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      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 com.example.android.supportv4.R;
     20 
     21 import android.support.v4.app.Fragment;
     22 import android.support.v4.app.FragmentActivity;
     23 import android.support.v4.app.FragmentManager;
     24 import android.support.v4.app.FragmentTransaction;
     25 
     26 import android.os.Bundle;
     27 import android.view.LayoutInflater;
     28 import android.view.View;
     29 import android.view.ViewGroup;
     30 import android.view.View.OnClickListener;
     31 import android.widget.Button;
     32 import android.widget.TextView;
     33 
     34 public class FragmentStackSupport extends FragmentActivity {
     35     int mStackLevel = 1;
     36 
     37     @Override
     38     protected void onCreate(Bundle savedInstanceState) {
     39         super.onCreate(savedInstanceState);
     40         setContentView(R.layout.fragment_stack);
     41 
     42         // Watch for button clicks.
     43         Button button = (Button)findViewById(R.id.new_fragment);
     44         button.setOnClickListener(new OnClickListener() {
     45             public void onClick(View v) {
     46                 addFragmentToStack();
     47             }
     48         });
     49         button = (Button)findViewById(R.id.home);
     50         button.setOnClickListener(new OnClickListener() {
     51             public void onClick(View v) {
     52                 // If there is a back stack, pop it all.
     53                 FragmentManager fm = getSupportFragmentManager();
     54                 if (fm.getBackStackEntryCount() > 0) {
     55                     fm.popBackStack(fm.getBackStackEntryAt(0).getId(),
     56                             FragmentManager.POP_BACK_STACK_INCLUSIVE);
     57                 }
     58             }
     59         });
     60 
     61         if (savedInstanceState == null) {
     62             // Do first time initialization -- add initial fragment.
     63             Fragment newFragment = CountingFragment.newInstance(mStackLevel);
     64             FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
     65             ft.add(R.id.simple_fragment, newFragment).commit();
     66         } else {
     67             mStackLevel = savedInstanceState.getInt("level");
     68         }
     69     }
     70 
     71     @Override
     72     public void onSaveInstanceState(Bundle outState) {
     73         super.onSaveInstanceState(outState);
     74         outState.putInt("level", mStackLevel);
     75     }
     76 
     77 //BEGIN_INCLUDE(add_stack)
     78     void addFragmentToStack() {
     79         mStackLevel++;
     80 
     81         // Instantiate a new fragment.
     82         Fragment newFragment = CountingFragment.newInstance(mStackLevel);
     83 
     84         // Add the fragment to the activity, pushing this transaction
     85         // on to the back stack.
     86         FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
     87         ft.replace(R.id.simple_fragment, newFragment);
     88         ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
     89         ft.addToBackStack(null);
     90         ft.commit();
     91     }
     92 //END_INCLUDE(add_stack)
     93 
     94 //BEGIN_INCLUDE(fragment)
     95     public static class CountingFragment extends Fragment {
     96         int mNum;
     97 
     98         /**
     99          * Create a new instance of CountingFragment, providing "num"
    100          * as an argument.
    101          */
    102         static CountingFragment newInstance(int num) {
    103             CountingFragment f = new CountingFragment();
    104 
    105             // Supply num input as an argument.
    106             Bundle args = new Bundle();
    107             args.putInt("num", num);
    108             f.setArguments(args);
    109 
    110             return f;
    111         }
    112 
    113         /**
    114          * When creating, retrieve this instance's number from its arguments.
    115          */
    116         @Override
    117         public void onCreate(Bundle savedInstanceState) {
    118             super.onCreate(savedInstanceState);
    119             mNum = getArguments() != null ? getArguments().getInt("num") : 1;
    120         }
    121 
    122         /**
    123          * The Fragment's UI is just a simple text view showing its
    124          * instance number.
    125          */
    126         @Override
    127         public View onCreateView(LayoutInflater inflater, ViewGroup container,
    128                 Bundle savedInstanceState) {
    129             View v = inflater.inflate(R.layout.hello_world, container, false);
    130             View tv = v.findViewById(R.id.text);
    131             ((TextView)tv).setText("Fragment #" + mNum);
    132             tv.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.gallery_thumb));
    133             return v;
    134         }
    135     }
    136 //END_INCLUDE(fragment)
    137 }
    138