1 files changed, 88 insertions, 0 deletions
diff --git a/4a-hal/4a-hal-controllers/4a-hal-controllers-value-handler.c b/4a-hal/4a-hal-controllers/4a-hal-controllers-value-handler.c
index 18c4113..7a3dedd 100644
--- a/4a-hal/4a-hal-controllers/4a-hal-controllers-value-handler.c
+++ b/4a-hal/4a-hal-controllers/4a-hal-controllers-value-handler.c
@@ -262,4 +262,92 @@ int HalCtlsConvertJsonValues(AFB_ApiT apiHandle,
 	*ConvertedJ = convertedArrayJ;
 
 	return 0;
+}
+
+int HalCtlsChangePreviousValuesUsingJson(AFB_ApiT apiHandle,
+					 struct CtlHalAlsaCtlProperties *alsaCtlProperties,
+					 json_object *requestedPercentageVariationJ,
+					 json_object *previousControlValuesJ,
+					 json_object **ChangedJ)
+{
+	int requestedPercentageVariation, requestedeVariation, toChangeValue, changedValue, idx, count;
+
+	char *requestedPercentageVariationString, *conversionEnd;
+
+	json_object *toChangeObjectJ, *changedArrayJ;
+
+	*ChangedJ = NULL;
+
+	requestedPercentageVariationString = (char *) json_object_get_string(requestedPercentageVariationJ);
+
+	requestedPercentageVariation = (int) strtol(requestedPercentageVariationString, &conversionEnd, 10);
+	if(conversionEnd == requestedPercentageVariationString) {
+		AFB_ApiError(apiHandle,
+			     "Tried to increase/decrease an integer control \
+			     but string sent in json is not a increase/decrease string : '%s'",
+			     json_object_get_string(requestedPercentageVariationJ));
+		return -1;
+	}
+
+	if(alsaCtlProperties->type != SND_CTL_ELEM_TYPE_INTEGER &&
+	   alsaCtlProperties->type != SND_CTL_ELEM_TYPE_INTEGER64) {
+		AFB_ApiError(apiHandle,
+			     "Tried to increase/decrease values on a incompatible \
+			     control type (%i), control type must be an integer",
+			     alsaCtlProperties->type);
+		return -2;
+	}
+
+	if(requestedPercentageVariation < -100 || requestedPercentageVariation > 100) {
+		AFB_ApiError(apiHandle,
+			     "Tried to increase/decrease values but specified change is \
+			     not a valid percentage, it should be between -100 and 100");
+		return -3;
+	}
+
+	requestedeVariation = HalCtlsConvertPercentageToValue((int) abs(requestedPercentageVariation),
+							      alsaCtlProperties->minval,
+							      alsaCtlProperties->maxval);
+
+	if(requestedeVariation == -INT_MAX) {
+		AFB_ApiError(apiHandle,
+			     "Didn't succeed to convert %i (using min %i et max %i)",
+			     requestedPercentageVariation,
+			     alsaCtlProperties->minval,
+			     alsaCtlProperties->maxval);
+		return -4;
+	}
+
+	if(requestedPercentageVariation < 0)
+		requestedeVariation = -requestedeVariation;
+
+	count = (int) json_object_array_length(previousControlValuesJ);
+
+	changedArrayJ = json_object_new_array();
+
+	for(idx = 0; idx < count; idx++) {
+		toChangeObjectJ = json_object_array_get_idx(previousControlValuesJ, idx);
+
+		if(! json_object_is_type(toChangeObjectJ, json_type_int)) {
+			AFB_ApiError(apiHandle,
+			     "Current json object %s is not an integer",
+			     json_object_get_string(toChangeObjectJ));
+			return -(10 + idx);
+		}
+
+		toChangeValue = json_object_get_int(toChangeObjectJ);
+
+		if((toChangeValue + requestedeVariation) < alsaCtlProperties->minval)
+			changedValue = alsaCtlProperties->minval;
+		else if((toChangeValue + requestedeVariation) > alsaCtlProperties->maxval)
+			changedValue = alsaCtlProperties->maxval;
+		else
+			changedValue = toChangeValue + requestedeVariation;
+
+		json_object_array_put_idx(changedArrayJ, idx, json_object_new_int(changedValue));
+	}
+
+	*ChangedJ = changedArrayJ;
+
+	return 0;
 }
 \ No newline at end of file