Android rayshader sample.

samples/android_sample/jni/activity_handler.h

+#ifndef ACTIVITY_HANDLER_H
+#define ACTIVITY_HANDLER_H
+
+class ActivityHandler {
+  public:
+    virtual int32_t onActivate() = 0;
+    virtual void onDeactivate() = 0;
+    virtual int32_t onStep() = 0;
+    virtual void onStart() {};
+    virtual void onResume() {};
+    virtual void onPause() {};
+    virtual void onStop() {};
+    virtual void onDestroy() {};
+    virtual void onSaveState(void** pData, size_t* pSize) {};
+    virtual void onConfigurationChanged() {};
+    virtual void onLowMemory() {};
+    virtual void onCreateWindow() {};
+    virtual void onDestroyWindow() {};
+    virtual void onGainedFocus() {};
+    virtual void onLostFocus() {};
+};
+    
+#endif