CircularSlider.java 文件源码

@Override
protected void onSizeChanged(int w, int h, int oldW, int oldH) {
    // use smaller dimension for calculations (depends on parent size)
    int smallerDim = w > h ? h : w;

    // find circle's rectangle points
    int largestCenteredSquareLeft = (w - smallerDim) / 2;
    int largestCenteredSquareTop = (h - smallerDim) / 2;
    int largestCenteredSquareRight = largestCenteredSquareLeft + smallerDim;
    int largestCenteredSquareBottom = largestCenteredSquareTop + smallerDim;

    // save circle coordinates and radius in fields
    mCircleCenterX = largestCenteredSquareRight / 2 + (w - largestCenteredSquareRight) / 2;
    mCircleCenterY = largestCenteredSquareBottom / 2 + (h - largestCenteredSquareBottom) / 2;
    mCircleRadius = smallerDim / 2 - mBorderThickness / 2 - mPadding;

    if (mBorderGradientColors != null) {
        mGradientShader = new SweepGradient(mCircleRadius, mCircleRadius, mBorderGradientColors, null);
    }

    // works well for now, should we call something else here?
    super.onSizeChanged(w, h, oldW, oldH);
}