How do I know if the keyboard is visible?

There is no direct method to achieve this. What we can do is check if the height of our layout has changed.

For this, declare a method that will be executed when our Layout has its state or visibility changed.

final View activityRootView = findViewById(R.id.activityRoot);
activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        int heightDiff = activityRootView.getRootView().getHeight() - activityRootView.getHeight();
        if (heightDiff > 100) { // Se são mais de 100 pixels, provávelmente é o keyboard...
            //... faça aqui o que quer quando o teclado passa a ser visível.
        }
     }
});  

Notes

  

1 - This code should be placed in the onCreate method of our Activity .   2 - The Layout root of Activity must have a Id assigned so that it can be referenced in the code, in this case it is activityRoot .   3 - You should add this attribute to your Activity : android:windowSoftInputMode="adjustResize"

Adapted from this answer from SO.com

Try this:

InputMethodManager imm = (InputMethodManager) getActivity()
            .getSystemService(Context.INPUT_METHOD_SERVICE);

    if (imm.isAcceptingText()) {
        writeToLog("Visível");
    } else {
        writeToLog("Não visível");
    }

More details here .