I am trying to add a PreferenceFragment to a FragmentPagerAdapter.
My class extends FragmentActivity, I have tried FragmentTransaction, as shown below as well as trying to add to the container and can't seem to get anything to work. No errors are thrown, in fact nothing happens.
Main Activity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
}
activity_main.xml:
<android.support.v4.view.ViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
</android.support.v4.view.ViewPager>
My Options menu selection:
android.app.FragmentManager fm;
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_settings:
JJSettings settings = new JJSettings();
fm = getFragmentManager();
FragmentTransaction fragTrans = fm.beginTransaction();
// I also tried `replace()` here as well. Same 'nothing happens' result.
fragTrans.add(settings, "settings");
fragTrans.commit();
return true;
case R.id.menu_help:
menuHelp();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
My settings Fragment:
public class JJSettings extends PreferenceFragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.settings);
}
}
My preference would be to stick with Fragments if possible, meaning I'd rather not extend PreferenceActivity or take the user to another Activity that calls the PreferenceFragment, if at all possible. I'm just hoping I missed something in my research.
Edit
public class SectionsPagerAdapter extends FragmentPagerAdapter {
private int _count = 2;
public SectionsPagerAdapter(FragmentManager fm) { super(fm); }
#Override
public Object instantiateItem(ViewGroup container, int position) {
return super.instantiateItem(container, position);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new JJMainFragment();
case 1:
return new JJPendingFragment();
default:
return null;
}
}
public void setCount(int count) { this._count = count; }
#Override
public int getCount() { return this._count; }
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return getString(R.string.c_list).toUpperCase(Locale.ENGLISH);
case 1:
return getString(R.string.c_pending).toUpperCase(Locale.ENGLISH);
}
return null;
}
}
This answer led me to the solution of using the v13 support library, which includes a FragmentPagerAdapter that uses bona-fide android.app.Fragments so it can support the PreferenceFragment.
Assuming you use Eclipse and run the new app wizard with the "Scrollable Tabs + Swipe" Navigation (which gives you the v4 pager boilerplate), here are the modifications you need to make to upgrade to v13:
Delete "android-support-v4.jar" file from your libs folder
Copy "android-support-v13.jar" from SDK_PATH\extras\android\support\v13; if it's not there, use the SDK manager to install or update "Extras/Android Support Library"
Then, in the Java file:
Change FragmentPagerAdapter import from v4 to v13
Change FragmentActivity to a plain Activity
Change calls to getSupportFragmentManager to getFragmentManager
Import all necessary classes from android.app instead of android.support.v4
(Except: you still need to use the v4 ViewPager, but it's compatible)
I've copied the modified source below, verified on latest Jellybean.
MainActivity.java:
package com.example.pagerwithpreferencesfragment;
import java.util.Locale;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.os.Bundle;
import android.preference.PreferenceFragment;
import android.support.v13.app.FragmentPagerAdapter; // instead of v4.app...
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MainActivity extends Activity { // no longer FragmentActivity
// these comments are now out-of-date; v13, not v4
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link android.support.v4.app.FragmentPagerAdapter} derivative, which
* will keep every loaded fragment in memory. If this becomes too memory
* intensive, it may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
mSectionsPagerAdapter = new SectionsPagerAdapter(
getFragmentManager()); // instead of getSupportFragmentMangager
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// this is just to show it compiles
if (position == 0) {
// you should really make this a public class elsewhere..
return new PreferenceFragment() {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.settings_preferences);
}
};
}
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_dummy,
container, false);
TextView dummyTextView = (TextView) rootView
.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(
ARG_SECTION_NUMBER)));
return rootView;
}
}
}
settings_preferences.xml:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory
android:key="my_category_key"
android:title="My Title">
<CheckBoxPreference
android:key="pref_key"
android:title="Title"
android:summary="Summary"
android:defaultValue="false"
/>
</PreferenceCategory>
</PreferenceScreen>
Documentation
I think you need to specify a container view id for the fragment transaction. Try giving it the id of your ViewPager. Or, put the ViewPager inside another container, give that an id, and use that.
Related
So it seems the previous ways of creating tabbed activities that allow swiping the screen left and right have all been deprecated.
I tried searching through various other guides, but all of them use deprecated fragments methods.
So I tried using the built in "Tabbed Activity" in Eclipse here:
New -> Other -> Android Activity -> Tabbed Activity
I created 2 additional fragment activities called fragment2_activity, fragment3_activity.
Going by that, where in the code below do I add the second and third fragments?
import java.util.Locale;
import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.support.v13.app.FragmentPagerAdapter;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class InformationActivity extends Activity {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a {#link FragmentPagerAdapter}
* derivative, which will keep every loaded fragment in memory. If this
* becomes too memory intensive, it may be best to switch to a
* {#link android.support.v13.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_information);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.information, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class
// below).
return PlaceholderFragment.newInstance(position + 1);
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_information,
container, false);
return rootView;
}
}
}
I managed to fix my problem, I was importing an incorrect package.
I am a beginner at android programming and I'm using eclipse luna. I created a new activity and I chose Tabbed Activity instead of Blank activity. It already has codes with swiping. But there are codes that I cannot understand. I dont know how I can change the activity when I swipe. In the Case, I am wondering why it is string instead of the reference of the activity.
Here's the code from tabbed activity:
package com.e_learningforchildren.sarah;
import java.util.Locale;
import android.support.v7.app.ActionBarActivity;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
public class TopicsActivity extends ActionBarActivity {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a {#link FragmentPagerAdapter}
* derivative, which will keep every loaded fragment in memory. If this
* becomes too memory intensive, it may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_topics);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(
getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.topics, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class
// below).
return PlaceholderFragment.newInstance(position + 1);
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_topics,
container, false);
return rootView;
}
}
}
here is my code of swipe tabs with fragments
not included imports
public class MainActivity extends FragmentActivity {
ViewPager viewpager;
ActionBar actionbar;
String[] tabs={"temperature","information"};
tabpageadapter adapterm;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewpager=( ViewPager)findViewById(R.id.pager);
actionbar=getActionBar();
adapterm= new tabpageadapter(getSupportFragmentManager());
viewpager.setAdapter(adapterm);
actionbar.setHomeButtonEnabled(false);
actionbar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
actionbar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#1F2230")));
actionbar.setStackedBackgroundDrawable(new ColorDrawable(Color.parseColor("#323445")));
for(String tabb:tabs)
{
actionbar.addTab(actionbar.newTab().setText(tabb).setTabListener(this));
}
viewpager.setOnPageChangeListener(this);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
this is page adapter for viewpager
public class tabpageadapter extends FragmentPagerAdapter{
public tabpageadapter(FragmentManager fm) {
super(fm);
// TODO Auto-generated constructor stub
}
#Override
public Fragment getItem(int index) {
// TODO Auto-generated method stub
switch(index)
{
case 0:
return new temperature_fragment();
case 1:
return new information_fragment();
}
return null;
}
#Override
public int getCount() {
// TODO Auto-generated method stub
return 2;
}
}
these is a fragment file just create another one with diff name so 2 tabs will be availble
public class temperature_fragment extends Fragment{
TextView tvtemp,farenhit;
LinearLayout llfortemp;
Intent inte;
BatteryManager bm;
double i,j;
int l,k;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View rootview=inflater.inflate(R.layout.temperature_xml, container,false);
Context cc=getActivity();
tvtemp=(TextView)rootview.findViewById(R.id.texttemp);
farenhit=(TextView)rootview.findViewById(R.id.textViewfarenhit);
llfortemp=(LinearLayout)rootview.findViewById(R.id.llfortemp);
return rootview;
}
}
Actually you are not swiping Activities you are just swiping a fragment and the string is your page title.
I think you should learn about fragments and how to manage then or replace them.
Adding you with the link
http://developer.android.com/guide/components/fragments.html
If you're just starting, I don't recommend going with the Swiping example first, the swipe is for "Fragment"s not "Activity" which is pretty advanced subject if you're a beginner in Android development.
I'd recommend that you go through this tutorial as it will teach you all you need to know about Activities, Fragments, Actionbars, Menus, Layout components, ... etc. Eventually you'll have a solid basis that you just need to build on top of. (Ignore the parts about command line since you're using Eclipse).
https://developer.android.com/training/basics/firstapp/creating-project.html
Hope this helps, good luck.
I want add activity for each tab. I am trying to figure it out.
I want to show activity per tab. Where should put the code for showing activity per tab, assuming that my actvity is called "activityHome"
package me.imran.app;
import java.util.Locale;
import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class HomeActivity extends FragmentActivity implements
ActionBar.TabListener {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link android.support.v4.app.FragmentPagerAdapter} derivative, which
* will keep every loaded fragment in memory. If this becomes too memory
* intensive, it may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
// Set up the action bar.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the four
// primary sections of the app.
mSectionsPagerAdapter = new SectionsPagerAdapter(
getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager
.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.home, menu);
return true;
}
#Override
public void onTabSelected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
#Override
public void onTabReselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
}
#Override
public int getCount() {
// Show 4 total pages.
return 4;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
case 3:
return getString(R.string.title_section4).toUpperCase(l);
}
return null;
}
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_home_dummy,
container, false);
TextView dummyTextView = (TextView) rootView
.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(
ARG_SECTION_NUMBER)));
return rootView;
}
}
}
RESOLVED!
I just posted the answer of how you can show activity in each tab, using the fragment(Fixed tabs template from android).
In getItem I added case for each tab.
Then I added fragment for each tab using the existing dummy code and modifying it.
Getting error in showing activity via Fragment
I created an application "fixed tabs + swipe" with Eclipse, I can not understand how I can create a Fragment for each tab. I know it's a stupid question but I just can not understand. Thanks to all who respond.
The code is as follows
package com.example.newapp;
import java.util.Locale;
import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.NavUtils;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MainActivity extends FragmentActivity implements
ActionBar.TabListener {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link android.support.v4.app.FragmentPagerAdapter} derivative, which
* will keep every loaded fragment in memory. If this becomes too memory
* intensive, it may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Set up the action bar.
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
mSectionsPagerAdapter = new SectionsPagerAdapter(
getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager
.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public void onTabSelected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
#Override
public void onTabReselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main_dummy,
container, false);
TextView dummyTextView = (TextView) rootView
.findViewById(R.id.section_label);
dummyTextView.setText(Integer.toString(getArguments().getInt(
ARG_SECTION_NUMBER)));
return rootView;
}
}
}
The Fragments have to be created in your implementation of the FragmentPagerAdapter (SectionsPagerAdapter), in the method getItem(). See example :
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new MyFragment0();
case 1:
return new MyFragment1();
case 2:
return new MyFragment2();
}
return null;
}
The getCount method should return the number of fragments you want to be available. Then, the FragmentActivity will call getItem when a fragment is needed.
I found the ViewPager in the android SDK and was messing around with it. Basically my final task is to create a youtube, facebook, and twitter feed all in one app, using the ViewPager and Fragments to scroll between the 3 categories. I'm having a bit of a hard time understanding house these work, more specifically, how to I add an element (Button) to a specific Fragment? Here's my code so far:
package com.ito.mindtrekkers;
import java.util.ArrayList;
import twitter4j.Query;
import twitter4j.QueryResult;
import twitter4j.Twitter;
import twitter4j.TwitterException;
import twitter4j.TwitterFactory;
import android.annotation.SuppressLint;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import android.widget.TextView;
import android.widget.Toast;
#SuppressLint("ShowToast")
//Brady Mahar
public class Main extends FragmentActivity {
/**
* The {#link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {#link android.support.v4.app.FragmentPagerAdapter} derivative, which
* will keep every loaded fragment in memory. If this becomes too memory
* intensive, it may be best to switch to a
* {#link android.support.v4.app.FragmentStatePagerAdapter}.
*/
SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {#link ViewPager} that will host the section contents.
*/
ViewPager mViewPager;
ArrayList<String> tweetList = new ArrayList<String>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.main);
// Create the adapter that will return a fragment for each of the three
// primary sections of the app.
mSectionsPagerAdapter = new SectionsPagerAdapter(
getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
mViewPager.setCurrentItem(1); //sets initial page to "Facebook"
new DownloadFilesTask().execute("weather" , null, null);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
/**
* A {#link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a DummySectionFragment (defined as a static inner class
// below) with the page number as its lone argument.
Fragment fragment = new DummySectionFragment();
Bundle args = new Bundle();
args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
}
#Override
public int getCount() {
// Show 3 total pages.
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return getString(R.string.title_youtube);
case 1:
return getString(R.string.title_facebook);
case 2:
return getString(R.string.title_twitter);
}
return null;
}
}
/**
* A dummy fragment representing a section of the app, but that simply
* displays dummy text.
*/
public static class DummySectionFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
public static final String ARG_SECTION_NUMBER = "section_number";
public DummySectionFragment() {
}
#SuppressLint("ShowToast")
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Create a new TextView and set its text to the fragment's section
// number argument value.
TextView textView = new TextView(getActivity());
textView.setGravity(Gravity.CENTER);
textView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER)));
return textView;
}
}
/**
* Class for handling NetworkOnMainThread
* Sends the command Asynchronously
* #author austinn
*
*/
private class DownloadFilesTask extends AsyncTask<String, Void, String> {
protected String doInBackground(String... command) {
Twitter twitter = new TwitterFactory().getInstance();
Query query = new Query("from:MindTrekkers");
query.setRpp(100);
try {
QueryResult result = twitter.search(query);
for(twitter4j.Tweet tweet : result.getTweets()) {
//Toast.makeText(getApplicationContext(), tweet.getText(), Toast.LENGTH_SHORT);
Log.v("Tweet", tweet.getText());
tweetList.add(tweet.getText());
}
} catch (TwitterException e) {
//Toast.makeText(getApplicationContext(), e + "", Toast.LENGTH_SHORT);
Log.v("Error", e+"");
}
return null;
}
protected void onProgressUpdate(Void... progress) {}
protected void onPostExecute(String result) {}
}
}
Implement your 3 Fragment categories (youtube, facebook, and twitter) in separate Fragment classes with a Singleton instance getter. Here's an Facebook Fragment example (note the onCreateView() inflates a fragment_facebook layout):
public class FaceBookFragment extends Fragment {
private static FaceBookFragment instance = null;
public static FaceBookFragment newInstance() {
if(instance == null) {
instance = new FaceBookFragment();
Bundle args = new Bundle();
instance.setArguments(args);
return instance;
}
return instance;
}
public FaceBookFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_facebook, container,
false);
...
return rootView;
}
}
Then in your FragmentPagerAdapter (located in the MainActivity of your code above), have the getItem() return the Fragment instance:
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
Fragment frag = null;
switch (position) {
case 0:
frag = FaceBookFragment.newInstance();
break;
case 1:
frag = TwitterFragment.newInstance();
break;
case 2:
frag = YouTubeFragment.newInstance();
break;
}
return frag;
}
}
BONUS: Also, I know your code was experimental, but your tweetlist won't be accessible from any of your Fragments.
A Fragment is a new class object and can't access anything in the MainActivity directly unless you pass a reference to an object (the tweetlist) during construction (limiting), or get a 'final' on an object/variable if the Fragment code is under MainActivity (the list will never change from the Fragment's perspective). Maybe I didn't articulate this statement as well as other might, but tweetlist will not be accessible from your Fragment as it is.
There's a couple of solutions:
Move tweetlist to the Twitter Fragment and have it call the downloader. Then your TwitterFragment can construct and hold the list and update the UI as necessary. HOWEVER, consider the Fragment lifecycle (http://developer.android.com/guide/components/fragments.html), see the lifecycle section and diagram) The onDestroyView() method will be called when you swipe/flip over a couple of Fragments and back again. e.g. Android will not keep an indefinite number of Fragment alive and will destroy/re-create the view as needed. Don't try to update the Fragment's UI/layout objects from an AsyncTask. It's possible the Fragment might call onDestoryView() before your task completes. (you'll probably get NullPointerExceptions then) Instead have your AsyncTask only update Fragment scope variables (tweetlist) and have your onCreateView() use that same variable. (maybe synchronize the variable too)
Keep your major variable/objects/AsyncTask invoking code, all in the MainActivity, and add methods to access them from a Fragment, and have the Fragment getActivity() and cast it to MainActivity and call the method when needed:
public class MainActivity extends ActionBarActivity implements ActionBar.TabListener {
ArrayList<String> tweetList = new ArrayList<String>();
...
public ArrayList<String> getTweetlist() {
return tweetlist;
}
...
}
public class TwitterFragment extends Fragment {
...
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_twitter, container, false);
...
ArrayList<String> tweetList = ((MainActivity)getActivity()).getTweetlist();
...
return rootView;
}
...
}
Let me try to explain, first use this FragmentPagerAdapter:
public class TestFragmentAdapter extends FragmentPagerAdapter implements IconPagerAdapter {
protected static final String[] CONTENT = new String[] { "CATEGORIAS", "PRINCIPAL", "AS MELHORES", };
protected static final int[] ICONS = new int[] {
R.drawable.perm_group_calendar,
R.drawable.perm_group_camera,
R.drawable.perm_group_device_alarms,
};
private int mCount = CONTENT.length;
public TestFragmentAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {Fragment f = null;
switch(position){
case 0:
{
f = new ArrayListFragment();//YourFragment
// set arguments here, if required
Bundle args = new Bundle();
f.setArguments(args);
break;
}
case 1:
{
f = new HomeFragment();//YourFragment
// set arguments here, if required
Bundle args = new Bundle();
f.setArguments(args);
break;
}
case 2:
{
f = new EndlessCustomView();//YourFragment
// set arguments here, if required
Bundle args = new Bundle();
f.setArguments(args);
break;
}
default:
throw new IllegalArgumentException("not this many fragments: " + position);
}
return f;
}
#Override
public int getCount() {
return mCount;
}
#Override
public CharSequence getPageTitle(int position) {
return TestFragmentAdapter.CONTENT[position % CONTENT.length];
}
#Override
public int getIconResId(int index) {
return ICONS[index % ICONS.length];
}
public void setCount(int count) {
if (count > 0 && count <= 10) {
mCount = count;
notifyDataSetChanged();
}
}
}
As you can see, ArrayListFragment, HomeFragment and EndlessCustomView is a class that extends Fragment, so for each of these classes inside onCreate() , You can setContentView(R.layout.your_layout);
Then you can add a button or whatever you want in this layout.