PhilJay/MPAndroidChart simple manager class for BarChart

BarChart

A bar chart or bar graph is a chart/graph that presents data points with rectangular bars with heights or lengths proportional to the values that they represent.

Let’s jump to the coding part.

Add the following dependencies inbuild.gradle project level

allprojects {
    repositories {
        maven { url 'https://jitpack.io' }
    }
}

Add the following dependencies in build.gradle app-level

implementation 'com.github.PhilJay:MPAndroidChart:v3.1.0'

xml file for the BarChart to be displayed

<androidx.coordinatorlayout.widget.CoordinatorLayout
    android:id="@+id/dataLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginTop="@dimen/margin_standard"
    android:layout_marginBottom="@dimen/margin_standard">

    <com.google.android.material.textview.MaterialTextView
        android:id="@+id/barChartTitle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:minWidth="@dimen/barTitleMinWidth"
        android:textAlignment="center" />

    <com.github.mikephil.charting.charts.BarChart
        android:id="@+id/barChart"
        android:layout_width="match_parent"
        android:layout_height="@dimen/graph_height_default"
        android:layout_marginTop="@dimen/margin_standard" />

</androidx.coordinatorlayout.widget.CoordinatorLayout>
    android:id="@+id/dataLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginTop="@dimen/margin_standard"
    android:layout_marginBottom="@dimen/margin_standard">

    <com.google.android.material.textview.MaterialTextView
        android:id="@+id/barChartTitle"
        style="@style/eliqBodySmallText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:minWidth="@dimen/barTitleMinWidth"
        android:textAlignment="center"
        tools:text="kWh" />

    <com.github.mikephil.charting.charts.BarChart
        android:id="@+id/barChart"
        android:layout_width="match_parent"
        android:layout_height="@dimen/graph_height_default"
        android:layout_marginTop="@dimen/margin_standard" />

</androidx.coordinatorlayout.widget.CoordinatorLayout>

Let’s jump to the Manager class.

lass BarChartManager(
    private val context: Context,
    private val barChart: BarChart,
    labels: List<String>,
    private val values: List<BarEntry>,
    unit: String
) {
}

The unit parameter is for my custom marker view. Now, initialize BarChart properties.

init {
    barChart.setDrawBarShadow(false)
    barChart.setDrawValueAboveBar(false)

    barChart.description.isEnabled = false

    // if more than 60 entries are displayed in the chart, no values will be drawn
    barChart.setMaxVisibleValueCount(values.size)

    // scaling can now only be done on x- and y-axis separately
    barChart.setPinchZoom(false)
    barChart.isDoubleTapToZoomEnabled = false
    barChart.setScaleEnabled(false)

    barChart.setDrawGridBackground(false)

    // barChart.setDrawYLabels(false);
    val xAxisFormatter: ValueFormatter = IndexAxisValueFormatter(labels)
    val xAxis = barChart.xAxis

    xAxis.setLabelCount(values.size, true)
    xAxis.valueFormatter = xAxisFormatter
    xAxis.labelCount = values.size

    xAxis.position = XAxis.XAxisPosition.BOTTOM
    xAxis.setDrawGridLines(false)
    xAxis.granularity = 1f // only intervals of 1 day
    xAxis.textColor = ContextCompat.getColor(context, R.color.colorPrimary)
    xAxis.axisLineColor = ContextCompat.getColor(context, R.color.colorDefaultIndicator)

    val custom: ValueFormatter = MyValueFormatter(Locale.getDefault())

    val leftAxis = barChart.axisLeft
    leftAxis.setLabelCount(3, true)
    leftAxis.valueFormatter = custom
    leftAxis.setPosition(YAxis.YAxisLabelPosition.OUTSIDE_CHART)
    leftAxis.spaceTop = 0f
    leftAxis.axisMinimum = 0f // this replaces setStartAtZero(true)
    leftAxis.textColor = ContextCompat.getColor(context, R.color.colorPrimary)
    leftAxis.axisLineColor = ContextCompat.getColor(context, R.color.colorDefaultIndicator)
    leftAxis.zeroLineColor = ContextCompat.getColor(context, R.color.colorDefaultIndicator)

    barChart.axisRight.isEnabled = false
    /*val rightAxis = barChart.axisRight
    rightAxis.setDrawGridLines(false)
    rightAxis.setLabelCount(8, false)
    rightAxis.valueFormatter = custom
    rightAxis.spaceTop = 15f
    rightAxis.axisMinimum = 0f // this replaces setStartAtZero(true)*/


    val l = barChart.legend
    l.verticalAlignment = Legend.LegendVerticalAlignment.BOTTOM
    l.horizontalAlignment = Legend.LegendHorizontalAlignment.LEFT
    l.orientation = Legend.LegendOrientation.HORIZONTAL
    l.setDrawInside(false)
    l.form = Legend.LegendForm.NONE
    l.formSize = 9f
    l.textSize = 11f
    l.xEntrySpace = 1f

    val mv = CustomMarkerView(context, xAxisFormatter, unit)
    mv.chartView = barChart // For bounds control

    barChart.marker = mv // Set the marker to the chart

    val roundedBarChartRenderer =
        RoundedBarChartRenderer(barChart, barChart.animator, barChart.viewPortHandler)
    roundedBarChartRenderer.setRadius(context.resources.getDimension(R.dimen.barCornerRadius))
    barChart.renderer = roundedBarChartRenderer

    setData()
}

I believe all properties are self-explanatory. Let’s set data to BarChart now.

private fun setData() {

    val set1: BarDataSet
    if (barChart.data != null &&
        barChart.data.dataSetCount > 0
    ) {
        set1 = barChart.data.getDataSetByIndex(0) as BarDataSet
        set1.values = values
        barChart.data.notifyDataChanged()
        barChart.notifyDataSetChanged()
    } else {
        set1 = BarDataSet(values, null)

        set1.setDrawIcons(false)
        set1.setDrawValues(false)
        //set color of bars
        val startColor1 = ContextCompat.getColor(context, R.color.colorPrimary)
        val endColor1 = ContextCompat.getColor(context, R.color.colorPrimary)
        val gradientColors: MutableList<GradientColor> = ArrayList()
        gradientColors.add(GradientColor(startColor1, endColor1))
        set1.gradientColors = gradientColors
        val dataSets = ArrayList<IBarDataSet>()
        dataSets.add(set1)

        val data = BarData(dataSets)
        data.setDrawValues(false)
        data.barWidth = 0.9f
        barChart.data = data
    }

}

I have one getter for BarChart at the end.

fun getBarChart() = barChart

That’s it, ladies and gentlemen.

Photo by Martin W. Kirst on Unsplash

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