안드로이드 - Looper

Looper

키보드, 모션(터치) 등을 처리하는 기능.

..\Android\android-ndk-r13b\platforms\android-12\arch-x86\usr\include\android\looper.h

/**

 * For callback-based event loops, this is the prototype of the function

 * that is called when a file descriptor event occurs.

 * It is given the file descriptor it is associated with,

 * a bitmask of the poll events that were triggered (typically ALOOPER_EVENT_INPUT),

 * and the data pointer that was originally supplied.

 *

 * Implementations should return 1 to continue receiving callbacks, or 0

 * to have this file descriptor and callback unregistered from the looper.

 */

typedef int (*ALooper_callbackFunc)(int fd, int events, void* data);

/**

 * Waits for events to be available, with optional timeout in milliseconds.

 * Invokes callbacks for all file descriptors on which an event occurred.

 *

 * If the timeout is zero, returns immediately without blocking.

 * If the timeout is negative, waits indefinitely until an event appears.

 *

 * Returns ALOOPER_POLL_WAKE if the poll was awoken using wake() before

 * the timeout expired and no callbacks were invoked and no other file

 * descriptors were ready.

 *

 * Returns ALOOPER_POLL_CALLBACK if one or more callbacks were invoked.

 *

 * Returns ALOOPER_POLL_TIMEOUT if there was no data before the given

 * timeout expired.

 *

 * Returns ALOOPER_POLL_ERROR if an error occurred.

 *

 * Returns a value >= 0 containing an identifier if its file descriptor has data

 * and it has no callback function (requiring the caller here to handle it).

 * In this (and only this) case outFd, outEvents and outData will contain the poll

 * events and data associated with the fd, otherwise they will be set to NULL.

 *

 * This method does not return until it has finished invoking the appropriate callbacks

 * for all file descriptors that were signalled.

 */

int ALooper_pollOnce(int timeoutMillis, int* outFd, int* outEvents, void** outData);

/**

 * Like ALooper_pollOnce(), but performs all pending callbacks until all

 * data has been consumed or a file descriptor is available with no callback.

 * This function will never return ALOOPER_POLL_CALLBACK.

 */

int ALooper_pollAll(int timeoutMillis, int* outFd, int* outEvents, void** outData);

   // loop waiting for stuff to do.

//on_program_start();

while (1) {

// Read all pending events.

int ident;

int events;

struct android_poll_source* source;

// If not animating, we will block forever waiting for events.

// If animating, we loop until all events are read, then continue

// to draw the next frame of animation.

while ((ident=ALooper_pollAll(engine.animating ? 0 : -1, NULL, &events,

(void**)&source)) >= 0) {

// Process this event.

if (source != NULL) {

source->process(state, source);

}

// Check if we are exiting.

if (state->destroyRequested != 0) {

DEBUG_socket_printf("Engine thread destroy requested!\r\n");

//engine_term_display(&engine);

goto end;//return;

}

}

if (engine.animating)

{

engine_draw_frame(&engine);

}

}