Added pie chart to statistics page

1 files changed, 120 insertions, 0 deletions

diff --git a/app/src/main/java/de/danoeh/antennapod/view/PieChartView.java b/app/src/main/java/de/danoeh/antennapod/view/PieChartView.java
new file mode 100644
index 000000000..46252f0d1
--- /dev/null
+++ b/app/src/main/java/de/danoeh/antennapod/view/PieChartView.java
@@ -0,0 +1,120 @@
+package de.danoeh.antennapod.view;
+
+import android.annotation.SuppressLint;
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.ColorFilter;
+import android.graphics.Paint;
+import android.graphics.PixelFormat;
+import android.graphics.RectF;
+import android.graphics.drawable.Drawable;
+import android.support.annotation.NonNull;
+import android.support.v7.widget.AppCompatImageView;
+import android.util.AttributeSet;
+import io.reactivex.annotations.Nullable;
+
+public class PieChartView extends AppCompatImageView {
+    private PieChartDrawable drawable;
+
+    public PieChartView(Context context) {
+        super(context);
+        setup();
+    }
+
+    public PieChartView(Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+        setup();
+    }
+
+    public PieChartView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        setup();
+    }
+
+    @SuppressLint("ClickableViewAccessibility")
+    private void setup() {
+        drawable = new PieChartDrawable();
+        setImageDrawable(drawable);
+    }
+
+    /**
+     * Set array od names, array of values and array of colors.
+     */
+    public void setData(float[] dataValues) {
+        drawable.dataValues = dataValues;
+        drawable.valueSum = 0;
+        for (float datum : dataValues) {
+            drawable.valueSum += datum;
+        }
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        int width = getMeasuredWidth();
+        setMeasuredDimension(width, width / 2);
+    }
+
+    private static class PieChartDrawable extends Drawable {
+        private static final float MIN_DEGREES = 10f;
+        private static final float PADDING_DEGREES = 3f;
+        private static final float STROKE_SIZE = 15f;
+        private static final int[] COLOR_VALUES = {0xFF3775E6,0xffe51c23,0xffff9800,0xff259b24,0xff9c27b0,
+                        0xff0099c6,0xffdd4477,0xff66aa00,0xffb82e2e,0xff316395,
+                        0xff994499,0xff22aa99,0xffaaaa11,0xff6633cc,0xff0073e6};
+        private float[] dataValues;
+        private float valueSum;
+        private final Paint linePaint;
+
+        private PieChartDrawable() {
+            linePaint = new Paint();
+            linePaint.setStyle(Paint.Style.STROKE);
+            linePaint.setStrokeJoin(Paint.Join.ROUND);
+            linePaint.setStrokeCap(Paint.Cap.ROUND);
+            linePaint.setStrokeWidth(STROKE_SIZE);
+        }
+
+        @Override
+        public void draw(@NonNull Canvas canvas) {
+            if (valueSum == 0) {
+                return;
+            }
+            float radius = getBounds().height() - STROKE_SIZE;
+            float center = getBounds().width() / 2.f;
+            RectF arc_bounds = new RectF(center - radius, STROKE_SIZE, center + radius, STROKE_SIZE + radius * 2);
+
+            float startAngle = 180;
+            for (int i = 0; i < dataValues.length; i++) {
+                float datum = dataValues[i];
+                float sweepAngle = 180 * datum / valueSum;
+                if (sweepAngle < MIN_DEGREES) {
+                    break;
+                }
+                linePaint.setColor(COLOR_VALUES[i % COLOR_VALUES.length]);
+                float padding = i == 0 ? PADDING_DEGREES / 2 : PADDING_DEGREES;
+                canvas.drawArc(arc_bounds, startAngle + padding, sweepAngle - padding, false, linePaint);
+                startAngle = startAngle + sweepAngle;
+            }
+
+            linePaint.setColor(Color.GRAY);
+            float sweepAngle = 360 - startAngle - PADDING_DEGREES / 2;
+            if (sweepAngle > PADDING_DEGREES) {
+                canvas.drawArc(arc_bounds, startAngle + PADDING_DEGREES, sweepAngle - PADDING_DEGREES, false, linePaint);
+            }
+        }
+
+        @Override
+        public int getOpacity() {
+            return PixelFormat.TRANSLUCENT;
+        }
+
+        @Override
+        public void setAlpha(int alpha) {
+        }
+
+        @Override
+        public void setColorFilter(ColorFilter cf) {
+        }
+    }
+}