BarChart

MainActivity.kt

package com.nesterchung.chart

import android.content.Context
import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.text.format.DateUtils
import android.util.Log
import android.view.WindowManager
import com.github.mikephil.charting.charts.BarChart
import com.github.mikephil.charting.components.AxisBase
import com.github.mikephil.charting.components.XAxis
import com.github.mikephil.charting.data.BarData
import com.github.mikephil.charting.data.BarDataSet
import com.github.mikephil.charting.data.BarEntry
import com.github.mikephil.charting.formatter.IAxisValueFormatter
import com.github.mikephil.charting.interfaces.datasets.IBarDataSet
import com.github.mikephil.charting.utils.ColorTemplate
import java.util.*


class MainActivity : AppCompatActivity() {

    companion object {
        const val TAG = "MainActivity"

    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN)
        setContentView(R.layout.activity_main)

        val mChart: BarChart = findViewById(R.id.chart1)

        val xAxisFormatter = DayAxisValueFormatter(mChart, this)

        val xAxis = mChart.xAxis
        xAxis.position = XAxis.XAxisPosition.BOTTOM
        xAxis.setDrawGridLines(false)
        xAxis.granularity = 1f // only intervals of 1 day
        xAxis.valueFormatter = xAxisFormatter
        xAxis.setLabelCount(6, true)


        val leftAxis = mChart.axisLeft
        leftAxis.setDrawGridLines(false)
        leftAxis.setLabelCount(10, false)
        leftAxis.spaceTop = 15f
        leftAxis.axisMinimum = 0f // this replaces setStartAtZero(true)


        val yVals = ArrayList<BarEntry>()
        val halfHour = 60.0f

        for (x in 1..6) {
            val minute = Math.round((x-1).times(halfHour))
            Log.d(TAG, "Relative Timestamp:$minute")
            yVals.add(BarEntry(minute.toFloat(), x.toFloat()))
        }

        var set = BarDataSet(yVals, "????")

        set.setDrawIcons(false)
        set.colors = ColorTemplate.MATERIAL_COLORS.toList()
        val dataSets = ArrayList<IBarDataSet>()
        dataSets.add(set)
        val data = BarData(dataSets)
        data.setValueTextSize(10f)
        data.barWidth = 10f
        mChart.data = data
    }

    class DayAxisValueFormatter(mChart: BarChart, val mContext: Context) : IAxisValueFormatter {

        companion object {
            const val TAG = "DayAxisValueFormatter"
        }

        private var currentDate = 0L

        init {
            val cal = Calendar.getInstance()
            cal.set(Calendar.HOUR_OF_DAY, 0)
            cal.set(Calendar.MINUTE, 0)
            cal.set(Calendar.SECOND, 0)
            cal.set(Calendar.MILLISECOND, 0)
            currentDate = cal.timeInMillis
            Log.d(TAG, "currentDate:$currentDate)")
        }

        override fun getFormattedValue(value: Float, axis: AxisBase?): String {

            val date = currentDate + value.toInt() * 60 * 1000
            val formatDateTime = DateUtils.formatDateTime(mContext, date, DateUtils.FORMAT_SHOW_TIME)
            Log.d(TAG, "R-Value: $value, A-Value:$date, format:$formatDateTime")
            return formatDateTime
        }
    }
}