public SoundLevels(final Context context, final AttributeSet attrs, final int defStyle) {
super(context, attrs, defStyle);
// Safe source, replaced with system one when attached.
mLevelSource = new AudioLevelSource();
mLevelSource.setSpeechLevel(0);
final TypedArray a =
context.obtainStyledAttributes(attrs, R.styleable.SoundLevels, defStyle, 0);
mMaximumLevelSize = a.getDimensionPixelOffset(R.styleable.SoundLevels_maxLevelRadius, 0);
mMinimumLevelSize = a.getDimensionPixelOffset(R.styleable.SoundLevels_minLevelRadius, 0);
mMinimumLevel = mMinimumLevelSize / mMaximumLevelSize;
mPrimaryLevelPaint = new Paint();
mPrimaryLevelPaint.setColor(a.getColor(R.styleable.SoundLevels_primaryColor, Color.BLACK));
mPrimaryLevelPaint.setFlags(Paint.ANTI_ALIAS_FLAG);
a.recycle();
// This animator generates ticks that invalidate the
// view so that the animation is synced with the global animation loop.
// TODO: We could probably remove this in favor of using postInvalidateOnAnimation
// which might improve things further.
mSpeechLevelsAnimator = new TimeAnimator();
mSpeechLevelsAnimator.setRepeatCount(ObjectAnimator.INFINITE);
mSpeechLevelsAnimator.setTimeListener(
new TimeListener() {
@Override
public void onTimeUpdate(
final TimeAnimator animation, final long totalTime, final long deltaTime) {
invalidate();
}
});
}
@Override
protected void onDraw(final Canvas canvas) {
if (!mIsEnabled) {
return;
}
if (!mCenterDefined) {
// One time computation here, because we can't rely on getWidth() to be computed at
// constructor time or in onFinishInflate :(.
mCenterX = getWidth() / 2;
mCenterY = getWidth() / 2;
mCenterDefined = true;
}
final int level = mLevelSource.getSpeechLevel();
// Either ease towards the target level, or decay away from it depending on whether
// its higher or lower than the current.
if (level > mCurrentVolume) {
mCurrentVolume = mCurrentVolume + ((level - mCurrentVolume) / 4);
} else {
mCurrentVolume = mCurrentVolume * 0.95f;
}
final float radius = mMinimumLevel + (1f - mMinimumLevel) * mCurrentVolume / 100;
mPrimaryLevelPaint.setStyle(Style.FILL);
canvas.drawCircle(mCenterX, mCenterY, radius * mMaximumLevelSize, mPrimaryLevelPaint);
}