Android system ui definitions.

PhoneWindowManager.java

        // SystemUI (status bar) layout policy
        int shortSizeDp = shortSize
                * DisplayMetrics.DENSITY_DEFAULT
                / DisplayMetrics.DENSITY_DEVICE;

        if (shortSizeDp < 600) {
            // 0-599dp: "phone" UI with a separate status & navigation bar
            mHasSystemNavBar = false;
            mNavigationBarCanMove = true;
        } else if (shortSizeDp < 720) {
            // 600-719dp: "phone" UI with modifications for larger screens
            mHasSystemNavBar = false;
            mNavigationBarCanMove = false;
        } else {
            // 720dp: "tablet" UI with a single combined status & navigation bar
            mHasSystemNavBar = true;
            mNavigationBarCanMove = false;
        }