Classes in depth Chapter 22 of 35

What each chart type's data set adds on top of the shared settings, from line modes and bar corners to candle colors and pie value lines.

Everything in The DataSet class works on all of them. This chapter only lists what is new per class. Three intermediate classes sit in between and are shared by several chart types, so they come first.

Highlight settings shared by several types#

BarLineScatterCandleBubbleDataSet is the base of every set that lives on an x and a y axis, so bar, line, scatter, candle and bubble. It adds one property:

BarDataSet overrides that default with black.

LineScatterCandleRadarDataSet adds the crosshair lines drawn through a highlighted entry, for line, scatter, candle and radar sets:

Copyset.setDrawHighlightIndicators(false)      // both at once
set.enableDashedHighlightLine(8f, 8f, 0f)  // dash length, gap, phase, all in px
set.disableDashedHighlightLine()

isDashedHighlightLineEnabled tells you whether a pattern is set.

Line and radar fill#

LineRadarDataSet is the base of LineDataSet and RadarDataSet: a stroked line with an optional filled area under it.

Copyset.lineWidth = 3f
set.isDrawFilledEnabled = true
set.fillColor = Color.BLUE
set.fillAlpha = 90

Assigning fillColor clears fillDrawable, so whichever you set last is the one that is drawn. Filling clips the canvas to a path and costs more than drawing the line alone. Where the fill stops is decided by the fill formatter.

The old documentation gives the minimum line width as 0.2. It is 0, which draws the thinnest line the device can.

LineDataSet#

The mode decides how the points are connected.

Copyset.mode = LineDataSet.Mode.CUBIC_BEZIER
set.cubicIntensity = 0.18f   // clamped to 0.05 (almost straight) to 1, default 0.2

A cubic line is one path with one color. Only LINEAR and STEPPED draw a segment per entry and use the whole colors list.

Circles at the entries:

setCircleColors(vararg colors: Int) and setCircleColors(colorResIds, context) fill the list, resetCircleColors() empties it.

Dashed lines:

Copyset.enableDashedLine(10f, 5f, 0f)  // dash length, gap, phase, all in px
set.disableDashedLine()

isDashedLineEnabled reports the state and dashPathEffect gives you the effect itself. A dashed line is rendered onto the chart's internal bitmap rather than straight onto the canvas.

Fill and highlight:

The ring is drawn in three layers: a halo in highlightColor at 70 alpha, a disc in circleHoleColor, and a stroke in the set's color.

BarDataSet#

Copyval set = BarDataSet(entries, "Orders")
set.barCornerRadius = 7f
set.barBorderWidth = 1f
set.barBorderColor = Color.BLACK
set.highlightAlpha = 0

barCornerRadius is new in version 4. The radius is capped at half the bar's width and height, so a short bar keeps a sane shape. On a stacked bar only the top corners of the last stack segment are rounded, which keeps the stack looking like one bar.

Bar shadows are switched on at the chart, with chart.isDrawBarShadowEnabled = true, and then use each set's barShadowColor.

Stacking is decided by the entries: a BarEntry with stackValues is a stacked bar. Three read-only properties describe it, the last of them on BarDataSet rather than on the interface:

For fills, see Setting colors. setGradientColor(startColor, endColor) is the shortcut for one gradient on every bar.

ScatterDataSet#

Copyval set = ScatterDataSet(entries, "DS 2")
set.setScatterShape(ScatterChart.ScatterShape.CIRCLE)
set.scatterShapeSize = 8f
set.scatterShapeHoleRadius = 3f
set.scatterShapeHoleColor = ColorTemplate.COLORFUL_COLORS[3]

setScatterShape(shape) swaps in the built-in renderer for SQUARE, CIRCLE, TRIANGLE, CROSS, X, CHEVRON_UP or CHEVRON_DOWN. Only square, circle and triangle draw a hole.

For a shape of your own, implement IShapeRenderer and assign it to shapeRenderer directly. ScatterDataSet.getRendererForShape(shape) returns a fresh built-in renderer if you want to wrap one.

CandleDataSet#

A candle set colors the body by direction. All four colors start at ColorTemplate.COLOR_NONE, which means the renderer falls back to the entry's color from colors.

Copyset.increasingColor = Color.rgb(122, 242, 84)
set.increasingPaintStyle = Paint.Style.STROKE
set.decreasingColor = Color.RED
set.decreasingPaintStyle = Paint.Style.FILL
set.shadowColor = Color.DKGRAY
set.shadowWidth = 0.7f

The y range of a candle set comes from the entries' low and high, not from their y.

BubbleDataSet#

maxSize is recomputed from scratch whenever the full ranges are, so it shrinks again after an entry is removed or after notifyDataSetChanged(). Adding a single entry can only widen it.

RadarDataSet#

A radar set is a LineRadarDataSet, so it has the line width and the fill settings above. On top it configures the ring on a highlighted entry.

PieDataSet#

A PieData holds exactly one pie set. Only the y range is tracked, because pie entries have no x.

Labels and values can sit inside the slice or outside it, each on its own:

Copyset.xValuePosition = PieDataSet.ValuePosition.OUTSIDE_SLICE
set.yValuePosition = PieDataSet.ValuePosition.OUTSIDE_SLICE

xValuePosition places the entry label, yValuePosition the value. Both default to INSIDE_SLICE. Once something sits outside, a connector line is drawn to it:

copy() on a pie set carries over the inherited styling only. None of the properties in this section are copied.