Detect home button press in android

Question

This has been driving me nuts for a while now.

Is there any way of reliably detecting if the home button has been pressed in an android application?

Failing

Answer 1

Recently I was trying to detect the home press button, because I needed it to do the same as the method "onBackPressed()". In order to do this, I had to override the method "onSupportNavigateUp()" like this:

override fun onSupportNavigateUp(): Boolean {
    onBackPressed()
    return true
}

It worked perfectly. =)

Answer 2

It's a bad idea to change the behavior of the home key. This is why Google doesn't allow you to override the home key. I wouldn't mess with the home key generally speaking. You need to give the user a way to get out of your app if it goes off into the weeds for whatever reason.

I'd image any work around will have unwanted side effects.

Answer 3

An option for your application would be to write a replacement Home Screen using the android.intent.category.HOME Intent. I believe this type of Intent you can see the home button.

More details:

http://developer.android.com/guide/topics/intents/intents-filters.html#imatch

Answer 4

Override onUserLeaveHint() in the activity. There will never be any callback to the activity when a new activity comes over it or user presses back press.

Answer 5

Following code works for me :)

HomeWatcher mHomeWatcher = new HomeWatcher(this);
mHomeWatcher.setOnHomePressedListener(new OnHomePressedListener() {
    @Override
    public void onHomePressed() {
        // do something here...
    }
    @Override
    public void onHomeLongPressed() {
    }
});
mHomeWatcher.startWatch();

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.util.Log;

public class HomeWatcher {

    static final String TAG = "hg";
    private Context mContext;
    private IntentFilter mFilter;
    private OnHomePressedListener mListener;
    private InnerReceiver mReceiver;

    public HomeWatcher(Context context) {
        mContext = context;
        mFilter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
    }

    public void setOnHomePressedListener(OnHomePressedListener listener) {
        mListener = listener;
        mReceiver = new InnerReceiver();
    }

    public void startWatch() {
        if (mReceiver != null) {
            mContext.registerReceiver(mReceiver, mFilter);
        }
    }

    public void stopWatch() {
        if (mReceiver != null) {
            mContext.unregisterReceiver(mReceiver);
        }
    }

    class InnerReceiver extends BroadcastReceiver {
        final String SYSTEM_DIALOG_REASON_KEY = "reason";
        final String SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS = "globalactions";
        final String SYSTEM_DIALOG_REASON_RECENT_APPS = "recentapps";
        final String SYSTEM_DIALOG_REASON_HOME_KEY = "homekey";

        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (action.equals(Intent.ACTION_CLOSE_SYSTEM_DIALOGS)) {
                String reason = intent.getStringExtra(SYSTEM_DIALOG_REASON_KEY);
                if (reason != null) {
                    Log.e(TAG, "action:" + action + ",reason:" + reason);
                    if (mListener != null) {
                        if (reason.equals(SYSTEM_DIALOG_REASON_HOME_KEY)) {
                            mListener.onHomePressed();
                        } else if (reason.equals(SYSTEM_DIALOG_REASON_RECENT_APPS)) {
                            mListener.onHomeLongPressed();
                        }
                    }
                }
            }
        }
    }
}

public interface OnHomePressedListener {
    void onHomePressed();
    void onHomeLongPressed();
}

Answer 6

It is impossible to detect and/or intercept the HOME button from within an Android app. This is built into the system to prevent malicious apps that cannot be exited.