1 /*
2  * Copyright (C) 2013 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.example.android.slidingtabsbasic;
18 
19 import com.example.android.common.logger.Log;
20 import com.example.android.common.view.SlidingTabLayout;
21 
22 import android.os.Bundle;
23 import android.support.v4.app.Fragment;
24 import android.support.v4.view.PagerAdapter;
25 import android.support.v4.view.ViewPager;
26 import android.view.LayoutInflater;
27 import android.view.View;
28 import android.view.ViewGroup;
29 import android.widget.TextView;
30 
31 /**
32  * A basic sample which shows how to use {@link com.example.android.common.view.SlidingTabLayout}
33  * to display a custom {@link ViewPager} title strip which gives continuous feedback to the user
34  * when scrolling.
35  */
36 public class SlidingTabsBasicFragment extends Fragment {
37 
38     static final String LOG_TAG = "SlidingTabsBasicFragment";
39 
40     /**
41      * A custom {@link ViewPager} title strip which looks much like Tabs present in Android v4.0 and
42      * above, but is designed to give continuous feedback to the user when scrolling.
43      */
44     private SlidingTabLayout mSlidingTabLayout;
45 
46     /**
47      * A {@link ViewPager} which will be used in conjunction with the {@link SlidingTabLayout} above.
48      */
49     private ViewPager mViewPager;
50 
51     /**
52      * Inflates the {@link View} which will be displayed by this {@link Fragment}, from the app's
53      * resources.
54      */
55     @Override
onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)56     public View onCreateView(LayoutInflater inflater, ViewGroup container,
57             Bundle savedInstanceState) {
58         return inflater.inflate(R.layout.fragment_sample, container, false);
59     }
60 
61     // BEGIN_INCLUDE (fragment_onviewcreated)
62     /**
63      * This is called after the {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)} has finished.
64      * Here we can pick out the {@link View}s we need to configure from the content view.
65      *
66      * We set the {@link ViewPager}'s adapter to be an instance of {@link SamplePagerAdapter}. The
67      * {@link SlidingTabLayout} is then given the {@link ViewPager} so that it can populate itself.
68      *
69      * @param view View created in {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)}
70      */
71     @Override
onViewCreated(View view, Bundle savedInstanceState)72     public void onViewCreated(View view, Bundle savedInstanceState) {
73         // BEGIN_INCLUDE (setup_viewpager)
74         // Get the ViewPager and set it's PagerAdapter so that it can display items
75         mViewPager = (ViewPager) view.findViewById(R.id.viewpager);
76         mViewPager.setAdapter(new SamplePagerAdapter());
77         // END_INCLUDE (setup_viewpager)
78 
79         // BEGIN_INCLUDE (setup_slidingtablayout)
80         // Give the SlidingTabLayout the ViewPager, this must be done AFTER the ViewPager has had
81         // it's PagerAdapter set.
82         mSlidingTabLayout = (SlidingTabLayout) view.findViewById(R.id.sliding_tabs);
83         mSlidingTabLayout.setViewPager(mViewPager);
84         // END_INCLUDE (setup_slidingtablayout)
85     }
86     // END_INCLUDE (fragment_onviewcreated)
87 
88     /**
89      * The {@link android.support.v4.view.PagerAdapter} used to display pages in this sample.
90      * The individual pages are simple and just display two lines of text. The important section of
91      * this class is the {@link #getPageTitle(int)} method which controls what is displayed in the
92      * {@link SlidingTabLayout}.
93      */
94     class SamplePagerAdapter extends PagerAdapter {
95 
96         /**
97          * @return the number of pages to display
98          */
99         @Override
getCount()100         public int getCount() {
101             return 10;
102         }
103 
104         /**
105          * @return true if the value returned from {@link #instantiateItem(ViewGroup, int)} is the
106          * same object as the {@link View} added to the {@link ViewPager}.
107          */
108         @Override
isViewFromObject(View view, Object o)109         public boolean isViewFromObject(View view, Object o) {
110             return o == view;
111         }
112 
113         // BEGIN_INCLUDE (pageradapter_getpagetitle)
114         /**
115          * Return the title of the item at {@code position}. This is important as what this method
116          * returns is what is displayed in the {@link SlidingTabLayout}.
117          * <p>
118          * Here we construct one using the position value, but for real application the title should
119          * refer to the item's contents.
120          */
121         @Override
getPageTitle(int position)122         public CharSequence getPageTitle(int position) {
123             return "Item " + (position + 1);
124         }
125         // END_INCLUDE (pageradapter_getpagetitle)
126 
127         /**
128          * Instantiate the {@link View} which should be displayed at {@code position}. Here we
129          * inflate a layout from the apps resources and then change the text view to signify the position.
130          */
131         @Override
instantiateItem(ViewGroup container, int position)132         public Object instantiateItem(ViewGroup container, int position) {
133             // Inflate a new layout from our resources
134             View view = getActivity().getLayoutInflater().inflate(R.layout.pager_item,
135                     container, false);
136             // Add the newly created View to the ViewPager
137             container.addView(view);
138 
139             // Retrieve a TextView from the inflated View, and update it's text
140             TextView title = (TextView) view.findViewById(R.id.item_title);
141             title.setText(String.valueOf(position + 1));
142 
143             Log.i(LOG_TAG, "instantiateItem() [position: " + position + "]");
144 
145             // Return the View
146             return view;
147         }
148 
149         /**
150          * Destroy the item from the {@link ViewPager}. In our case this is simply removing the
151          * {@link View}.
152          */
153         @Override
destroyItem(ViewGroup container, int position, Object object)154         public void destroyItem(ViewGroup container, int position, Object object) {
155             container.removeView((View) object);
156             Log.i(LOG_TAG, "destroyItem() [position: " + position + "]");
157         }
158 
159     }
160 }
161