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
17package com.example.android.supportv4.app;
18
19import android.os.Bundle;
20import android.view.LayoutInflater;
21import android.view.View;
22import android.view.View.OnClickListener;
23import android.view.ViewGroup;
24import android.widget.Button;
25import android.widget.TextView;
26
27import androidx.core.content.ContextCompat;
28import androidx.core.view.ViewCompat;
29import androidx.fragment.app.Fragment;
30import androidx.fragment.app.FragmentActivity;
31import androidx.fragment.app.FragmentManager;
32import androidx.fragment.app.FragmentTransaction;
33
34import com.example.android.supportv4.R;
35
36public class FragmentStackSupport extends FragmentActivity {
37    int mStackLevel = 1;
38
39    @Override
40    protected void onCreate(Bundle savedInstanceState) {
41        super.onCreate(savedInstanceState);
42        setContentView(R.layout.fragment_stack);
43
44        // Watch for button clicks.
45        Button button = findViewById(R.id.new_fragment);
46        button.setOnClickListener(new OnClickListener() {
47            @Override
48            public void onClick(View v) {
49                addFragmentToStack();
50            }
51        });
52        button = findViewById(R.id.home);
53        button.setOnClickListener(new OnClickListener() {
54            @Override
55            public void onClick(View v) {
56                // If there is a back stack, pop it all.
57                FragmentManager fm = getSupportFragmentManager();
58                if (fm.getBackStackEntryCount() > 0) {
59                    fm.popBackStack(fm.getBackStackEntryAt(0).getId(),
60                            FragmentManager.POP_BACK_STACK_INCLUSIVE);
61                }
62            }
63        });
64
65        if (savedInstanceState == null) {
66            // Do first time initialization -- add initial fragment.
67            Fragment newFragment = CountingFragment.newInstance(mStackLevel);
68            FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
69            ft.add(R.id.simple_fragment, newFragment).commit();
70        } else {
71            mStackLevel = savedInstanceState.getInt("level");
72        }
73    }
74
75    @Override
76    public void onSaveInstanceState(Bundle outState) {
77        super.onSaveInstanceState(outState);
78        outState.putInt("level", mStackLevel);
79    }
80
81//BEGIN_INCLUDE(add_stack)
82    void addFragmentToStack() {
83        mStackLevel++;
84
85        // Instantiate a new fragment.
86        Fragment newFragment = CountingFragment.newInstance(mStackLevel);
87
88        // Add the fragment to the activity, pushing this transaction
89        // on to the back stack.
90        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
91        ft.replace(R.id.simple_fragment, newFragment);
92        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
93        ft.addToBackStack(null);
94        ft.commit();
95    }
96//END_INCLUDE(add_stack)
97
98//BEGIN_INCLUDE(fragment)
99    public static class CountingFragment extends Fragment {
100        int mNum;
101
102        /**
103         * Create a new instance of CountingFragment, providing "num"
104         * as an argument.
105         */
106        static CountingFragment newInstance(int num) {
107            CountingFragment f = new CountingFragment();
108
109            // Supply num input as an argument.
110            Bundle args = new Bundle();
111            args.putInt("num", num);
112            f.setArguments(args);
113
114            return f;
115        }
116
117        /**
118         * When creating, retrieve this instance's number from its arguments.
119         */
120        @Override
121        public void onCreate(Bundle savedInstanceState) {
122            super.onCreate(savedInstanceState);
123            mNum = getArguments() != null ? getArguments().getInt("num") : 1;
124        }
125
126        /**
127         * The Fragment's UI is just a simple text view showing its
128         * instance number.
129         */
130        @Override
131        public View onCreateView(LayoutInflater inflater, ViewGroup container,
132                Bundle savedInstanceState) {
133            View v = inflater.inflate(R.layout.hello_world, container, false);
134            View tv = v.findViewById(R.id.text);
135            ((TextView) tv).setText("Fragment #" + mNum);
136            ViewCompat.setBackground(tv,
137                    ContextCompat.getDrawable(getContext(), android.R.drawable.gallery_thumb));
138            return v;
139        }
140    }
141//END_INCLUDE(fragment)
142}
143