android - MPAndroidChart fill color gradient

Question

Is it possible with MPAndroidChart (or any other Android chart library) to fill the chart under the draw line with a gradient color? Something like this:

set1.setFillColor(getResources().getColor(R.drawable.chart_fill));

then in chart_fill.xml:

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >

    <gradient
        android:angle="90"
        android:endColor="#FF207a54"
        android:startColor="#FFffffff" />

</shape>

Answer 1

You can use the following two methods:

LineRadarDataSet#setDrawFilled(boolean isFilled); 
LineRadarDataSet#setFillDrawable(Drawable d);

Here's a link to the javadoc for that class.

This is the example from the MPAndroidChart sample project:

set1.setDrawFilled(true);
if (Utils.getSDKInt() >= 18) {
    // fill drawable only supported on api level 18 and above
    Drawable drawable = ContextCompat.getDrawable(this, R.drawable.fade_red);
    set1.setFillDrawable(drawable);
}
else {
    set1.setFillColor(Color.BLACK);
}

In fade_red.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:angle="90"
        android:startColor="#00ff0000"
        android:endColor="#ffff0000" />
</shape>

Here's a sample of what it looks like on a LineChart: