Fixed issue concering LineChart filling (#179). Made changes to the logic of filling and added FillFormatter interface for implementing a custom fill logic.

Author: PhilJay

MPChartExample/libs/mpandroidchartlibrary-1-7-2.jar renamed to MPChartExample/libs/mpandroidchartlibrary-1-7-3.jar

@@ -492,13 +492,16 @@ protected void calcMinMax(boolean fixedValues) {
             // additional handling for space (default 15% space)
             // float space = Math.abs(mDeltaY / 100f * 15f);
             float space = Math
-                    .abs(Math.max(Math.abs(mYChartMax), Math.abs(mYChartMin)) / 100f * 15f);
-            if (Math.abs(mYChartMax) - Math.abs(mYChartMin) < 0.00001f) {
+                    .abs(Math.abs(Math.max(Math.abs(mYChartMax), Math.abs(mYChartMin))) / 100f * 20f);
+            
+            if (Math.abs(mYChartMax - mYChartMin) < 0.00001f) {
                 if (Math.abs(mYChartMax) < 10f)
                     space = 1f;
                 else
-                    space = Math.abs(mYChartMax / 100f * 15f);
+                    space = Math.abs(mYChartMax / 100f * 20f);
             }
+            
+            Log.i(LOG_TAG, "Space: " + space);
 
             if (mStartAtZero) {
 

MPChartLib/src/com/github/mikephil/charting/charts/BarLineChartBase.java

@@ -7,9 +7,12 @@
 import android.graphics.Path;
 import android.util.AttributeSet;
 
+import com.github.mikephil.charting.data.ChartData;
+import com.github.mikephil.charting.data.DataSet;
 import com.github.mikephil.charting.data.Entry;
 import com.github.mikephil.charting.data.LineData;
 import com.github.mikephil.charting.data.LineDataSet;
+import com.github.mikephil.charting.utils.FillFormatter;
 
 import java.util.ArrayList;
 
@@ -26,6 +29,8 @@ public class LineChart extends BarLineChartBase<LineData> {
     /** paint for the inner circle of the value indicators */
     protected Paint mCirclePaintInner;
 
+    private FillFormatter mFillFormatter;
+
     public LineChart(Context context) {
         super(context);
     }
@@ -42,6 +47,8 @@ public LineChart(Context context, AttributeSet attrs, int defStyle) {
     protected void init() {
         super.init();
 
+        mFillFormatter = new DefaultFillFormatter();
+
         mCirclePaintInner = new Paint(Paint.ANTI_ALIAS_FLAG);
         mCirclePaintInner.setStyle(Paint.Style.FILL);
         mCirclePaintInner.setColor(Color.WHITE);
@@ -263,9 +270,9 @@ && isOffContentBottom(valuePoints[j + 1]))
 
                     // mRenderPaint.setShader(dataSet.getShader());
 
-                    float fillMin = dataSet.getYMin() >= 0 ? mYChartMin : 0;
-
-                    Path filled = generateFilledPath(entries, fillMin);
+                    Path filled = generateFilledPath(entries,
+                            mFillFormatter.getFillLinePosition(dataSet, mOriginalData, mYChartMax,
+                                    mYChartMin));
 
                     transformPath(filled);
 
@@ -469,4 +476,45 @@ public Paint getPaint(int which) {
 
         return null;
     }
+
+    /**
+     * Default formatter that calculates the position of the filled line.
+     * 
+     * @author Philipp Jahoda
+     */
+    private class DefaultFillFormatter implements FillFormatter {
+
+        @Override
+        public float getFillLinePosition(LineDataSet dataSet, LineData data,
+                float chartMaxY, float chartMinY) {
+
+            float fillMin = 0f;
+
+            if (dataSet.getYMax() > 0 && dataSet.getYMin() < 0) {
+                fillMin = 0f;
+            } else {
+
+                if (!mStartAtZero) {
+
+                    float max, min;
+
+                    if (data.getYMax() > 0)
+                        max = 0f;
+                    else
+                        max = chartMaxY;
+                    if (data.getYMin() < 0)
+                        min = 0f;
+                    else
+                        min = chartMinY;
+
+                    fillMin = dataSet.getYMin() >= 0 ? min : max;
+                } else {
+                    fillMin = 0f;
+                }
+
+            }
+
+            return fillMin;
+        }
+    }
 }

MPChartLib/src/com/github/mikephil/charting/charts/LineChart.java

@@ -0,0 +1,27 @@
+
+package com.github.mikephil.charting.utils;
+
+import com.github.mikephil.charting.data.LineData;
+import com.github.mikephil.charting.data.LineDataSet;
+
+/**
+ * Interface for providing a custom logic to where the filling line of a DataSet
+ * should end. If setFillEnabled(...) is set to true.
+ * 
+ * @author Philipp Jahoda
+ */
+public interface FillFormatter {
+
+    /**
+     * Returns the vertical (y-axis) position where the filled-line of the
+     * DataSet should end.
+     * 
+     * @param dataSet
+     * @param data
+     * @param chartMaxY
+     * @param chartMinY
+     * @return
+     */
+    public float getFillLinePosition(LineDataSet dataSet, LineData data, float chartMaxY,
+            float chartMinY);
+}