Develop Reference

Tabs are not coming in layout of android studio

I am trying to create tabs in my layout. But instead of showing tab it is showing the below screen in design:
Below is the code:
**activity_mail.xml**
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginTop="200dp"
android:id="#+id/appBarLayout2">
<com.google.android.material.tabs.TabLayout
android:id="#+id/sliding_tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="fixed"/>
</android.support.design.widget.AppBarLayout>
<androidx.viewpager.widget.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:background="#android:color/white"/>
</LinearLayout>
MainActivity.java
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager.widget.ViewPager;
import com.google.android.material.tabs.TabLayout;
public class MainActivity extends AppCompatActivity {
/* private TabAdapter adapter;
private TabLayout tabLayout;
private ViewPager viewPager;*/
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager viewPager = (ViewPager) findViewById(R.id.viewPager);
viewPager.setAdapter(new TabAdapter(getSupportFragmentManager(),
MainActivity.this));
TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
tabLayout.setupWithViewPager(viewPager);
}
}
Tab1Fragment.java
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.fragment.app.Fragment;
public class Tab1Fragment extends Fragment {
public static final String ARG_PAGE = "ARG_PAGE";
private int mPage;
public static Tab1Fragment newInstance(int page) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
Tab1Fragment fragment = new Tab1Fragment();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPage = getArguments().getInt(ARG_PAGE);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_main, container, false);
TextView textView = (TextView) view;
textView.setText("Fragment #" + mPage);
return view;
}
}
TabAdapter.Java
import android.content.Context;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentStatePagerAdapter;
public class TabAdapter extends FragmentStatePagerAdapter {
final int PAGE_COUNT = 3;
private String tabTitles[] = new String[] { "Tab1", "Tab2", "Tab3" };
private Context context;
public TabAdapter(FragmentManager fm, Context context) {
super(fm);
this.context = context;
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int position) {
return Tab1Fragment.newInstance(position + 1);
}
#Override
public CharSequence getPageTitle(int position) {
// Generate title based on item position
return tabTitles[position];
}
}
fragment_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/mainLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.main.PlaceholderFragment">
<TextView
android:id="#+id/section_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="#dimen/activity_horizontal_margin"
android:layout_marginTop="#dimen/activity_vertical_margin"
android:layout_marginEnd="#dimen/activity_horizontal_margin"
android:layout_marginBottom="#dimen/activity_vertical_margin"
android:text="#string/sparta"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:layout_constraintLeft_creator="1"
tools:layout_constraintTop_creator="1" />
</androidx.constraintlayout.widget.ConstraintLayout>
Also when trying to run it in my mobile, it is showing error something like:
android.widget.RelativeLayout cannot be cast to android.widget.TextView
Please suggest the way to solve this issue.

After androidX, support library are removed,
so you need to use material design which help you.
Replace your appbar with below code
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginTop="200dp"
android:id="#+id/appBarLayout2">
this will help you.

You're using deprecated design support AppBarLayout, You need to replace it with androidx library , so replace android.support.design.widget.AppBarLayout with com.google.android.material.appbar.AppBarLayout in your layout.
<?xml version="1.0" encoding="utf-8"?><?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/appBarLayout2"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginTop="200dp">
<com.google.android.material.tabs.TabLayout
android:id="#+id/sliding_tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="fixed" />
</com.google.android.material.appbar.AppBarLayout>
<androidx.viewpager.widget.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:background="#android:color/white" />
</LinearLayout>
For the android.widget.RelativeLayout cannot be cast to android.widget.TextView, please post the entire stack trace.
UPDATE
tab names are not coming. only green background of the tablayout is shown.
this is odd behavior, as I you already override getPageTitle in the adapter.. I just suggest not to use a hard-coded array of Strings in the adapter, instead add the tab titles in the strings.xml
Strings.xml
<resources>
<string name="tab1">Tab1</string>
<string name="tab2">Tab2</string>
<string name="tab3">Tab3</string>
</resources>
Adapter
public class TabAdapter extends FragmentStatePagerAdapter {
final int PAGE_COUNT = 3;
// private String tabTitles[] = new String[] { "Tab1", "Tab2", "Tab3" };
private int[] tabTitles = new int[]{R.string.tab1, R.string.tab2, R.string.tab3};
private Context context;
public TabAdapter(FragmentManager fm, Context context) {
super(fm);
this.context = context;
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int position) {
return Tab1Fragment.newInstance(position + 1);
}
#Override
public CharSequence getPageTitle(int position) {
// Generate title based on item position
// return tabTitles[position];
return context.getString(tabTitles[position]);
}
}
Please have a look at this question that might be relevant.
UPDATE 2
Try to add those listeners
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager viewPager = (ViewPager) findViewById(R.id.viewPager);
viewPager.setAdapter(new TabAdapter(getSupportFragmentManager(),
MainActivity.this));
TabLayout tabLayout = (TabLayout) findViewById(R.id.sliding_tabs);
tabLayout.setupWithViewPager(viewPager);
// listeners
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(viewPager));
}
if not working , try to set the current item of the ViewPager
viewPager.setCurrentItem(itemPosition);

Change TextView values with method inside Fragment (NullPointerException)

I'm trying to make an app (for learning purposes) where I have a few tabs with scrollable content.
I have a collapsing app bar with a ViewPager for the main layout and three identical layouts with a TextView inside a NestedScrollView where the only difference is the image on top of the text. I also have three fragment classes with the same code inside. Everything worked fine.
But since I'm using the same layout in each tab, I thought that instead of a xml file and a java class for each tab, I could just have one of each and then somehow change the content for each tab inside my Adapter.
So I tried to just create a method to do that inside my tabFragment class. But I can't seem to find a way to modify the TextView. I keep getting a NullPointerException every time.
What am I missing?
Is my approach wrong? If so, what would be a better one? How do I solve this?
Thank you in advance :)
Here's my fragment class right now (the only one remaining ):
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.fragment.app.Fragment;
import com.example.tablayoutwithscrollview.R;
public class TabFragment extends Fragment {
private TextView textView;
private int text, image;
public TabFragment(){}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.tab1, container, false);
//textView = view.findViewById(R.id.textView);
return view;
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState)
{
super.onViewCreated(view, savedInstanceState);
textView = getView().findViewById(R.id.textView);
}
public void setTabContent(int text, int image)
{
textView.setText(text);
textView.setCompoundDrawablesWithIntrinsicBounds(0,image,0,0);
}
}
My adapter class:
import android.content.Context;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;
import com.example.tablayoutwithscrollview.Tabs.TabFragment;
public class MyAdapter extends FragmentPagerAdapter {
private static int tabCount;
Context context;
public MyAdapter(FragmentManager fm, int tabCount, Context context){
super(fm);
this.tabCount = tabCount;
this.context = context;
}
#Override
public Fragment getItem(int position) {
TabFragment fragment;
switch (position)
{
case 0:
fragment = new TabFragment();
fragment.setTabContent(R.string.lorem_ipsum, R.drawable.jackfruit);
return fragment;
case 1:
fragment = new TabFragment();
fragment.setTabContent(R.string.lorem_ipsum, R.drawable.guava);
return fragment;
case 2:
fragment = new TabFragment();
fragment.setTabContent(R.string.lorem_ipsum, R.drawable.pomegranate);
return fragment;
default:
return null;
}
}
#Override
public CharSequence getPageTitle(int position)
{
switch (position)
{
case 0:
return context.getString(R.string.tab1_title);
case 1:
return context.getString(R.string.tab2_title);
case 2:
return context.getString(R.string.tab3_title);
default:
return null;
}
}
#Override
public int getCount() {
return tabCount;
}
}
MainActivity:
package com.example.tablayoutwithscrollview;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.widget.NestedScrollView;
import androidx.viewpager.widget.ViewPager;
import android.os.Bundle;
import com.google.android.material.tabs.TabLayout;
public class MainActivity extends AppCompatActivity {
private TabLayout tabLayout;
private ViewPager viewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tabLayout = findViewById(R.id.tabLayout);
viewPager = findViewById(R.id.viewPager);
populatesTabLayout(tabLayout);
MyAdapter myAdapter = new MyAdapter(getSupportFragmentManager(), tabLayout.getTabCount(), this);
viewPager.setAdapter(myAdapter);
tabLayout.setupWithViewPager(viewPager);
}
private void populatesTabLayout(TabLayout tabLayout)
{
for (int i = 0; i<3; i++)
{
tabLayout.addTab(tabLayout.newTab());
}
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/coordLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="#+id/collapseToolBar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
app:toolbarId="#+id/toolbar">
<ImageView
android:id="#+id/imageView7"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:srcCompat="#drawable/strawberry" />
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"></androidx.appcompat.widget.Toolbar>
</com.google.android.material.appbar.CollapsingToolbarLayout>
<com.google.android.material.tabs.TabLayout
android:id="#+id/tabLayout"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:visibility="visible" />
</com.google.android.material.appbar.AppBarLayout>
<androidx.viewpager.widget.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
And my tab layout:
<?xml version="1.0" encoding="utf-8"?>
<androidx.core.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/tabNestedScrollView"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:drawableTop="#drawable/jackfruit"
android:text="#string/lorem_ipsum" />
</androidx.core.widget.NestedScrollView>
Here's how it's supposed to work (from before when each tab had a fragment class and a layout file):

The problem is that the created TabFragment instance has not been attached to the activity yet, therefore the textView does not inflated at that point.
You should pass the text to the TabFragment instance as an argument in the MyAdapter#getItem(..) method.
...
case 0:
fragment = new TabFragment();
Bundle args = new Bundle();
args.putString("key", textString);
fragment.setArguments(args);
return fragment
...
After that set the text for the TextView instance in the onViewCreated(...) method:
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
textView = getView().findViewById(R.id.textView);
textView.setText(getArguments().getString("key"));
}
Or you can see a nice example at the Android Reference.

Android fragment tab host + viewpager swipe?

I currently have a fragment tab host, made by this tutorial
http://maxalley.wordpress.com/2013/05/18/android-creating-a-tab-layout-with-fragmenttabhost-and-fragments/
The only difference is that I'm using this inside a fragment.
So I have a fragment with the tabs, each tab has another fragment..
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TabWidget
android:id="#android:id/tabs"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom" />
<FrameLayout
android:id="#android:id/tabcontent"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" />
</LinearLayout>
The fragment class
public class AddServiceFragment extends Fragment {
public AddServiceFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_add_service, container, false);
FragmentTabHost mTabHost = (FragmentTabHost) view.findViewById(android.R.id.tabhost);
mTabHost.setup(getActivity(), getChildFragmentManager(), android.R.id.tabcontent);
String[] tabs = new String[]{"text1", "text2"};
mTabHost.addTab(
mTabHost.newTabSpec("tab1").setIndicator(tabs[0], null),
MedicalHistoryFragment.class, null);
mTabHost.addTab(
mTabHost.newTabSpec("tab2").setIndicator(tabs[1], null),
MedicalHistoryFragment.class, null);
return view;
}
This works, I can see my tabs.
Now I want to implement a viewpager, in order to be able to swipe left or right.
I've read this from the android developer page
http://developer.android.com/training/animation/screen-slide.html
But I can't figure out, where should I put my viewpager?
I want my fragment to be independent of my activity...

TabHost doesn't provide ViewPager support.
Also, I suggest you to not use TabHost – this is old style.
Use PagerTabStrip
Look this Gist.
UPD:
I add some code, for case, if this Gist be deleted;
MainActivity.java
package ch.pboos.android.sample.viewpager;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MainActivity extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
viewPager.setAdapter(new SampleFragmentPagerAdapter());
}
public class SampleFragmentPagerAdapter extends FragmentPagerAdapter {
final int PAGE_COUNT = 5;
public SampleFragmentPagerAdapter() {
super(getSupportFragmentManager());
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int position) {
return PageFragment.create(position + 1);
}
}
public static class PageFragment extends Fragment {
public static final String ARG_PAGE = "ARG_PAGE";
private int mPage;
public static PageFragment create(int page) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
PageFragment fragment = new PageFragment();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPage = getArguments().getInt(ARG_PAGE);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_page, container, false);
TextView textView = (TextView) view;
textView.setText("Fragment #" + mPage);
return view;
}
}
}
activity_main.xml (without PagerTabStrip)
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</android.support.v4.view.ViewPager>
activity_main_2.xml (with PagerTabStrip)
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.v4.view.PagerTabStrip
android:id="#+id/pager_header"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="top"
android:background="#000"
android:paddingBottom="4dp"
android:paddingTop="4dp"
android:textColor="#fff" />
</android.support.v4.view.ViewPager>
fragment_page.xml
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center" />
getPageTitle
public CharSequence getPageTitle(int position) {
return "Page " + (position + 1);
}
UPD 2
With Fragment:
public class MainFragment extends Fragment{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.activity_main_2, container, false);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
viewPager.setAdapter(new SampleFragmentPagerAdapter());
}
public class SampleFragmentPagerAdapter extends FragmentPagerAdapter {
final int PAGE_COUNT = 5;
public SampleFragmentPagerAdapter() {
super(getSupportFragmentManager());
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int position) {
return PageFragment.create(position + 1);
}
}
public static class PageFragment extends Fragment {
public static final String ARG_PAGE = "ARG_PAGE";
private int mPage;
public static PageFragment create(int page) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
PageFragment fragment = new PageFragment();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mPage = getArguments().getInt(ARG_PAGE);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_page, container, false);
TextView textView = (TextView) view;
textView.setText("Fragment #" + mPage);
return view;
}
}
}
Hope it helps

use the following solution i have put the view page like below.. and my work done..
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<TabHost
android:id="#android:id/tabhost"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TabWidget
android:id="#android:id/tabs"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0"
android:orientation="horizontal" />
<FrameLayout
android:id="#android:id/tabcontent"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_weight="0" />
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:overScrollMode="never" />
</LinearLayout>
</TabHost>

You can implement the viewpager as a library.
First thing you need to import viewpager project to the eclipse workspace.
[ I think you are modifying the project :Tabhost example]
so right click your Tabhost example project thn build path -> configure build path..
thn click Android ...when you click android you can see 2 section Project build Target & Library.So in Library you can add the viewpager Library.

Inorder to include viewpager library to the project ,you should import the library
"Existing Project” to your current one.
Step 1:-Download source code from GitHub.(https://github.com/JakeWharton/Android-ViewPagerIndicator)
Step2 :-In your Android Studio Project:
File -> Project Structure -> add (+ symbol) -> Import Existing Project. Import just the folder called ”library”, not the entire project (leave the import options as Android Studio suggests).
step 3:-If the "compileSdkVersion" specified in your build.gradle doesn’t match with the one specified in the Android-ViewPagerIndicator project, change the second one.
The same apply with any other property, such as "minSdkVersion" or even the current support library.
Step 4:-Add Android-ViewPagerIndicator project as a dependency to your build.gradle module:
dependencies {
compile project(':library')
}
Step 5:- Sync project with gradle files.

Android - ActionBarActivity with ViewPager

i have a problem with ActionBarActivity and ViewPager.
On my "main-activity" which is a ActionBarActivity i have some tabs, which are fragments.
I want to implement the "swipe-feature" between these tabs.
I've already read the following tutorial:
http://developer.android.com/training/implementing-navigation/lateral.html
Actually i have implemented the whole code, but my app wont work. :(
There is no "swipe-feature" between the tabs.
Here is my code of the main-activity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_hauptmenue_extended);
try {
actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// ViewPager ...
pagerAdapter = new CollectionPagerAdapter(
getSupportFragmentManager());
viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPager.setAdapter(pagerAdapter);
viewPager.setCurrentItem(1);
viewPager
.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// Add all tabs to the actionbar...
Tab tabB = actionBar.newTab();
tabB.setText("Home");
tabB.setIcon(R.drawable.icon_home);
tabB.setTabListener(new TabListener<Startmenue_activity>(this,
"Start", Startmenue_activity.class, viewPager));
actionBar.addTab(tabB);
Tab tabA = actionBar.newTab();
tabA.setText("");
tabA.setIcon(R.drawable.icon_nachrichten_sel);
tabA.setTabListener(new TabListener<Nachrichten_activity>(this,
"News", Nachrichten_activity.class, viewPager));
actionBar.addTab(tabA);
Tab tabC = actionBar.newTab();
tabC.setText("");
tabC.setIcon(R.drawable.icon_favoriten);
tabC.setTabListener(new TabListener<Favoriten_activity>(this,
"Favs", Favoriten_activity.class, viewPager));
actionBar.addTab(tabC);
And my adapter looks like this:
public class CollectionPagerAdapter extends FragmentPagerAdapter {
final int NUM_ITEMS = 3; // number of tabs
List<Fragment> fragments = new ArrayList<Fragment>();
public Fragment getItem(int pos) {
return fragments.get(pos);
}
public void addFragment(Fragment f) {
fragments.add(f);
}
public CollectionPagerAdapter(FragmentManager fm) {
super(fm);
Fragment home_Fragment = new Startmenue_activity();
addFragment(home_Fragment);
Fragment news_Fragment = new Nachrichten_activity();
addFragment(news_Fragment);
Fragment favoriten_Fragment = new Favoriten_activity();
addFragment(favoriten_Fragment);
}
#Override
public int getCount() {
return NUM_ITEMS;
}
}
Oh and my XML of the main-activity looks like this:
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/fragView"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Hauptmenue_extended" >
<!-- The ViewPager -->
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<!-- The main content view -->
<FrameLayout
android:id="#+id/main"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</FrameLayout>
<!-- The navigation drawer -->
<ListView
android:id="#+id/left_drawer"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:background="#fff"
android:choiceMode="singleChoice"
android:divider="#android:color/transparent"
android:dividerHeight="0dp" />
</android.support.v4.view.ViewPager>
</android.support.v4.widget.DrawerLayout>

There's a bunch of things that I don't fully understand about your code, for example, why are you putting a ListView inside the ViewPager?. Anyways if you want to implement some tabs with the swipe feature. Here is how do it:
First the xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.v4.view.PagerTabStrip
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="top" />
</android.support.v4.view.ViewPager>
Now the activity:
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
public class MainActivity extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager pager = (ViewPager) findViewById(R.id.pager);
pager.setAdapter(new SampleAdapter(this, getSupportFragmentManager()));
}
}
The adapter:
import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
public class SampleAdapter extends FragmentStatePagerAdapter {
Context ctxt = null;
public SampleAdapter(Context ctxt, FragmentManager mgr) {
super(mgr);
this.ctxt = ctxt;
}
#Override
public int getCount() {
return 3;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new SimpleFragment("Hi");
case 1:
return new SimpleFragment("There");
case 2:
return new SimpleFragment("Fella");
}
return null;
}
#Override
public String getPageTitle(int position) {
switch (position) {
case 0:
return "First Tab";
case 1:
return "Second Tab";
case 2:
return "Third Tab";
}
return null;
}
}
And the SimpleFragment:
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
#SuppressLint("ValidFragment")
public class SimpleFragment extends Fragment {
String text;
public SimpleFragment(String string) {
text = string;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment, container, false);
TextView textview = (TextView) root.findViewById(R.id.textView1);
textview.setText(text);
return root;
}
}
And the fragment.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:text="Large Text"
android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>
Hope this helps :)

Try this out. But I've not tested it.
http://wptrafficanalyzer.in/blog/swipable-navigation-tabs-using-actionbarcompat-library/

Tutorial to implement the use of TabHost in Android 2.2 + ViewPager and Fragments

A short tutorial for people like me who had some trouble finding a way to implement TabHost and ViewPager, including page swiping with fingers and tab click to change pages. The shown solution is compatible with Android versions 2.2+.
It includes Tabs initialization, ViewPager connected with Tabs and Page Scrolling management.
Its main peculiarity is the optimization for earlier versions of Android (Android 2.2 (Froyo), API version 8) and the simple implementation for different purposes.

The tutorial includes 4 classes and 2 layouts. It has been tested with an Android phone 2.2, and you can just copy & paste to try it.
MainActivity.java (the main activity):
package samples.tabhost.andreaoid.net;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.widget.TabHost;
import android.widget.TabHost.OnTabChangeListener;
public class MainActivity extends FragmentActivity implements OnTabChangeListener, OnPageChangeListener {
MyPageAdapter pageAdapter;
private ViewPager mViewPager;
private TabHost mTabHost;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mViewPager = (ViewPager) findViewById(R.id.viewpager);
// Tab Initialization
initialiseTabHost();
// Fragments and ViewPager Initialization
List<Fragment> fragments = getFragments();
pageAdapter = new MyPageAdapter(getSupportFragmentManager(), fragments);
mViewPager.setAdapter(pageAdapter);
mViewPager.setOnPageChangeListener(MainActivity.this);
}
// Method to add a TabHost
private static void AddTab(MainActivity activity, TabHost tabHost, TabHost.TabSpec tabSpec) {
tabSpec.setContent(new MyTabFactory(activity));
tabHost.addTab(tabSpec);
}
// Manages the Tab changes, synchronizing it with Pages
public void onTabChanged(String tag) {
int pos = this.mTabHost.getCurrentTab();
this.mViewPager.setCurrentItem(pos);
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
// Manages the Page changes, synchronizing it with Tabs
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
int pos = this.mViewPager.getCurrentItem();
this.mTabHost.setCurrentTab(pos);
}
#Override
public void onPageSelected(int arg0) {
}
private List<Fragment> getFragments(){
List<Fragment> fList = new ArrayList<Fragment>();
// TODO Put here your Fragments
MySampleFragment f1 = MySampleFragment.newInstance("Sample Fragment 1");
MySampleFragment f2 = MySampleFragment.newInstance("Sample Fragment 2");
MySampleFragment f3 = MySampleFragment.newInstance("Sample Fragment 3");
fList.add(f1);
fList.add(f2);
fList.add(f3);
return fList;
}
// Tabs Creation
private void initialiseTabHost() {
mTabHost = (TabHost) findViewById(android.R.id.tabhost);
mTabHost.setup();
// TODO Put here your Tabs
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab1").setIndicator("Tab1"));
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab2").setIndicator("Tab2"));
MainActivity.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Tab3").setIndicator("Tab3"));
mTabHost.setOnTabChangedListener(this);
}
}
MyPageAdapter.java (fragment manager):
package samples.tabhost.andreaoid.net;
import java.util.List;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class MyPageAdapter extends FragmentPagerAdapter {
private List<Fragment> fragments;
public MyPageAdapter(FragmentManager fm, List<Fragment> fragments) {
super(fm);
this.fragments = fragments;
}
#Override
public Fragment getItem(int position) {
return this.fragments.get(position);
}
#Override
public int getCount() {
return this.fragments.size();
}
}
MyTabFactory (tab manager):
package samples.tabhost.andreaoid.net;
import android.content.Context;
import android.view.View;
import android.widget.TabHost.TabContentFactory;
public class MyTabFactory implements TabContentFactory {
private final Context mContext;
public MyTabFactory(Context context) {
mContext = context;
}
public View createTabContent(String tag) {
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
MySampleFragment.java (the single fragment - included for demonstration purposes):
package samples.tabhost.andreaoid.net;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MySampleFragment extends Fragment {
private static View mView;
public static final MySampleFragment newInstance(String sampleText) {
MySampleFragment f = new MySampleFragment();
Bundle b = new Bundle();
b.putString("bString", sampleText);
f.setArguments(b);
return f;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
mView = inflater.inflate(R.layout.sample_fragment, container, false);
String sampleText = getArguments().getString("bString");
TextView txtSampleText = (TextView) mView.findViewById(R.id.txtViewSample);
txtSampleText.setText(sampleText);
return mView;
}
}
activity_main.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TabHost
android:id="#android:id/tabhost"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TabWidget
android:id="#android:id/tabs"
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="0" />
<FrameLayout
android:id="#android:id/tabcontent"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_weight="0" />
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom" />
</LinearLayout>
</TabHost>
</RelativeLayout>
sample_fragment.xml (you can put here your fragment layout):
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/txtViewSample"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="" />
</RelativeLayout>