content: /*
   * Copyright (C) 2017 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.example.android.autofill.app.commoncases;
  
  import android.content.Context;
  import android.content.Intent;
  import android.os.Bundle;
  import android.support.annotation.NonNull;
  import android.support.v7.app.AppCompatActivity;
  import android.util.Log;
  import android.view.View;
  import android.view.autofill.AutofillManager;
  import android.widget.ArrayAdapter;
  import android.widget.AutoCompleteTextView;
  import android.widget.TextView;
  import android.widget.Toast;
  
  import com.example.android.autofill.app.R;
  import com.example.android.autofill.app.WelcomeActivity;
  
  import static com.example.android.autofill.app.Util.TAG;
  
  public class StandardAutoCompleteSignInActivity extends AppCompatActivity {
      private AutoCompleteTextView mUsernameAutoCompleteField;
      private TextView mPasswordField;
      private TextView mLoginButton;
      private TextView mClearButton;
      private boolean mAutofillReceived = false;
      private AutofillManager.AutofillCallback mAutofillCallback;
      private AutofillManager mAutofillManager;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
  
          setContentView(R.layout.login_with_autocomplete_activity);
  
          mLoginButton = findViewById(R.id.login);
          mClearButton = findViewById(R.id.clear);
          mUsernameAutoCompleteField = findViewById(R.id.usernameField);
          mPasswordField = findViewById(R.id.passwordField);
          mLoginButton.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View v) {
                  login();
              }
          });
          mClearButton.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View v) {
                  AutofillManager afm = getSystemService(AutofillManager.class);
                  if (afm != null) {
                      afm.cancel();
                  }
                  resetFields();
              }
          });
          mAutofillCallback = new MyAutofillCallback();
          mAutofillManager = getSystemService(AutofillManager.class);
          ArrayAdapter<CharSequence> mockAutocompleteAdapter = ArrayAdapter.createFromResource
                  (this, R.array.mock_autocomplete_sign_in_suggestions,
                          android.R.layout.simple_dropdown_item_1line);
          mUsernameAutoCompleteField.setAdapter(mockAutocompleteAdapter);
      }
  
      @Override
      protected void onResume() {
          super.onResume();
          mAutofillManager.registerCallback(mAutofillCallback);
      }
  
      @Override
      protected void onPause() {
          super.onPause();
          mAutofillManager.unregisterCallback(mAutofillCallback);
      }
  
      private void resetFields() {
          mUsernameAutoCompleteField.setText("");
          mPasswordField.setText("");
      }
  
      /**
       * Emulates a login action.
       */
      private void login() {
          String username = mUsernameAutoCompleteField.getText().toString();
          String password = mPasswordField.getText().toString();
          boolean valid = isValidCredentials(username, password);
          if (valid) {
              Intent intent = WelcomeActivity.getStartActivityIntent(StandardAutoCompleteSignInActivity.this);
              startActivity(intent);
              finish();
          } else {
              Toast.makeText(this, "Authentication failed.", Toast.LENGTH_SHORT).show();
          }
      }
  
      /**
       * Dummy implementation for demo purposes. A real service should use secure mechanisms to
       * authenticate users.
       */
      public boolean isValidCredentials(String username, String password) {
          return username != null && password != null && username.equals(password);
      }
  
      private class MyAutofillCallback extends AutofillManager.AutofillCallback {
          @Override
          public void onAutofillEvent(@NonNull View view, int event) {
              if (view instanceof AutoCompleteTextView) {
                  switch (event) {
                      case AutofillManager.AutofillCallback.EVENT_INPUT_UNAVAILABLE:
                          // no break on purpose
                      case AutofillManager.AutofillCallback.EVENT_INPUT_HIDDEN:
                          if (!mAutofillReceived) {
                              ((AutoCompleteTextView) view).showDropDown();
                          }
                          break;
                      case AutofillManager.AutofillCallback.EVENT_INPUT_SHOWN:
                          mAutofillReceived = true;
                          ((AutoCompleteTextView) view).setAdapter(null);
                          break;
                      default:
                          Log.d(TAG, "Unexpected callback: " + event);
                  }
              }
          }
      }
  }