Develop Reference

PreferenceScreen change colors

I have an issue styling the (PreferenceScreen) in my project.
How can I change the colors of of (Title) & (Summary) texts.
No luck after trying for hours with different methods, I must be doing something wrong
SettingsFragment.Java
public class SettingsFragment extends Fragment {
public SettingsFragment() {
// Required empty public constructor
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
getActivity().getFragmentManager().beginTransaction()
.replace(R.id.flContent, new SettingsPreference())
.commit();
}
public static class SettingsPreference extends PreferenceFragment {
public SettingsPreference() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Load the preferences from an XML resource
addPreferencesFromResource(R.xml.settings);
}
}
}
fragment_setings.xml
<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"
android:background="?attr/app_background"
android:clickable="true"
android:focusable="true"
tools:context="com.companyv.app.fragments.SettingsFragment">
</FrameLayout>
settings.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory
android:key="pref_key_storage_settings"
android:title="First">
<CheckBoxPreference
android:defaultValue="false"
android:key="pref_key_auto_delete"
android:summary="Sub 1 summary"
android:title="Sub 1" />
<Preference
android:dependency="pref_key_auto_delete"
android:key="pref_key_sms_delete_limit"
android:summary="Sub 2 summary"
android:title="Sub 2" />
<Preference
android:dependency="pref_key_auto_delete"
android:key="pref_key_mms_delete_limit"
android:summary="Sub 3 summary"
android:title="Sub 3" />
</PreferenceCategory>
</PreferenceScreen>

I have done this before by using a custom preference theme and setting the
android:textColor(title color) and android:textColorSecondary(summary color) in the custom theme. For example, black title and white summary:
<style name="AppTheme" parent="Theme.AppCompat.NoActionBar">
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
<item name="preferenceTheme">#style/AppPreferenceTheme</item>
</style>
<!-- Custom Preference Theme -->
<style name="AppPreferenceTheme"
parent="#style/PreferenceThemeOverlay.v14.Material">
<item name="android:textColor">#android:color/black</item>
<item name="android:textColorSecondary">#android:color/white</item>
</style>
You can rename "AppPreferenceTheme" to whatever name you like.

Cannot get anything to change color from spinner menu

I am trying to get my spinner menu to respond by changing the color of anything. Can not change color of anything. See picture before selecting green and after. I am learning how to program for android.
Here is my MainActivity.java
package com.romanescotech.mydropdownnavigation;
import android.graphics.Color;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.SpinnerAdapter;
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
Spinner spinner;
ArrayAdapter adapter;
Toolbar toolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
spinner = (Spinner) findViewById(R.id.spinnerMy);
adapter = ArrayAdapter.createFromResource(this, R.array.colors, R.layout.support_simple_spinner_dropdown_item);
adapter.setDropDownViewResource(R.layout.support_simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
}
#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_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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onItemSelected(AdapterView<?> parent , View view, int pos, long id) {
parent.getItemAtPosition(pos);
String[] colors = getResources().getStringArray(R.array.colors);
String selectedColor = colors[pos];
getWindow().getDecorView().setBackgroundColor(Color.parseColor(selectedColor));
spinner.setBackgroundColor(Color.parseColor(selectedColor));
view.setBackgroundColor(Color.parseColor(selectedColor));
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
// do nothing
}
}
Here is my activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="?attr/colorPrimary"
app:popupTheme="#style/AppTheme.PopupOverlay" />
<Spinner
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/spinnerMy"
android:alpha=".8" />
</android.support.design.widget.AppBarLayout>
<include layout="#layout/content_main" />
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin"
app:srcCompat="#android:drawable/ic_dialog_email" />
Here is my string.xml
<resources>
<string name="app_name">MyDropDownNavigation</string>
<string-array name="colors">
<item>White</item>
<item>Red</item>
<item>Green</item>
<item>Blue</item>
<item>Yellow</item>
</string-array>
<string name="action_settings">Settings</string>
Here is my Manifest file
<?xml version="1.0" encoding="utf-8"?>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".MainActivity"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
Here is my styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />
Here is my other v21/styles xml
<resources>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
<item name="android:windowDrawsSystemBarBackgrounds">true</item>
<item name="android:statusBarColor">#android:color/transparent</item>
</style>
And here is a picture of it running before making selecting
before making selection
Here is after making selection, manues, background everything is the same color.
after making selection
I am guessing my problem lies in this method.
public void onItemSelected(AdapterView<?> parent , View view, int pos, long id) {
parent.getItemAtPosition(pos);
String[] colors = getResources().getStringArray(R.array.colors);
String selectedColor = colors[pos];
getWindow().getDecorView().setBackgroundColor(Color.parseColor(selectedColor));
spinner.setBackgroundColor(Color.parseColor(selectedColor));
view.setBackgroundColor(Color.parseColor(selectedColor));
in the java code

Your program looks correct except for one change. After the View changes, you need to notify so that view gets to know a change has occured and reflects it in the UI. Try calling adapter.notifydatasetchanged at the end of method onItemSelected().
Hope it helps you.

Action Bar not showing because of Intent?

Update:
I fix it by changing MainActivityFragment extends FragmentActivity to MainActivityFragment extends AppCompatActivity.
Thanks Guys.
The Action Bar will show if i don't comment the Intent. If I run the Intent in onCreate MainActivity, the Action Bar doesn't show. How do I show the Action Bar with the Intent. I provide the Intent (Main Activity) and Android Manifest code below.
Link to screenshot:
Non-Intent
Intent
MainActivity.java :
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_main); // this is the start layout
Intent intent = new Intent(this, MainActivityFragment.class);
startActivity(intent);
}
AndroidManifest.xml :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.romi1.popularmoviesapp">
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<dependency>
<groupId>
info.movito
</groupId>
<artifactId>
themoviedbapi
</artifactId>
<version>
1.3
</version>
</dependency>
<activity android:name=".MainActivityFragment"></activity>
<activity android:name=".MoviesDetailAdapter"></activity>
</application>
</manifest>
Style.xml:
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
<!--Theme.AppCompat.Light.DarkActionBar-->
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
</style>
</resources>
MainActivityFragment :
public class MainActivityFragment extends FragmentActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_main);
movies = new Movies[1000];
jsonParser(json);
moviesAdapter = new MoviesAdapter(this, movies);
setContentView(R.layout.fragment_main);
GridView gridView = (GridView) findViewById(R.id.listView);
gridView.setAdapter(moviesAdapter);
// This for setting what happen when one of the movie is selected
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
// Make another fragment class for this Adapter
// And figure out away to send the clicked parcelable variable
Movies topRatedMovieJson = moviesAdapter.getItem(i);
Log.v(LOG_TAG, "topRatedMovieJson : " + i);
Log.v(LOG_TAG, "topRatedMovieJson : " + topRatedMovieJson.title.toString());
Intent intent = new Intent(getBaseContext(), MoviesDetailAdapter.class);
intent.putExtra("parcelable", topRatedMovieJson);
startActivity(intent);
}
});
}
}
Update:
I fix it by changing MainActivityFragment extends FragmentActivity to MainActivityFragment extends AppCompatActivity.
Thanks Guys.

There are 2 ways to do that
1. Change that activity to fragment
2. Add Actionbar to second activity's layout and in your activity.

You can set two style and apply it to your activities.
describe style like this :
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
</style>
<style name="SecondTheme" parent="Theme.AppCompat.Light.NoActionBar">
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
</style>
and apply it to activities :
<activity android:name=".MainActivityFragment" android:theme="#style/SecondTheme"/>
<activity android:name=".MoviesDetailAdapter" android:theme="#style/SecondTheme"/>

This Activity already has an action bar supplied by the window decor?

I am making an Android app using Toolbar with Custom style but when i'm running the app, i'm getting the following error:
Caused by: java.lang.IllegalStateException: This Activity already has
an action bar supplied by the window decor. Do not request
Window.FEATURE_SUPPORT_ACTION_BAR and set windowActionBar to false in
your theme to use a Toolbar instead.
Styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorPrimary</item>
<item name="android:textColor">#color/textColorPrimary</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="android:textColorSecondary">#color/textColorPrimary</item>
</style>
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar"/>
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light"/>
<style name="MyMaterialTheme" parent="Theme.AppCompat.Light.NoActionBar">
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorPrimary</item>
</style>
<style name="MyEditTextTheme" parent="Theme.AppCompat.Light.NoActionBar">
<!-- Used for the bottom line when not selected / focused -->
<item name="colorAccent">#color/colorPrimary</item>
<item name="android:textColor">#color/colorPrimary</item>
<item name="android:colorBackground">#color/colorBackground</item>
<item name="android:textStyle">bold</item>
<item name="android:endColor">#color/colorPrimary</item>
<!-- colorControlActivated & colorControlHighlight use the colorAccent color by default -->
</style>
<style name="TabTextAppearance" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorPrimary</item>
<item name="android:colorBackground">#color/colorBackground</item>
<item name="android:textAllCaps">false</item>
<item name="android:textStyle">bold</item>
</style>
MainActivity:
public class MainActivity extends AppCompatActivity {
private TabLayout tabLayout;
private ViewPager viewPager;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.content_information_category1);
Toolbar toolbar=(Toolbar)findViewById(R.id.toolbar_information);
setSupportActionBar(toolbar);
viewPager = (ViewPager) findViewById(R.id.viewpager);
setupViewPager(viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(new TodayInformationFragment(), "Today");
adapter.addFragment(new ThisWeekInformationFragment(), "This Week");
adapter.addFragment(new ThisMonthInformationFragment(), "This Month");
adapter.addFragment(new AllyearInformationFragment(), "All");
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
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();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
}

Clearly error says:
This Activity already has an action bar supplied by the window decor.
Do not request Window.FEATURE_SUPPORT_ACTION_BAR and set
windowActionBar to false in your theme to use a Toolbar instead
Use this in your Styles:
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
Updated:
Android studio's default example is like this, take a look at the AppTheme.NoActionBar:
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.NoActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#color/colorPrimary</item>
<item name="colorPrimaryDark">#color/colorPrimaryDark</item>
<item name="colorAccent">#color/colorAccent</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />
</resources>
And in your Manifest:
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".MainActivity"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
And make sure your Toolbar implemented correctly.
For example, with AppbarLayout:
<android.support.design.widget.AppBarLayout
android:id="#+id/app_bar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/transparent"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbarmain"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#color/ColorPrimary"
app:layout_collapseMode="pin"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar" />

Just go to your Manifest file and in the specific activity add
android:theme="#style/AppTheme.NoActionBar"/>

in my case that happened because the phone was in dark mode and I didn't provide a dark mode for my app maybe. it works fine after disabling the dark mode.

in my case i was testing on mobile which was in dark theme i got this and the following code done work for me
<style name="Theme.QrCodeScanner"
parent="Theme.MaterialComponents.DayNight.NoActionBar">
set this in both themes.xm and themes.xml(night)
or if you want it for a specific activty then do the following in your manifest in specific activity
android:theme="#style/AppTheme.NoActionBar"/>

java.lang.NullPointerException: Attempt to invoke virtual method 'ActionBar.setNavigationMode(int)' on a null object reference

I am getting this error at runtime.
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.app.ActionBar.setNavigationMode(int)' on a null object reference
Main Activity.java
public class MainActivity <T extends Fragment> extends ActionBarActivity implements ListView.OnItemClickListener
{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
actionBar.setDisplayShowTitleEnabled(false);
ActionBar.Tab tab;
tab = actionBar.newTab()
.setText("Categories")
.setTabListener(new TabListener<CategoriesFragment>(
this, "Categories", CategoriesFragment.class));
actionBar.addTab(tab);
tab = actionBar.newTab()
.setText("Acceuil")
.setTabListener(new TabListener<AcceuilFragment>(
this, "Acceuil", AcceuilFragment.class));
actionBar.addTab(tab);
tab = actionBar.newTab()
.setText("Topics")
.setTabListener(new TabListener<TopicsFragment>(
this, "Topics", TopicsFragment.class));
actionBar.addTab(tab);
tab = actionBar.newTab()
.setText("Tendances")
.setTabListener(new TabListener<TendancesFragment>(
this, "Tendances", TendancesFragment.class));
actionBar.addTab(tab);
setRef();
//Set the custom toolbar
if (toolbar != null)
{
toolbar.setTitle(R.string.app_name);
setSupportActionBar(toolbar);
}
drawerToggle = new ActionBarDrawerToggle(
this,
drawerLayout,
toolbar,
R.string.open,
R.string.close
)
{
public void onDrawerClosed(View view)
{
Log.d("MainActivity", "OnDrawerClosed");
super.onDrawerClosed(view);
invalidateOptionsMenu();
}
public void onDrawerOpened(View drawerView)
{
Log.d("MainActivity", "OnDrawerOpened");
super.onDrawerOpened(drawerView);
invalidateOptionsMenu();
}
};
drawerLayout.setDrawerListener(drawerToggle);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
// use this setting to improve performance if you know that changes
// in content do not change the layout size of the RecyclerView
mRecyclerView.setHasFixedSize(true);
// use a linear layout manager
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
// specify an adapter (see also next example)
mAdapter = new MyAdapter(myDataset);
mRecyclerView.setAdapter(mAdapter);
}
#Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
drawerToggle.syncState();
}
private void setRef()
{
// create reference to the xml views
mRecyclerView = (android.support.v7.widget.RecyclerView) findViewById(R.id.my_recycler_view);
fab = (Button) findViewById(R.id.addButton);
drawerLayout = (android.support.v4.widget.DrawerLayout) findViewById(R.id.drawer_layout);
drawerLayout.setStatusBarBackground(R.color.primarydark);
toolbar = (android.support.v7.widget.Toolbar) findViewById(R.id.toolbar);
leftDrawerList = (ListView) findViewById(R.id.list_drawer);
View list_header = getLayoutInflater().inflate(R.layout.drawerlist_header, null);
leftDrawerList.addHeaderView(list_header);
navigationDrawerAdapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_expandable_list_item_1, leftSliderData);
leftDrawerList.setAdapter(navigationDrawerAdapter);
leftDrawerList.setOnItemClickListener(this);
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
Toast.makeText(getApplicationContext(), "Clicked on " + leftSliderData[position - 1], Toast.LENGTH_LONG).show();
}
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
// Check if the fragment is already initialized
if (mFragment == null) {
// If not, instantiate and add it to the activity
mFragment = Fragment.instantiate(mActivity, mClass.getName());
ft.add(android.R.id.content, mFragment, mTag);
} else {
// If it exists, simply attach it in order to show it
ft.attach(mFragment);
}
}
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {
if (mFragment != null) {
// Detach the fragment, because another one is being attached
ft.detach(mFragment);
}
}
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {
// User selected the already selected tab. Usually do nothing.
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".MainActivity">
<!-- Setting this one to true makes the status bar
to have a non-transparent shitty background -->
<!--
As the main content view, the view below consumes the entire
space available using match_parent in both dimensions.
-->
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="false">
<include layout="#layout/actionbarlayout"></include>
<include layout="#layout/content_view"></include>
<Button
android:id="#+id/addButton"
android:text="+"
android:textSize="25sp"
android:textColor="#android:color/white"
android:textAlignment="center"
android:layout_marginRight="15dp"
android:layout_marginBottom="15dp"
android:background="#drawable/circlebtn"
android:layout_width="56dp"
android:layout_height="56dp"
android:stateListAnimator="#animator/anim"
android:elevation="4dp"
style="?android:buttonStyleSmall"
android:layout_gravity="right|bottom" >
</Button>
</FrameLayout>
<com.androprogrammer.test.materialapp1.ScrimInsetsFrameLayout
android:id="#+id/container"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
android:elevation="8dp"
android:layout_gravity="start"
app:insetForeground="#4000">
<ListView
android:id="#+id/list_drawer"
android:layout_width="#dimen/drawer_width"
android:layout_height="match_parent"
android:choiceMode="singleChoice"
android:background="#android:color/white"
android:fitsSystemWindows="true">
</ListView>
</com.androprogrammer.test.materialapp1.ScrimInsetsFrameLayout>
</android.support.v4.widget.DrawerLayout>
values/styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="AppTheme.Base"/>
<style name="AppTheme.Base" parent="Theme.AppCompat.Light">
<item name="colorPrimary">#color/primary</item>
<item name="colorPrimaryDark">#color/primarydark</item>
<item name="colorAccent">#color/primary</item>
<item name="colorControlHighlight">#color/primary</item>
<item name="android:windowNoTitle">true</item>
<item name="windowActionBar">false</item>
<item name="drawerArrowStyle">#style/DrawerArrowStyle</item>
<item name="windowActionModeOverlay">true</item>
</style>
<style name="DrawerArrowStyle" parent="Widget.AppCompat.DrawerArrowToggle">
<item name="spinBars">true</item>
<item name="color">#android:color/white</item>
</style>
</resources>
v21/styles.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="AppTheme" parent="AppTheme.Base">
<item name="android:windowDrawsSystemBarBackgrounds">true</item>
<item name="android:statusBarColor">#android:color/transparent</item>
<item name="android:windowContentTransitions">true</item>
<item name="android:windowAllowEnterTransitionOverlap">true</item>
<item name="android:windowAllowReturnTransitionOverlap">true</item>
<item name="android:windowSharedElementEnterTransition">#android:transition/move</item>
<item name="android:windowSharedElementExitTransition">#android:transition/move</item>
</style>
</resources>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.androprogrammer.test.materialapp1" >
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Help Please :)

Try to change the parent style
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
and ActionBarActivity is deprecated, you should use AppCompatActivity

In your style.xml you have to have the actionbar enabled. If the actionbar is disabled (set to false) then it will not be added in to the activity at runtime (ie getActionBar() returns null).