Class BarChart

java.lang.Object

com.codename1.charts.views.AbstractChart

com.codename1.charts.views.XYChart

com.codename1.charts.views.BarChart

Direct Known Subclasses:

RangeBarChart

public class BarChart
extends XYChart

Renders a bar chart based on an XYMultipleSeriesDataset.

Create an instance together with a matching XYMultipleSeriesRenderer and wrap it in a com.codename1.charts.ChartComponent to display it in the UI. A minimal setup looks like this:

XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
dataset.addSeries(mySeries);

XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();
renderer.addSeriesRenderer(new XYSeriesRenderer());

BarChart chart = new BarChart(dataset, renderer, BarChart.Type.DEFAULT);
Form form = new Form(new BorderLayout());
form.add(BorderLayout.CENTER, new ChartComponent(chart));
form.show();

The Type supplied to the constructor controls whether the bars are rendered in their default style, stacked or heaped.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	BarChart.Type	The bar chart type enum.

Field Summary

Fields

Modifier and Type	Field	Description
protected BarChart.Type	mType	The chart type.
static final String	TYPE	The constant to identify this chart type.

Fields inherited from class XYChart

mDataset, mRenderer

Constructor Summary

Constructors

Constructor	Description
BarChart(XYMultipleSeriesDataset dataset, XYMultipleSeriesRenderer renderer, BarChart.Type type)	Builds a new bar chart instance.

Method Summary

Modifier and Type	Method	Description
protected ClickableArea[]	clickableAreasForPoints(List<Float> points, List<Double> values, float yAxisValue, int seriesIndex, int startIndex)	Returns the clickable areas for all passed points
protected void	drawBar(Canvas canvas, float xMin, float yMin, float xMax, float yMax, float halfDiffX, int seriesNr, int seriesIndex, Paint paint)	Draws a bar.
protected void	drawBar(Canvas canvas, float xMin, float yMin, float xMax, float yMax, int scale, int seriesIndex, Paint paint)	Draws a bar.
protected void	drawChartValuesText(Canvas canvas, XYSeries series, XYSeriesRenderer renderer, Paint paint, List<Float> points, int seriesIndex, int startIndex)	The graphical representation of the series values as text.
void	drawLegendShape(Canvas canvas, SimpleSeriesRenderer renderer, float x, float y, int seriesIndex, Paint paint)	The graphical representation of the legend shape.
void	drawSeries(Canvas canvas, Paint paint, List<Float> points, XYSeriesRenderer seriesRenderer, float yAxisValue, int seriesIndex, int startIndex)	The graphical representation of a series.
String	getChartType()	Returns the chart type identifier.
protected float	getCoeficient()	Returns the value of a constant used to calculate the half-distance.
double	getDefaultMinimum()	Returns the default axis minimum.
protected int	getGradientPartialColor(int minColor, int maxColor, float fraction)
protected float	getHalfDiffX(List<Float> points, int length, int seriesNr)	Calculates and returns the half-distance in the graphical representation of 2 consecutive points.
int	getLegendShapeWidth(int seriesIndex)	Returns the legend shape width.
protected boolean	isRenderNullValues()	Returns if the chart should display the null values.

Methods inherited from class XYChart

draw, drawPoints, drawSeries, drawText, drawXLabels, drawXTextLabels, drawYLabels, getCalcRange, getDataset, getPointsChart, getRenderer, getScreenR, getSeriesAndPointForScreenCoordinate, getXLabels, getYLabels, isRenderPoints, setCalcRange, setDatasetRenderer, setScreenR, toRealPoint, toRealPoint, toScreenPoint, toScreenPoint

Methods inherited from class AbstractChart

calculateDrawPoints, drawBackground, drawLabel, drawLegend, drawPath, drawPath, drawString, getExceed, getLabel, getLegendSize, isNullValue, isVertical

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

TYPE

public static final String TYPE

The constant to identify this chart type.

See Also:

• Constant Field Values

mType

protected BarChart.Type mType

The chart type.

Constructor Details

BarChart

public BarChart(XYMultipleSeriesDataset dataset,
 XYMultipleSeriesRenderer renderer,
 BarChart.Type type)

Builds a new bar chart instance.

Parameters

• dataset: the multiple series dataset

• renderer: the multiple series renderer

• type: the bar chart type

Method Details

clickableAreasForPoints

protected ClickableArea[] clickableAreasForPoints(List<Float> points,
 List<Double> values,
 float yAxisValue,
 int seriesIndex,
 int startIndex)

Description copied from class: XYChart

Returns the clickable areas for all passed points

Parameters

• points: the array of points

• values: the array of values of each point

• yAxisValue: the minimum value of the y axis

• seriesIndex: the index of the series to which the points belong

• startIndex: the start index of the rendering points

Returns

an array of rectangles with the clickable area

Specified by:

clickableAreasForPoints in class XYChart

drawSeries

public void drawSeries(Canvas canvas,
 Paint paint,
 List<Float> points,
 XYSeriesRenderer seriesRenderer,
 float yAxisValue,
 int seriesIndex,
 int startIndex)

The graphical representation of a series.

Parameters

• canvas: the canvas to paint to

• paint: the paint to be used for drawing

• points: the array of points to be used for drawing the series

• seriesRenderer: the series renderer

• yAxisValue: the minimum value of the y axis

• seriesIndex: the index of the series currently being drawn

• startIndex: the start index of the rendering points

Specified by:

drawSeries in class XYChart

drawBar

protected void drawBar(Canvas canvas,
 float xMin,
 float yMin,
 float xMax,
 float yMax,
 float halfDiffX,
 int seriesNr,
 int seriesIndex,
 Paint paint)

Draws a bar.

Parameters

• canvas: the canvas

• xMin: the X axis minimum

• yMin: the Y axis minimum

• xMax: the X axis maximum

• yMax: the Y axis maximum

• halfDiffX: half the size of a bar

• seriesNr: the total number of series

• seriesIndex: the current series index

• paint: the paint

drawBar

protected void drawBar(Canvas canvas,
 float xMin,
 float yMin,
 float xMax,
 float yMax,
 int scale,
 int seriesIndex,
 Paint paint)

Draws a bar.

Parameters

• canvas: the canvas

• xMin: the X axis minimum

• yMin: the Y axis minimum

• xMax: the X axis maximum

• yMax: the Y axis maximum

• scale: the scale index

• seriesIndex: the current series index

• paint: the paint

getGradientPartialColor

protected int getGradientPartialColor(int minColor,
 int maxColor,
 float fraction)

drawChartValuesText

protected void drawChartValuesText(Canvas canvas,
 XYSeries series,
 XYSeriesRenderer renderer,
 Paint paint,
 List<Float> points,
 int seriesIndex,
 int startIndex)

The graphical representation of the series values as text.

Parameters

• canvas: the canvas to paint to

• series: the series to be painted

• renderer: the series renderer

• paint: the paint to be used for drawing

• points: the array of points to be used for drawing the series

• seriesIndex: the index of the series currently being drawn

• startIndex: the start index of the rendering points

Overrides:

drawChartValuesText in class XYChart

getLegendShapeWidth

public int getLegendShapeWidth(int seriesIndex)

Returns the legend shape width.

Parameters

• seriesIndex: the series index

Returns

the legend shape width

Specified by:

getLegendShapeWidth in class AbstractChart

drawLegendShape

public void drawLegendShape(Canvas canvas,
 SimpleSeriesRenderer renderer,
 float x,
 float y,
 int seriesIndex,
 Paint paint)

The graphical representation of the legend shape.

Parameters

• canvas: the canvas to paint to

• renderer: the series renderer

• x: the x value of the point the shape should be drawn at

• y: the y value of the point the shape should be drawn at

• seriesIndex: the series index

• paint: the paint to be used for drawing

Specified by:

drawLegendShape in class AbstractChart

getHalfDiffX

protected float getHalfDiffX(List<Float> points,
 int length,
 int seriesNr)

Calculates and returns the half-distance in the graphical representation of 2 consecutive points.

Parameters

• points: the points

• length: the points length

• seriesNr: the series number

Returns

the calculated half-distance value

getCoeficient

protected float getCoeficient()

Returns the value of a constant used to calculate the half-distance.

Returns

the constant value

isRenderNullValues

protected boolean isRenderNullValues()

Returns if the chart should display the null values.

Returns

if null values should be rendered

Overrides:

isRenderNullValues in class XYChart

getDefaultMinimum

public double getDefaultMinimum()

Returns the default axis minimum.

Returns

the default axis minimum

Overrides:

getDefaultMinimum in class XYChart

getChartType

public String getChartType()

Returns the chart type identifier.

Returns

the chart type

Specified by:

getChartType in class XYChart