feat: Add Grouped Charts support (#17)

library/src/main/java/com/dzeio/charts/ChartType.kt

@@ -0,0 +1,21 @@
+package com.dzeio.charts
+
+enum class ChartType {
+
+    /**
+     * Basic Chart where items go over the other
+     */
+    BASIC,
+
+    /**
+     * each series are next to each other nicely
+     */
+    GROUPED,
+
+    /**
+     * WILL NOT DO ANYTHING CURRENTLY
+     *
+     * Each series are stacked over the other one
+     */
+    STACKED
+}

library/src/main/java/com/dzeio/charts/ChartView.kt

@@ -21,6 +21,8 @@ class ChartView @JvmOverloads constructor(context: Context?, attrs: AttributeSet
         const val TAG = "Charts/ChartView"
     }
 
+    override var type: ChartType = ChartType.BASIC
+
     override var debug: Boolean = false
 
     override val xAxis = XAxis(this)

library/src/main/java/com/dzeio/charts/ChartViewInterface.kt

@@ -6,6 +6,11 @@ import com.dzeio.charts.series.SerieInterface
 
 interface ChartViewInterface {
 
+    /**
+     * Chart Type
+     */
+    var type: ChartType
+
     /**
      * Make the whole view in debug mode
      *

library/src/main/java/com/dzeio/charts/axis/XAxis.kt

@@ -5,6 +5,7 @@ import android.graphics.Color
 import android.graphics.Paint
 import android.graphics.Rect
 import android.graphics.RectF
+import com.dzeio.charts.ChartType
 import com.dzeio.charts.ChartViewInterface
 import com.dzeio.charts.Entry
 import kotlin.math.roundToInt
@@ -51,11 +52,13 @@ class XAxis(
     }
 
     override fun getPositionOnRect(entry: Entry, drawableSpace: RectF): Double {
-        return translatePositionToRect(entry.x, drawableSpace)
+        val result = drawableSpace.width() * (entry.x - x) / getDataWidth()
-    }
+        if (view.type == ChartType.GROUPED) {
-
+            val serie = view.series.find { it.entries.contains(entry) }
-    fun translatePositionToRect(value: Double, drawableSpace: RectF): Double {
+            val index = view.series.indexOf(serie)
-        return drawableSpace.width() * (value - x) / getDataWidth()
+            return result + getEntryWidth(drawableSpace) * index + spacing / 2 * index
+        }
+        return result
     }
 
     override fun getXMax(): Double {
@@ -123,8 +126,15 @@ class XAxis(
             }
         }
 
-        return (drawableSpace.width() * smallest / getDataWidth() - spacing)
+        val result = (drawableSpace.width() * smallest / getDataWidth() - spacing)
             .coerceIn(1.0, drawableSpace.width().toDouble())
+
+        // handle grouped series
+        if (view.type == ChartType.GROUPED) {
+            return result / view.series.size - spacing / 2 * (view.series.size - 1)
+        }
+
+        return result
     }
 
     override fun getDataWidth(): Double {

sample/src/main/java/com/dzeio/chartstest/ui/MainFragment.kt

@@ -6,6 +6,7 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.fragment.app.Fragment
+import com.dzeio.charts.ChartType
 import com.dzeio.charts.ChartView
 import com.dzeio.charts.Entry
 import com.dzeio.charts.series.BarSerie
@@ -30,21 +31,27 @@ class MainFragment : Fragment() {
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
 
-        binding.chart1.apply {
+        binding.chartGrouped.apply {
             // setup the Serie
-            val serie = BarSerie(this)
+            val serie1 = BarSerie(this)
+            val serie2 = BarSerie(this)
+
+            // transform the chart into a grouped chart
+            type = ChartType.GROUPED
 
             // utils function to use Material3 auto colors
             materielTheme(this, requireView())
+            serie2.barPaint.color = Color.RED
 
             // give the serie it's entries
-            serie.entries = generateRandomDataset(10)
+            serie1.entries = generateRandomDataset(10)
+            serie2.entries = generateRandomDataset(10)
 
             // refresh the Chart
             refresh()
         }
 
-        binding.chart2.apply {
+        binding.chartLine.apply {
             // setup the Serie
             val serie = LineSerie(this)
 
@@ -58,7 +65,21 @@ class MainFragment : Fragment() {
             refresh()
         }
 
-        binding.chart3.apply {
+        binding.chartBar.apply {
+            // setup the Serie
+            val serie = BarSerie(this)
+
+            // utils function to use Material3 auto colors
+            materielTheme(this, requireView())
+
+            // give the serie its entries
+            serie.entries = generateRandomDataset(10)
+
+            // refresh the Chart
+            refresh()
+        }
+
+        binding.chartCustomization.apply {
             // setup the Series
             val serie1 = BarSerie(this)
             val serie2 = LineSerie(this)

sample/src/main/res/drawable/shape_divider.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <size
+        android:height="16dp"
+        android:width="0dp" />
+</shape>

sample/src/main/res/layout/fragment_main.xml

@@ -6,35 +6,39 @@
     android:layout_height="match_parent"
     tools:context=".ui.MainFragment">
 
-<!--    <ScrollView-->
+    <ScrollView
-<!--        android:layout_width="match_parent"-->
+        android:layout_width="match_parent"
-<!--        android:layout_height="match_parent">-->
+        android:layout_height="match_parent">
 
         <LinearLayout
             android:orientation="vertical"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
+            android:showDividers="middle"
+            android:divider="@drawable/shape_divider"
             android:padding="16dp">
 
             <com.dzeio.charts.ChartView
-                android:id="@+id/chart1"
+                android:id="@+id/chart_grouped"
                 android:layout_width="match_parent"
                 android:layout_height="200dp" />
 
             <com.dzeio.charts.ChartView
-                android:id="@+id/chart3"
+                android:id="@+id/chart_customization"
-                android:layout_marginVertical="16dp"
                 android:layout_width="match_parent"
                 android:layout_height="200dp" />
 
             <com.dzeio.charts.ChartView
-                android:id="@+id/chart2"
+                android:id="@+id/chart_bar"
+                android:layout_width="match_parent"
+                android:layout_height="200dp" />
+
+            <com.dzeio.charts.ChartView
+                android:id="@+id/chart_line"
                 android:layout_width="match_parent"
                 android:layout_height="200dp" />
         </LinearLayout>
 
-<!--    </ScrollView>-->
+    </ScrollView>
-
-
 
 </androidx.constraintlayout.widget.ConstraintLayout>