First prototype for volume visualization

2020-04-15 19:51:20 +02:00
parent 816f4554bb
commit 3991687565
4 changed files with 104 additions and 16 deletions
--- a/app/src/main/java/protect/babymonitor/VolumeView.java
+++ b/app/src/main/java/protect/babymonitor/VolumeView.java
@@ -0,0 +1,58 @@
+package protect.babymonitor;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.support.annotation.Nullable;
+import android.util.AttributeSet;
+import android.view.View;
+
+public class VolumeView extends View {
+    private double volume = 0;
+    private double maxVolume = 0;
+
+    public VolumeView(Context context) {
+        super(context);
+    }
+
+    public VolumeView(Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public VolumeView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public void onAudioData(byte[] data) {
+        double sum = 0;
+        for (int i = 0; i < data.length; i++) {
+            double rel = Math.abs(data[i]) / (double)32767f;
+            sum+=rel;
+        }
+        volume = sum/data.length;
+        if (volume > maxVolume) {
+            maxVolume = volume;
+        }
+        invalidate();
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        double relativeBrightness = 0;
+        if (maxVolume > 0) {
+            relativeBrightness = volume / (float) maxVolume;
+            relativeBrightness = Math.max(0.2, relativeBrightness );
+        }
+        int blue;
+        int rest;
+        if (relativeBrightness > 0.5) {
+            blue = 255;
+            rest = (int) (2 * 255 * (relativeBrightness - 0.5));
+        } else {
+            blue = (int) (2 * 255 * relativeBrightness);
+            rest = 0;
+        }
+        int rgb = Color.rgb(rest, rest, blue);
+        canvas.drawColor(rgb);
+    }
+}