src/power/macosx/SDL_syspower.c

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#ifndef SDL_POWER_DISABLED
#ifdef SDL_POWER_MACOSX

#include <Carbon/Carbon.h>
#include <IOKit/ps/IOPowerSources.h>
#include <IOKit/ps/IOPSKeys.h>

#include "SDL_power.h"

/* Carbon is so verbose... */
#define STRMATCH(a,b) (CFStringCompare(a, b, 0) == kCFCompareEqualTo)
#define GETVAL(k,v) \
    CFDictionaryGetValueIfPresent(dict, CFSTR(k), (const void **) v)

/* Note that AC power sources also include a laptop battery it is charging. */
static void
checkps(CFDictionaryRef dict, SDL_bool * have_ac, SDL_bool * have_battery,
        SDL_bool * charging, int *seconds, int *percent)
{
    CFStringRef strval;         /* don't CFRelease() this. */
    CFBooleanRef bval;
    CFNumberRef numval;
    SDL_bool charge = SDL_FALSE;
    SDL_bool choose = SDL_FALSE;
    SDL_bool is_ac = SDL_FALSE;
    int secs = -1;
    int maxpct = -1;
    int pct = -1;

    if ((GETVAL(kIOPSIsPresentKey, &bval)) && (bval == kCFBooleanFalse)) {
        return;                 /* nothing to see here. */
    }

    if (!GETVAL(kIOPSPowerSourceStateKey, &strval)) {
        return;
    }

    if (STRMATCH(strval, CFSTR(kIOPSACPowerValue))) {
        is_ac = *have_ac = SDL_TRUE;
    } else if (!STRMATCH(strval, CFSTR(kIOPSBatteryPowerValue))) {
        return;                 /* not a battery? */
    }

    if ((GETVAL(kIOPSIsChargingKey, &bval)) && (bval == kCFBooleanTrue)) {
        charge = SDL_TRUE;
    }

    if (GETVAL(kIOPSMaxCapacityKey, &numval)) {
        SInt32 val = -1;
        CFNumberGetValue(numval, kCFNumberSInt32Type, &val);
        if (val > 0) {
            *have_battery = SDL_TRUE;
            maxpct = (int) val;
        }
    }

    if (GETVAL(kIOPSMaxCapacityKey, &numval)) {
        SInt32 val = -1;
        CFNumberGetValue(numval, kCFNumberSInt32Type, &val);
        if (val > 0) {
            *have_battery = SDL_TRUE;
            maxpct = (int) val;
        }
    }

    if (GETVAL(kIOPSTimeToEmptyKey, &numval)) {
        SInt32 val = -1;
        CFNumberGetValue(numval, kCFNumberSInt32Type, &val);

        /* Mac OS X reports 0 minutes until empty if you're plugged in. :( */
        if ((val == 0) && (is_ac)) {
            val = -1;           /* !!! FIXME: calc from timeToFull and capacity? */
        }

        secs = (int) val;
        if (secs > 0) {
            secs *= 60;         /* value is in minutes, so convert to seconds. */
        }
    }

    if (GETVAL(kIOPSCurrentCapacityKey, &numval)) {
        SInt32 val = -1;
        CFNumberGetValue(numval, kCFNumberSInt32Type, &val);
        pct = (int) val;
    }

    if ((pct > 0) && (maxpct > 0)) {
        pct = (int) ((((double) pct) / ((double) maxpct)) * 100.0);
    }

    if (pct > 100) {
        pct = 100;
    }

    /*
     * We pick the battery that claims to have the most minutes left.
     *  (failing a report of minutes, we'll take the highest percent.)
     */
    if ((secs < 0) && (*seconds < 0)) {
        if ((pct < 0) && (*percent < 0)) {
            choose = SDL_TRUE;  /* at least we know there's a battery. */
        }
        if (pct > *percent) {
            choose = SDL_TRUE;
        }
    } else if (secs > *seconds) {
        choose = SDL_TRUE;
    }

    if (choose) {
        *seconds = secs;
        *percent = pct;
        *charging = charge;
    }
}

#undef GETVAL
#undef STRMATCH


SDL_bool
SDL_GetPowerInfo_MacOSX(SDL_PowerState * state, int *seconds, int *percent)
{
    CFTypeRef blob = IOPSCopyPowerSourcesInfo();

    *seconds = -1;
    *percent = -1;
    *state = SDL_POWERSTATE_UNKNOWN;

    if (blob != NULL) {
        CFArrayRef list = IOPSCopyPowerSourcesList(blob);
        if (list != NULL) {
            /* don't CFRelease() the list items, or dictionaries! */
            SDL_bool have_ac = SDL_FALSE;
            SDL_bool have_battery = SDL_FALSE;
            SDL_bool charging = SDL_FALSE;
            const CFIndex total = CFArrayGetCount(list);
            CFIndex i;
            for (i = 0; i < total; i++) {
                CFTypeRef ps = (CFTypeRef) CFArrayGetValueAtIndex(list, i);
                CFDictionaryRef dict =
                    IOPSGetPowerSourceDescription(blob, ps);
                if (dict != NULL) {
                    checkps(dict, &have_ac, &have_battery, &charging,
                            seconds, percent);
                }
            }

            if (!have_battery) {
                *state = SDL_POWERSTATE_NO_BATTERY;
            } else if (charging) {
                *state = SDL_POWERSTATE_CHARGING;
            } else if (have_ac) {
                *state = SDL_POWERSTATE_CHARGED;
            } else {
                *state = SDL_POWERSTATE_ON_BATTERY;
            }

            CFRelease(list);
        }
        CFRelease(blob);
    }

    return SDL_TRUE;            /* always the definitive answer on Mac OS X. */
}

#endif /* SDL_POWER_MACOSX */
#endif /* SDL_POWER_DISABLED */

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