Intercept back button from soft keyboard

Android Problem Overview

I have the activity with several input fields. When activity started soft keyboard is shown. When back button pressed soft keyboard closes and to close activity I need to press back button one more time.

So the question: is it possible to intercept back button to close soft keyboard and finish activity in one press of back button without creating custom InputMethodService?

P.S. I know how to intercept back button in other cases: onKeyDown() or onBackPressed() but it doesn't work in this case: only second press of back button is intercepted.

Android Solutions

Solution 1 - Android

onKeyDown() and onBackPressed() doesn't work for this case. You have to use onKeyPreIme.

Initially, you have to create custom edit text that extends EditText. And then you have to implement onKeyPreIme method which controls KeyEvent.KEYCODE_BACK. After this, one back press enough for solve your problem. This solution works for me perfectly.

CustomEditText.java

public class CustomEditText extends EditText {

    public CustomEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
    }
   
    @Override
    public boolean onKeyPreIme(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            // User has pressed Back key. So hide the keyboard
            InputMethodManager mgr = (InputMethodManager)         
            
           getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
            mgr.hideSoftInputFromWindow(this.getWindowToken(), 0);
            // TODO: Hide your view as you do it in your activity
        }
        return false;
}

In your XML

<com.YOURAPP.CustomEditText
     android:id="@+id/CEditText"
     android:layout_height="wrap_content"
     android:layout_width="match_parent"/>

In your Activity

public class MainActivity extends Activity {
   private CustomEditText editText;
   
   @Override
   public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      editText = (CustomEditText) findViewById(R.id.CEditText);
   }
}

Solution 2 - Android

Yes, it is completely possible to show and hide the keyboard and intercept the calls to the back button. It is a little extra effort as it has been mentioned there is no direct way to do this in the API. The key is to override boolean dispatchKeyEventPreIme(KeyEvent) within a layout. What we do is create our layout. I chose RelativeLayout since it was the base of my Activity.

<?xml version="1.0" encoding="utf-8"?>
<com.michaelhradek.superapp.utilities.SearchLayout
	xmlns:android="http://schemas.android.com/apk/res/android"
	xmlns:app="http://schemas.android.com/apk/res/com.michaelhradek.superapp"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/white">

Inside our Activity we set up our input fields and call the setActivity(...) function.

private void initInputField() {
	mInputField = (EditText) findViewById(R.id.searchInput);		
	
	InputMethodManager imm = 
		(InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE); 
	imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, 
			InputMethodManager.HIDE_IMPLICIT_ONLY);
	
	mInputField.setOnEditorActionListener(new OnEditorActionListener() {

		@Override
		public boolean onEditorAction(TextView v, int actionId,
				KeyEvent event) {
	        if (actionId == EditorInfo.IME_ACTION_SEARCH) {
            	performSearch();
            	return true;
        	}
	
        	return false;
		}
	});
	
    // Let the layout know we are going to be overriding the back button
	SearchLayout.setSearchActivity(this);
}

Obviously, the initInputField() function sets up the input field. It also enables the enter key to execute the functionality (in my case a search).

@Override
public void onBackPressed() {
	// It's expensive, if running turn it off.
	DataHelper.cancelSearch();
	hideKeyboard();
	super.onBackPressed();
}

So when the onBackPressed() is called within our layout we then can do whatever we want like hide the keyboard:

private void hideKeyboard() {
	InputMethodManager imm = (InputMethodManager) 
		getSystemService(Context.INPUT_METHOD_SERVICE);
	imm.hideSoftInputFromWindow(mInputField.getWindowToken(), 0);
}

Anyway, here is my override of the RelativeLayout.

package com.michaelhradek.superapp.utilities;

import android.app.Activity;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.KeyEvent;
import android.widget.RelativeLayout;

/**
 * The root element in the search bar layout. This is a custom view just to 
 * override the handling of the back button.
 * 
 */
public class SearchLayout extends RelativeLayout {
	
	private static final String TAG = "SearchLayout";

    private static Activity mSearchActivity;;

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

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

    public static void setSearchActivity(Activity searchActivity) {
    	mSearchActivity = searchActivity;
    }

    /**
     * Overrides the handling of the back key to move back to the 
     * previous sources or dismiss the search dialog, instead of 
     * dismissing the input method.
     */
    @Override
    public boolean dispatchKeyEventPreIme(KeyEvent event) {
        Log.d(TAG, "dispatchKeyEventPreIme(" + event + ")");
        if (mSearchActivity != null && 
                    event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
            KeyEvent.DispatcherState state = getKeyDispatcherState();
            if (state != null) {
                if (event.getAction() == KeyEvent.ACTION_DOWN
                        && event.getRepeatCount() == 0) {
                    state.startTracking(event, this);
                    return true;
                } else if (event.getAction() == KeyEvent.ACTION_UP
                        && !event.isCanceled() && state.isTracking(event)) {
                	mSearchActivity.onBackPressed();
                    return true;
                }
            }
        }
        
        return super.dispatchKeyEventPreIme(event);
    }
}

Unfortunately I can't take all the credit. If you check the Android http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.1_r2/android/app/SearchDialog.java#SearchDialog.SearchBar">source for the quick SearchDialog box you will see where the idea came from.

Solution 3 - Android

I found out, that overriding the dispatchKeyEventPreIme method of the Layout Class also works well. Just set your main Activity as an attribute and launch a predefined method.

public class LinearLayoutGradient extends LinearLayout {
	MainActivity a;

	public void setMainActivity(MainActivity a) {
		this.a = a;
	}

	@Override
	public boolean dispatchKeyEventPreIme(KeyEvent event) {
		if (a != null) {
			InputMethodManager imm = (InputMethodManager) a
				.getSystemService(Context.INPUT_METHOD_SERVICE);

			if (imm.isActive() && event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
				a.launchMethod;
			}
		}

		return super.dispatchKeyEventPreIme(event);
	}
}

Solution 4 - Android

I had success by overriding dispatchKeyEvent:

@Override
public boolean dispatchKeyEvent(KeyEvent event) {
	if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
		finish();
		return true;
	}
	return super.dispatchKeyEvent(event);
}

It hides the keyboard and finishes the activity.

Solution 5 - Android

How are you showing the soft keyboard?

If you are using InputMethodManager.showSoftInput(), you can try passing in a ResultReceiver and implementing onReceiveResult() to handle RESULT_HIDDEN

http://developer.android.com/reference/android/view/inputmethod/InputMethodManager.html

Solution 6 - Android

I had the same problem but got around it by intercepting the back key press. In my case (HTC Desire, Android 2.2, Application API Level 4) it closes the Keyboard and immediately finishes the Activity. Don't know why this should not work for you too:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
	if (keyCode == KeyEvent.KEYCODE_BACK) {
		return true;
	}
	return super.onKeyDown(keyCode, event);
}

@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
	if (keyCode == KeyEvent.KEYCODE_BACK) {
		onBackPressed();
		return true;
	}
	return super.onKeyUp(keyCode, event);
}

/**
 * Called when the activity has detected the user's press of the back key
 */
private void onBackPressed() {
	Log.e(TAG, "back pressed");
	finish();
}

Solution 7 - Android

Use onKeyPreIme(int keyCode, KeyEvent event) method and check for KeyEvent.KEYCODE_BACK event. It's very simple without doing any fancy coding.

Solution 8 - Android

Try this code in your BackPressed implementation(https://stackoverflow.com/questions/3988478/block-back-button-in-android/3988567#3988567):

InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(myEditText.getWindowToken(), 0);

I suggest you to have a look @ https://stackoverflow.com/questions/1109022/how-to-close-hide-the-android-soft-keyboard

Solution 9 - Android

my version of @mhradek solution:

Layout

class BazingaLayout @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0) :
    ConstraintLayout(context, attrs, defStyleAttr) {

var activity: Activity? = null

override fun dispatchKeyEventPreIme(event: KeyEvent): Boolean {
    activity?.let {
        if (event.keyCode == KeyEvent.KEYCODE_BACK) {
            val state = keyDispatcherState
            if (state != null) {
                if (event.action == KeyEvent.ACTION_DOWN
                    && event.repeatCount == 0) {
                    state.startTracking(event, this)
                    return true
                } else if (event.action == KeyEvent.ACTION_UP && !event.isCanceled && state.isTracking(event)) {
                    it.onBackPressed()
                    return true
                }
            }
        }
    }
    return super.dispatchKeyEventPreIme(event)
}

}

xml file

<com... BazingaLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/grey">
 </com... BazingaLayout>

Fragment

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        (view as BazingaLayout).activity = activity
        super.onViewCreated(view, savedInstanceState)
}

Solution 10 - Android

Here's my variation of @kirill-rakhman's solution.

I needed to know when the hardware or gesture back button was pressed while the keyboard was showing so I could react and show a button that had previously been hidden when any of the edit text views had received focus.

First declare the call back interface your require

interface KeyboardEventListener {
   fun onKeyBoardDismissedIme()
}

Then create the custom view with the listener for pre ime key events

class KeyboardAwareConstraintLayout(context: Context, attrs: AttributeSet) :
    ConstraintLayout(context, attrs) {

    var listener: KeyboardEventListener? = null

    override fun dispatchKeyEventPreIme(event: KeyEvent?): Boolean {
        val imm: InputMethodManager =
            context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
        if (imm.isActive && event?.keyCode == KeyEvent.KEYCODE_BACK) {
            listener?.onKeyBoardDismissedIme()
        }
        return super.dispatchKeyEventPreIme(event)
    }
}

Wrap your layout with the custom layout view

<com.package_name.KeyboardAwareLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/keyBoardAwareLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

{Your layout children here}    

</com.package_name.KeyboardAwareLayout>

Next implement the callback interface in your activity or fragment and set on the keyboard aware layout

class MyFragment : Fragment, KeyboardEventListener {

    // TODO: Setup some viewbinding to retrieve the view reference

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        binding.keyBoardAwareLayout.listener = this
    }

    override fun onKeyBoardDismissedIme() {
        // TODO: React to keyboard hidden with back button
    }
}

Content Type	Original Author	Original Content on Stackoverflow
Question	Sergey Glotov	View Question on Stackoverflow
Solution 1 - Android	Alican Temel	View Answer on Stackoverflow
Solution 2 - Android	mhradek	View Answer on Stackoverflow
Solution 3 - Android	Kirill Rakhman	View Answer on Stackoverflow
Solution 4 - Android	jaseelder	View Answer on Stackoverflow
Solution 5 - Android	superuser	View Answer on Stackoverflow
Solution 6 - Android	whlk	View Answer on Stackoverflow
Solution 7 - Android	Umair	View Answer on Stackoverflow
Solution 8 - Android	100rabh	View Answer on Stackoverflow
Solution 9 - Android	tasjapr	View Answer on Stackoverflow
Solution 10 - Android	speedynomads	View Answer on Stackoverflow