Android fragment tab host + viewpager swipe?

Android fragment tab host + viewpager swipe? - android

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.

Related

Android ViewPager2 with different Fragments : Error->Shows always the same fragment

i am using the new android viewpager2, but when i load different fragments, the viewpager2 shows only the same fragments..
Is this an error? in the older viewpager everything worked.
As you can see here in the images, the android app load the same fragments.
In the viewPagerAdapter I load or create for each position a different fragment
Code ViewPagerAdaptor
public class ViewPagerAdapter extends FragmentStateAdapter {
public ViewPagerAdapter(#NonNull FragmentActivity fragmentActivity)
{
super(fragmentActivity);
}
#NonNull
#Override
public Fragment createFragment(int position) {
switch (position) {
case 0:
return new page1();
case 1:
return new page2();
default:
return new pageDefault();
}
}
#Override
public int getItemCount() {return 3; }
}
The MainActivity.class
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tabLayout = findViewById(R.id.tabs);
viewPager2 = findViewById(R.id.view_pager);
ViewPagerAdapter adapter = new ViewPagerAdapter(this);
viewPager2.setAdapter(adapter);
new TabLayoutMediator(tabLayout, viewPager2,
new TabLayoutMediator.TabConfigurationStrategy() {
#Override
public void onConfigureTab(#NonNull TabLayout.Tab tab, int position) {
tab.setText("Tab " + (position + 1));
}
}).attach();
}
here come the fragments
fragment_page1
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/fragment_page1"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".page1">
<!-- TODO: Update blank fragment layout -->
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:textSize="20sp"
android:textStyle="bold"
android:text="This is Page 0" />
</FrameLayout>
and fragment_page2
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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=".page2">
<!-- TODO: Update blank fragment layout -->
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:textSize="20sp"
android:textStyle="bold"
android:text="This is Page 02"
android:background="#color/red_100"/>
</FrameLayout>
and the java code of page1.java
package com.example.demo_viewpager2;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class page1 extends Fragment {
public page1() {
// Required empty public constructor
}
public static page1 newInstance() {
page1 fragment = new page1();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
return inflater.inflate(R.layout.fragment_page1, container, false);
}
}

After trying the code provided and add the missing files, i am unable to replicate your issue and is working fine on my testing.
ViewPagerAdapter.java file
package com.example.adapter;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentActivity;
import androidx.viewpager2.adapter.FragmentStateAdapter;
import com.example.fragment.page1;
import com.example.fragment.page2;
import com.example.fragment.pageDefault;
public class ViewPagerAdapter extends FragmentStateAdapter {
public ViewPagerAdapter(#NonNull FragmentActivity fragmentActivity) {
super(fragmentActivity);
}
#NonNull
#Override
public Fragment createFragment(int position) {
switch (position) {
case 0:
return new page1();
case 1:
return new page2();
default:
return new pageDefault();
}
}
#Override
public int getItemCount() {
return 3;
}
}
MainActivity.java file
package com.example.view;
import android.app.Activity;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.FragmentActivity;
import androidx.viewpager2.widget.ViewPager2;
import com.example.R;
import com.example.adapter.ViewPagerAdapter;
import com.google.android.material.tabs.TabLayout;
import com.google.android.material.tabs.TabLayoutMediator;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TabLayout tabLayout = findViewById(R.id.tabs);
ViewPager2 viewPager2 = findViewById(R.id.view_pager);
ViewPagerAdapter adapter = new ViewPagerAdapter(this);
viewPager2.setAdapter(adapter);
new TabLayoutMediator(tabLayout, viewPager2,
new TabLayoutMediator.TabConfigurationStrategy() {
#Override
public void onConfigureTab(#NonNull TabLayout.Tab tab, int position) {
tab.setText("Tab " + (position + 1));
}
}).attach();
}
}
page1.java file
public class page1 extends Fragment {
public page1() {
// Required empty public constructor
}
public static page1 newInstance() {
page1 fragment = new page1();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
return inflater.inflate(R.layout.fragment_page1, container, false);
}
}
page2.java file
public class page2 extends Fragment {
public page2() {
// Required empty public constructor
}
public static page2 newInstance() {
page2 fragment = new page2();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_page2, container, false);
}
}
pageDefault.java file
public class pageDefault extends Fragment {
public pageDefault() {
// Required empty public constructor
}
public static pageDefault newInstance() {
pageDefault fragment = new pageDefault();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_page_default, container, false);
}
}
main_activity.xml file
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.google.android.material.tabs.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
</LinearLayout>
fragment_page1.xml file
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragment_page1"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- TODO: Update blank fragment layout -->
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:text="This is Page 0"
android:textSize="20sp"
android:textStyle="bold" />
</FrameLayout>
fragment_page2.xml file
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- TODO: Update blank fragment layout -->
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:textSize="20sp"
android:textStyle="bold"
android:text="This is Page 02"
android:background="#android:color/holo_red_light"/>
</FrameLayout>
fragment_page_default.xml file
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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">
<!-- TODO: Update blank fragment layout -->
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:textSize="20sp"
android:textStyle="bold"
android:text="This is Page Default"/>
</FrameLayout>
Output:

thank you, this workes really fine.
there was an typo error in the inflate of page2 to the page1
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_page1, container, false);
}

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.

View pager and ImageView not showing android

I got a problem. When im using a pagerView everything inside is showing up beside ImageView.
I'm using this :
<!-- activity_screen_slide.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:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
android:id="#+id/relativeLayout">
<android.support.v4.view.ViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pager"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:elevation="0dp" />
</RelativeLayout>
and this :
<?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:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<Button
android:id="#+id/button2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button" />
<ImageView
android:id="#+id/imageView2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:srcCompat="#drawable/common_google_signin_btn_icon_dark" />
</LinearLayout>
And i use this for fragment
package com.example.gebruiker.drumio.SlideScreenTrackPreview;
import android.graphics.Color;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import com.example.gebruiker.drumio.R;
public class TestFragment extends Fragment {
ImageView hihat;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup
container, #Nullable Bundle savedInstanceState) {
ViewGroup rootView = (ViewGroup)
inflater.inflate(R.layout.track_preview_test,container,false);
hihat =(ImageView)rootView.findViewById(R.id.imageView2);
hihat.setBackgroundColor(Color.BLACK);
hihat.setColorFilter(Color.BLACK);
return rootView;
}
}
Except the button, nothing is showing up.
Here is the code for the activity that i use :
package com.example.gebruiker.drumio.SlideScreenTrackPreview;
public class ScreenSliderActivity extends FragmentActivity {
private static final int NUM_PAGES = 5;
private PagerAdapter mPagerAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_screen_slide);
// Instantiate a ViewPager and a PagerAdapter.
mPager = (ViewPager) findViewById(R.id.pager);
mPager.setBackgroundColor(Color.WHITE);
mPagerAdapter = new
ScreenSlidePagerAdapter(getSupportFragmentManager());
mPager.setAdapter(mPagerAdapter);
}
#Override
public void onBackPressed() {
if (mPager.getCurrentItem() == 0) {
super.onBackPressed();
} else {
// Otherwise, select the previous step.
mPager.setCurrentItem(mPager.getCurrentItem() - 1);
}
}
private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {
public ScreenSlidePagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return new TestFragment();
}
#Override
public int getCount() {
return NUM_PAGES;
}
}
}

Your activity works for me if you inherit from AppCompatActivity instead of from FragmentActivity. I don't know why; maybe somebody with more experience can elucidate.

TabHost with Fragments and FragmentActivity

I'm working on an Android App and I want to use 3 tabs for navigation using Fragments for each tab, but I don't know how to create the structure for doing it.
I want to add each fragment separately because each one is different, but I don't know where to add them in FragmentActivity.
I have these files.
tabs_layout.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_height="match_parent"
android:layout_width="match_parent">
<TabHost android:id="#android:id/tabhost"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TabWidget
android:id="#android:id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<FrameLayout
android:id="#android:id/tabcontent"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<FrameLayout
android:id="#+id/tabRateAPet"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
<FrameLayout
android:id="#+id/tabViewMyRates"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
<FrameLayout
android:id="#+id/tabViewGlobalRates"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</FrameLayout>
</LinearLayout>
</TabHost>
</LinearLayout>
TabsMain.java
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
public class MainTabsActivity extends FragmentActivity {
public static final String RATE_A_PET = "Rate a Pet";
public static final String MY_RATES = "My Rates";
public static final String GLOBAL_RATES = "Global Rates";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.tabs_layout);
}
}
Tabs.java
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TabHost;
import android.widget.TabHost.OnTabChangeListener;
import android.widget.TabHost.TabSpec;
import android.widget.TextView;
public class Tabs extends Fragment implements OnTabChangeListener {
private static final String TAG = "FragmentTabs";
public static final String RATE_A_PET = "Rate a Pet";
public static final String MY_RATES = "My Rates";
public static final String GLOBAL_RATES = "Global Rates";
private View mRoot;
private TabHost mTabHost;
private int mCurrentTab;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// super.onCreateView(inflater, container, savedInstanceState);
mRoot = inflater.inflate(R.layout.tabs_layout, null);
mTabHost = (TabHost) mRoot.findViewById(android.R.id.tabhost);
setupTabs();
return mRoot;
}
private void setupTabs() {
mTabHost.setup(); // important!
mTabHost.addTab(newTab(RATE_A_PET, R.string.tabRateAPet, R.id.tabRateAPet));
mTabHost.addTab(newTab(MY_RATES, R.string.tabViewMyRates, R.id.tabViewMyRates));
}
private TabSpec newTab(String tag, int labelId, int tabContentId) {
Log.d(TAG, "buildTab(): tag=" + tag);
View indicator = LayoutInflater.from(getActivity()).inflate(
R.layout.tab,
(ViewGroup) mRoot.findViewById(android.R.id.tabs), false);
((TextView) indicator.findViewById(R.id.text)).setText(labelId);
TabSpec tabSpec = mTabHost.newTabSpec(tag);
tabSpec.setIndicator(indicator);
tabSpec.setContent(tabContentId);
return tabSpec;
}
#Override
public void onTabChanged(String tabId) {
Log.d(TAG, "onTabChanged(): tabId=" + tabId);
if (RATE_A_PET.equals(tabId)) {
updateTab(tabId, R.id.tabRateAPet);
mCurrentTab = 0;
return;
}
if (MY_RATES.equals(tabId)) {
updateTab(tabId, R.id.tabViewMyRates);
mCurrentTab = 1;
return;
}
if (GLOBAL_RATES.equals(tabId)) {
updateTab(tabId, R.id.tabViewGlobalRates);
mCurrentTab = 2;
return;
}
}
private void updateTab(String tabId, int placeholder) {
FragmentManager fm = getFragmentManager();
if (fm.findFragmentByTag(tabId) == null) {
fm.beginTransaction()
.replace(placeholder, new RateMyPetActivity(), tabId)
.commit();
}
}
}

I would suggest creating a separate fragment file for each tab. I recently did this as well, so I have outlined my code below:
Layout Files
activity_main.xml
<android.support.v4.app.FragmentTabHost
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#android:id/tabhost"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TabWidget
android:id="#android:id/tabs"
android:orientation="horizontal"
android:layout_width="match_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"/>
<FrameLayout
android:id="#+id/realtabcontent"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"/>
</LinearLayout>
</android.support.v4.app.FragmentTabHost>
tab1_view.xml //add your respective tab layouts using this format (make sure to change string variables)
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
tools:context=".DeviceFragment" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/tab1_fragment_string" />
</LinearLayout>
SRC Files
MainActivity.java //notice that in the .addTab process I only used text. You can also add icons using drawables that you would need to add to your hdpi folder. I also only created three tabs in this example.
package com.example.applicationname;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTabHost;
public class MainActivity extends FragmentActivity {
// Fragment TabHost as mTabHost
private FragmentTabHost mTabHost;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTabHost = (FragmentTabHost)findViewById(android.R.id.tabhost);
mTabHost.setup(this, getSupportFragmentManager(), R.id.realtabcontent);
mTabHost.addTab(mTabHost.newTabSpec("tab1").setIndicator("Tab1"),
Tab1Fragment.class, null);
mTabHost.addTab(mTabHost.newTabSpec("tab2").setIndicator("Tab2"),
Tab2Fragment.class, null);
mTabHost.addTab(mTabHost.newTabSpec("tab3").setIndicator("Tab3"),
Tab3Fragment.class, null);
}
}
Tab1Fragment.java //once again replicate for desired number of tabs
package com.example.applicationname;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Tab1Fragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View V = inflater.inflate(R.layout.tab1_view, container, false);
return V;
}
}
Make sure that your R.java and strings.xml files are properly set up, and then your tabs should be up and running.

TabHost doesn't retains Fragment's states. So why using TabHost?
So use ViewPager with TabLayout instead.
Prons of Viewpager over Tabhost:
ViewPager retains Fragments states. Mean Fragment will not again recreated if switched.
Inbuilt swiping feature that gives user smoother experience.
Less CPU consumption, because Tabhost recreates Fragment/Activity again and again when Tab is switched.
See the difference :
Using Tablayout + ViewPager (Supports swipe, retains Fragments states
Using TabHost (Doesn't support swipe, doesn't retain states)
Small Code for Tablayout + ViewPager
// find views by id
ViewPager viewPager = findViewById(R.id.viewpager);
TabLayout tabLayout = findViewById(R.id.tablayout);
// attach tablayout with viewpager
tabLayout.setupWithViewPager(viewPager);
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
// add your fragments
adapter.addFrag(new SampleFragment(), "Tab1");
adapter.addFrag(new SampleFragment(), "Tab2");
adapter.addFrag(new SampleFragment(), "Tab3");
// set adapter on viewpager
viewPager.setAdapter(adapter);
XML layout
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<com.google.android.material.tabs.TabLayout
android:id="#+id/tablayout"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<androidx.viewpager.widget.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
</LinearLayout>
Note If you are not using AndroidX yet, you need to change following in layout.
Change com.google.android.material.tabs.TabLayout to android.support.design.widget.TabLayout
Chagne androidx.viewpager.widget.ViewPager to android.support.v4.view.ViewPager
But I'll strongly recommend to migrate to AndroidX, see #this answer to understand why.
And this is common ViewPagerAdapter for all your Viewpager in app.
public class ViewPagerAdapter extends FragmentStatePagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
public void addFrag(Fragment fragment) {
mFragmentList.add(fragment);
mFragmentTitleList.add("");
}
public void addFrag(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
}
Important Related Links
Difference between getSupportFragmentManager() and getChildFragmentManager()?
getSupportFragmentManager() versus getFragmentManager() in android 3.0+
Difference between FragmentPagerAdapter and FragmentStatePagerAdapter

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.

Android fragment tab host + viewpager swipe? - android

Related

Android ViewPager2 with different Fragments : Error->Shows always the same fragment

Tabs are not coming in layout of android studio

Change TextView values with method inside Fragment (NullPointerException)

View pager and ImageView not showing android

TabHost with Fragments and FragmentActivity

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