Added Rounded corner for Pie chart

Author: Mohini Katara

MPChartExample/src/main/java/com/xxmassdeveloper/mpchartexample/PieChartActivity.java

@@ -32,6 +32,7 @@
 import com.github.mikephil.charting.highlight.Highlight;
 import com.github.mikephil.charting.interfaces.datasets.IDataSet;
 import com.github.mikephil.charting.listener.OnChartValueSelectedListener;
+import com.github.mikephil.charting.renderer.PieChartRenderer;
 import com.github.mikephil.charting.utils.ColorTemplate;
 import com.github.mikephil.charting.utils.MPPointF;
 import com.xxmassdeveloper.mpchartexample.notimportant.DemoBase;
@@ -74,13 +75,14 @@ protected void onCreate(Bundle savedInstanceState) {
         chart.setCenterText(generateCenterSpannableText());
 
         chart.setDrawHoleEnabled(true);
-        chart.setHoleColor(Color.WHITE);
+        chart.setHoleColor(Color.TRANSPARENT);
 
-        chart.setTransparentCircleColor(Color.WHITE);
+        chart.setTransparentCircleColor(Color.TRANSPARENT);
         chart.setTransparentCircleAlpha(110);
 
-        chart.setHoleRadius(58f);
-        chart.setTransparentCircleRadius(61f);
+        chart.setHoleRadius(50f);
+
+        chart.setTransparentCircleRadius(0f);
 
         chart.setDrawCenterText(true);
 
@@ -170,6 +172,10 @@ private void setData(int count, float range) {
         // undo all highlights
         chart.highlightValues(null);
 
+        PieChartRenderer renderer =(PieChartRenderer) chart.getRenderer();
+        renderer.setRoundedCornerRadius(30f);
+        dataSet.setSliceSpace(renderer.getRoundedCornerRadius()/2);
+
         chart.invalidate();
     }
 

MPChartLib/src/main/java/com/github/mikephil/charting/renderer/PieChartRenderer.java

@@ -45,6 +45,11 @@ public class PieChartRenderer extends DataRenderer {
     protected Paint mTransparentCirclePaint;
     protected Paint mValueLinePaint;
 
+    /**
+     * paint object used for drawing the rounded corner slice
+     */
+    protected Paint mRoundedCornerPaint;
+
     /**
      * paint object for the text that can be displayed in the center of the
      * chart
@@ -68,6 +73,24 @@ public class PieChartRenderer extends DataRenderer {
 
     protected Canvas mBitmapCanvas;
 
+    /**
+     * Setter for the rounded corner slice paint object
+     */
+    public void setRoundedCornerRadius(float radius){
+        mRoundedCornerPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
+        mRoundedCornerPaint.setStyle(Style.STROKE);
+        mRoundedCornerPaint.setAntiAlias(true);
+        mRoundedCornerPaint.setStrokeWidth(radius);
+
+    }
+
+    /**
+     * Getter for the rounded corner slice paint object
+     */
+    public float getRoundedCornerRadius(){
+        return mRoundedCornerPaint.getStrokeWidth();
+    }
+
     public PieChartRenderer(PieChart chart, ChartAnimator animator,
                             ViewPortHandler viewPortHandler) {
         super(animator, viewPortHandler);
@@ -245,6 +268,11 @@ protected void drawDataSet(Canvas c, IPieDataSet dataSet) {
 
         final float sliceSpace = visibleAngleCount <= 1 ? 0.f : getSliceSpace(dataSet);
 
+      if (getRoundedCornerRadius()>0) {
+            mRoundedCornerPaint.setStrokeCap(Paint.Cap.ROUND);
+            mRoundedCornerPaint.setStrokeJoin(Paint.Join.ROUND);
+        }
+
         for (int j = 0; j < entryCount; j++) {
 
             float sliceAngle = drawAngles[j];
@@ -268,6 +296,9 @@ protected void drawDataSet(Canvas c, IPieDataSet dataSet) {
 
             mRenderPaint.setColor(dataSet.getColor(j));
 
+            // Set current data set color to paint object
+            mRoundedCornerPaint.setColor(dataSet.getColor(j));
+
             final float sliceSpaceAngleOuter = visibleAngleCount == 1 ?
                     0.f :
                     sliceSpace / (Utils.FDEG2RAD * radius);
@@ -398,6 +429,11 @@ protected void drawDataSet(Canvas c, IPieDataSet dataSet) {
 
             mBitmapCanvas.drawPath(mPathBuffer, mRenderPaint);
 
+            // Draw rounded corner path with paint object slice with the given radius
+            if (getRoundedCornerRadius()>0) {
+                mBitmapCanvas.drawPath(mPathBuffer, mRoundedCornerPaint);
+            }
+
             angle += sliceAngle * phaseX;
         }