Data as var (the magic)

Author: hannesa2

app/src/main/kotlin/info/appdev/chartexample/ListViewMultiChartActivity.kt

@@ -41,7 +41,7 @@ class ListViewMultiChartActivity : DemoBase() {
         binding = ActivityListviewChartBinding.inflate(layoutInflater)
         setContentView(binding.root)
 
-        val list = ArrayList<ChartItem>()
+        val list = ArrayList<ChartItem<*>>()
 
         // 30 items
         for (i in 0..29) {
@@ -59,7 +59,7 @@ class ListViewMultiChartActivity : DemoBase() {
     }
 
     /** adapter that supports 3 different item types  */
-    private class ChartDataAdapter(context: Context, objects: MutableList<ChartItem>) : ArrayAdapter<ChartItem>(context, 0, objects) {
+    private class ChartDataAdapter(context: Context, objects: MutableList<ChartItem<*>>) : ArrayAdapter<ChartItem<*>>(context, 0, objects) {
         override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
             return getItem(position)!!.getView(position, convertView, context)!!
         }

app/src/main/kotlin/info/appdev/chartexample/listviewitems/BarChartItem.kt

@@ -8,10 +8,9 @@ import android.view.View
 import info.appdev.charting.charts.BarChart
 import info.appdev.charting.components.XAxis.XAxisPosition
 import info.appdev.charting.data.BarData
-import info.appdev.charting.data.ChartData
 import info.appdev.chartexample.R
 
-class BarChartItem(chartData: ChartData<*>, context: Context) : ChartItem(chartData) {
+class BarChartItem(chartData: BarData, context: Context) : ChartItem<BarData>(chartData) {
     private val typeface: Typeface? = Typeface.createFromAsset(context.assets, "OpenSans-Regular.ttf")
 
     override val itemType: Int

app/src/main/kotlin/info/appdev/chartexample/listviewitems/ChartItem.kt

@@ -8,7 +8,7 @@ import info.appdev.charting.data.ChartData
  * Base class of the Chart ListView items
  */
 @Suppress("unused")
-abstract class ChartItem internal constructor(var chartData: ChartData<*>) {
+abstract class ChartItem<T : ChartData<*>> internal constructor(var chartData: T) {
     abstract val itemType: Int
 
     abstract fun getView(position: Int, convertView: View?, context: Context?): View?

app/src/main/kotlin/info/appdev/chartexample/listviewitems/LineChartItem.kt

@@ -7,11 +7,10 @@ import android.view.LayoutInflater
 import android.view.View
 import info.appdev.charting.charts.LineChart
 import info.appdev.charting.components.XAxis.XAxisPosition
-import info.appdev.charting.data.ChartData
 import info.appdev.charting.data.LineData
 import info.appdev.chartexample.R
 
-class LineChartItem(chartData: ChartData<*>, context: Context) : ChartItem(chartData) {
+class LineChartItem(lineData: LineData, context: Context) : ChartItem<LineData>(lineData) {
     private val typeface: Typeface? = Typeface.createFromAsset(context.assets, "OpenSans-Regular.ttf")
 
     override val itemType: Int

app/src/main/kotlin/info/appdev/chartexample/listviewitems/PieChartItem.kt

@@ -12,13 +12,12 @@ import android.view.LayoutInflater
 import android.view.View
 import info.appdev.charting.charts.PieChart
 import info.appdev.charting.components.Legend
-import info.appdev.charting.data.ChartData
 import info.appdev.charting.data.PieData
 import info.appdev.charting.formatter.PercentFormatter
 import info.appdev.charting.utils.ColorTemplate
 import info.appdev.chartexample.R
 
-class PieChartItem(chartData: ChartData<*>, context: Context) : ChartItem(chartData) {
+class PieChartItem(pieData: PieData, context: Context) : ChartItem<PieData>(pieData) {
     private val typeface: Typeface? = Typeface.createFromAsset(context.assets, "OpenSans-Regular.ttf")
     private val centerText: SpannableString
 

chartLib/src/main/kotlin/info/appdev/charting/charts/BarLineChartBase.kt

@@ -47,7 +47,7 @@ import kotlin.math.min
 @Suppress("unused")
 @SuppressLint("RtlHardcoded")
 abstract class BarLineChartBase<T : BarLineScatterCandleBubbleData<IBarLineScatterCandleBubbleDataSet<out Entry>>> : Chart<T>,
-    BarLineScatterCandleBubbleDataProvider {
+    BarLineScatterCandleBubbleDataProvider<T> {
     /**
      * the maximum number of entries to which values will be drawn
      * (entry numbers greater than this value will cause value-labels to disappear)

chartLib/src/main/kotlin/info/appdev/charting/charts/Chart.kt

@@ -49,7 +49,7 @@ import kotlin.math.abs
 import kotlin.math.max
 
 @Suppress("unused")
-abstract class Chart<T : ChartData<out IDataSet<out Entry>>> : ViewGroup, IBaseProvider {
+abstract class Chart<T : ChartData<out IDataSet<out Entry>>> : ViewGroup, IBaseProvider<T> {
     /**
      * Returns true if log-output is enabled for the chart, fals if not.
      */
@@ -237,35 +237,6 @@ abstract class Chart<T : ChartData<out IDataSet<out Entry>>> : ViewGroup, IBaseP
         this.legendRenderer = LegendRenderer(this.viewPortHandler, this.legend)
     }
 
-    /**
-     * Sets a new data object for the chart. The data object contains all values
-     * and information needed for displaying.
-     */
-    open fun setData(data: T?) {
-        mData = data
-        mOffsetsCalculated = false
-
-        if (data == null) {
-            return
-        }
-
-        // calculate how many digits are needed
-        setupDefaultFormatter(data.yMin, data.yMax)
-
-        for (set in mData!!.dataSets!!) {
-            if (set.needsFormatter() || set.valueFormatter === mDefaultValueFormatter) {
-                set.valueFormatter = mDefaultValueFormatter
-            }
-        }
-
-        // let the chart know there is new data
-        notifyDataSetChanged()
-
-        if (this.isLogEnabled) {
-            Timber.i("Data is set.")
-        }
-    }
-
     /**
      * Clears the chart from all data (sets it to null) and refreshes it (by
      * calling invalidate()).
@@ -1053,11 +1024,36 @@ abstract class Chart<T : ChartData<out IDataSet<out Entry>>> : ViewGroup, IBaseP
     }
 
     /**
-     * Returns the ChartData object that has been set for the chart.
+     * Data object for the chart. The data object contains all values and information needed for displaying.
      */
-    override fun getData(): T? {
-        return mData
-    }
+    override var data: T?
+        get() = mData
+        set(value) {
+                mData = value
+
+                if (value == null) {
+                    mOffsetsCalculated = false
+                    return
+                }
+
+                mOffsetsCalculated = false
+
+                // calculate how many digits are needed
+                setupDefaultFormatter(value.yMin, value.yMax)
+
+                for (set in mData!!.dataSets!!) {
+                    if (set.needsFormatter() || set.valueFormatter === mDefaultValueFormatter) {
+                        set.valueFormatter = mDefaultValueFormatter
+                    }
+                }
+
+                // let the chart know there is new data
+                notifyDataSetChanged()
+
+                if (isLogEnabled) {
+                    Timber.i("Data is set.")
+                }
+        }
 
     var renderer: DataRenderer?
         /**