ViewUtils.java 文件源码

public static RippleDrawable createRipple(@NonNull Palette palette,
        @FloatRange(from = 0f, to = 1f) float darkAlpha,
        @FloatRange(from = 0f, to = 1f) float lightAlpha,
        @ColorInt int fallbackColor,
        boolean bounded) {
    int rippleColor = fallbackColor;
    if (palette != null) {
        // try the named swatches in preference order
        if (palette.getVibrantSwatch() != null) {
            rippleColor =
                    ColorUtils.modifyAlpha(palette.getVibrantSwatch().getRgb(), darkAlpha);

        } else if (palette.getLightVibrantSwatch() != null) {
            rippleColor = ColorUtils.modifyAlpha(palette.getLightVibrantSwatch().getRgb(),
                    lightAlpha);
        } else if (palette.getDarkVibrantSwatch() != null) {
            rippleColor = ColorUtils.modifyAlpha(palette.getDarkVibrantSwatch().getRgb(),
                    darkAlpha);
        } else if (palette.getMutedSwatch() != null) {
            rippleColor = ColorUtils.modifyAlpha(palette.getMutedSwatch().getRgb(), darkAlpha);
        } else if (palette.getLightMutedSwatch() != null) {
            rippleColor = ColorUtils.modifyAlpha(palette.getLightMutedSwatch().getRgb(),
                    lightAlpha);
        } else if (palette.getDarkMutedSwatch() != null) {
            rippleColor =
                    ColorUtils.modifyAlpha(palette.getDarkMutedSwatch().getRgb(), darkAlpha);
        }
    }
    return new RippleDrawable(ColorStateList.valueOf(rippleColor), null,
            bounded ? new ColorDrawable(Color.WHITE) : null);
}