Initial commit of our new Android app to demo Skia.

tools/viewer/sk_app/android/surface_glue_android.h

+/*
+* Copyright 2016 Google Inc.
+*
+* Use of this source code is governed by a BSD-style license that can be
+* found in the LICENSE file.
+*/
+
+#ifndef surface_glue_android_DEFINED
+#define surface_glue_android_DEFINED
+
+#include <pthread.h>
+
+#include <android/native_window_jni.h>
+
+#include "../Application.h"
+#include "../Window.h"
+
+namespace sk_app {
+
+enum MessageType {
+    kUndefined,
+    kSurfaceCreated,
+    kSurfaceChanged,
+    kSurfaceDestroyed,
+    kDestroyApp,
+    kContentInvalidated
+};
+
+struct Message {
+    MessageType fType = kUndefined;
+    ANativeWindow* fNativeWindow = nullptr;
+
+    Message() {}
+    Message(MessageType t) : fType(t) {}
+};
+
+struct SkiaAndroidApp {
+    int fPipes[2];  // 0 is the read message pipe, 1 is the write message pipe
+    Application* fApp;
+    Window* fWindow;
+    ANativeWindow* fNativeWindow;
+
+    SkiaAndroidApp();
+    ~SkiaAndroidApp();
+    void postMessage(const Message& message);
+    void readMessage(Message* message);
+    void paintIfNeeded();
+
+private:
+    pthread_t fThread;
+};
+
+}  // namespace sk_app
+
+#endif