Add drawer with state information

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,
     kKeyPressed,
-    kTouched
+    kTouched,
+    kSetState
 };
 
 struct Message {
     MessageType fType = kUndefined;
     ANativeWindow* fNativeWindow = nullptr;
     int fKeycode = 0;
     int fTouchOwner, fTouchState;
     float fTouchX, fTouchY;
 
+    // Make sure to delete following SkStrings after consumption
+    SkString* stateName;

[djsollen, 2016/05/24 17:32:40]

don't store pointers just store an SkString

[liyuqian, 2016/05/24 20:18:05]

We'll preserve the pointers because of the message pipes.

+    SkString* stateValue;
+
     Message() {}
     Message(MessageType t) : fType(t) {}
 };
 
 struct SkiaAndroidApp {
     Application* fApp;
     Window* fWindow;
     jobject fAndroidApp;
 
     SkiaAndroidApp(JNIEnv* env, jobject androidApp);
 
     void postMessage(const Message& message) const;
     void readMessage(Message* message) const;
 
-    // This must be called in SkiaAndroidApp's own pthread because the JNIEnv is thread sensitive
+    // These must be called in SkiaAndroidApp's own pthread because the JNIEnv is thread sensitive
     void setTitle(const char* title) const;
+    void updateState(const char* stateJsonStr) const;
 
 private:
     pthread_t fThread;
     ANativeWindow* fNativeWindow;
     int fPipes[2];  // 0 is the read message pipe, 1 is the write message pipe
     JavaVM* fJavaVM;
     JNIEnv* fPThreadEnv;
-    jmethodID fSetTitleMethodID;
+    jmethodID fSetTitleMethodID, fUpdateStateMethodID;
 
     // This must be called in SkiaAndroidApp's own pthread because the JNIEnv is thread sensitive
     ~SkiaAndroidApp();
 
     static int message_callback(int fd, int events, void* data);
     static void* pthread_main(void*);
 };
 
 }  // namespace sk_app
 
 #endif