Add Action Bars to Preference activities

package com.fsck.k9.activity;

/*

 * Copyright (C) 2014 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.

 */

import android.content.res.Configuration;

import android.os.Bundle;

import android.preference.PreferenceActivity;

import android.support.annotation.LayoutRes;

import android.support.annotation.Nullable;

import android.support.v7.app.ActionBar;

import android.support.v7.app.AppCompatDelegate;

import android.support.v7.widget.Toolbar;

import android.view.MenuInflater;

import android.view.View;

import android.view.ViewGroup;

/**

 * A {@link android.preference.PreferenceActivity} which implements and proxies the necessary calls

 * to be used with AppCompat.

 * <p>

 * This technique can be used with an {@link android.app.Activity} class, not just

 * {@link android.preference.PreferenceActivity}.

 */

public abstract class AppCompatPreferenceActivity extends PreferenceActivity {

    private AppCompatDelegate mDelegate;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        getDelegate().installViewFactory();

        getDelegate().onCreate(savedInstanceState);

        super.onCreate(savedInstanceState);

    }

    @Override

    protected void onPostCreate(Bundle savedInstanceState) {

        super.onPostCreate(savedInstanceState);

        getDelegate().onPostCreate(savedInstanceState);

    }

    public ActionBar getSupportActionBar() {

        return getDelegate().getSupportActionBar();

    }

    public void setSupportActionBar(@Nullable Toolbar toolbar) {

        getDelegate().setSupportActionBar(toolbar);

    }

    @Override

    public MenuInflater getMenuInflater() {

        return getDelegate().getMenuInflater();

    }

    @Override

    public void setContentView(@LayoutRes int layoutResID) {

        getDelegate().setContentView(layoutResID);

    }

    @Override

    public void setContentView(View view) {

        getDelegate().setContentView(view);

    }

    @Override

    public void setContentView(View view, ViewGroup.LayoutParams params) {

        getDelegate().setContentView(view, params);

    }

    @Override

    public void addContentView(View view, ViewGroup.LayoutParams params) {

        getDelegate().addContentView(view, params);

    }

    @Override

    protected void onPostResume() {

        super.onPostResume();

        getDelegate().onPostResume();

    }

    @Override

    protected void onTitleChanged(CharSequence title, int color) {

        super.onTitleChanged(title, color);

        getDelegate().setTitle(title);

    }

    @Override

    public void onConfigurationChanged(Configuration newConfig) {

        super.onConfigurationChanged(newConfig);

        getDelegate().onConfigurationChanged(newConfig);

    }

    @Override

    protected void onStop() {

        super.onStop();

        getDelegate().onStop();

    }

    @Override

    protected void onDestroy() {

        super.onDestroy();

        getDelegate().onDestroy();

    }

    public void invalidateOptionsMenu() {

        getDelegate().invalidateOptionsMenu();

    }

    private AppCompatDelegate getDelegate() {

        if (mDelegate == null) {

            mDelegate = AppCompatDelegate.create(this, null);

        }

        return mDelegate;

    }

}

 No newline at end of file

package com.fsck.k9.activity;

import android.arch.lifecycle.Lifecycle;

import android.arch.lifecycle.Lifecycle.State;

import android.arch.lifecycle.LifecycleOwner;

import android.os.Bundle;

import android.preference.ListPreference;

import android.preference.Preference;

import android.preference.PreferenceActivity;

import android.support.annotation.NonNull;

import android.view.MenuItem;

import com.fsck.k9.K9;

public abstract class K9PreferenceActivity extends PreferenceActivity implements LifecycleOwner {

public abstract class K9PreferenceActivity extends AppCompatPreferenceActivity implements LifecycleOwner {

    private LifecycleRegistry lifecycleRegistry;

    @Override

        super.onCreate(icicle);

        lifecycleRegistry = new LifecycleRegistry(this);

        lifecycleRegistry.markState(State.CREATED);

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        if (item.getItemId() == android.R.id.home) {

            onBackPressed();

            return true;

        }

        return super.onOptionsItemSelected(item);

    }

    @Override