Swing
<< Click to Display Table of Contents >> Swing 
The Swing indicator will plot lines that represent the swing points based on the strength (number of bars to the left and right of the swing point) parameter provided, it's mostly a visual tool and not meant to be predictive in nature. Only after the strength number of bars has passed since the extreme point, the swing return value could be definitely set, thus the indicator updates it's calculations as new incoming data warrants so.
You can access methods within this indicator to determine the number of bars ago a swing point occurred or the current swing value.
Tip: To workaround the situation, where the indicator has to recalculate  you could only access the SwingHigh / Low values the number of swing strength bars ago  those values are calculated in their final state. 
High Bar
Swing(int strength).SwingHighBar(int barsAgo, int instance, int lookBackPeriod)
Swing(ISeries<double> input, int strength).SwingHighBar(int barsAgo, int instance, int lookBackPeriod)
Low Bar
Swing(int strength).SwingLowBar(int barsAgo, int instance, int lookBackPeriod)
Swing(ISeries<double> input, int strength).SwingLowBar(int barsAgo, int instance, int lookBackPeriod)
An int value representing the number of bars ago. Returns a value of 1 if a swing point is not found within the look back period.
High Value
Swing(int strength).SwingHigh[int barsAgo]
Swing(ISeries<double> input, int strength).SwingHigh[int barsAgo]
Low Value
Swing(int strength).SwingLow[int barsAgo]
Swing(ISeries<double> input, int strength).SwingLow[int barsAgo]
double; Accessing this method via an index value [int barsAgo] returns the indicator value of the referenced bar.
* A return value of 0 (zero) will be returned if the CurrentBar number is less than the "strength" value, or a swing pivot has not yet been found.
barsAgo 
The number of bars ago that serves as the starting bar from which to work backwards 
input 
Indicator source data (?) 
instance 
The occurrence to check for (1 is the most recent, 2 is the 2nd most recent, etc...) 
lookBackPeriod 
Number of bars to look back to check for the test condition, which is evaluated on the current bar and the bars in the look back period. 
strength 
The number of required bars to the left and right of the swing point 

You can view this indicator method source code by selecting the menu New > NinjaScript Editor > Indicators within the NinjaTrader Control Center window.