Save-Bundle with Fragments Not Saving State on Android

Save-Bundle with Fragments Not Saving State on Android - java

I have an android app that has two fragments that pass data from fragmentA to fragmentB. I can load all the data correctly but when I change the screen orientation it all reloads. I have set up the onSaveInstanceState and onViewStateRestored methods in the fragment I want to keep the state in, but nothing stays when the screen orientation changes.
The main problem that needs to be fixed is when text is loaded into the TextView in FragmentB - it needs to stay there when the screen orientation is changed.
MainActivity.Java
package com.example.tourguide;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.FragmentTransaction;
public class MainActivity extends AppCompatActivity implements FragmentA.FragmentAListener, FragmentB.FragmentBListener {
private FragmentA fragmentA;
private FragmentB fragmentB;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
fragmentA = new FragmentA();
fragmentB = new FragmentB();
if(savedInstanceState == null) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.container_a, new FragmentA());
ft.replace(R.id.container_b, new FragmentB());
ft.commitNow();
}
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
}
#Override
protected void onRestoreInstanceState(#NonNull Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
}
#Override
public void onInputASent(CharSequence input) {
fragmentB.updateEditText(input);
}
#Override
public void onInputBSent(CharSequence input) {
fragmentA.updateEditText(input);
}
}
FragmentA.Java
package com.example.tourguide;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.ListFragment;
public class FragmentA extends ListFragment implements AdapterView.OnItemClickListener {
private FragmentAListener listener;
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String[] locationList = getActivity().getResources().getStringArray(R.array.location_list);
updateEditText(locationList[position]);
listener.onInputASent(locationList[position]);
}
public interface FragmentAListener {
void onInputASent(CharSequence input);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_a, container, false);
return v;
}
#Override
public void onListItemClick(#NonNull ListView l, #NonNull View v, int position, long id) {
super.onListItemClick(l, v, position, id);
}
public void updateEditText(CharSequence newText) {
//editText.setText(newText);
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof FragmentAListener) {
listener = (FragmentAListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement FragmentAListener");
}
}
#Override
public void onDetach() {
super.onDetach();
listener = null;
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
ArrayAdapter arrayAdapter = ArrayAdapter.createFromResource(getActivity(), R.array.location_list, android.R.layout.simple_list_item_1);
setListAdapter(arrayAdapter);
getListView().setOnItemClickListener(this);
}
}
FragmentB.Java - This is the fragment that needs to be keep the string inside the TextView when the screen is rotated
package com.example.tourguide;
import android.content.Context;
import android.content.res.Resources;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
public class FragmentB extends Fragment {
private FragmentBListener listener;
private TextView resultsFrag;
private static final String KEY_TITLE = "title_key";
private String stateObject;
public interface FragmentBListener {
void onInputBSent(CharSequence input);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_b, container, false);
resultsFrag = v.findViewById(R.id.tvFragmentB);
//I used the same if block in three different locations and none of them worked
if (savedInstanceState != null) {
String itemTo = savedInstanceState.getString(KEY_TITLE);
resultsFrag.setText(itemTo);
} else {
Toast.makeText(getActivity(), "Error 1", Toast.LENGTH_SHORT).show();
}
return v;
}
public void updateEditText(CharSequence newText) {
String newOption = newText.toString();
stateObject = newText.toString();
Resources res = getResources();
String[] locationDesc = res.getStringArray(R.array.location_description);
if (newOption.equals("Calgary")) {
resultsFrag.setText(locationDesc[0]);
} else if (newOption.equals("Victoria")) {
resultsFrag.setText(locationDesc[1]);
} else if (newOption.equals("Vancouver")) {
resultsFrag.setText(locationDesc[2]);
} else if (newOption.equals("Toronto")) {
resultsFrag.setText(locationDesc[3]);
}
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof FragmentBListener) {
listener = (FragmentBListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement FragmentBListener");
}
}
#Override
public void onDetach() {
super.onDetach();
listener = null;
}
#Override
public void onSaveInstanceState(#NonNull Bundle outState) {
super.onSaveInstanceState(outState);
outState.putString(KEY_TITLE, resultsFrag.getText().toString());
}
#Override
public void onViewStateRestored(#Nullable Bundle savedInstanceState) {
super.onViewStateRestored(savedInstanceState);
//I used the same if block in three different locations and none of them worked
if (savedInstanceState != null) {
String itemTo = savedInstanceState.getString(KEY_TITLE);
resultsFrag.setText(itemTo);
} else {
Toast.makeText(getActivity(), "Error 2", Toast.LENGTH_SHORT).show();
}
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
//I used the same if block in three different locations and none of them worked
if (savedInstanceState != null) {
String itemTo = savedInstanceState.getString(KEY_TITLE);
resultsFrag.setText(itemTo);
} else {
Toast.makeText(getActivity(), "Error 3", Toast.LENGTH_SHORT).show();
}
}
}
fragment_b.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/holo_blue_light"
android:gravity="center_horizontal"
android:orientation="vertical"
android:padding="16dp">
<TextView
android:id="#+id/tvFragmentB"
android:layout_width="match_parent"
android:layout_height="602dp" />
</LinearLayout>
Strings
<resources>
<string name="app_name">Tour Guide</string>
<string-array name="location_list">
<item>Calgary</item>
<item>Victoria</item>
<item>Vancouver</item>
<item>Toronto</item>
</string-array>
<!-- Descriptions for the locations -->
<string-array name="location_description">
<item>This is a big description for CALGARY - THIS needs to load in for more information regarding CALGARY</item>
<item>This is a big description for VICTORIA - THIS needs to load in for more information regarding VICTORIA</item>
<item>This is a big description for VANCOUVER - THIS needs to load in for more information regarding VANCOUVER</item>
<item>This is a big description for TORONTO - THIS needs to load in for more information regarding TORONTO</item>
</string-array>
</resources>
fragment_a.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/holo_green_light"
android:gravity="center_horizontal"
android:orientation="vertical"
android:padding="16dp">
<ListView
android:id="#android:id/list"
android:layout_width="wrap_content"
android:layout_height="206dp" />
</LinearLayout>
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">
<FrameLayout
android:id="#+id/container_a"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<FrameLayout
android:id="#+id/container_b"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>

They are saved, but you are replacing them. Use this
if(savedInstanceState == null) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.container_a, new FragmentA());
ft.replace(R.id.container_b, new FragmentB());
ft.commit();
}
Please note that fragment instantiation is pretty much the ONLY scenario in which this check yields correct and expected results.
Do not keep a reference to a Fragment, unless it is obtained via findFragmentByTag + instantiation. You might want to use commitNow to get reliable results in this case.
EDIT: Update with more complete code:
public class MainActivity extends AppCompatActivity implements FragmentA.FragmentAListener, FragmentB.FragmentBListener {
private FragmentA fragmentA;
private FragmentB fragmentB;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(savedInstanceState == null) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.container_a, new FragmentA(), "fragmentA");
ft.replace(R.id.container_b, new FragmentB(), "fragmentB");
ft.commitNow();
}
fragmentA = getSupportFragmentManager().findFragmentByTag("fragmentA");
fragmentB = getSupportFragmentManager().findFragmentByTag("fragmentB");
}

Related

How to programmatically Next and Prev buttons for Master / Detail flow

I have created a sample app using the "Master / Detail flow" activity. I have added two buttons, Next and Prev to the detail activity. How to I set programmatically the buttons actions instead having to go back and forth between the List and detail?
item_detail.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingStart="30dp"
android:paddingEnd="30dp"
android:weightSum="4"
android:gravity="end"
android:orientation="horizontal">
<Button
android:id="#+id/button_prev"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Prev"/>
<Button
android:id="#+id/button_next"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="Next"/>
</LinearLayout>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/item_detail"
style="?android:attr/textAppearanceLarge"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp"
android:textIsSelectable="true"
tools:context="co.test.app.sample.itemapplication.ItemDetailFragment"/>
</LinearLayout>
activity_item_detail.xml
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="co.test.app.sample.itemapplication.ItemDetailActivity"
tools:ignore="MergeRootFrame">
<android.support.design.widget.AppBarLayout
android:id="#+id/app_bar"
android:layout_width="match_parent"
android:layout_height="#dimen/app_bar_height"
android:fitsSystemWindows="true"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/toolbar_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
app:toolbarId="#+id/toolbar">
<android.support.v7.widget.Toolbar
android:id="#+id/detail_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"/>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.widget.NestedScrollView
android:id="#+id/item_detail_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
</android.support.v4.widget.NestedScrollView>
</android.support.design.widget.CoordinatorLayout>
DummyContent.java
package co.test.app.sample.itemapplication.dummy;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Helper class for providing sample content for user interfaces created by
* Android template wizards.
* <p>
* TODO: Replace all uses of this class before publishing your app.
*/
public class DummyContent {
/**
* An array of sample (dummy) items.
*/
public static final List<DummyItem> ITEMS = new ArrayList<DummyItem>();
/**
* A map of sample (dummy) items, by ID.
*/
public static final Map<String, DummyItem> ITEM_MAP = new HashMap<String, DummyItem>();
private static final int COUNT = 25;
static {
// Add some sample items.
for (int i = 1; i <= COUNT; i++) {
addItem(createDummyItem(i));
}
}
private static void addItem(DummyItem item) {
ITEMS.add(item);
ITEM_MAP.put(item.id, item);
}
private static DummyItem createDummyItem(int position) {
return new DummyItem(String.valueOf(position), "Item " + position, makeDetails(position));
}
private static String makeDetails(int position) {
StringBuilder builder = new StringBuilder();
builder.append("Details about Item: ").append(position);
for (int i = 0; i < position; i++) {
builder.append("\nMore details information here.");
}
return builder.toString();
}
/**
* A dummy item representing a piece of content.
*/
public static class DummyItem {
public final String id;
public final String content;
public final String details;
public DummyItem(String id, String content, String details) {
this.id = id;
this.content = content;
this.details = details;
}
#Override
public String toString() {
return content;
}
}
}
ItemDetailActivity.java
package co.test.app.sample.itemapplication;
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.app.ActionBar;
import android.view.MenuItem;
/**
* An activity representing a single Item detail screen. This
* activity is only used narrow width devices. On tablet-size devices,
* item details are presented side-by-side with a list of items
* in a {#link ItemListActivity}.
*/
public class ItemDetailActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_item_detail);
Toolbar toolbar = (Toolbar) findViewById(R.id.detail_toolbar);
setSupportActionBar(toolbar);
// Show the Up button in the action bar.
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.setDisplayHomeAsUpEnabled(true);
}
// savedInstanceState is non-null when there is fragment state
// saved from previous configurations of this activity
// (e.g. when rotating the screen from portrait to landscape).
// In this case, the fragment will automatically be re-added
// to its container so we don't need to manually add it.
// For more information, see the Fragments API guide at:
//
// http://developer.android.com/guide/components/fragments.html
//
if (savedInstanceState == null) {
// Create the detail fragment and add it to the activity
// using a fragment transaction.
Bundle arguments = new Bundle();
arguments.putString(ItemDetailFragment.ARG_ITEM_ID,
getIntent().getStringExtra(ItemDetailFragment.ARG_ITEM_ID));
ItemDetailFragment fragment = new ItemDetailFragment();
fragment.setArguments(arguments);
getSupportFragmentManager().beginTransaction()
.add(R.id.item_detail_container, fragment)
.commit();
}
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
// This ID represents the Home or Up button. In the case of this
// activity, the Up button is shown. For
// more details, see the Navigation pattern on Android Design:
//
// http://developer.android.com/design/patterns/navigation.html#up-vs-back
//
navigateUpTo(new Intent(this, ItemListActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}
}
ItemListActivity.java
package co.test.app.sample.itemapplication;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import co.test.app.sample.itemapplication.dummy.DummyContent;
import java.util.List;
/**
* An activity representing a list of Items. This activity
* has different presentations for handset and tablet-size devices. On
* handsets, the activity presents a list of items, which when touched,
* lead to a {#link ItemDetailActivity} representing
* item details. On tablets, the activity presents the list of items and
* item details side-by-side using two vertical panes.
*/
public class ItemListActivity extends AppCompatActivity {
/**
* Whether or not the activity is in two-pane mode, i.e. running on a tablet
* device.
*/
private boolean mTwoPane;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_item_list);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
toolbar.setTitle(getTitle());
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();
}
});
View recyclerView = findViewById(R.id.item_list);
assert recyclerView != null;
setupRecyclerView((RecyclerView) recyclerView);
if (findViewById(R.id.item_detail_container) != null) {
// The detail container view will be present only in the
// large-screen layouts (res/values-w900dp).
// If this view is present, then the
// activity should be in two-pane mode.
mTwoPane = true;
}
}
private void setupRecyclerView(#NonNull RecyclerView recyclerView) {
recyclerView.setAdapter(new SimpleItemRecyclerViewAdapter(DummyContent.ITEMS));
}
public class SimpleItemRecyclerViewAdapter
extends RecyclerView.Adapter<SimpleItemRecyclerViewAdapter.ViewHolder> {
private final List<DummyContent.DummyItem> mValues;
public SimpleItemRecyclerViewAdapter(List<DummyContent.DummyItem> items) {
mValues = items;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.item_list_content, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
holder.mItem = mValues.get(position);
holder.mIdView.setText(mValues.get(position).id);
holder.mContentView.setText(mValues.get(position).content);
holder.mView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mTwoPane) {
Bundle arguments = new Bundle();
arguments.putString(ItemDetailFragment.ARG_ITEM_ID, holder.mItem.id);
ItemDetailFragment fragment = new ItemDetailFragment();
fragment.setArguments(arguments);
getSupportFragmentManager().beginTransaction()
.replace(R.id.item_detail_container, fragment)
.commit();
} else {
Context context = v.getContext();
Intent intent = new Intent(context, ItemDetailActivity.class);
intent.putExtra(ItemDetailFragment.ARG_ITEM_ID, holder.mItem.id);
context.startActivity(intent);
}
}
});
}
#Override
public int getItemCount() {
return mValues.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
public final View mView;
public final TextView mIdView;
public final TextView mContentView;
public DummyContent.DummyItem mItem;
public ViewHolder(View view) {
super(view);
mView = view;
mIdView = (TextView) view.findViewById(R.id.id);
mContentView = (TextView) view.findViewById(R.id.content);
}
#Override
public String toString() {
return super.toString() + " '" + mContentView.getText() + "'";
}
}
}
}

This is the code snippet used to forward to the detail page.
if (mTwoPane) {
Bundle arguments = new Bundle();
arguments.putString(ItemDetailFragment.ARG_ITEM_ID, holder.mItem.id);
ItemDetailFragment fragment = new ItemDetailFragment();
fragment.setArguments(arguments);
getSupportFragmentManager().beginTransaction()
.replace(R.id.item_detail_container, fragment)
.commit();
} else {
Context context = v.getContext();
Intent intent = new Intent(context, ItemDetailActivity.class);
intent.putExtra(ItemDetailFragment.ARG_ITEM_ID, holder.mItem.id);
context.startActivity(intent);
}
You can forward to any page by changing the value of arguments.putString(ItemDetailFragment.ARG_ITEM_ID, holder.mItem.id);
Use the above snippets in the onClick events of next and prev buttons. cheers :)

java.lang.NullPointerException: Android Studio

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference
I am getting a NullPointerException at line 67 while trying to set a listView with a chat adapter. Here is the class:
I have placed ** around the line I am getting the NullPointerException on. I'm not really understading why its returning as null when I'm setting messageAdapter to a new object of an inner class called ChatAdapter(this).
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class MessageListActivity extends AppCompatActivity {
/**
* Whether or not the activity is in two-pane mode, i.e. running on a tablet
* device.
*/
ListView listView;
Button sendButton;
ArrayList<String> arrayList = new ArrayList<String>();
ChatDatabaseHelper Cdb;
private boolean mTwoPane;
ChatAdapter messageAdapter = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_message_list);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
toolbar.setTitle(getTitle());
listView = (ListView)findViewById(R.id.chatListView);
final EditText editText = (EditText)findViewById(R.id.messageText);
sendButton = (Button)findViewById(R.id.sendButton);
messageAdapter = new ChatAdapter(this); // chatAdapter is a built in adapater
**listView.setAdapter(messageAdapter);**
Cdb = new ChatDatabaseHelper(this);
Cursor cursor = Cdb.getMessages(); // get messages method is of type Cursor from database helper class
// cursor will move through the database to find the next text if there is any.
while (cursor.moveToNext()) { arrayList.add(cursor.getString(cursor.getColumnIndex(Cdb.KEY_MESSAGE))); }
sendButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) { // on click listener for the send button
String chatText = editText.getText().toString(); // changing editText to String
arrayList.add(chatText); // adding the string from EditTest to arrayList
boolean isInserted = Cdb.insertData(chatText); // inserting the message text into the database
if(isInserted = true)
{ Toast.makeText(MessageListActivity.this,"Message Sent",Toast.LENGTH_SHORT).show(); } // if the message inserts into the database this toast will show
else {
Toast.makeText(MessageListActivity.this,"Message not Sent",Toast.LENGTH_SHORT).show(); } // if message does not nter the database this toast will show
messageAdapter.notifyDataSetChanged(); // notifying the adapter that a message has been sent, changing from incoming to outgoing
editText.setText(" "); // set the text on the send button to blank.
} // end of onClick view
}); // end of onClickListener
if (findViewById(R.id.message_detail_container) != null) {
// The detail container view will be present only in the
// large-screen layouts (res/values-w900dp).
// If this view is present, then the
// activity should be in two-pane mode.
mTwoPane = true;
}
}
class ChatAdapter extends ArrayAdapter<String> { // custom adapter class // when youc all the adapter it forms the for loop for you.
public ChatAdapter(MessageListActivity ctx) {
super(ctx, 0);
} // default constructor
// method to return the number of rows that will be in your array
// will tell how many times to run a for loop
public int getCount(){ return arrayList.size(); } // will return the size of the array
public String getItem(int position){ return arrayList.get(position); } // will return the item at position
// getview method
#Override
public View getView(int position, final View convertView, ViewGroup parent) {// inner class
LayoutInflater Inflater = MessageListActivity.this.getLayoutInflater(); // an inflater inflates the xml layout into a view.
View result = null;
if(position%2 == 0){ // if position number in the array is odd do this, if number is even, do this.
result = Inflater.inflate(R.layout.chat_row_incoming, null); // depending on the position, show layout incoming
} else {
result = Inflater.inflate(R.layout.chat_row_outgoing,null); // depending on the position, show layout outgoing
}
TextView message = (TextView)result.findViewById(R.id.messageText); // creating a message of type TextView connected to messageText
final String messageText = getItem(position) ;
message.setText(messageText);
result.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mTwoPane) {
Bundle arguments = new Bundle();
arguments.putString(MessageDetailFragment.ARG_ITEM_ID,messageText );
MessageDetailFragment fragment = new MessageDetailFragment();
fragment.setArguments(arguments);
getSupportFragmentManager().beginTransaction()
.replace(R.id.message_detail_container, fragment)
.commit();
} else {
Context context = v.getContext();
Intent intent = new Intent(context, MessageDetailActivity.class);
intent.putExtra(MessageDetailFragment.ARG_ITEM_ID,messageText );
context.startActivity(intent);
}
}
});
return result; // return the view which is the Inflater.
}
} // end of chat adapter class
private void setupRecyclerView(#NonNull RecyclerView recyclerView) {
recyclerView.setAdapter(new SimpleItemRecyclerViewAdapter(DummyContent.ITEMS));
}
public class SimpleItemRecyclerViewAdapter
extends RecyclerView.Adapter<SimpleItemRecyclerViewAdapter.ViewHolder> {
private final List<DummyContent.DummyItem> mValues;
public SimpleItemRecyclerViewAdapter(List<DummyContent.DummyItem> items) {
mValues = items;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.message_list_content, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
holder.mItem = mValues.get(position);
holder.mIdView.setText(mValues.get(position).id);
holder.mContentView.setText(mValues.get(position).content);
holder.mView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mTwoPane) {
Bundle arguments = new Bundle();
arguments.putString(MessageDetailFragment.ARG_ITEM_ID, holder.mItem.id);
MessageDetailFragment fragment = new MessageDetailFragment();
fragment.setArguments(arguments);
getSupportFragmentManager().beginTransaction()
.replace(R.id.message_detail_container, fragment)
.commit();
} else {
Context context = v.getContext();
Intent intent = new Intent(context, MessageDetailActivity.class);
intent.putExtra(MessageDetailFragment.ARG_ITEM_ID, holder.mItem.id);
context.startActivity(intent);
}
}
});
}
#Override
public int getItemCount() {
return mValues.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
public final View mView;
public final TextView mIdView;
public final TextView mContentView;
public DummyContent.DummyItem mItem;
public ViewHolder(View view) {
super(view);
mView = view;
mIdView = (TextView) view.findViewById(R.id.id);
mContentView = (TextView) view.findViewById(R.id.content);
}
#Override
public String toString() {
return super.toString() + " '" + mContentView.getText() + "'";
}
}
}
xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.ChatWindow">
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/chatListView"
android:layout_alignParentStart="true"
android:layout_alignParentEnd="true"
android:layout_alignParentTop="true"
android:layout_alignParentBottom="false"
android:layout_alignWithParentIfMissing="false"
android:layout_above="#+id/sendButton" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/sendButton"
android:id="#+id/sendButton"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:singleLine="true" />
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/messageText"
android:layout_toStartOf="#id/sendButton"
android:layout_alignParentStart="true"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:enabled="true"
/>
</RelativeLayout>

just try
messageAdapter = new ChatAdapter(MessageListActivity .this);

Android - No view found for fragment

I'm trying to get my replaced fragment to appear in the detail fragment but after debugging my app on a tablet emulator and selecting the necessary list view item, the log cat gives me this error:
Caused by: java.lang.IllegalArgumentException: No view found for id 0x7f0c0050 (com.apptacularapps.exitsexpertlondonlite:id/detail_container) for fragment FragmentWCBank{3b4ea8fb #0 id=0x7f0c0050}
I really don't understand why I'm getting this error when my fragment is there within my project. Does anyone know what I'm doing wrong and how to fix this?
FragmentWCLine.java
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class FragmentWCLine extends android.support.v4.app.Fragment {
public final static String EXTRA_MESSAGE = "Station_key";
private class WC {
private CharSequence station;
private CharSequence zone;
private Class<? extends Activity> activityClass;
private Class<? extends android.support.v4.app.Fragment> fragmentClass;
public WC(int stationResId, int zoneResId, Class<? extends Activity> activityClass, Class<? extends android.support.v4.app.Fragment> fragmentClass) {
this.fragmentClass = fragmentClass;
this.activityClass = activityClass;
this.station = getResources().getString(stationResId);
this.zone = getResources().getString(zoneResId);
}
#Override
public String toString() { return station.toString(); }
public String getzone(){ return zone.toString(); }
}
private static WC[] mWC;
private boolean mTwoPane;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
View v = inflater.inflate(R.layout.fragment_wc_line, container, false);
// Instantiate the list of stations.
mWC = new WC[]{
new WC(R.string.bank, R.string.zone_1, WCBankActivity.class, FragmentWCBank.class),
new WC(R.string.wat, R.string.zone_1, WCWATActivity.class, FragmentWCWAT.class)
};
final ListView listView = (ListView)v.findViewById(R.id.list_wc);
listView.setAdapter(new MyAdapter(getActivity(), mWC));
listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if(mTwoPane){
setItemNormal();
View rowView = view;
setItemSelected(rowView);
}
else{
Intent intent = new Intent(getActivity(), mWC[position].activityClass);
String station = mWC[position].station.toString();
intent.putExtra(EXTRA_MESSAGE, station);
startActivity(intent);
}
}
public void setItemSelected(View view){
View rowView = view;
view.setBackgroundColor(Color.parseColor("#66CCCC"));
TextView tv0 = (TextView)rowView.findViewById(R.id.list_item_station);
tv0.setTextColor(Color.parseColor("#000099"));
TextView tv1 = (TextView)rowView.findViewById(R.id.list_item_zone);
tv1.setTextColor(Color.parseColor("#000099"));
}
public void setItemNormal()
{
for (int i=0; i< listView.getChildCount(); i++) {
View v = listView.getChildAt(i);
v.setBackgroundColor(Color.TRANSPARENT);
TextView tv0 = ((TextView) v.findViewById(R.id.list_item_station));
tv0.setTextColor(Color.WHITE);
TextView tv1 = ((TextView) v.findViewById(R.id.list_item_zone));
tv1.setTextColor(Color.parseColor("#B5B5B5"));
}
}
});
return v;
}
static class MyAdapter extends BaseAdapter {
static class ViewHolder {
TextView station;
TextView zone;
}
LayoutInflater inflater;
WC[] mWC;
public MyAdapter(Context contexts, WC[] samples) {
this.mWC = samples;
inflater = LayoutInflater.from(contexts);
}
#Override
public int getCount() {
return mWC.length;
}
#Override
public Object getItem(int position) {
return mWC[position];
}
#Override
public long getItemId(int position) {
return 0;
}
/**set selected position**/
private int selectPosition = -1;
public void setSelectPosition(int position){
if(position!=selectPosition){
selectPosition = position;
}
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.list_item_dualline, null);
viewHolder = new ViewHolder();
viewHolder.station = (TextView) convertView.findViewById(R.id.list_item_station);
viewHolder.zone = (TextView) convertView.findViewById(R.id.list_item_zone);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.station.setText(mWC[position].station);
viewHolder.zone.setText(mWC[position].getzone());
//change item color
if(position==selectPosition){
convertView.setBackgroundColor(Color.parseColor("#000099"));
viewHolder.station.setTextColor(Color.parseColor("#000099"));
}else {
}
return convertView;
}
}
}
WCBankActivity.java
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.ActionBarActivity;
public class WCBankActivity extends ActionBarActivity {
public final static String EXTRA_MESSAGE = "Station_key";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_wc_bank);
if (savedInstanceState == null) {
// Get the message from the intent
Intent intent = getIntent();
// Notice to specify the sender Activity for the message
String station = intent.getStringExtra(WCBankActivity.EXTRA_MESSAGE);
FragmentWCBank newFragment = new FragmentWCBank();
FragmentTransaction transaction = this.getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.detail_container, newFragment);
transaction.commit();
}
}
}
FragmentWCBank.java
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class FragmentWCBank extends android.support.v4.app.Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_wc_bank, container, false);
return v;
}
}
fragment inflation
fragment_wc_bank.xml layout
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/detail_container">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Bank"
android:id="#+id/textView0"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />
</RelativeLayout>
fragment_wc_line.xml layout
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/fragmentwcline">
<ListView
android:id="#+id/list_wc"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerVertical="false"
android:layout_centerHorizontal="true"/>
</LinearLayout>
activity_main.xml layout
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/master_container"
android:name="com.apptacularapps.exitsexpertlondonlite.FragmentMainList"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
activity_main.xml layout (sw600dp)
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:showDividers="middle"
tools:context=".MainActivity" >
<RelativeLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:id="#+id/master_container"/>
<FrameLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="3"
android:id="#+id/detail_container"/>
</LinearLayout>
Undesired result

Your code transaction.replace(R.id.detail_container...Now this may be the correct UI element. I am assuming this is the correct UI. If so, fragment_wc_bank layout xml does not have that ID detail_container, hence you get error, simple as that. However activity_main.xml has that ID, again I am assuming detail_container is the correct UI that you want.
Suggested code FROM:
setContentView(R.layout.fragment_wc_bank);
TO:
setContentView(R.layout.activity_main.xml);
Notes:
activity_main.xml is the only difference between the 2 codes above.
This is a common error but we all have to learn from this. Learn more about layouts. It is a critical knowledge in making Android apps.
There are 2 different activity_main.xml files you posted. They should at least be similar. Otherwise you could be very confused.

Your activity is trying to inflate a layout, then place a fragment into it in place of the view detail_container. detail_container does not exist in that layout- either you forgot to add it or you're inflating the wrong thing. I notice you're inflating R.layout.fragment_wc_bank for both the fragment and the main activity, my guess is you're inflating the wrong layout in the activity.

NullPointerException - Android Google Maps Street View

I am trying to display a street view in a fragment.
public class StreetDisplay extends Fragment implements OnStreetViewPanoramaReadyCallback{
SupportStreetViewPanoramaFragment streetFrag;
static final LatLng PosOne = new LatLng(43.771925, -79.512460);
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.street_display, container, false);
initialize();
return v;
}
private void initialize() {
streetFrag =
(SupportStreetViewPanoramaFragment) getFragmentManager()
.findFragmentById(R.id.street);
streetFrag.getStreetViewPanoramaAsync(this);
}
//this method is needed for using a ViewPager swiping feature
public static StreetDisplay newInstance(){
StreetDisplay sd = new StreetDisplay();
return sd;
}
#Override
public void onStreetViewPanoramaReady(StreetViewPanorama panorama) {
panorama.setPosition(PosOne);
}
}
Here's the error message I get when I run my app
Process: com.example.nikhilbhaskar.mapplayground, PID: 22406
java.lang.NullPointerException
at com.example.nikhilbhaskar.mapplayground.StreetDisplay.initialize(StreetDisplay.java:43)
at com.example.nikhilbhaskar.mapplayground.StreetDisplay.onCreateView(StreetDisplay.java:33)
Line 33 is
initialize();
Line 43 is
streetFrag.getStreetViewPanoramaAsync(this);
I am not sure what the problem is - Can you help?

streetFrag =
(SupportStreetViewPanoramaFragment) getFragmentManager()
.findFragmentById(R.id.street);
It is possible that this statement is not creating the object for StreetFrag.
Check whether is streetFrag is null or not.

I tried the doc from official, and it worked perfectly.
My sample code:
StreetViewActivity
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import com.google.android.gms.maps.OnStreetViewPanoramaReadyCallback;
import com.google.android.gms.maps.StreetViewPanorama;
import com.google.android.gms.maps.StreetViewPanoramaFragment;
import com.google.android.gms.maps.model.LatLng;
public class StreetViewActivity extends FragmentActivity
implements OnStreetViewPanoramaReadyCallback {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_street_view);
StreetViewPanoramaFragment streetViewPanoramaFragment =
(StreetViewPanoramaFragment) getFragmentManager()
.findFragmentById(R.id.streetviewpanorama);
streetViewPanoramaFragment.getStreetViewPanoramaAsync(this);
}
#Override
public void onStreetViewPanoramaReady(StreetViewPanorama streetViewPanorama) {
streetViewPanorama.setPosition(new LatLng(-33.87365, 151.20689));
}
}
And for the activity_street_view.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context="com.bjiang.map_ex.StreetViewActivity">
<fragment
android:name="com.google.android.gms.maps.StreetViewPanoramaFragment"
android:id="#+id/streetviewpanorama"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</RelativeLayout>
For more details, please refer here.
EDIT:
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import com.google.android.gms.maps.OnStreetViewPanoramaReadyCallback;
import com.google.android.gms.maps.StreetViewPanorama;
import com.google.android.gms.maps.SupportStreetViewPanoramaFragment;
import com.google.android.gms.maps.model.LatLng;
public class StreetDisplay extends FragmentActivity implements OnStreetViewPanoramaReadyCallback {
static SupportStreetViewPanoramaFragment streetViewPanoramaFragment;
static final LatLng PosOne = new LatLng(43.771925, -79.512460);
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.street_display);
streetViewPanoramaFragment =
((SupportStreetViewPanoramaFragment)getSupportFragmentManager().findFragmentById(R.id.street));
streetViewPanoramaFragment.getStreetViewPanoramaAsync(this);
}
//this method is needed for using a ViewPager swiping feature
public static Fragment newInstance(){
return streetViewPanoramaFragment.newInstance();
}
#Override
public void onStreetViewPanoramaReady(StreetViewPanorama streetViewPanorama) {
streetViewPanorama.setPosition(new LatLng(-33.87365, 151.20689));
}
}

Within fragment use getChildFragmentManager() instead.
streetFrag = (SupportStreetViewPanoramaFragment) getChildFragmentManager()
.findFragmentById(R.id.street);

Launch a activity with button click using a FragmentActivity

Hey guys I need help I'm making a launcher that needs to have a button that when clicked it opens the AllApps.class activity witch shows a list of all installed apps
The other button needs to open a installed app that is on the device
and the last button needs to open the default web browser and open google.com
Here's my code!
Home.java:
package com.dva.schooltoolshome;
import java.util.Locale;
import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.content.Intent;
import android.net.Uri;
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.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.TextView;
public class Home extends FragmentActivity implements ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
final ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
actionBar.setDisplayShowHomeEnabled(false);
actionBar.setDisplayOptions(actionBar.getDisplayOptions()
^ ActionBar.DISPLAY_SHOW_TITLE);
mSectionsPagerAdapter = new SectionsPagerAdapter(
getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
mViewPager
.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
#Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
if (mSectionsPagerAdapter.getPageTitle(i).toString()
.equalsIgnoreCase("calc")) {
actionBar.addTab(actionBar.newTab()
.setIcon(R.drawable.calendar)
.setTabListener(this));
} else if (mSectionsPagerAdapter.getPageTitle(i).toString()
.equalsIgnoreCase("home")) {
actionBar.addTab(actionBar.newTab().setIcon(R.drawable.home)
.setTabListener(this));
} else if (mSectionsPagerAdapter.getPageTitle(i).toString()
.equalsIgnoreCase("drive")) {
actionBar.addTab(actionBar.newTab().setIcon(R.drawable.folder)
.setTabListener(this));
}
}
mViewPager.setCurrentItem(1);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.home, menu);
return true;
}
#Override
public void onTabSelected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
mViewPager.setCurrentItem(tab.getPosition());
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_settings:
startActivity(new Intent(android.provider.Settings.ACTION_APPLICATION_SETTINGS));
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#Override
public void onTabUnselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
#Override
public void onTabReselected(ActionBar.Tab tab,
FragmentTransaction fragmentTransaction) {
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
Fragment fragment = null;
switch (position) {
case 0:
fragment = new CalcFragment();
break;
case 1:
fragment = new HomeFragment();
break;
case 2:
fragment = new DriveFragment();
break;
}
return fragment;
}
#Override
public int getCount() {
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;
}
}
public static class HomeFragment extends Fragment {
public static final String ARG_SECTION_NUMBER = "section_number";
public HomeFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_homebar,
container, false);
return rootView;
}
}
public static class CalcFragment extends Fragment {
public static final String ARG_SECTION_NUMBER = "section_number";
public CalcFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_calculator,
container, false);
return rootView;
}
}
public static class DriveFragment extends Fragment {
public static final String ARG_SECTION_NUMBER = "section_number";
public DriveFragment() {
}
#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("DRIVE");
return rootView;
}
}
}
activity_homebar
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/bg"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".HomeBar" >
<ImageButton
android:id="#+id/apps"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:background="#drawable/appdrawer"
android:src="#drawable/appdrawer" />
<ImageButton
android:id="#+id/wbrowser"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignTop="#+id/apps"
android:src="#drawable/browser" />
</RelativeLayout>
AllApps.java:
package com.dva.schooltoolshome;
import android.app.LauncherActivity;
import android.content.Intent;
public class AllApps extends LauncherActivity {
#Override
protected Intent getTargetIntent () {
// just a example, you should replace the method yourself
Intent intent = new Intent();
intent.setAction(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
return intent;
}
}
I'm am still learning so please don't judge
Thanks in advance
Regards
Rapsong11

You can easily find the answer to your question with a bit of googling. It has been asked many times before. I will point you in the right direction.
To add functionality to a button you have to first make the button (view) aware it can be clicked. This can be done in java programatically (research this yourself) or in the xml like so:
android:onClick="onClickDoStuff"
Then you have to implement the onClickDoStuff method which will look like:
public void onClickDoStuff(View view) {
//Do stuff on click
}
You wanted the button to open a new activity onClick to do that you would require an intent have a look here for futher guidance

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