| /* |
| * Copyright 2012 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.example.android.effectivenavigation; |
| |
| import android.app.ActionBar; |
| import android.content.Intent; |
| import android.os.Bundle; |
| import android.support.v4.app.Fragment; |
| import android.support.v4.app.FragmentActivity; |
| import android.support.v4.app.FragmentManager; |
| import android.support.v4.app.FragmentStatePagerAdapter; |
| import android.support.v4.app.NavUtils; |
| import android.support.v4.app.TaskStackBuilder; |
| import android.support.v4.view.ViewPager; |
| import android.view.LayoutInflater; |
| import android.view.MenuItem; |
| import android.view.View; |
| import android.view.ViewGroup; |
| import android.widget.TextView; |
| |
| public class CollectionDemoActivity extends FragmentActivity { |
| |
| /** |
| * The {@link android.support.v4.view.PagerAdapter} that will provide fragments representing |
| * each object in a collection. We use a {@link android.support.v4.app.FragmentStatePagerAdapter} |
| * derivative, which will destroy and re-create fragments as needed, saving and restoring their |
| * state in the process. This is important to conserve memory and is a best practice when |
| * allowing navigation between objects in a potentially large collection. |
| */ |
| DemoCollectionPagerAdapter mDemoCollectionPagerAdapter; |
| |
| /** |
| * The {@link android.support.v4.view.ViewPager} that will display the object collection. |
| */ |
| ViewPager mViewPager; |
| |
| public void onCreate(Bundle savedInstanceState) { |
| super.onCreate(savedInstanceState); |
| setContentView(R.layout.activity_collection_demo); |
| |
| // Create an adapter that when requested, will return a fragment representing an object in |
| // the collection. |
| // |
| // ViewPager and its adapters use support library fragments, so we must use |
| // getSupportFragmentManager. |
| mDemoCollectionPagerAdapter = new DemoCollectionPagerAdapter(getSupportFragmentManager()); |
| |
| // Set up action bar. |
| final ActionBar actionBar = getActionBar(); |
| |
| // Specify that the Home button should show an "Up" caret, indicating that touching the |
| // button will take the user one step up in the application's hierarchy. |
| actionBar.setDisplayHomeAsUpEnabled(true); |
| |
| // Set up the ViewPager, attaching the adapter. |
| mViewPager = (ViewPager) findViewById(R.id.pager); |
| mViewPager.setAdapter(mDemoCollectionPagerAdapter); |
| } |
| |
| @Override |
| public boolean onOptionsItemSelected(MenuItem item) { |
| switch (item.getItemId()) { |
| case android.R.id.home: |
| // This is called when the Home (Up) button is pressed in the action bar. |
| // Create a simple intent that starts the hierarchical parent activity and |
| // use NavUtils in the Support Package to ensure proper handling of Up. |
| Intent upIntent = new Intent(this, MainActivity.class); |
| if (NavUtils.shouldUpRecreateTask(this, upIntent)) { |
| // This activity is not part of the application's task, so create a new task |
| // with a synthesized back stack. |
| TaskStackBuilder.from(this) |
| // If there are ancestor activities, they should be added here. |
| .addNextIntent(upIntent) |
| .startActivities(); |
| finish(); |
| } else { |
| // This activity is part of the application's task, so simply |
| // navigate up to the hierarchical parent activity. |
| NavUtils.navigateUpTo(this, upIntent); |
| } |
| return true; |
| } |
| return super.onOptionsItemSelected(item); |
| } |
| |
| /** |
| * A {@link android.support.v4.app.FragmentStatePagerAdapter} that returns a fragment |
| * representing an object in the collection. |
| */ |
| public static class DemoCollectionPagerAdapter extends FragmentStatePagerAdapter { |
| |
| public DemoCollectionPagerAdapter(FragmentManager fm) { |
| super(fm); |
| } |
| |
| @Override |
| public Fragment getItem(int i) { |
| Fragment fragment = new DemoObjectFragment(); |
| Bundle args = new Bundle(); |
| args.putInt(DemoObjectFragment.ARG_OBJECT, i + 1); // Our object is just an integer :-P |
| fragment.setArguments(args); |
| return fragment; |
| } |
| |
| @Override |
| public int getCount() { |
| // For this contrived example, we have a 100-object collection. |
| return 100; |
| } |
| |
| @Override |
| public CharSequence getPageTitle(int position) { |
| return "OBJECT " + (position + 1); |
| } |
| } |
| |
| /** |
| * A dummy fragment representing a section of the app, but that simply displays dummy text. |
| */ |
| public static class DemoObjectFragment extends Fragment { |
| |
| public static final String ARG_OBJECT = "object"; |
| |
| @Override |
| public View onCreateView(LayoutInflater inflater, ViewGroup container, |
| Bundle savedInstanceState) { |
| View rootView = inflater.inflate(R.layout.fragment_collection_object, container, false); |
| Bundle args = getArguments(); |
| ((TextView) rootView.findViewById(android.R.id.text1)).setText( |
| Integer.toString(args.getInt(ARG_OBJECT))); |
| return rootView; |
| } |
| } |
| } |