RetroArch/frontend/drivers/android_native_app_glue.c

/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2015 - Daniel De Matteis
 *  Copyright (C) 2012-2015 - Michael Lelli
 * 
 *  RetroArch is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include "platform_android.h"

struct android_app *g_android;
struct android_app_userdata *g_android_userdata;

static void free_saved_state(struct android_app* android_app)
{
    pthread_mutex_lock(&android_app->mutex);
    if (android_app->savedState != NULL)
    {
        free(android_app->savedState);
        android_app->savedState = NULL;
        android_app->savedStateSize = 0;
    }
    pthread_mutex_unlock(&android_app->mutex);
}

void android_app_write_cmd(struct android_app *android_app, int8_t cmd)
{
   if (write(android_app->msgwrite, &cmd, sizeof(cmd)) != sizeof(cmd))
      RARCH_ERR("Failure writing android_app cmd: %s\n", strerror(errno));
}

int8_t android_app_read_cmd(struct android_app *android_app)
{
   int8_t cmd;
   if (read(android_app->msgread, &cmd, sizeof(cmd)) == sizeof(cmd))
   {
      switch (cmd)
      {
         case APP_CMD_SAVE_STATE:
            free_saved_state(android_app);
            break;
      }
      return cmd;
   }
   else
   {
      RARCH_ERR("No data on command pipe.\n");
   }
   return 1;
}

static void android_app_set_input(void *data, AInputQueue* inputQueue)
{
   struct android_app *android_app = (struct android_app*)data;

   if (!android_app)
      return;

   pthread_mutex_lock(&android_app->mutex);
   android_app->pendingInputQueue = inputQueue;
   android_app_write_cmd(android_app, APP_CMD_INPUT_CHANGED);

   while (android_app->inputQueue != android_app->pendingInputQueue)
      pthread_cond_wait(&android_app->cond, &android_app->mutex);

   pthread_mutex_unlock(&android_app->mutex);
}

static void android_app_set_window(void *data, ANativeWindow* window)
{
   struct android_app *android_app = (struct android_app*)data;

   if (!android_app)
      return;

   pthread_mutex_lock(&android_app->mutex);
   if (android_app->pendingWindow)
      android_app_write_cmd(android_app, APP_CMD_TERM_WINDOW);

   android_app->pendingWindow = window;

   if (window)
      android_app_write_cmd(android_app, APP_CMD_INIT_WINDOW);

   while (android_app->window != android_app->pendingWindow)
      pthread_cond_wait(&android_app->cond, &android_app->mutex);

   pthread_mutex_unlock(&android_app->mutex);
}

static void android_app_set_activity_state(void *data, int8_t cmd)
{
   struct android_app *android_app = (struct android_app*)data;

   if (!android_app)
      return;

   pthread_mutex_lock(&android_app->mutex);
   android_app_write_cmd(android_app, cmd);
   while (android_app->activityState != cmd
         && android_app->activityState != APP_CMD_DEAD)
      pthread_cond_wait(&android_app->cond, &android_app->mutex);
   pthread_mutex_unlock(&android_app->mutex);

   if (android_app->activityState == APP_CMD_DEAD)
      RARCH_LOG("RetroArch native thread is dead.\n");
}

static void android_app_free(struct android_app* android_app)
{
    pthread_mutex_lock(&android_app->mutex);
    android_app_write_cmd(android_app, APP_CMD_DESTROY);
    while (!android_app->destroyed)
        pthread_cond_wait(&android_app->cond, &android_app->mutex);
    pthread_mutex_unlock(&android_app->mutex);

    close(android_app->msgread);
    close(android_app->msgwrite);
    pthread_cond_destroy(&android_app->cond);
    pthread_mutex_destroy(&android_app->mutex);
    free(android_app);
}

static void onDestroy(ANativeActivity* activity)
{
   RARCH_LOG("Destroy: %p\n", activity);
   android_app_free((struct android_app*)activity->instance);
}

static void onStart(ANativeActivity* activity)
{
   RARCH_LOG("Start: %p\n", activity);
   android_app_set_activity_state((struct android_app*)
         activity->instance, APP_CMD_START);
}

static void onResume(ANativeActivity* activity)
{
   RARCH_LOG("Resume: %p\n", activity);
   android_app_set_activity_state((struct android_app*)
         activity->instance, APP_CMD_RESUME);
}

static void* onSaveInstanceState(ANativeActivity* activity, size_t* outLen)
{
   struct android_app* android_app = (struct android_app*)activity->instance;
   void* savedState = NULL;

   pthread_mutex_lock(&android_app->mutex);
   android_app->stateSaved = 0;
   android_app_write_cmd(android_app, APP_CMD_SAVE_STATE);
   while (!android_app->stateSaved)
      pthread_cond_wait(&android_app->cond, &android_app->mutex);

   if (android_app->savedState != NULL)
   {
      savedState = android_app->savedState;
      *outLen = android_app->savedStateSize;
      android_app->savedState = NULL;
      android_app->savedStateSize = 0;
   }

   pthread_mutex_unlock(&android_app->mutex);

   return savedState;
}

static void onPause(ANativeActivity* activity)
{
   RARCH_LOG("Pause: %p\n", activity);
   android_app_set_activity_state((struct android_app*)
         activity->instance, APP_CMD_PAUSE);
}

static void onStop(ANativeActivity* activity)
{
   RARCH_LOG("Stop: %p\n", activity);
   android_app_set_activity_state((struct android_app*)
         activity->instance, APP_CMD_STOP);
}

static void onConfigurationChanged(ANativeActivity *activity)
{
   struct android_app* android_app = (struct android_app*)
      activity->instance;

   if (!android_app)
      return;

   RARCH_LOG("ConfigurationChanged: %p\n", activity);
   android_app_write_cmd(android_app, APP_CMD_CONFIG_CHANGED);
}

static void onLowMemory(ANativeActivity* activity)
{
    struct android_app* android_app = (struct android_app*)activity->instance;
    android_app_write_cmd(android_app, APP_CMD_LOW_MEMORY);
}

static void onWindowFocusChanged(ANativeActivity* activity, int focused)
{
   RARCH_LOG("WindowFocusChanged: %p -- %d\n", activity, focused);
   android_app_write_cmd((struct android_app*)activity->instance,
         focused ? APP_CMD_GAINED_FOCUS : APP_CMD_LOST_FOCUS);
}

static void onNativeWindowCreated(ANativeActivity* activity,
      ANativeWindow* window)
{
   RARCH_LOG("NativeWindowCreated: %p -- %p\n", activity, window);
   android_app_set_window((struct android_app*)activity->instance, window);
}

static void onNativeWindowDestroyed(ANativeActivity* activity,
      ANativeWindow* window)
{
   RARCH_LOG("NativeWindowDestroyed: %p -- %p\n", activity, window);
   android_app_set_window((struct android_app*)activity->instance, NULL);
}

static void onInputQueueCreated(ANativeActivity* activity, AInputQueue* queue)
{
   RARCH_LOG("InputQueueCreated: %p -- %p\n", activity, queue);
   android_app_set_input((struct android_app*)activity->instance, queue);
}

static void onInputQueueDestroyed(ANativeActivity* activity,
      AInputQueue* queue)
{
   RARCH_LOG("InputQueueDestroyed: %p -- %p\n", activity, queue);
   android_app_set_input((struct android_app*)activity->instance, NULL);
}

static void *android_app_entry(void *param)
{
   struct android_app* android_app = (struct android_app*)param;
   ALooper *looper = (ALooper*)ALooper_prepare(ALOOPER_PREPARE_ALLOW_NON_CALLBACKS);
   ALooper_addFd(looper, android_app->msgread, LOOPER_ID_MAIN,
         ALOOPER_EVENT_INPUT, NULL, NULL);
   android_app->looper = looper;

   pthread_mutex_lock(&android_app->mutex);
   android_app->running = 1;
   pthread_cond_broadcast(&android_app->cond);
   pthread_mutex_unlock(&android_app->mutex);

   android_main(android_app);
   return NULL;
}

static struct android_app* android_app_create(ANativeActivity* activity,
        void* savedState, size_t savedStateSize)
{
   int msgpipe[2];
   struct android_app* android_app = (struct android_app*)
      calloc(1, sizeof(*android_app));
   android_app->activity = activity;

   pthread_mutex_init(&android_app->mutex, NULL);
   pthread_cond_init(&android_app->cond, NULL);

   if (savedState != NULL)
   {
      android_app->savedState = malloc(savedStateSize);
      android_app->savedStateSize = savedStateSize;
      memcpy(android_app->savedState, savedState, savedStateSize);
   }

   if (pipe(msgpipe))
   {
      RARCH_ERR("could not create pipe: %s.\n", strerror(errno));
      activity->instance = NULL;
   }
   android_app->msgread  = msgpipe[0];
   android_app->msgwrite = msgpipe[1];

   pthread_attr_t attr; 
   pthread_attr_init(&attr);
   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
   pthread_create(&android_app->thread, &attr, android_app_entry, android_app);

   /* Wait for thread to start. */
   pthread_mutex_lock(&android_app->mutex);
   while (!android_app->running)
      pthread_cond_wait(&android_app->cond, &android_app->mutex);
   pthread_mutex_unlock(&android_app->mutex);

   /* These are set only for the native activity,
    * and are reset when it ends. */
   ANativeActivity_setWindowFlags(activity, AWINDOW_FLAG_KEEP_SCREEN_ON
         | AWINDOW_FLAG_FULLSCREEN, 0);

   return android_app;
}

/*
 * Native activity interaction (called from main thread)
 **/

void ANativeActivity_onCreate(ANativeActivity* activity,
      void* savedState, size_t savedStateSize)
{
   RARCH_LOG("Creating Native Activity: %p\n", activity);
   activity->callbacks->onDestroy               = onDestroy;
   activity->callbacks->onStart                 = onStart;
   activity->callbacks->onResume                = onResume;
   activity->callbacks->onSaveInstanceState     = onSaveInstanceState;
   activity->callbacks->onPause                 = onPause;
   activity->callbacks->onStop                  = onStop;
   activity->callbacks->onConfigurationChanged  = onConfigurationChanged;
   activity->callbacks->onLowMemory             = onLowMemory;
   activity->callbacks->onWindowFocusChanged    = onWindowFocusChanged;
   activity->callbacks->onNativeWindowCreated   = onNativeWindowCreated;
   activity->callbacks->onNativeWindowDestroyed = onNativeWindowDestroyed;
   activity->callbacks->onInputQueueCreated     = onInputQueueCreated;
   activity->callbacks->onInputQueueDestroyed   = onInputQueueDestroyed;

   activity->instance = android_app_create(activity, savedState, savedStateSize);
}

int system_property_get(const char *name, char *value)
{
   FILE *pipe;
   int length = 0;
   char buffer[PATH_MAX_LENGTH];
   char cmd[PATH_MAX_LENGTH];
   char *curpos = NULL;

   snprintf(cmd, sizeof(cmd), "getprop %s", name);

   pipe = popen(cmd, "r");

   if (!pipe)
   {
      RARCH_ERR("Could not create pipe.\n");
      return 0;
   }

   curpos = value;
   
   while (!feof(pipe))
   {
      if (fgets(buffer, 128, pipe) != NULL)
      {
         int curlen = strlen(buffer);

         memcpy(curpos, buffer, curlen);

         curpos    += curlen;
         length    += curlen;
      }
   }

   *curpos = '\0';

   pclose(pipe);

   return length;
}