Detect Android Navigation Bar orientation

My solution

public static boolean hasNavBar (Resources resources)
{
    int id = resources.getIdentifier("config_showNavigationBar", "bool", "android");
    if (id > 0)
        return resources.getBoolean(id);
    else
        return false;
}

public static int getNavigationBarHeight (Resources resources)
{
    if (!Utils.hasNavBar(resources))
        return 0;

    int orientation = resources.getConfiguration().orientation;

    //Only phone between 0-599 has navigationbar can move
    boolean isSmartphone = resources.getConfiguration().smallestScreenWidthDp < 600;
    if (isSmartphone && Configuration.ORIENTATION_LANDSCAPE == orientation)
        return 0;

    int id = resources
        .getIdentifier(orientation == Configuration.ORIENTATION_PORTRAIT ? "navigation_bar_height" : "navigation_bar_height_landscape", "dimen", "android");
    if (id > 0)
        return resources.getDimensionPixelSize(id);

    return 0;
}

public static int getNavigationBarWidth (Resources resources)
{
    if (!Utils.hasNavBar(resources))
        return 0;

    int orientation = resources.getConfiguration().orientation;

    //Only phone between 0-599 has navigationbar can move
    boolean isSmartphone = resources.getConfiguration().smallestScreenWidthDp < 600;

    if (orientation == Configuration.ORIENTATION_LANDSCAPE && isSmartphone)
    {
        int id = resources.getIdentifier("navigation_bar_width", "dimen", "android");
        if (id > 0)
            return resources.getDimensionPixelSize(id);
    }

    return 0;
}

Solution based on https://android.googlesource.com/platform/frameworks/base/+/9f65c4c34abb07bdda54649ed510af26f16e9c1b/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java

Working Solution for me is:

public static boolean hasNavBar(Context context) {
        WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        Point realPoint = new Point();
        Display display = wm.getDefaultDisplay();
        display.getRealSize(realPoint);
        DisplayMetrics metrics = new DisplayMetrics();
        wm.getDefaultDisplay().getMetrics(metrics);
        return metrics.heightPixels + metrics.widthPixels != realPoint.y + realPoint.x;
    }

    public static boolean isSystemBarOnBottom(Context context) {
        WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        Point realPoint = new Point();
        Display display = wm.getDefaultDisplay();
        display.getRealSize(realPoint);
        DisplayMetrics metrics = new DisplayMetrics();
        wm.getDefaultDisplay().getMetrics(metrics);
        Configuration cfg = context.getResources().getConfiguration();
        boolean canMove = (metrics.widthPixels != metrics.heightPixels &&
                cfg.smallestScreenWidthDp < 600);

        return (!canMove || metrics.widthPixels < metrics.heightPixels);
    }

By using the properties of the decor view in combination with the current DisplayMetrics you can find out on which side the navigation bar is positioned.

// retrieve the position of the DecorView
Rect visibleFrame = new Rect();
getWindow().getDecorView().getWindowVisibleDisplayFrame(visibleFrame);

DisplayMetrics dm = getResources().getDisplayMetrics();
// check if the DecorView takes the whole screen vertically or horizontally
boolean isRightOfContent = dm.heightPixels == visibleFrame.bottom;
boolean isBelowContent   = dm.widthPixels  == visibleFrame.right;

Based in part on Pauland's answer (in turn based on the implementation of PhoneWindowManager), here is what I am using at the moment:

  public static boolean isSystemBarOnBottom(Context ctxt) {
    Resources res=ctxt.getResources();
    Configuration cfg=res.getConfiguration();
    DisplayMetrics dm=res.getDisplayMetrics();
    boolean canMove=(dm.widthPixels != dm.heightPixels &&
        cfg.smallestScreenWidthDp < 600);

    return(!canMove || dm.widthPixels < dm.heightPixels);
  }

This works on a Nexus 7 2012 and a Nexus 4, each running Android 5.1.

On devices that have a permanent MENU key, there is no system bar. Depending upon your use case, you may need to check for this case:

ViewConfiguration.get(ctxt).hasPermanentMenuKey()

(where ctxt is some Context)

Personally, I am using this to try to have a sliding panel be on the opposite axis from the system bar, as bezel swipes on the side with the system bar are a bit difficult to trigger. I would not use this, or any other algorithm (like the ones that depend upon getDecorView()), for anything critical.