setColorForSwipeBack()方法能否优化一下

 * 为滑动返回界面设置状态栏颜色
 *
 * @param activity       需要设置的activity
 * @param color          状态栏颜色值
 * @param statusBarAlpha 状态栏透明度
 */
public static void setColorForSwipeBack(Activity activity, @ColorInt int color,
    @IntRange(from = 0, to = 255) int statusBarAlpha) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {

        ViewGroup contentView = ((ViewGroup) activity.findViewById(android.R.id.content));
        View rootView = contentView.getChildAt(0);
        int statusBarHeight = getStatusBarHeight(activity);
        if (rootView != null && rootView instanceof CoordinatorLayout) {
            final CoordinatorLayout coordinatorLayout = (CoordinatorLayout) rootView;
            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
                coordinatorLayout.setFitsSystemWindows(false);
                contentView.setBackgroundColor(calculateStatusColor(color, statusBarAlpha));
                boolean isNeedRequestLayout = contentView.getPaddingTop() < statusBarHeight;
                if (isNeedRequestLayout) {
                    contentView.setPadding(0, statusBarHeight, 0, 0);
                    coordinatorLayout.post(new Runnable() {
                        @Override
                        public void run() {
                            coordinatorLayout.requestLayout();
                        }
                    });
                }
            } else {
                coordinatorLayout.setStatusBarBackgroundColor(calculateStatusColor(color, statusBarAlpha));
            }
        } else {
            contentView.setPadding(0, statusBarHeight, 0, 0);
            contentView.setBackgroundColor(calculateStatusColor(color, statusBarAlpha));
        }
        setTransparentForWindow(activity);
    }
}

不给根布局设置背景，这样会导致整个布局都是状态栏的颜色，必须在自己界面的布局设置底色来覆盖状态栏的颜色，有时候这两次绘制是浪费的，导致过渡绘制了；

/**

为滑动返回界面设置状态栏颜色
@param activity 需要设置的activity
@param color 状态栏颜色值

@param statusBarAlpha 状态栏透明度 */ public static void setColorForSwipeBack(Activity activity, @ColorInt int color, @IntRange(from = 0, to = 255) int statusBarAlpha) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {

    ViewGroup contentView = ((ViewGroup) activity.findViewById(android.R.id.content));
    View rootView = contentView.getChildAt(0);
    int statusBarHeight = getStatusBarHeight(activity);
    Log.v("statusBarHeight", "statusBarHeight = " + statusBarHeight);
    View statusView = createStatusBarView(activity, color, statusBarAlpha);
    contentView.addView(statusView);

    if (rootView != null && rootView instanceof CoordinatorLayout) {
        Log.v("statusBarHeight", "rootView instanceof CoordinatorLayout -------> true" );
        final CoordinatorLayout coordinatorLayout = (CoordinatorLayout) rootView;
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
            coordinatorLayout.setFitsSystemWindows(false);

            //contentView.setBackgroundColor(calculateStatusColor(color, statusBarAlpha));

            boolean isNeedRequestLayout = contentView.getPaddingTop() < statusBarHeight;
            if (isNeedRequestLayout) {
                contentView.setPadding(0, statusBarHeight, 0, 0);
                coordinatorLayout.post(new Runnable() {
                    @Override
                    public void run() {
                        coordinatorLayout.requestLayout();
                    }
                });
            }
        } else {
            //coordinatorLayout.setStatusBarBackgroundColor(calculateStatusColor(color, statusBarAlpha));
        }
    } else {
        rootView.setPadding(0, statusBarHeight, 0, 0);
        //contentView.setBackgroundColor(calculateStatusColor(color, statusBarAlpha));
    }
    setTransparentForWindow(activity);
    if (Color.WHITE == color) {
        StatusBarUtil2.setLightMode(activity);
    }
}

} 这样添加一个状态栏高度的View背景设置为状态栏颜色，看看是否可行

laobie / StatusBarUtil

setColorForSwipeBack()方法能否优化一下 #239