ColorPicker.java 文件源码

private Bitmap createColorDiscBitmap(int radius) {
    int centerColor, edgeColor;
    Bitmap bitmap = Bitmap.createBitmap(2 * radius, 2 * radius, Config.ARGB_8888);

    Canvas canvas = new Canvas(bitmap);
    mHSV[0] = 0; mHSV[1] = 1; mHSV[2] = 1;   //red
    SweepGradient sweepGradient = new SweepGradient(radius, radius, getColors(mHSV), null);
    mColorPaint.setShader(sweepGradient);
    canvas.drawCircle(radius, radius, radius, mColorPaint);

    mHSV[0] = 0; mHSV[1] = 0; mHSV[2] = 1;   //white
    centerColor = Color.HSVToColor(255, mHSV);
    edgeColor = Color.HSVToColor(0, mHSV);
    RadialGradient radialGradient = new RadialGradient(radius, radius, radius, centerColor, edgeColor, TileMode.CLAMP);
    mColorPaint.setShader(radialGradient);
    canvas.drawCircle(radius, radius, radius, mColorPaint);

    return bitmap;
}