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      1 /*
      2  * Copyright (C) 2012 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ANDROID_BUBBLE_LEVEL_
     18 #define ANDROID_BUBBLE_LEVEL_
     19 
     20 // Callback for level measurements. isLevel is true when the device lies flat.
     21 #define BL_POLL_INTERVAL_MIN_SEC 1
     22 #define BL_POLL_INTERVAL_DEFAULT_SEC 10
     23 
     24 typedef void (*BubbleLevel_CallBack_t)(bool isLevel, void *userData);
     25 
     26 #ifdef __cplusplus
     27 
     28 class BubbleLevel
     29 {
     30 public:
     31     virtual ~BubbleLevel() {}
     32 
     33     static BubbleLevel *create();
     34 
     35     // Set a callback called every time level measurement is complete
     36     virtual int setCallback(BubbleLevel_CallBack_t callback, void *userData) = 0;
     37     // Set the callback interval in seconds
     38     virtual int setPollInterval(unsigned int seconds) = 0;
     39     // Start polling for level: the callback will be called every poll interval
     40     virtual int startPolling() = 0;
     41     // Start polling for level: the callback will not be called any more and the accelerometer
     42     // resource is released
     43     virtual int stopPolling() = 0;
     44     // The callback will be called once with current level measurement
     45     virtual int pollOnce() = 0;
     46 };
     47 
     48 extern "C" {
     49 #endif /* __cplusplus */
     50 
     51 struct bubble_level *bubble_level_create();
     52 void bubble_level_release(const struct bubble_level *bubble_level);
     53 
     54 struct bubble_level
     55 {
     56     // Set a callback called every time level measurement is complete
     57     int (*set_callback)(const struct bubble_level *bubble_level,
     58                      BubbleLevel_CallBack_t callback, void *userData);
     59     // Set the callback interval in seconds
     60     int (*set_poll_interval)(const struct bubble_level *bubble_level,
     61                           unsigned int seconds);
     62     // Start polling for level: the callback will be called every poll interval
     63     int (*start_polling)(const struct bubble_level *bubble_level);
     64     // Start polling for level: the callback will not be called any more and the accelerometer
     65     // resource is released
     66     int (*stop_polling)(const struct bubble_level *bubble_level);
     67     // The callback will be called once with current level measurement
     68     int (*poll_once)(const struct bubble_level *bubble_level);
     69 };
     70 
     71 #ifdef __cplusplus
     72 };
     73 #endif /* __cplusplus */
     74 
     75 #endif /*ANDROID_BUBBLE_LEVEL_*/
     76