--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/power/uikit/SDL_syspower.m	Fri Apr 30 00:39:31 2010 -0400
@@ -0,0 +1,100 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997-2010 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_UIKIT
+
+#import <UIKit/UIKit.h>
+
+#include "SDL_power.h"
+#include "SDL_timer.h"
+#include "SDL_assert.h"
+
+// turn off the battery monitor if it's been more than X ms since last check.
+static const int BATTERY_MONITORING_TIMEOUT = 3000;
+static Uint32 SDL_UIKitLastPowerInfoQuery = 0;
+
+void
+SDL_UIKit_UpdateBatteryMonitoring(void)
+{
+    if (SDL_UIKitLastPowerInfoQuery) {
+        const Uint32 prev = SDL_UIKitLastPowerInfoQuery;
+        const UInt32 now = SDL_GetTicks();
+        const UInt32 ticks = now - prev;
+        // if timer wrapped (now < prev), shut down, too.
+        if ((now < prev) || (ticks >= BATTERY_MONITORING_TIMEOUT)) {
+            UIDevice *uidev = [UIDevice currentDevice];
+            SDL_assert([uidev isBatteryMonitoringEnabled] == YES);
+            [uidev setBatteryMonitoringEnabled:NO];
+            SDL_UIKitLastPowerInfoQuery = 0;
+        }
+    }
+}
+
+SDL_bool
+SDL_GetPowerInfo_UIKit(SDL_PowerState * state, int *seconds, int *percent)
+{
+    UIDevice *uidev = [UIDevice currentDevice];
+
+    if (!SDL_UIKitLastPowerInfoQuery) {
+        SDL_assert([uidev isBatteryMonitoringEnabled] == NO);
+        [uidev setBatteryMonitoringEnabled:YES];
+    }
+
+    // UIKit_GL_SwapWindow() (etc) will check this and disable the battery
+    //  monitoring if the app hasn't queried it in the last X seconds.
+    //  Apparently monitoring the battery burns battery life.  :)
+    //  Apple's docs say not to monitor the battery unless you need it.
+    SDL_UIKitLastPowerInfoQuery = SDL_GetTicks();
+
+    *seconds = -1;   // no API to estimate this in UIKit.
+
+    switch ([uidev batteryState])
+    {
+        case UIDeviceBatteryStateCharging:
+            *state = SDL_POWERSTATE_CHARGING;
+            break;
+
+        case UIDeviceBatteryStateFull:
+            *state = SDL_POWERSTATE_CHARGED;
+            break;
+
+        case UIDeviceBatteryStateUnplugged:
+            *state = SDL_POWERSTATE_ON_BATTERY;
+            break;
+
+        case UIDeviceBatteryStateUnknown:
+        default:
+            *state = SDL_POWERSTATE_UNKNOWN;
+            break;
+    }
+
+    const float level = [uidev batteryLevel];
+    *percent = ( (level < 0.0f) ? -1 : (((int) (level + 0.5f)) * 100) );
+    return SDL_TRUE;            /* always the definitive answer on iPhoneOS. */
+}
+
+#endif /* SDL_POWER_UIKIT */
+#endif /* SDL_POWER_DISABLED */
+
+/* vi: set ts=4 sw=4 expandtab: */