on Android.

gm/androidfallback.cpp

+/*
+ * 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"
+
+namespace skiagm {
+
+class AndroidFallbackGM : public GM {
+public:
+    AndroidFallbackGM() {
+        this->setBGColor(0xFFCCCCCC);
+    }
+
+protected:
+    virtual SkString onShortName() SK_OVERRIDE {
+        return SkString("android_paint");
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE {
+        return make_isize(500, 500);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+
+        SkPaint paint;
+        paint.setTextEncoding(SkPaint::kUTF16_TextEncoding);
+        paint.setTextSize(24);
+
+#if SK_BUILD_FOR_ANDROID
+        SkPaintOptionsAndroid options = paint.getPaintOptionsAndroid();
+        options.setUseFontFallbacks(true);
+        paint.setPaintOptionsAndroid(options);
+#endif
+
+        // "א foo 免舌 bar क"
+        const uint16_t unicodeStr[] = {0x05D0, 0x0020, 0x0066, 0x006F, 0x006F, 0x0020, 0x514D,
+                                       0x820c, 0x0020, 0x0062, 0x0061, 0x0072, 0x0020, 0x0915};
+        const int strLength = sizeof(unicodeStr) / sizeof(uint16_t);
+        const int strByteLength = sizeof(unicodeStr);
+
+        SkScalar posX[strLength];
+        SkPoint posXY[strLength];
+
+        for (int i = 0; i < strLength; ++i) {
+            posX[i] = SkIntToScalar(i * 24);
+            posXY[i].fX = posX[i];
+            posXY[i].fY = SkIntToScalar(24 + i);
+        }
+
+        canvas->translate(SkIntToScalar(10), SkIntToScalar(25));
+        // This currently causes the PDF backend to assert
+        // canvas->drawText(unicodeStr, strByteLength, 0, 0, paint);
+
+        canvas->translate(0, SkIntToScalar(75));
+        canvas->drawPosTextH(unicodeStr, strByteLength, posX, 0, paint);
+
+#if SK_BUILD_FOR_ANDROID
+        options.setLanguage("ja");
+        paint.setPaintOptionsAndroid(options);
+#endif
+
+        canvas->translate(0, SkIntToScalar(75));
+        canvas->drawPosText(unicodeStr, strByteLength, posXY, paint);
+
+        SkPath path;
+        path.moveTo(0, 0);
+        path.quadTo(50.0f, 100.0f, 250.0f, 150.0f);
+
+        canvas->translate(0, SkIntToScalar(75));
+        canvas->drawTextOnPath(unicodeStr, strByteLength, path, NULL, paint);
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+#if SK_BUILD_FOR_ANDROID
+DEF_GM( return SkNEW(AndroidFallbackGM); )
+#endif
+
+}