CODEWITHSUNDEEP
android
Nick
Nick

Reputation: 9373

Android: Proper Way to use onBackPressed() with Toast

I wrote a piece of code that will give the user a prompt asking them to press back again if they would like to exit. I currently have my code working to an extent but I know it is written poorly and I assume there is a better way to do it. Any suggestions would be helpful!

Code:

public void onBackPressed(){
    backpress = (backpress + 1);
    Toast.makeText(getApplicationContext(), " Press Back again to Exit ", Toast.LENGTH_SHORT).show();

    if (backpress>1) {
        this.finish();
    }
}

Upvotes: 88

Views: 288102

Answers (13)

Mast Pahadi
Mast Pahadi

Reputation: 1

implementing onBackPressed() by System time, if pressed twice within 2 sec, then will exit

public class MainActivity extends AppCompatActivity {
   private long backPressedTime;   // for back button timing less than 2 sec
   private Toast backToast;     // to hold message of exit
   @Override
public void onBackPressed() {


if (backPressedTime + 2000 > System.currentTimeMillis()) {

backToast.cancel();    // abruptly cancles the toast when pressed BACK Button *back2back*
super.onBackPressed();

} else {

backToast = Toast.makeText(getBaseContext(), "Press back again to exit", 
Toast.LENGTH_SHORT);
backToast.show();

}
backPressedTime = System.currentTimeMillis();

}

}

Upvotes: 0

Yogesh Rathi
Yogesh Rathi

Reputation: 6499

This is the best way, because if user not back more than two seconds then reset backpressed value.

declare one global variable.

 private boolean backPressToExit = false;

Override onBackPressed Method.

@Override
public void onBackPressed() {

    if (backPressToExit) {
        super.onBackPressed();
        return;
    }
    this.backPressToExit = true;
    Snackbar.make(findViewById(R.id.yourview), getString(R.string.exit_msg), Snackbar.LENGTH_SHORT).show();
    new Handler().postDelayed(new Runnable() {

        @Override
        public void run() {
            backPressToExit = false;
        }
    }, 2000);
}

Upvotes: 1

Manisa
Manisa

Reputation: 1

Use this, it may help.

@Override
public void onBackPressed() {
    new AlertDialog.Builder(this)
            .setTitle("Message")
            .setMessage("Do you want to exit app?")
            .setNegativeButton("NO", null)
            .setPositiveButton("YES", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    UserLogin.super.onBackPressed();
                }
            }).create().show();
}

Upvotes: 0

Steve Prentice
Steve Prentice

Reputation: 23514

I would implement a dialog asking the user if they wanted to exit and then call super.onBackPressed() if they did.

@Override
public void onBackPressed() {
    new AlertDialog.Builder(this)
        .setTitle("Really Exit?")
        .setMessage("Are you sure you want to exit?")
        .setNegativeButton(android.R.string.no, null)
        .setPositiveButton(android.R.string.yes, new OnClickListener() {

            public void onClick(DialogInterface arg0, int arg1) {
                WelcomeActivity.super.onBackPressed();
            }
        }).create().show();
}

In the above example, you'll need to replace WelcomeActivity with the name of your activity.

Upvotes: 221

Tabish khan
Tabish khan

Reputation: 782

If you want to exit your application from direct Second Activity without going to First Activity then try this code..`

In Second Activity put this code..

 @Override
public void onBackPressed() {
    new AlertDialog.Builder(this)
            .setTitle("Really Exit?")
            .setMessage("Are you sure you want to exit?")
            .setNegativeButton(android.R.string.no, null)
            .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface arg0, int arg1) {
                    setResult(RESULT_OK, new Intent().putExtra("EXIT", true));
                    finish();
                }

            }).create().show();
}

And Your First Activity Put this code.....

public class FirstActivity extends AppCompatActivity {

Button next;
private final static int EXIT_CODE = 100;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    next = (Button) findViewById(R.id.next);
    next.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View view) {

            startActivityForResult(new Intent(FirstActivity.this, SecondActivity.class), EXIT_CODE);
        }
    });
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == EXIT_CODE) {
        if (resultCode == RESULT_OK) {
            if (data.getBooleanExtra("EXIT", true)) {
                finish();
            }
        }
    }
}

}

Upvotes: 1

Pankaj Lilan
Pankaj Lilan

Reputation: 4453

You can also use onBackPressed by following ways using customized Toast:

enter image description here

customized_toast.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/txtMessage"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:drawableStart="@drawable/ic_white_exit_small"
    android:drawableLeft="@drawable/ic_white_exit_small"
    android:drawablePadding="8dp"
    android:paddingTop="8dp"
    android:paddingBottom="8dp"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:gravity="center"
    android:textColor="@android:color/white"
    android:textSize="16sp"
    android:text="Press BACK again to exit.."
    android:background="@drawable/curve_edittext"/>

MainActivity.java

@Override
public void onBackPressed() {

    if (doubleBackToExitPressedOnce) {
        android.os.Process.killProcess(Process.myPid());
        System.exit(1);
        return;
    }

    this.doubleBackToExitPressedOnce = true;
    Toast toast = new Toast(Dashboard.this);
    View view = getLayoutInflater().inflate(R.layout.toast_view,null);
    toast.setView(view);
    toast.setDuration(Toast.LENGTH_SHORT);
    int margin = getResources().getDimensionPixelSize(R.dimen.toast_vertical_margin);
    toast.setGravity(Gravity.BOTTOM | Gravity.CENTER_VERTICAL, 0, margin);
    toast.show();

    new Handler().postDelayed(new Runnable() {

        @Override
        public void run() {
            doubleBackToExitPressedOnce=false;
        }
    }, 2000);
}

Upvotes: 0

marc
marc

Reputation: 243

I just had this issue and solved it by adding the following method:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
             // click on 'up' button in the action bar, handle it here
             return true;

        default:
            return super.onOptionsItemSelected(item);
    }
}

Upvotes: 0

M.zar
M.zar

Reputation: 9

use to .onBackPressed() to back Activity specify

@Override
public void onBackPressed(){
    backpress = (backpress + 1);
    Toast.makeText(getApplicationContext(), " Press Back again to Exit ", Toast.LENGTH_SHORT).show();

    if (backpress>1) {
        this.finish();
    }
}

Upvotes: 0

kaMChy
kaMChy

Reputation: 441

additionally, you need to dissmis dialog before calling activity.super.onBackPressed(), otherwise you'll get "Activity has leaked.." error.

Example in my case with sweetalerdialog library:

 @Override
    public void onBackPressed() {
        //super.onBackPressed();
        SweetAlertDialog progressDialog = new SweetAlertDialog(this, SweetAlertDialog.WARNING_TYPE);
        progressDialog.setCancelable(false);
        progressDialog.setTitleText("Are you sure you want to exit?");
        progressDialog.setCancelText("No");
        progressDialog.setConfirmText("Yes");
        progressDialog.setCanceledOnTouchOutside(true);
        progressDialog.setConfirmClickListener(new SweetAlertDialog.OnSweetClickListener() {
            @Override
            public void onClick(SweetAlertDialog sweetAlertDialog) {
                sweetAlertDialog.dismiss();
                MainActivity.super.onBackPressed();
            }
        });
        progressDialog.show();
    }

Upvotes: 0

SoloPilot
SoloPilot

Reputation: 1534

I use this much simpler approach...

public class XYZ extends Activity {
    private long backPressedTime = 0;    // used by onBackPressed()


    @Override
    public void onBackPressed() {        // to prevent irritating accidental logouts
        long t = System.currentTimeMillis();
        if (t - backPressedTime > 2000) {    // 2 secs
            backPressedTime = t;
            Toast.makeText(this, "Press back again to logout",
                                Toast.LENGTH_SHORT).show();
        } else {    // this guy is serious
            // clean up
            super.onBackPressed();       // bye
        }
    }
}

Upvotes: 14

A Person
A Person

Reputation: 1350

You don't need a counter for back presses.

Just store a reference to the toast that is shown:

private Toast backtoast;

Then,

public void onBackPressed() {
    if(USER_IS_GOING_TO_EXIT) {
        if(backtoast!=null&&backtoast.getView().getWindowToken()!=null) {
            finish();
        } else {
            backtoast = Toast.makeText(this, "Press back to exit", Toast.LENGTH_SHORT);
            backtoast.show();
        }
    } else {
        //other stuff...
        super.onBackPressed();
    }
}

This will call finish() if you press back while the toast is still visible, and only if the back press would result in exiting the application.

Upvotes: 19

Alex Gitelman
Alex Gitelman

Reputation: 24722

You may also need to reset counter in onPause to prevent cases when user presses home or navigates away by some other means after first back press. Otherwise, I don't see an issue.

Upvotes: 2

yep
yep

Reputation: 94

Both your way and @Steve's way are acceptable ways to prevent accidental exits.

If choosing to continue with your implementation, you will need to make sure to have backpress initialized to 0, and probably implement a Timer of some sort to reset it back to 0 on keypress, after a cooldown period. (~5 seconds seems right)

Upvotes: 2

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