AccountServerBaseFragment.java revision 55110ca1ad8ce48a5429f9f351d013691c10b806 
1/*
2 * Copyright (C) 2010 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
17package com.android.email.activity.setup;
18
19import com.android.email.R;
20
21import android.app.Activity;
22import android.app.Fragment;
23import android.content.Context;
24import android.os.Bundle;
25import android.view.Menu;
26import android.view.MenuInflater;
27import android.view.MenuItem;
28
29/**
30 * Common base class for server settings fragments, so they can be more easily manipulated by
31 * AccountSettingsXL.  Provides the following common functionality:
32 *
33 * Activity-provided callbacks
34 * Activity callback during onAttach
35 * Present "Next" button and respond to its clicks
36 */
37public abstract class AccountServerBaseFragment extends Fragment {
38
39    protected Context mContext;
40    protected Callback mCallback = EmptyCallback.INSTANCE;
41    protected boolean mNextButtonEnabled;
42
43    /**
44     * Callback interface that owning activities must provide
45     */
46    public interface Callback {
47        /**
48         * Called each time the user-entered input transitions between valid and invalid
49         * @param enable true to enable proceed/next button, false to disable
50         */
51        public void onEnableProceedButtons(boolean enable);
52        /**
53         * Called when user clicks "next"
54         * @param checkMode values from {@link SetupData}
55         */
56        public void onProceedNext(int checkMode);
57    }
58
59    private static class EmptyCallback implements Callback {
60        public static final Callback INSTANCE = new EmptyCallback();
61        @Override public void onEnableProceedButtons(boolean enable) { }
62        @Override public void onProceedNext(int checkMode) { }
63    }
64
65    /**
66     * Called when a fragment is first attached to its activity.
67     * {@link #onCreate(Bundle)} will be called after this.
68     */
69    @Override
70    public void onAttach(Activity activity) {
71        super.onAttach(activity);
72        mContext = activity;
73
74        // Notify the activity that we're here.
75        if (activity instanceof AccountSettingsXL) {
76            ((AccountSettingsXL)activity).onAttach(this);
77        }
78    }
79
80    /**
81     * Called to do initial creation of a fragment.  This is called after
82     * {@link #onAttach(Activity)} and before {@link #onActivityCreated(Bundle)}.
83     */
84    @Override
85    public void onCreate(Bundle savedInstanceState) {
86        super.onCreate(savedInstanceState);
87
88        setHasOptionsMenu(true);
89        mNextButtonEnabled = false;
90    }
91
92    // Add a "Next" button when this fragment is displayed
93    @Override
94    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
95        super.onCreateOptionsMenu(menu, inflater);
96        inflater.inflate(R.menu.account_settings_next_option, menu);
97    }
98
99    /**
100     * Enable/disable "next" button
101     */
102    @Override
103    public void onPrepareOptionsMenu(Menu menu) {
104        MenuItem item = menu.findItem(R.id.next);
105        item.setEnabled(mNextButtonEnabled);
106    }
107
108    /**
109     * Respond to clicks in the "Next" button
110     */
111    @Override
112    public boolean onOptionsItemSelected(MenuItem item) {
113        switch (item.getItemId()) {
114            case R.id.next:
115                onNext();
116                return true;
117        }
118        return super.onOptionsItemSelected(item);
119    }
120
121    /**
122     * Activity provides callbacks here.
123     */
124    public void setCallback(Callback callback) {
125        mCallback = (callback == null) ? EmptyCallback.INSTANCE : callback;
126        mContext = getActivity();
127    }
128
129    /**
130     * Enable/disable the "next" button
131     */
132    public void enableNextButton(boolean enable) {
133        // We have to set mNextButtonEnabled first, because invalidateOptionsMenu calls
134        // onPrepareOptionsMenu immediately
135        boolean wasEnabled = mNextButtonEnabled;
136        mNextButtonEnabled = enable;
137
138        if (enable != wasEnabled) {
139            getActivity().invalidateOptionsMenu();
140        }
141
142        // TODO: This supports the legacy activities and will be removed
143        mCallback.onEnableProceedButtons(enable);
144    }
145
146    /**
147     * Handle OK result from check settings.  Save settings, and exit to previous fragment.
148     */
149    public void onCheckSettingsOk() {
150        saveSettingsAfterEdit();
151        getActivity().onBackPressed();
152    }
153
154    /**
155     * Save settings after "OK" result from checker.  Concrete classes must implement.
156     */
157    public abstract void saveSettingsAfterEdit();
158
159    /**
160     * Respond to a click of the "Next" button.  Concrete classes must implement.
161     */
162    public abstract void onNext();
163}
164