Solution: I tried everything available on internet and nothing really worked for me. Then I found a solution. I didnt have the values-v23 folder in my project. If you don't have that, DO IT! and add this in style.xml of the Values- v23 folder
<resources>
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="windowActionBar">true</item>
<item name="windowNoTitle">false</item>
</style>
</resources>
I had splash screen and slider which was overlaying the action bar and android studi somehow got confused and my actionbar was returning null. After 2 weeks of research I found a tiny issue which no one seem to point out. I edited the line
android:theme="@style/AppTheme">
with the actual theme i was using i.e
<android:theme="@style/Theme.AppCompat.Light.DarkActionBar">
It worked for me..
Question
I had this app working totally fine until I made some changes.
I reverted back all of the changes but now I am getting NUllPointerException on ActionBar
ActionBar ab = getSupportActionBar();
if (ab != null) {
ab.setLogo(R.mipmap.icon);
ab.setDisplayUseLogoEnabled(true); //shows logo
ab.setDisplayShowHomeEnabled(true); //shows home page
}
else {
Toast.makeText(HomeScreen.this, "Feature not supported!", Toast.LENGTH_SHORT).show();
}
I put the if else statements to check where the problem was. It runs the else part only. The piece of Home Screen code is this
package com.example.dell.optasia;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.media.MediaPlayer;
import android.speech.RecognizerIntent;
import android.speech.tts.TextToSpeech;
import android.support.v4.view.GestureDetectorCompat;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Locale;
import static android.view.GestureDetector.OnDoubleTapListener;
import static android.view.GestureDetector.OnGestureListener;
import static com.example.dell.optasia.R.id.editText;
public class HomeScreen extends AppCompatActivity implements
OnGestureListener, OnDoubleTapListener {
//used for text to speech
TextToSpeech ttsobject;
int result;
TextView et;
String text;
String texttoplay;
//uptil here
private GestureDetectorCompat GestureDetect;
private static TextView Viewtext;
//used for speech to text
public static final int REQUEST_OK = 1;
public static TextView finalRes;
public static ImageView imgBtn;
//uptill here
public MediaPlayer mp1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home_screen);
mp1 = MediaPlayer.create(HomeScreen.this, R.raw.startup);
mp1.start();
ActionBar ab = getSupportActionBar();
if (ab != null) {
ab.setLogo(R.mipmap.icon);
ab.setDisplayUseLogoEnabled(true); //shows logo
ab.setDisplayShowHomeEnabled(true); //shows home page
}
else {
Toast.makeText(HomeScreen.this, "Feature not supported!", Toast.LENGTH_SHORT).show();
}
//for tap and hold and all other gestures
Viewtext = (TextView) findViewById(R.id.textView);
//onlongpress code needs this
GestureDetect = new GestureDetectorCompat(this, this);
GestureDetect.setOnDoubleTapListener(this);
//text to speech code here
et = (TextView) findViewById(editText);
ttsobject = new TextToSpeech(HomeScreen.this, new TextToSpeech.OnInitListener() {
@Override
public void onInit(int status) {
if (status == TextToSpeech.SUCCESS) {
result = ttsobject.setLanguage(Locale.UK);
} else {
Toast.makeText(HomeScreen.this, "Feature not supported!", Toast.LENGTH_SHORT).show();
}
}
});
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
package="com.example.dell.optasia">
<uses-sdk android:minSdkVersion="11" />
<application
android:allowBackup="true"
android:icon="@mipmap/icon"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".Splashscreen">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".HomeScreen">
<intent-filter>
<action android:name="com.example.dell.optasia.HomeScreen" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
<activity android:name=".AboutUs">
<intent-filter>
<action android:name="com.example.dell.optasia.AboutUs" />
<category android:name="android.intent.category.About" />
</intent-filter>
</activity>
<activity android:name=".Help"></activity>
</application>
Style.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>
<item name="windowActionBar">true</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>
