java.lang.Object

com.arbergashi.charts.render.BaseRenderer

com.arbergashi.charts.render.financial.OBVRenderer

All Implemented Interfaces:: ChartRenderer

public final class OBVRenderer extends BaseRenderer

OBVRenderer - On-Balance Volume

Professional OBV indicator renderer for volume-based momentum analysis. Measures buying and selling pressure as a cumulative indicator.

Features:

OBV Line: Cumulative volume indicator
Trend Identification: Rising OBV = bullish, falling OBV = bearish
Divergence Detection: Visual comparison with price
Zero Line: Reference baseline

Data Requirements:

Requires price (close) and volume data.

Calculation:

If Close > PrevClose: OBV = PrevOBV + Volume
If Close < PrevClose: OBV = PrevOBV - Volume
If Close = PrevClose: OBV = PrevOBV

Interpretation:

Rising OBV = Accumulation (bullish)
Falling OBV = Distribution (bearish)
OBV confirms trend if it moves with price
Divergence = potential reversal signal

Since:: 2026-01-01
Version:: 1.0.0
Author:: Arber Gashi

Field Summary

Fields inherited from class BaseRenderer
PIXEL_BUF, PIXEL_BUF4
Constructor Summary

Constructors

Constructor

Description

OBVRenderer()
Method Summary

Modifier and Type

Method

Description

protected void

drawData(Graphics2D g, ChartModel model, PlotContext context)

Implementation-specific drawing logic.

double[]

getPreferredYRange(ChartModel model)

Optional Y-range override for autoscaling.

Methods inherited from class BaseRenderer
drawHighlightPoint, drawI18nLabel, drawLabel, getArc, getCachedFont, getCachedGradient, getCachedStroke, getCachedStroke, getCachedStroke, getCubicCurve, getEllipse, getId, getLayerIndex, getLegendColor, getLine, getName, getPathCache, getPointAt, getRect, getRoundRectangle, getSeriesColor, getSeriesStroke, getTheme, getTooltipText, isLegendRequired, isMultiColor, pBuffer, pBuffer4, render, resolveTheme, seriesOrBase, setLayerIndex, setMultiColor, setTheme, setupQualityHints, themeAccent, themeAxisLabel, themeBackground, themeBearish, themeBullish, themeForeground, themeGrid, themeSeries

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface ChartRenderer
clearHover, createContext, getFocusValues, renderEmptyState, supportsEmptyState

Constructor Details
- OBVRenderer
  
  public OBVRenderer()
Method Details
- drawData
  
  protected void drawData(Graphics2D g, ChartModel model, PlotContext context)
  
  Description copied from class: BaseRenderer
  
  Implementation-specific drawing logic. Must follow Zero-Allocation rules.
  
  Specified by:
  
  drawData in class BaseRenderer
- getPreferredYRange
  
  public double[] getPreferredYRange(ChartModel model)
  
  Description copied from interface: ChartRenderer
  
  Optional Y-range override for autoscaling.
  Renderers may return a {minY, maxY} array when the visible range should be based on derived data rather than the model's raw Y-values (e.g. indicators like MACD).
  
  Parameters:
  
  model - the layer model
  
  Returns:
  
  {minY, maxY} or null to use model Y-values