/*
* Copyright (C) 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.apis.app;
import java.util.ArrayList;
import com.example.android.apis.R;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TabHost;
/**
* Sample fragment that contains tabs of other fragments.
*/
public class FragmentTabsFragment extends Fragment {
TabManager mTabManager;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mTabManager = new TabManager(getActivity(), getChildFragmentManager(),
R.id.realtabcontent);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_tabs_fragment, container, false);
TabHost host = mTabManager.handleCreateView(v);
mTabManager.addTab(host.newTabSpec("result").setIndicator("Result"),
FragmentReceiveResult.ReceiveResultFragment.class, null);
mTabManager.addTab(host.newTabSpec("contacts").setIndicator("Contacts"),
LoaderCursor.CursorLoaderListFragment.class, null);
mTabManager.addTab(host.newTabSpec("apps").setIndicator("Apps"),
LoaderCustom.AppListFragment.class, null);
mTabManager.addTab(host.newTabSpec("throttle").setIndicator("Throttle"),
LoaderThrottle.ThrottledLoaderListFragment.class, null);
return v;
}
@Override
public void onViewStateRestored(Bundle savedInstanceState) {
super.onViewStateRestored(savedInstanceState);
mTabManager.handleViewStateRestored(savedInstanceState);
}
@Override
public void onDestroyView() {
super.onDestroyView();
mTabManager.handleDestroyView();
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
mTabManager.handleSaveInstanceState(outState);
}
/**
* This is a helper class that implements a generic mechanism for
* associating fragments with the tabs in a tab host. DO NOT USE THIS.
* If you want tabs in a fragment, use the support v13 library's
* FragmentTabHost class, which takes care of all of this for you (in
* a simpler way even).
*/
public static class TabManager implements TabHost.OnTabChangeListener {
private final Context mContext;
private final FragmentManager mManager;
private final int mContainerId;
private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
private TabHost mTabHost;
private TabInfo mLastTab;
private boolean mInitialized;
private String mCurrentTabTag;
static final class TabInfo {
private final String tag;
private final Class<?> clss;
private final Bundle args;
private Fragment fragment;
TabInfo(String _tag, Class<?> _class, Bundle _args) {
tag = _tag;
clss = _class;
args = _args;
}
}
static class DummyTabFactory implements TabHost.TabContentFactory {
private final Context mContext;
public DummyTabFactory(Context context) {
mContext = context;
}
@Override
public View createTabContent(String tag) {
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
public TabManager(Context context, FragmentManager manager, int containerId) {
mContext = context;
mManager = manager;
mContainerId = containerId;
}
public TabHost handleCreateView(View root) {
if (mTabHost != null) {
throw new IllegalStateException("TabHost already set");
}
mTabHost = (TabHost)root.findViewById(android.R.id.tabhost);
mTabHost.setup();
mTabHost.setOnTabChangedListener(this);
return mTabHost;
}
public void addTab(TabHost.TabSpec tabSpec, Class<?> clss, Bundle args) {
tabSpec.setContent(new DummyTabFactory(mContext));
String tag = tabSpec.getTag();
TabInfo info = new TabInfo(tag, clss, args);
mTabs.add(info);
mTabHost.addTab(tabSpec);
}
public void handleViewStateRestored(Bundle savedInstanceState) {
if (savedInstanceState != null) {
mCurrentTabTag = savedInstanceState.getString("tab");
}
mTabHost.setCurrentTabByTag(mCurrentTabTag);
String currentTab = mTabHost.getCurrentTabTag();
// Go through all tabs and make sure their fragments match
// the correct state.
FragmentTransaction ft = null;
for (int i=0; i<mTabs.size(); i++) {
TabInfo tab = mTabs.get(i);
tab.fragment = mManager.findFragmentByTag(tab.tag);
if (tab.fragment != null && !tab.fragment.isDetached()) {
if (tab.tag.equals(currentTab)) {
// The fragment for this tab is already there and
// active, and it is what we really want to have
// as the current tab. Nothing to do.
mLastTab = tab;
} else {
// This fragment was restored in the active state,
// but is not the current tab. Deactivate it.
if (ft == null) {
ft = mManager.beginTransaction();
}
ft.detach(tab.fragment);
}
}
}
// We are now ready to go. Make sure we are switched to the
// correct tab.
mInitialized = true;
ft = doTabChanged(currentTab, ft);
if (ft != null) {
ft.commit();
mManager.executePendingTransactions();
}
}
public void handleDestroyView() {
mCurrentTabTag = mTabHost.getCurrentTabTag();
mTabHost = null;
mTabs.clear();
mInitialized = false;
}
public void handleSaveInstanceState(Bundle outState) {
outState.putString("tab", mTabHost != null
? mTabHost.getCurrentTabTag() : mCurrentTabTag);
}
@Override
public void onTabChanged(String tabId) {
if (!mInitialized) {
return;
}
FragmentTransaction ft = doTabChanged(tabId, null);
if (ft != null) {
ft.commit();
}
}
private FragmentTransaction doTabChanged(String tabId, FragmentTransaction ft) {
TabInfo newTab = null;
for (int i=0; i<mTabs.size(); i++) {
TabInfo tab = mTabs.get(i);
if (tab.tag.equals(tabId)) {
newTab = tab;
}
}
if (newTab == null) {
throw new IllegalStateException("No tab known for tag " + tabId);
}
if (mLastTab != newTab) {
if (ft == null) {
ft = mManager.beginTransaction();
}
if (mLastTab != null) {
if (mLastTab.fragment != null) {
ft.detach(mLastTab.fragment);
}
}
if (newTab != null) {
if (newTab.fragment == null) {
newTab.fragment = Fragment.instantiate(mContext,
newTab.clss.getName(), newTab.args);
ft.add(mContainerId, newTab.fragment, newTab.tag);
} else {
ft.attach(newTab.fragment);
}
}
mLastTab = newTab;
}
return ft;
}
}
}