Develop Reference

How to launch activity based on tab bar item?

I want to start different activities depending on the click of the tab bar item but I get a blank page as started activity in the "windows class". What I intended to do is start different activities on click of tab bar item.
Tab Bar Activity Class
import android.app.ActionBar;
import android.app.Activity;
import android.app.FragmentTransaction;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TabHost;
public class TabBar extends FragmentActivity {
ViewPager Tab;
TabPagerAdapter TabAdapter;
ActionBar actionBar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.tabbardefault);
try {
TabAdapter = new TabPagerAdapter(getSupportFragmentManager());
Tab = (ViewPager) findViewById(R.id.pager);
Tab.setOnPageChangeListener(
new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar = getActionBar();
actionBar.setSelectedNavigationItem(position);
}
});
Tab.setAdapter(TabAdapter);
actionBar = getActionBar();
//Enable Tabs on Action Bar
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
}
catch (Exception e)
{
}
ActionBar.TabListener tabListener = new ActionBar.TabListener(){
#Override
public void onTabReselected(android.app.ActionBar.Tab tab,
FragmentTransaction ft) {
// TODO Auto-generated method stub
}
#Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
Tab.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(android.app.ActionBar.Tab tab,
FragmentTransaction ft) {
// TODO Auto-generated method stub
}};
//Add New Tab
actionBar.addTab(actionBar.newTab().setText("Home").setTabListener(tabListener));
actionBar.addTab(actionBar.newTab().setText("Celeb").setTabListener(tabListener));
actionBar.addTab(actionBar.newTab().setText("Videos").setTabListener(tabListener));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_tab_bar, 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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
TabPagerAdapter
import android.content.Intent;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
public class TabPagerAdapter extends FragmentStatePagerAdapter {
public TabPagerAdapter(FragmentManager fm) {
super(fm);
// TODO Auto-generated constructor stub
}
#Override
public Fragment getItem(int i) {
switch (i) {
case 0:
//Fragement for Android Tab
return new Android();
case 1:
//Fragment for Ios Tab
return new Ios();
case 2:
//Fragment for Windows Tab
return new Windows();
}
return null;
}
#Override
public int getCount() {
// TODO Auto-generated method stub
return 3; //No of Tabs
}
}
Windows
public class Windows extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View windows = inflater.inflate(R.layout.feed_main, container, false);
//((TextView)windows.findViewById(R.id.textView)).setText("Windows");
return windows;
}}

To answer you, you are not actually starting an Activity you a switching through Fragments, Fragment is just a Custom View, and you inflate an xml to represent the Custom View which is the Fragment, if you want to start an Activity after your Tab is selected then you call startActivity(Intent); startActivity(new Intent(classname.this,the_class_i_want_to_start.class));
and your Windows class extends Fragment it should be Activity if what you want is the functionality of Fragment then you aint got a problem
hope its lucid

How to access controls(views)in tabs from another one in android?

i'm working on application in eclipse that have 5 tab and i have spent much time for that but now i have a big problem :
when one of tabs is activated the next tab and prev tab is loading too
and onCreated() method is called but i don't need that i need just
calling onCreated() method when switching to tabs
This is my project files
mainActivity.java
package info.androidhive.tabsswipe;
import info.androidhive.tabsswipe.adapter.TabsPagerAdapter;
import ir.zinoo.mankan.R;
import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.FragmentTransaction;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.content.SharedPreferences;
public class MainActivity extends FragmentActivity implements ActionBar.TabListener {
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Initilization
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getActionBar();
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
//Adding Tabs
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setTabListener(this));
}
actionBar.setStackedBackgroundDrawable(new ColorDrawable(Color.parseColor("#333333")));
actionBar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#333333")));
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// on tab selected
// show respected fragment view
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
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 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);
}
}
tabPagerAdapter.java class
package info.androidhive.tabsswipe.adapter;
import info.androidhive.tabsswipe.BmiFragment;
import info.androidhive.tabsswipe.CaloriFragment;
import info.androidhive.tabsswipe.FatFragment;
import info.androidhive.tabsswipe.KamarFragment;
import info.androidhive.tabsswipe.OstokhanFragment;
import info.androidhive.tabsswipe.OtherFragment;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class TabsPagerAdapter extends FragmentPagerAdapter {
public TabsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int index) {
switch (index) {
case 0:
// Top Rated fragment activity
return new BmiFragment();
case 1:
// Games fragment activity
return new CaloriFragment();
case 2:
// Movies fragment activity
return new KamarFragment();
case 3:
// Movies fragment activity
return new OstokhanFragment();
case 4:
// Movies fragment activity
return new FatFragment();
case 5:
// Movies fragment activity
return new OtherFragment();
}
return null;
}
#Override
public int getCount() {
//get item count - equal to number of tabs
return 6;
}
}
Now My question is How to avoid calling on created method of other tabs when in switch to special tab?

From Android Documentation about FragmentPagerAdapter :
This version of the pager is best for use when there are a handful of typically more static fragments to be paged through, such as a set of tabs. The fragment of each page the user visits will be kept in memory, though its view hierarchy may be destroyed when not visible. This can result in using a significant amount of memory since fragment instances can hold on to an arbitrary amount of state. For larger sets of pages, consider FragmentStatePagerAdapter
FragmentStatePagerAdapter :
This version of the pager is more useful when there are a large number
of pages, working more like a list view. When pages are not visible to
the user, their entire fragment may be destroyed, only keeping the
saved state of that fragment. This allows the pager to hold on to much
less memory associated with each visited page as compared to
FragmentPagerAdapter at the cost of potentially more overhead when
switching between pages.
So, as you are using FragmentPagerAdapter, FrgmentManager will add all your fragment in memory while user is using app. Furthermore, when user switches to any page, FragmentManager loads previous and next page and it will call onCreate() of your tabs.
As you have now 6 tabs, may be you want to add more tabs, FragmentStatePagerAdapter is more suitable.
For checking exactly which fragment is visible to user, you can do something like this :
public class TabsPagerAdapter extends FragmentPagerAdapter {
/* declare fragment objects here globally */
BmiFragment mBmi = new BmiFragment();
CaloriFragment mCalori = new CaloriFragment();
KamarFragment mKamar = new KamarFragment();
public TabsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int index) {
switch (index) {
case 0:
// Top Rated fragment activity
mBmi.setUserVisibleHint(false);
return mBmi;
case 1:
// Games fragment activity
mCalori.setUserVisibleHint(false);
return mCalori;
case 2:
// Movies fragment activity
mKamar.setUserVisibleHint(false);
return mKamar;
/* like this for all case*/
}
return null;
}
}
Set onPageChangeListener to ViewPager from your Activity :
mPager.setOnPageChangeListener(new OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// position tab is visible to user
switch(position) {
case 0 :
mBmi.setUserVisibleHint(true);
break;
/* like this for all case */
}
}
});
Override setUserVisibleHint() method in all fragments :
public class <Your_Fragment> extends Fragment {
#Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser) {
// do something, your fragment is visible
} else {
// your fragment is loaded, but not visible to user currently
}
}
}

PagerSlidingTabStrip cannot help me change tab Indicator color [Android]

I have followed the example
https://github.com/astuetz/PagerSlidingTabStrip
by extracting the resources xml attributes and Pager class to implement into my class such that the tab indicator color is not pale blue but other colors by setting SetIndicator
When it comes tto the implementation, it seems that I cannot change the color as wished. Would you please tell me how to import the library project or other ways such that I can change the tab indicator color?
The below is my code:
import android.os.Bundle;
import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.ActionBar.TabListener;
import android.app.FragmentTransaction;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
public class MainActivity extends FragmentActivity implements TabListener {
private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
// Tab titles
private String[] tabs ;
private PagerSlidingTabStrip strip;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Initilization
strip = (PagerSlidingTabStrip) findViewById(R.id.tabs);
viewPager = (ViewPager) findViewById(R.id.pager);
actionBar = getActionBar();
actionBar.setBackgroundDrawable(new ColorDrawable(Color.BLACK));
mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(mAdapter);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
strip.setIndicatorColor(Color.parseColor("#00ffbf"));
// strip.setShouldExpand(true);
//strip.setIndicatorColor(Color.parseColor("#00ffbf"));
// strip.setViewPager(viewPager);
// Adding Tabs
tabs = this.getResources().getStringArray(R.array.options);
for (String tab_name : tabs) {
actionBar.addTab(actionBar.newTab().setText(tab_name)
.setTabListener(this));
}
/**
* on swiping the viewpager make respective tab selected
* */
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageSelected(int position) {
// on changing the page
// make respected tab selected
actionBar.setSelectedNavigationItem(position);
//actionBar.getTabAt(position).getCustomView().setBackgroundColor(Color.parseColor("#00ffbf"));
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
}
#Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}
#Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
// on tab selected
// show respected fragment view
viewPager.setCurrentItem(tab.getPosition());
// tab.set
//
}
#Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}
#Override
protected void onResume() {
super.onResume();
// mSensorManager.registerListener(mSensorListener, mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL);
}
#Override
protected void onPause() {
super.onPause();
// mSensorManager.unregisterListener(mSensorListener);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// The action bar home/up action should open or close the drawer.
// ActionBarDrawerToggle will take care of this.
/* if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}*/
// Handle action buttons
switch(item.getItemId()) {
/* case R.id.action_profile:
startActivity(new Intent(MainActivity.this, Profile.class));
return true;*/
default:
return super.onOptionsItemSelected(item);
}
}
}

parseColor() supports two formats: #RRGGBB and #AARRGGBB, Have you tried with the alpha format?:
strip.setIndicatorColor(Color.parseColor("#ff00ffbf"));
If that doesn't work, you can try changing the default color directly from the PagerSlidingTabStrip class:
private int indicatorColor = 0xFF00FFBF;

Try this,in easy way
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabIndicatorColor="#android:color/white" />

"Unfortunately, appname has stopped running" after attempting to use ActionBar.addTab

I've been trying to add tabs to the action bar while going through a few Android tutorials, but every time I use addTab, something breaks. My code currently looks like this:
package com.example.myfirstapp;
import android.app.ActionBar;
import android.app.ActionBar.TabListener;
import android.app.ActionBar.Tab;
import android.app.FragmentTransaction;
import android.app.FragmentManager;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends FragmentActivity {
public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final ActionBar actionBar = getActionBar();
// actionBar.setSubtitle("mytest");
actionBar.setTitle("Title Goes Here");
// Set up the action bar to show tabs.
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Here are a couple tabs
ActionBar.Tab PlayerTab = actionBar.newTab().setText("Fragment A");
ActionBar.Tab StationsTab = actionBar.newTab().setText("Fragment B");
// for each of the sections in the app, add a tab to the action bar.
actionBar.addTab(PlayerTab);
actionBar.addTab(StationsTab);
// Create a tab listener that is called when the user changes tabs.
// ActionBar.TabListener tabListener = new ActionBar.TabListener() {
// public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
// // show the given tab
// }
//
// public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {
// // hide the given tab
// }
//
// public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {
// // probably ignore this event
// }
// };
//
// // Add 3 tabs, specifying the tab's text and TabListener
// for (int i = 0; i < 3; i++) {
// actionBar.addTab(
// actionBar.newTab()
// .setText("Tab " + (i + 1))
// .setTabListener(tabListener));
// }
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// First run
// getMenuInflater().inflate(R.menu.main, menu);
// return true;
// Inflate the menu items for use in the action bar
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return super.onCreateOptionsMenu(menu);
}
public void openSearch() {
Toast.makeText(this, "Search button pressed", Toast.LENGTH_SHORT).show();
}
public void openSettings() {
Toast.makeText(this, "Settings pressed", Toast.LENGTH_SHORT).show();
}
// Finding selected option item
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle presses on the action bar items
switch (item.getItemId()) {
case R.id.action_search:
openSearch();
// menuItem = item;
// menuItem.setActionView(R.layout.progressbar);
// menuItem.expandActionView();
// TestTask task = new TestTask();
// task.execute("test");
// break;
return true;
case R.id.action_settings:
openSettings();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
// Do something in response to button
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
}
If I comment out the lines with
actionBar.addTab(PlayerTab);
actionBar.addTab(StationsTab);
the code works okay (shows a blank tabs bar), but once I add them in, my app crashes.

As per the docs for FragmentActivty:
If you want to implement an activity that includes an action bar, you
should instead use the ActionBarActivity class, which is a subclass of
this one, so allows you to use Fragment APIs on API level 7 and
higher.
FragmentActivity's getActionBar() is for API 11+. If your minSDKVersion is 11+ you should use the android.app.Activity version of Activity and get a reference of the ActionBar like you are doing now. If you want to be able to use Fragments and the ActionBar use ActionBarActivity which is part of the v7 support library

Android Tab navigation in different activities

I tried to implement 3 tabs in android using the google tutorial.....but i am unable to create different activities for each one and navigate through them....
package com.example.tab;
import android.app.ActionBar;
import android.app.Activity;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Important-the following code in onCreate class adds tabs to action
// bar
final ActionBar actionBar = getActionBar();
// Specify that tabs should be displayed in the action bar.
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create a tab listener that is called when the user changes tabs.
ActionBar.TabListener tabListener = new ActionBar.TabListener() {
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
// show the given tab
}
public void onTabUnselected(ActionBar.Tab tab,
FragmentTransaction ft) {
// hide the given tab
}
public void onTabReselected(ActionBar.Tab tab,
FragmentTransaction ft) {
// probably ignore this event
}
};
// Now we add 3 Tabs specifying tab names and Tablistener
for (int i = 0; i < 3; i++) {
if (i == 0) {
actionBar.addTab(actionBar.newTab().setText("Tech")
.setTabListener(tabListener));
}
if (i == 1) {
actionBar.addTab(actionBar.newTab().setText("Politics")
.setTabListener(tabListener));
}
if (i == 2) {
actionBar.addTab(actionBar.newTab().setText("Sports")
.setTabListener(tabListener));
}
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) { // Method to add action bar
// Inflate the menu; this adds items to the action bar if it is present.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.action_bar, menu);
return super.onCreateOptionsMenu(menu);
}
}
What should I try after this and creating 3 activities for each tab??

You should create just one Activity with a ViewPager and multiple Fragments (one for each tab). This tutorial describes how to do this.
Next you can listen for the selection of an action bar tab to change the viewpager and vice versa.

You should use FragmentActivity and Fragment for Tab and its different view in Activity.
see here for ActionBar Tab and for Fragment