How to check if the current activity has a dialog in front?

Question

I am using a third-party library and sometimes it pops up a dialog. Before I finish the current activity, I want to check whether there is a dialog popped up in the current con

Answer 1

This uses reflection and hidden APIs to get the currently active view roots. If an alert dialog shows this will return an additional view root. But careful as even a toast popup will return an additional view root.

I've confirmed compatibility from Android 4.1 to Android 6.0 but of course this may not work in earlier or later Android versions.

I've not checked the behavior for multi-window modes.

@SuppressWarnings("unchecked")
public static List getViewRoots() {

    List viewRoots = new ArrayList<>();

    try {
        Object windowManager;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            windowManager = Class.forName("android.view.WindowManagerGlobal")
                    .getMethod("getInstance").invoke(null);
        } else {
            Field f = Class.forName("android.view.WindowManagerImpl")
                    .getDeclaredField("sWindowManager");
            f.setAccessible(true);
            windowManager = f.get(null);
        }

        Field rootsField = windowManager.getClass().getDeclaredField("mRoots");
        rootsField.setAccessible(true);

        Field stoppedField = Class.forName("android.view.ViewRootImpl")
                .getDeclaredField("mStopped");
        stoppedField.setAccessible(true);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            List viewParents = (List) rootsField.get(windowManager);
            // Filter out inactive view roots
            for (ViewParent viewParent : viewParents) {
                boolean stopped = (boolean) stoppedField.get(viewParent);
                if (!stopped) {
                    viewRoots.add(viewParent);
                }
            }
        } else {
            ViewParent[] viewParents = (ViewParent[]) rootsField.get(windowManager);
            // Filter out inactive view roots
            for (ViewParent viewParent : viewParents) {
                boolean stopped = (boolean) stoppedField.get(viewParent);
                if (!stopped) {
                    viewRoots.add(viewParent);
                }
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }

    return viewRoots;
}