ANativeWindow是个什么东西
公司经常组织一些培训，培训的都是些奇技淫巧。什么设计模式啦，开发策略啦，git啦，repo啦，另外就是培训一些开发流程的东东，例如CMMI啦。可是，却忘记了，程序员终究要归结到三个问题上：
1.解决什么问题？
2.为什么这样解决问题？
3.有没有更好的解决方案？
这些东东才是最核心的东东。但是却是一个程序员一辈子都无法完全掌握的东西。很多人以为写出了高难度的反射代码就是很牛，也有人认为利用C++模板来进行编程就多牛多牛，还有人觉得会写makefile文件，掌握了某种高难度语言很牛。但是我认为这些都不重要，重要的是要有思想。思考者比行动者在关键时候定大局。中国人的技术书籍缺乏的就是思想。在中国，可以肯定，没有几个人能写出像thinking in java这样的鸿篇巨著，更没有人能够超越 design pattern，来描述其思想。反之，像《自己动手写操作系统》，《21天学java》，《程序员的自我修养》，《面试宝典》，《C++面试一百例》, android内核开发要点等等等等一系列的书籍在中国却是层出不穷。为什么，因为缺乏思考，来不及思考，更或者懒得思考。然而，作为一名专业级的程序员，不思考就意味着退步，不学习就意味着淘汰。
这几天一直在思考ANativeWindow是个什么东西，今天终于找到了，代码贴出来，大家参考一下。
struct ANativeWindow
{
#ifdef __cplusplus
ANativeWindow()
: flags(0), minSwapInterval(0), maxSwapInterval(0), xdpi(0), ydpi(0)
{
common.magic = ANDROID_NATIVE_WINDOW_MAGIC;
common.version = sizeof(ANativeWindow);
memset(common.reserved, 0, sizeof(common.reserved));
}
/* Implement the methods that sp expects so that it
can be used to automatically refcount ANativeWindow's. */
void incStrong(const void* id) const {
common.incRef(const_cast(&common));
}
void decStrong(const void* id) const {
common.decRef(const_cast(&common));
}
#endif
struct android_native_base_t common;
/* flags describing some attributes of this surface or its updater */
const uint32_t flags;
/* min swap interval supported by this updated */
const int minSwapInterval;
/* max swap interval supported by this updated */
const int maxSwapInterval;
/* horizontal and vertical resolution in DPI */
const float xdpi;
const float ydpi;
/* Some storage reserved for the OEM's driver. */
intptr_t oem[4];
/*
* Set the swap interval for this surface.
*
* Returns 0 on success or -errno on error.
*/
int (*setSwapInterval)(struct ANativeWindow* window,
int interval);
/*
* Hook called by EGL to acquire a buffer. After this call, the buffer
* is not locked, so its content cannot be modified. This call may block if
* no buffers are available.
*
* The window holds a reference to the buffer between dequeueBuffer and
* either queueBuffer or cancelBuffer, so clients only need their own
* reference if they might use the buffer after queueing or canceling it.
* Holding a reference to a buffer after queueing or canceling it is only
* allowed if a specific buffer count has been set.
*
* Returns 0 on success or -errno on error.
*/
int (*dequeueBuffer)(struct ANativeWindow* window,
struct ANativeWindowBuffer** buffer);
/*
* hook called by EGL to lock a buffer. This MUST be called before modifying
* the content of a buffer. The buffer must have been acquired with
* dequeueBuffer first.
*
* Returns 0 on success or -errno on error.
*/
int (*lockBuffer)(struct ANativeWindow* window,
struct ANativeWindowBuffer* buffer);
/*
* Hook called by EGL when modifications to the render buffer are done.
* This unlocks and post the buffer.
*
* The window holds a reference to the buffer between dequeueBuffer and
* either queueBuffer or cancelBuffer, so clients only need their own
* reference if they might use the buffer after queueing or canceling it.
* Holding a reference to a buffer after queueing or canceling it is only
* allowed if a specific buffer count has been set.
*
* Buffers MUST be queued in the same order than they were dequeued.
*
* Returns 0 on success or -errno on error.
*/
int (*queueBuffer)(struct ANativeWindow* window,
struct ANativeWindowBuffer* buffer);
/*
* hook used to retrieve information about the native window.
*
* Returns 0 on success or -errno on error.
*/
int (*query)(const struct ANativeWindow* window,
int what, int* value);
/*
* hook used to perform various operations on the surface.
* (*perform)() is a generic mechanism to add functionality to
* ANativeWindow while keeping backward binary compatibility.
*
* DO NOT CALL THIS HOOK DIRECTLY. Instead, use the helper functions
* defined below.
*
* (*perform)() returns -ENOENT if the 'what' parameter is not supported
* by the surface's implementation.
*
* The valid operations are:
* NATIVE_WINDOW_SET_USAGE
* NATIVE_WINDOW_CONNECT (deprecated)
* NATIVE_WINDOW_DISCONNECT (deprecated)
* NATIVE_WINDOW_SET_CROP
* NATIVE_WINDOW_SET_BUFFER_COUNT
* NATIVE_WINDOW_SET_BUFFERS_GEOMETRY (deprecated)
* NATIVE_WINDOW_SET_BUFFERS_TRANSFORM
* NATIVE_WINDOW_SET_BUFFERS_TIMESTAMP
* NATIVE_WINDOW_SET_BUFFERS_DIMENSIONS
* NATIVE_WINDOW_SET_BUFFERS_FORMAT
* NATIVE_WINDOW_SET_SCALING_MODE
* NATIVE_WINDOW_LOCK (private)
* NATIVE_WINDOW_UNLOCK_AND_POST (private)
* NATIVE_WINDOW_API_CONNECT (private)
* NATIVE_WINDOW_API_DISCONNECT (private)
*
*/
int (*perform)(struct ANativeWindow* window,
int operation, ... );
/*
* Hook used to cancel a buffer that has been dequeued.
* No synchronization is performed between dequeue() and cancel(), so
* either external synchronization is needed, or these functions must be
* called from the same thread.
*
* The window holds a reference to the buffer between dequeueBuffer and
* either queueBuffer or cancelBuffer, so clients only need their own
* reference if they might use the buffer after queueing or canceling it.
* Holding a reference to a buffer after queueing or canceling it is only
* allowed if a specific buffer count has been set.
*/
int (*cancelBuffer)(struct ANativeWindow* window,
struct ANativeWindowBuffer* buffer);
void* reserved_proc[2];
};