src/power/SDL_power.c

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2026 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_internal.h"
#include "SDL_syspower.h"

/*
 * Returns true if we have a definitive answer.
 * false to try next implementation.
 */
typedef bool (*SDL_GetPowerInfo_Impl)(SDL_PowerState *state, int *seconds,
                                          int *percent);

#ifndef SDL_POWER_DISABLED
#ifdef SDL_POWER_HARDWIRED
// This is for things that _never_ have a battery
static bool SDL_GetPowerInfo_Hardwired(SDL_PowerState *state, int *seconds, int *percent)
{
    *seconds = -1;
    *percent = -1;
    *state = SDL_POWERSTATE_NO_BATTERY;
    return true;
}
#endif

static SDL_GetPowerInfo_Impl implementations[] = {
#ifdef SDL_POWER_LINUX // in order of preference. More than could work.
    SDL_GetPowerInfo_Linux_org_freedesktop_upower,
    SDL_GetPowerInfo_Linux_sys_class_power_supply,
    SDL_GetPowerInfo_Linux_proc_acpi,
    SDL_GetPowerInfo_Linux_proc_apm,
#endif
#ifdef SDL_POWER_WINDOWS // handles Win32, Win64, PocketPC.
    SDL_GetPowerInfo_Windows,
#endif
#ifdef SDL_POWER_UIKIT // handles iPhone/iPad/etc
    SDL_GetPowerInfo_UIKit,
#endif
#ifdef SDL_POWER_MACOSX // handles macOS, Darwin.
    SDL_GetPowerInfo_MacOSX,
#endif
#ifdef SDL_POWER_HAIKU // with BeOS euc.jp apm driver. Does this work on Haiku?
    SDL_GetPowerInfo_Haiku,
#endif
#ifdef SDL_POWER_ANDROID // handles Android.
    SDL_GetPowerInfo_Android,
#endif
#ifdef SDL_POWER_PSP // handles PSP.
    SDL_GetPowerInfo_PSP,
#endif
#ifdef SDL_POWER_VITA // handles PSVita.
    SDL_GetPowerInfo_VITA,
#endif
#ifdef SDL_POWER_N3DS // handles N3DS.
    SDL_GetPowerInfo_N3DS,
#endif
#ifdef SDL_POWER_EMSCRIPTEN // handles Emscripten
    SDL_GetPowerInfo_Emscripten,
#endif

#ifdef SDL_POWER_HARDWIRED
    SDL_GetPowerInfo_Hardwired,
#endif
};
#endif

SDL_PowerState SDL_GetPowerInfo(int *seconds, int *percent)
{
#ifndef SDL_POWER_DISABLED
    const int total = SDL_arraysize(implementations);
    SDL_PowerState result = SDL_POWERSTATE_UNKNOWN;
    int i;
#endif

    int _seconds, _percent;
    // Make these never NULL for platform-specific implementations.
    if (!seconds) {
        seconds = &_seconds;
    }
    if (!percent) {
        percent = &_percent;
    }

#ifndef SDL_POWER_DISABLED
    for (i = 0; i < total; i++) {
        if (implementations[i](&result, seconds, percent)) {
            return result;
        }
    }
#endif

    // nothing was definitive.
    *seconds = -1;
    *percent = -1;
    return SDL_POWERSTATE_UNKNOWN;
}