Allow custom legend data

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

@@ -305,7 +305,8 @@ public void notifyDataSetChanged() {
 
         mXAxisRenderer.computeAxis(mData.getXValAverageLength(), mData.getXVals());
 
-        mLegendRenderer.computeLegend(mData);
+        if (mLegend != null && !mLegend.isLegendCustom())
+            mLegendRenderer.computeLegend(mData);
 
         calculateOffsets();
     }

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

@@ -91,7 +91,8 @@ public void notifyDataSetChanged() {
 
         calcMinMax();
 
-        mLegendRenderer.computeLegend(mData);
+        if (mLegend != null && !mLegend.isLegendCustom())
+            mLegendRenderer.computeLegend(mData);
 
         calculateOffsets();
     }

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

@@ -140,7 +140,8 @@ public void notifyDataSetChanged() {
         mYAxisRenderer.computeAxis(mYAxis.mAxisMinimum, mYAxis.mAxisMaximum);
         mXAxisRenderer.computeAxis(mData.getXValAverageLength(), mData.getXVals());
 
-        mLegendRenderer.computeLegend(mData);
+        if (mLegend != null && !mLegend.isLegendCustom())
+            mLegendRenderer.computeLegend(mData);
 
         calculateOffsets();
     }

MPChartLib/src/com/github/mikephil/charting/components/Legend.java

@@ -43,6 +43,12 @@ public enum LegendDirection {
     /** labels that will be appended to the end of the labels array after calculating the legend. a null label will start a group. */
     private String[] mExtraLabels;
 
+    /**
+     * Are the legend labels/colors a custom value or auto calculated? If false, then it's auto, if true, then custom.
+     * default false (automatic legend)
+     */
+    private boolean mIsLegendCustom = false;
+
     /** the position relative to the chart the legend is drawn on */
     private LegendPosition mPosition = LegendPosition.BELOW_CHART_LEFT;
 
@@ -257,6 +263,55 @@ public void setExtraLabels(String[] labels) {
         this.mExtraLabels = labels;
     }
 
+    /**
+     * Sets a custom legend's labels and colors arrays.
+     * The colors count should match the labels count.
+     * * Each color is for the form drawn at the same index.
+     * * A null label will start a group.
+     * * A (-2) color will avoid drawing a form
+     * This will disable the feature that automatically calculates the legend labels and colors from the datasets.
+     * Call resetLegendToAuto(...) to re-enable automatic calculation.
+     */
+    public void setLegend(int[] colors, String[] labels)
+    {
+        mLabels = labels;
+        mColors = colors;
+        mIsLegendCustom = true;
+    }
+
+    /**
+     * Sets a custom legend's labels and colors arrays.
+     * The colors count should match the labels count.
+     * * Each color is for the form drawn at the same index.
+     * * A null label will start a group.
+     * * A (-2) color will avoid drawing a form
+     * This will disable the feature that automatically calculates the legend labels and colors from the datasets.
+     * Call resetLegendToAuto(...) to re-enable automatic calculation (and then notifyDataSetChanged() is needed)
+     */
+    public void setLegend(List<Integer> colors, List<String> labels)
+    {
+        mColors = Utils.convertIntegers(colors);
+        mLabels = Utils.convertStrings(labels);
+        mIsLegendCustom = true;
+    }
+
+    /**
+     * Calling this will disable the custom legend labels (set by setLegend(...)). Instead, the labels will again be calculated automatically (after notifyDataSetChanged() is called).
+     */
+    public void resetLegendToAuto()
+    {
+        mIsLegendCustom = false;
+    }
+
+    /**
+     * @return true if a custom legend labels and colors has been set
+     * default false (automatic legend)
+     */
+    public boolean isLegendCustom()
+    {
+        return mIsLegendCustom;
+    }
+
     /**
      * returns the position of the legend relative to the chart
      *