Kotlin items

Author: hannesa2

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

@@ -65,15 +65,15 @@ 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)
+            return getItem(position)!!.getView(position, convertView, context)!!
         }
 
         override fun getItemViewType(position: Int): Int {
             // return the views type
             val ci = getItem(position)
-            return if (ci != null) ci.getItemType() else 0
+            return if (ci != null) ci.itemType else 0
         }
 
         override fun getViewTypeCount(): Int {

app/src/main/java/info/appdev/chartexample/listviewitems/BarChartItem.java

@@ -0,0 +1,77 @@
+package info.appdev.chartexample.listviewitems
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.graphics.Typeface
+import android.view.LayoutInflater
+import android.view.View
+import com.github.mikephil.charting.charts.BarChart
+import com.github.mikephil.charting.components.XAxis.XAxisPosition
+import com.github.mikephil.charting.data.BarData
+import com.github.mikephil.charting.data.ChartData
+import info.appdev.chartexample.R
+
+class BarChartItem(cd: ChartData<*>, c: Context) : ChartItem(cd) {
+    private val typeface: Typeface? = Typeface.createFromAsset(c.assets, "OpenSans-Regular.ttf")
+
+    override val itemType: Int
+        get() = TYPE_BARCHART
+
+    @SuppressLint("InflateParams")
+    override fun getView(position: Int, convertView: View?, c: Context?): View? {
+        var convertView = convertView
+        val holder: ViewHolder
+
+        if (convertView == null) {
+            holder = ViewHolder()
+
+            convertView = LayoutInflater.from(c).inflate(
+                R.layout.list_item_barchart, null
+            )
+            holder.chart = convertView.findViewById(R.id.chart)
+
+            convertView.tag = holder
+        } else {
+            holder = convertView.tag as ViewHolder
+        }
+
+        // apply styling
+        holder.chart!!.description.isEnabled = false
+        holder.chart!!.setDrawGridBackground(false)
+        holder.chart!!.setDrawBarShadow(false)
+
+        val xAxis = holder.chart!!.xAxis
+        xAxis.position = XAxisPosition.BOTTOM
+        xAxis.typeface = typeface
+        xAxis.setDrawGridLines(false)
+        xAxis.setDrawAxisLine(true)
+
+        val leftAxis = holder.chart!!.axisLeft
+        leftAxis.typeface = typeface
+        leftAxis.setLabelCount(5, false)
+        leftAxis.spaceTop = 20f
+        leftAxis.setAxisMinimum(0f) // this replaces setStartAtZero(true)
+
+        val rightAxis = holder.chart!!.axisRight
+        rightAxis.typeface = typeface
+        rightAxis.setLabelCount(5, false)
+        rightAxis.spaceTop = 20f
+        rightAxis.setAxisMinimum(0f) // this replaces setStartAtZero(true)
+
+        chartData.setValueTypeface(typeface)
+
+        // set data
+        holder.chart!!.setData(chartData as BarData?)
+        holder.chart!!.setFitBars(true)
+
+        // do not forget to refresh the chart
+//        holder.chart.invalidate();
+        holder.chart!!.animateY(700)
+
+        return convertView
+    }
+
+    private class ViewHolder {
+        var chart: BarChart? = null
+    }
+}

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

@@ -0,0 +1,21 @@
+package info.appdev.chartexample.listviewitems
+
+import android.content.Context
+import android.view.View
+import com.github.mikephil.charting.data.ChartData
+
+/**
+ * Base class of the Chart ListView items
+ */
+@Suppress("unused")
+abstract class ChartItem internal constructor(@JvmField var chartData: ChartData<*>) {
+    abstract val itemType: Int
+
+    abstract fun getView(position: Int, convertView: View?, c: Context?): View?
+
+    companion object {
+        const val TYPE_BARCHART: Int = 0
+        const val TYPE_LINECHART: Int = 1
+        const val TYPE_PIECHART: Int = 2
+    }
+}