1 /*
2  * Copyright (C) 2009 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.contacts.common.preference;
18 
19 import android.content.Context;
20 import android.os.Bundle;
21 import android.app.ActionBar;
22 import android.preference.PreferenceActivity;
23 import android.view.MenuItem;
24 
25 import com.android.contacts.common.R;
26 
27 /**
28  * Contacts settings.
29  */
30 public final class ContactsPreferenceActivity extends PreferenceActivity {
31 
32     private static final String TAG_ABOUT_CONTACTS = "about_contacts";
33 
34     @Override
onCreate(Bundle savedInstanceState)35     protected void onCreate(Bundle savedInstanceState) {
36         super.onCreate(savedInstanceState);
37 
38         final ActionBar actionBar = getActionBar();
39         if (actionBar != null) {
40             actionBar.setDisplayOptions(ActionBar.DISPLAY_HOME_AS_UP, ActionBar.DISPLAY_HOME_AS_UP);
41         }
42 
43         if (savedInstanceState == null) {
44             getFragmentManager().beginTransaction()
45                     .replace(android.R.id.content, new DisplayOptionsPreferenceFragment())
46                     .commit();
47             setActivityTitle(R.string.activity_title_settings);
48         } else {
49             final AboutPreferenceFragment fragment = (AboutPreferenceFragment) getFragmentManager()
50                     .findFragmentByTag(TAG_ABOUT_CONTACTS);
51             setActivityTitle(fragment == null ?
52                     R.string.activity_title_settings : R.string.setting_about);
53         }
54     }
55 
showAboutFragment()56     public void showAboutFragment() {
57         getFragmentManager().beginTransaction()
58                 .replace(android.R.id.content, new AboutPreferenceFragment(), TAG_ABOUT_CONTACTS)
59                 .addToBackStack(null)
60                 .commit();
61         setActivityTitle(R.string.setting_about);
62     }
63 
64     /**
65      * Returns true if there are no preferences to display and therefore the
66      * corresponding menu item can be removed.
67      */
isEmpty(Context context)68     public static boolean isEmpty(Context context) {
69         return !context.getResources().getBoolean(R.bool.config_sort_order_user_changeable)
70                 && !context.getResources().getBoolean(R.bool.config_display_order_user_changeable)
71                 && !context.getResources().getBoolean(
72                         R.bool.config_default_account_user_changeable);
73     }
74 
75     @Override
onOptionsItemSelected(MenuItem item)76     public boolean onOptionsItemSelected(MenuItem item) {
77         if (item.getItemId() == android.R.id.home) {
78             onBackPressed();
79             return true;
80         }
81         return false;
82     }
83 
84     @Override
onBackPressed()85     public void onBackPressed() {
86         if (getFragmentManager().getBackStackEntryCount() > 0) {
87             setActivityTitle(R.string.activity_title_settings);
88             getFragmentManager().popBackStack();
89         } else {
90             super.onBackPressed();
91         }
92     }
93 
setActivityTitle(int res)94     private void setActivityTitle(int res) {
95         final ActionBar actionBar = getActionBar();
96         if (actionBar != null) {
97             actionBar.setTitle(res);
98         }
99     }
100 }
101