1 /*
2  * Copyright (C) 2011 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.supportv4.app;
18 
19 import android.os.Bundle;
20 import android.view.LayoutInflater;
21 import android.view.View;
22 import android.view.View.OnClickListener;
23 import android.view.ViewGroup;
24 import android.widget.Button;
25 import android.widget.TextView;
26 
27 import androidx.fragment.app.Fragment;
28 import androidx.fragment.app.FragmentActivity;
29 import androidx.fragment.app.FragmentManager;
30 import androidx.fragment.app.FragmentTransaction;
31 
32 import com.example.android.supportv4.R;
33 
34 /**
35  * Demonstration of hiding and showing fragments.
36  */
37 public class FragmentHideShowSupport extends FragmentActivity {
38 
39     @Override
onCreate(Bundle savedInstanceState)40     protected void onCreate(Bundle savedInstanceState) {
41         super.onCreate(savedInstanceState);
42         setContentView(R.layout.fragment_hide_show_support);
43 
44         // The content view embeds two fragments; now retrieve them and attach
45         // their "hide" button.
46         FragmentManager fm = getSupportFragmentManager();
47         Fragment fragment1 = fm.findFragmentById(R.id.fragment1);
48         addShowHideListener(R.id.frag1hide, fragment1);
49         final Button button1 = (Button)findViewById(R.id.frag1hide);
50         button1.setText(fragment1.isHidden() ? "Show" : "Hide");
51         Fragment fragment2 = fm.findFragmentById(R.id.fragment2);
52         addShowHideListener(R.id.frag2hide, fragment2);
53         final Button button2 = (Button)findViewById(R.id.frag2hide);
54         button2.setText(fragment2.isHidden() ? "Show" : "Hide");
55     }
56 
addShowHideListener(int buttonId, final Fragment fragment)57     void addShowHideListener(int buttonId, final Fragment fragment) {
58         final Button button = (Button)findViewById(buttonId);
59         button.setOnClickListener(new OnClickListener() {
60             @Override
61             public void onClick(View v) {
62                 FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
63                 ft.setCustomAnimations(android.R.anim.fade_in,
64                         android.R.anim.fade_out);
65                 if (fragment.isHidden()) {
66                     ft.show(fragment);
67                     button.setText("Hide");
68                 } else {
69                     ft.hide(fragment);
70                     button.setText("Show");
71                 }
72                 ft.commit();
73             }
74         });
75     }
76 
77     public static class FirstFragment extends Fragment {
78         TextView mTextView;
79 
80         @Override
onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)81         public View onCreateView(LayoutInflater inflater, ViewGroup container,
82                 Bundle savedInstanceState) {
83             View v = inflater.inflate(R.layout.labeled_text_edit, container, false);
84             View tv = v.findViewById(R.id.msg);
85             ((TextView)tv).setText("The fragment saves and restores this text.");
86 
87             // Retrieve the text editor, and restore the last saved state if needed.
88             mTextView = (TextView)v.findViewById(R.id.saved);
89             if (savedInstanceState != null) {
90                 mTextView.setText(savedInstanceState.getCharSequence("text"));
91             }
92             return v;
93         }
94 
95         @Override
onSaveInstanceState(Bundle outState)96         public void onSaveInstanceState(Bundle outState) {
97             super.onSaveInstanceState(outState);
98 
99             // Remember the current text, to restore if we later restart.
100             outState.putCharSequence("text", mTextView.getText());
101         }
102     }
103 
104     public static class SecondFragment extends Fragment {
105 
106         @Override
onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)107         public View onCreateView(LayoutInflater inflater, ViewGroup container,
108                 Bundle savedInstanceState) {
109             View v = inflater.inflate(R.layout.labeled_text_edit, container, false);
110             View tv = v.findViewById(R.id.msg);
111             ((TextView)tv).setText("The TextView saves and restores this text.");
112 
113             // Retrieve the text editor and tell it to save and restore its state.
114             // Note that you will often set this in the layout XML, but since
115             // we are sharing our layout with the other fragment we will customize
116             // it here.
117             ((TextView)v.findViewById(R.id.saved)).setSaveEnabled(true);
118             return v;
119         }
120     }
121 }
122