Notify the user (once) if during a video call the battery level goes below 10%

Classes/CallDelegate.h

@@ -24,7 +24,8 @@ enum CallDelegateType {
     CD_UNDEFINED = 0,
     CD_NEW_CALL,
     CD_ZRTP,
-    CD_VIDEO_UPDATE
+    CD_VIDEO_UPDATE,
+    CD_STOP_VIDEO_ON_LOW_BATTERY
 };
 
 @protocol UIActionSheetCustomDelegate 

Classes/IncallViewController.m

@@ -207,6 +207,38 @@ void addAnimationFadeTransition(UIView* view, float duration) {
     hideControlsTimer = nil;
 }
 
+-(void) batteryLevelChanged: (NSNotification*) notif {
+    LinphoneCall* call = linphone_core_get_current_call([LinphoneManager getLc]);
+    if (!call || !linphone_call_params_video_enabled(linphone_call_get_current_params(call)))
+        return;
+    LinphoneCallAppData* appData = (LinphoneCallAppData*) linphone_call_get_user_pointer(call);
+    if ([UIDevice currentDevice].batteryState == UIDeviceBatteryStateUnplugged) {
+        float level = [UIDevice currentDevice].batteryLevel;
+        ms_message("Video call is running. Battery level: %.2f", level);
+        if (level < 0.1 && !appData->batteryWarningShown) {
+            // notify user
+            CallDelegate* cd = [[CallDelegate alloc] init];
+            cd.eventType = CD_STOP_VIDEO_ON_LOW_BATTERY;
+            cd.delegate = self;
+            cd.call = call;
+            
+            if (visibleActionSheet != nil) {
+                [visibleActionSheet dismissWithClickedButtonIndex:visibleActionSheet.cancelButtonIndex animated:TRUE];
+            }
+            NSString* title = NSLocalizedString(@"Battery is running low. Stop video ?",nil);
+            visibleActionSheet = [[UIActionSheet alloc] initWithTitle:title
+                                                             delegate:cd 
+                                                    cancelButtonTitle:NSLocalizedString(@"Continue video",nil) 
+                                               destructiveButtonTitle:NSLocalizedString(@"Stop video",nil) 
+                                                    otherButtonTitles:nil];
+            
+            visibleActionSheet.actionSheetStyle = UIActionSheetStyleDefault;
+            [visibleActionSheet showInView:self.view];
+            appData->batteryWarningShown = TRUE;
+        }
+    }
+}
+
 -(void) enableVideoDisplay {
     [self orientationChanged:nil];
     
@@ -233,6 +265,8 @@ void addAnimationFadeTransition(UIView* view, float duration) {
         NSLog(@"new center: %f %f", videoView.center.x, videoView.center.y);
         done = true;
     }
+    
+    [self batteryLevelChanged:nil];
 }
 
 -(void) disableVideoDisplay {
@@ -392,7 +426,9 @@ void addAnimationFadeTransition(UIView* view, float duration) {
     
     [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(orientationChanged:) name:UIDeviceOrientationDidChangeNotification object:nil];
-
+    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(batteryLevelChanged:) name:UIDeviceBatteryLevelDidChangeNotification object:nil];
+    
+    
     [videoCameraSwitch setPreview:videoPreview];
     addVideo.videoUpdateIndicator = videoUpdateIndicator;
     
@@ -976,6 +1012,16 @@ void addAnimationFadeTransition(UIView* view, float duration) {
             visibleActionSheet = nil;
             break;
         }
+        case CD_STOP_VIDEO_ON_LOW_BATTERY: {
+            LinphoneCall* call = (LinphoneCall*)datas;
+            LinphoneCallParams* paramsCopy = linphone_call_params_copy(linphone_call_get_current_params(call));
+            if ([visibleActionSheet destructiveButtonIndex] == buttonIndex) {
+                // stop video
+                linphone_call_params_enable_video(paramsCopy, FALSE);
+                linphone_core_update_call([LinphoneManager getLc], call, paramsCopy);
+            }
+            break;
+        }
         default:
             ms_error("Unhandled CallDelegate event of type: %d received - ignoring", type);
     }

Classes/LinphoneAppDelegate.m

@@ -207,6 +207,8 @@ int __aeabi_idiv(int a, int b) {
 	[window makeKeyAndVisible];
 	
 	[[LinphoneManager instance] setCallDelegate:myPhoneViewController];
+    
+    [UIDevice currentDevice].batteryMonitoringEnabled = YES;
 }
 
 -(void) setupGSMInteraction {

Classes/LinphoneUI/LinphoneManager.h

@@ -42,6 +42,10 @@ struct NetworkReachabilityContext {
     void (*networkStateChanged) (Connectivity newConnectivity);
 };
 
+typedef struct _LinphoneCallAppData {
+    bool_t batteryWarningShown;
+} LinphoneCallAppData;
+
 
 @interface LinphoneManager : NSObject <AVAudioSessionDelegate> {
 @protected

Classes/LinphoneUI/LinphoneManager.m

@@ -150,6 +150,12 @@ extern  void libmsbcg729_init();
     
     bool canHideInCallView = (linphone_core_get_calls([LinphoneManager getLc]) == NULL);
 	
+    if (!linphone_call_get_user_pointer(call)) {
+        LinphoneCallAppData* data = (LinphoneCallAppData*) malloc(sizeof(LinphoneCallAppData));
+        data->batteryWarningShown = FALSE;
+        linphone_call_set_user_pointer(call, data);
+    }
+    
 	switch (new_state) {					
 		case LinphoneCallIncomingReceived: 
 			[callDelegate	displayIncomingCall:call 
@@ -262,6 +268,9 @@ extern  void libmsbcg729_init();
                 [callDelegate displayInCall:call FromUI:mCurrentViewController forUser:lUserName withDisplayName:lDisplayName];
             }
 			break;
+        case LinphoneCallReleased:
+            free (linphone_call_get_user_pointer(call));
+            break;
         default:
             break;
 	}