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javaandroidandroid-studioandroid-layoutandroid-coordinatorlayout

CoordinatorLayout cannot be cast to android.support.v7.widget.Toolbar

I am trying to use this Firebase authentication in my project, and I am getting an error that i can't figure out how to solve, and what causes it:

My xml of the layout:

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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/toolbar"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context="info.androidhive.firebase.LoginActivity">

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="@color/colorPrimary"
        android:gravity="center"
        android:orientation="vertical"
        android:padding="@dimen/activity_horizontal_margin">


        <ImageView
            android:layout_width="@dimen/logo_w_h"
            android:layout_height="@dimen/logo_w_h"
            android:layout_gravity="center_horizontal"
            android:layout_marginBottom="30dp"
            android:src="@mipmap/ic_launcher" />

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <EditText
                android:id="@+id/email"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="10dp"
                android:hint="@string/hint_email"
                android:inputType="textEmailAddress"
                android:textColor="@android:color/white"
                android:textColorHint="@android:color/white" />
        </android.support.design.widget.TextInputLayout>

        <android.support.design.widget.TextInputLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <EditText
                android:id="@+id/password"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="10dp"
                android:hint="@string/hint_password"
                android:inputType="textPassword"
                android:textColor="@android:color/white"
                android:textColorHint="@android:color/white" />
        </android.support.design.widget.TextInputLayout>

        <!-- Login Button -->

        <Button
            android:id="@+id/btn_login"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dip"
            android:background="@color/colorAccent"
            android:text="@string/btn_login"
            android:textColor="@android:color/black" />

        <Button
            android:id="@+id/btn_reset_password"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dip"
            android:background="@null"
            android:text="@string/btn_forgot_password"
            android:textAllCaps="false"
            android:textColor="@color/colorAccent" />

        <!-- Link to Login Screen -->

        <Button
            android:id="@+id/btn_signup"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dip"
            android:background="@null"
            android:text="@string/btn_link_to_register"
            android:textAllCaps="false"
            android:textColor="@color/white"
            android:textSize="15dp" />
    </LinearLayout>

    <ProgressBar
        android:id="@+id/progressBar"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_gravity="center|bottom"
        android:layout_marginBottom="20dp"
        android:visibility="gone" />

My code

package com.esmad.pdm.friendlymanager;

import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;

public class LoginActivity extends AppCompatActivity {


    private EditText inputEmail, inputPassword;
    private FirebaseAuth auth;
    private ProgressBar progressBar;
    private Button btnSignup, btnLogin, btnReset;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        auth = FirebaseAuth.getInstance();

        if (auth.getCurrentUser() != null) {
            startActivity(new Intent(LoginActivity.this, MainActivity.class));
            finish();
        }

        setContentView(R.layout.activity_login);


        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        inputEmail = (EditText) findViewById(R.id.email);
        inputPassword = (EditText) findViewById(R.id.password);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
        btnSignup = (Button) findViewById(R.id.btn_signup);
        btnLogin = (Button) findViewById(R.id.btn_login);
        btnReset = (Button) findViewById(R.id.btn_reset_password);

        //Get Firebase auth instance
        auth = FirebaseAuth.getInstance();

        btnSignup.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(LoginActivity.this, SignupActivity.class));
            }
        });

        btnReset.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(LoginActivity.this, ResetPasswordActivity.class));
            }
        });

        btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String email = inputEmail.getText().toString();
                final String password = inputPassword.getText().toString();

                if (TextUtils.isEmpty(email)) {
                    Toast.makeText(getApplicationContext(), "Enter email address!", Toast.LENGTH_SHORT).show();
                    return;
                }

                if (TextUtils.isEmpty(password)) {
                    Toast.makeText(getApplicationContext(), "Enter password!", Toast.LENGTH_SHORT).show();
                    return;
                }

                progressBar.setVisibility(View.VISIBLE);

                //authenticate user
                auth.signInWithEmailAndPassword(email, password)
                        .addOnCompleteListener(LoginActivity.this, new OnCompleteListener<AuthResult>() {
                            @Override
                            public void onComplete(@NonNull Task<AuthResult> task) {
                                // If sign in fails, display a message to the user. If sign in succeeds
                                // the auth state listener will be notified and logic to handle the
                                // signed in user can be handled in the listener.
                                progressBar.setVisibility(View.GONE);
                                if (!task.isSuccessful()) {
                                    // there was an error
                                    if (password.length() < 6) {
                                        inputPassword.setError(getString(R.string.minimum_password));
                                    } else {
                                        Toast.makeText(LoginActivity.this, getString(R.string.auth_failed), Toast.LENGTH_LONG).show();
                                    }
                                } else {
                                    Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                                    startActivity(intent);
                                    finish();
                                }
                            }
                        });
            }
        });
    }
}

Why I keep getting this error, I'm using ConstraintLayouts to build this application, what am I missing?

Solution

  • Your CoordinatorLayout has the id 'toolbar'

    <android.support.design.widget.CoordinatorLayout 
  ..
  android:id="@+id/toolbar"
  ..>

    But in Java you cast it to a Toolbar object

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);

    This throws the exception because the View associated with the id R.id.toolbar is not a Toolbar.

    To fix this, remove the above two lines from your Java code, since you do not actually have a Toolbar in your layout.
    You should probably also change the id for the CoordinatorLayout to something more descriptive such as "@+id/coordinator"

    Edit: If I look at the example you are recreating, there is no Toolbar there. Layout Example And honestly for a login page it wouldn't make the most sense. However if you want to add it you could add this to your layout. Place it as the first child of the top LinearLayout:

        <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay" />

    But if you are not really confident with handling layouts and such, I would highly advice to read some more documentations and try simpler examples to get famillar with the platform.
    A good place to start is here: https://developer.android.com/guide/topics/ui/declaring-layout.html