Coloring.java 文件源码

/**
 * Creates a new drawable (implementation of the Drawable object may vary depending on the OS version).
 * The result Drawable will be colored with the given color, and clipped to match the given bounds.
 * Note that the drawable's alpha is set to 0 when argument color is {@link Color#TRANSPARENT}.
 *
 * @param color  Integer color used to color the output drawable
 * @param bounds Four-dimensional vector representing drawable bounds
 * @return Colored and clipped drawable object
 */
@NonNull
public static Drawable createColoredDrawable(@ColorInt final int color, @Nullable final Rect bounds) {
    // create the drawable depending on the OS (pre-Honeycomb couldn't use color drawables inside state lists)
    Drawable drawable;
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB || bounds != null) {
        drawable = new GradientDrawable(Orientation.BOTTOM_TOP, new int[] { color, color }).mutate();
    } else {
        drawable = new ColorDrawable(color).mutate();
    }

    // set the alpha value
    if (color == Color.TRANSPARENT) {
        drawable.setAlpha(0);
    }

    // update bounds
    if (bounds != null) {
        drawable.setBounds(bounds);
    }
    return drawable;
}