This is my adaptation of the answer given on http://stackoverflow.com/questions/19731261/android-draw-circle-with-2-colors-pie-chart by Sherif elKhatib.
It allows the user to select a normal pie mode, or an outline mode - which only marks the percentage around the edge. I have included my edits to Sherif's code for that fix the issue of the background not showing. It will show the percentage in 3 different colours based on the percentage. These can be over ridden by using the setHighColour, setMedColour, and setLowColour. You can change the background with setBackgroundColour.
Usage:
Layout:
<path.to.your.class.PercentView
android:id="@+id/percentView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_centerInParent="true"/>
Code:
int myPercentage = 55;
PercentView pv = (PercentView) findViewById (R.id.percentView1);
pv.setPercentage(myPercentage);
pv.setOutlineSize(10); // sets the width of the outline mode - default value if not defined is 10.
pv.setOutlineOnly(false); //set to true to use the outline, otherwise it will be a standard pie.
pv.setBackgroundColour(this.getResources().getColor(R.color.cardsLightBackground)); //fully qualify your colours to override
pv.setHighColour(this.getResources().getColor(R.color.flatgreen));
pv.setMedColour(this.getResources().getColor(R.color.flatyellow));
pv.setLowColour(this.getResources().getColor(R.color.flatred));
For the colours, if you are not using resources, you can supply a colour from aRGB hex using: Color.parseColor("#ff57d78d");