Call onChartScale listener after double-tap-zoom

ChartsOrg/Charts#3770

Author: danielgindi

MPChartLib/src/main/java/com/github/mikephil/charting/listener/BarLineChartTouchListener.java

@@ -580,12 +580,19 @@ public boolean onDoubleTap(MotionEvent e) {
 
             MPPointF trans = getTrans(e.getX(), e.getY());
 
-            mChart.zoom(mChart.isScaleXEnabled() ? 1.4f : 1f, mChart.isScaleYEnabled() ? 1.4f : 1f, trans.x, trans.y);
+            float scaleX = mChart.isScaleXEnabled() ? 1.4f : 1f;
+            float scaleY = mChart.isScaleYEnabled() ? 1.4f : 1f;
+
+            mChart.zoom(scaleX, scaleY, trans.x, trans.y);
 
             if (mChart.isLogEnabled())
                 Log.i("BarlineChartTouch", "Double-Tap, Zooming In, x: " + trans.x + ", y: "
                         + trans.y);
 
+            if (l != null) {
+                l.onChartScale(e, scaleX, scaleY);
+            }
+
             MPPointF.recycleInstance(trans);
         }
 

MPChartLib/src/main/java/com/github/mikephil/charting/listener/OnChartGestureListener.java

@@ -57,7 +57,7 @@ public interface OnChartGestureListener {
     void onChartFling(MotionEvent me1, MotionEvent me2, float velocityX, float velocityY);
 
     /**
-     * Callbacks when the chart is scaled / zoomed via pinch zoom gesture.
+     * Callbacks when the chart is scaled / zoomed via pinch zoom / double-tap gesture.
      *
      * @param me
      * @param scaleX scalefactor on the x-axis