src/power/uikit/SDL_syspower.m
author Sam Lantinga <slouken@libsdl.org>
Sun, 20 Oct 2013 20:42:55 -0700
changeset 7857 6388f5229bb7
parent 7191 75360622e65f
child 8093 b43765095a6f
permissions -rw-r--r--
Added a macro SDL_TICKS_PASSED() to correctly compare two 32-bit tick values.
Went through the code and used the macro and fixed a couple places that were using incorrect timestamp comparisons.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 #include "SDL_config.h"
    22 
    23 #ifndef SDL_POWER_DISABLED
    24 #if SDL_POWER_UIKIT
    25 
    26 #import <UIKit/UIKit.h>
    27 
    28 #include "SDL_power.h"
    29 #include "SDL_timer.h"
    30 #include "SDL_assert.h"
    31 #include "SDL_syspower.h"
    32 
    33 /* turn off the battery monitor if it's been more than X ms since last check. */
    34 static const int BATTERY_MONITORING_TIMEOUT = 3000;
    35 static Uint32 SDL_UIKitLastPowerInfoQuery = 0;
    36 
    37 void
    38 SDL_UIKit_UpdateBatteryMonitoring(void)
    39 {
    40     if (SDL_UIKitLastPowerInfoQuery) {
    41         if (SDL_TICKS_PASSED(SDL_GetTicks(), SDL_UIKitLastPowerInfoQuery + BATTERY_MONITORING_TIMEOUT)) {
    42             UIDevice *uidev = [UIDevice currentDevice];
    43             SDL_assert([uidev isBatteryMonitoringEnabled] == YES);
    44             [uidev setBatteryMonitoringEnabled:NO];
    45             SDL_UIKitLastPowerInfoQuery = 0;
    46         }
    47     }
    48 }
    49 
    50 SDL_bool
    51 SDL_GetPowerInfo_UIKit(SDL_PowerState * state, int *seconds, int *percent)
    52 {
    53     UIDevice *uidev = [UIDevice currentDevice];
    54 
    55     if (!SDL_UIKitLastPowerInfoQuery) {
    56         SDL_assert([uidev isBatteryMonitoringEnabled] == NO);
    57         [uidev setBatteryMonitoringEnabled:YES];
    58     }
    59 
    60     /* UIKit_GL_SwapWindow() (etc) will check this and disable the battery
    61      *  monitoring if the app hasn't queried it in the last X seconds.
    62      *  Apparently monitoring the battery burns battery life.  :)
    63      *  Apple's docs say not to monitor the battery unless you need it.
    64      */
    65     SDL_UIKitLastPowerInfoQuery = SDL_GetTicks();
    66 
    67     *seconds = -1;   /* no API to estimate this in UIKit. */
    68 
    69     switch ([uidev batteryState])
    70     {
    71         case UIDeviceBatteryStateCharging:
    72             *state = SDL_POWERSTATE_CHARGING;
    73             break;
    74 
    75         case UIDeviceBatteryStateFull:
    76             *state = SDL_POWERSTATE_CHARGED;
    77             break;
    78 
    79         case UIDeviceBatteryStateUnplugged:
    80             *state = SDL_POWERSTATE_ON_BATTERY;
    81             break;
    82 
    83         case UIDeviceBatteryStateUnknown:
    84         default:
    85             *state = SDL_POWERSTATE_UNKNOWN;
    86             break;
    87     }
    88 
    89     const float level = [uidev batteryLevel];
    90     *percent = ( (level < 0.0f) ? -1 : (((int) (level + 0.5f)) * 100) );
    91     return SDL_TRUE;            /* always the definitive answer on iPhoneOS. */
    92 }
    93 
    94 #endif /* SDL_POWER_UIKIT */
    95 #endif /* SDL_POWER_DISABLED */
    96 
    97 /* vi: set ts=4 sw=4 expandtab: */