Detecting when user has dismissed the soft keyboard

Question

I know a way to do this. Subclass the EditText and implement:

@Override
public boolean onKeyPreIme(int keyCode, KeyEvent event) {
  if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
    // Do your thing.
    return true;  // So it is not propagated.
  }
  return super.dispatchKeyEvent(event);
}

Here is a link on how to use your custom views (for when you subclass EditText): http://developer.android.com/guide/topics/ui/custom-components.html

Jay, your solution is good ! thanks :)

public class EditTextBackEvent extends EditText {

    private EditTextImeBackListener mOnImeBack;

    public EditTextBackEvent(Context context) {
        super(context);
    }

    public EditTextBackEvent(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public EditTextBackEvent(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    public boolean onKeyPreIme(int keyCode, KeyEvent event) {
        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK && 
            event.getAction() == KeyEvent.ACTION_UP) {
            if (mOnImeBack != null) 
                mOnImeBack.onImeBack(this, this.getText().toString());
        }
        return super.dispatchKeyEvent(event);
    }

    public void setOnEditTextImeBackListener(EditTextImeBackListener listener) {
        mOnImeBack = listener;
    }

}

public interface EditTextImeBackListener {
    public abstract void onImeBack(EditTextBackEvent ctrl, String text);
}

I made a slight change on Jay's solution by calling super.onKeyPreIme():

_e = new EditText(inflater.getContext()) {
    @Override
    public boolean onKeyPreIme(int keyCode, KeyEvent event) {
        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK){
            cancelTextInput();
        }
        return super.onKeyPreIme(keyCode, event);
    }
};

Wonderful solution, Jay, +1!

Here is my custom EditText to detect whether keyboard is showing or not

/**
 * Created by TheFinestArtist on 9/24/15.
 */
public class KeyboardEditText extends EditText {

    public KeyboardEditText(Context context) {
        super(context);
    }

    public KeyboardEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public KeyboardEditText(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
        super.onFocusChanged(focused, direction, previouslyFocusedRect);
        if (listener != null)
            listener.onStateChanged(this, true);
    }

    @Override
    public boolean onKeyPreIme(int keyCode, @NonNull KeyEvent event) {
        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK
                && event.getAction() == KeyEvent.ACTION_UP) {
            if (listener != null)
                listener.onStateChanged(this, false);
        }
        return super.onKeyPreIme(keyCode, event);
    }

    /**
     * Keyboard Listener
     */
    KeyboardListener listener;

    public void setOnKeyboardListener(KeyboardListener listener) {
        this.listener = listener;
    }

    public interface KeyboardListener {
        void onStateChanged(KeyboardEditText keyboardEditText, boolean showing);
    }
}

It's 2019 now...
So I created a more neat solution with Kotlin

1.Create an extension function:

fun Activity.addKeyboardToggleListener(onKeyboardToggleAction: (shown: Boolean) -> Unit): KeyboardToggleListener? {
    val root = findViewById<View>(android.R.id.content)
    val listener = KeyboardToggleListener(root, onKeyboardToggleAction)
    return root?.viewTreeObserver?.run {
        addOnGlobalLayoutListener(listener)
        listener
    }
}

2.Where the toggle listener is:

open class KeyboardToggleListener(
        private val root: View?,
        private val onKeyboardToggleAction: (shown: Boolean) -> Unit
) : ViewTreeObserver.OnGlobalLayoutListener {
    private var shown = false
    override fun onGlobalLayout() {
        root?.run {
            val heightDiff = rootView.height - height
            val keyboardShown = heightDiff > dpToPx(200f)
            if (shown != keyboardShown) {
                onKeyboardToggleAction.invoke(keyboardShown)
                shown = keyboardShown
            }
        }
    }
}

fun View.dpToPx(dp: Float) = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, resources.displayMetrics).roundToInt()

3.Use it in any Activity as simple as this:

addKeyboardToggleListener {shown ->
          // hurray! Now you know when the keyboard is shown and hidden!!
      }

Using @olivier_sdg's answer, but converted to Kotlin:

class KeyboardEditText : AppCompatEditText {

    var listener: Listener? = null
  
    constructor(context: Context) : super(context)
    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
    constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
  
    override fun onKeyPreIme(keyCode: Int, event: KeyEvent): Boolean {
        if (event.keyCode == KeyEvent.KEYCODE_BACK && event.action == KeyEvent.ACTION_UP) {
            listener?.onImeBack(this)
        }
        return super.dispatchKeyEvent(event)
    }
  
    interface Listener {
        fun onImeBack(editText: KeyboardEditText)
    }

}

Usage:

keyboardEditText.listener = object : KeyboardEditText.Listener {
    override fun onImeBack(editText: KeyboardEditText) {
        //Back detected
    }
}