In this tutorial we are concerned with GridView and Firebase Realtime Database. We see how to perform CRUD operations against Firebase Realtime Database and show data in a GridView.
Firebase Realtime database is a database backend as a service Cloud hosted solution that gives us the platform to build rich apps.Read more about Firebase Realtime Database here .
GridView is an android widget that allows show data in grids. We can define the number of columns we want shown using the android:numColumns
attribute.
This is an android firebase gridview tutorial. How to save data to firebase,retrieve then show that data in a simple gridview.
Head over to Firebase Console, create a Firebase App, Register your app id and download the google-services.json
file. Add it to your app folder.
Head over to project level(project folder) build.gradle
and
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:2.3.3'
classpath 'com.google.gms:google-services:3.1.0'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
jcenter()
maven {
url "https://maven.google.com" // Google's Maven repository
}
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
Add them in you app level(app folder) build.gradle, then
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.3.0'
compile 'com.android.support:design:23.3.0'
compile 'com.android.support:cardview-v7:23.3.0'
compile 'com.google.firebase:firebase-core:11.8.0'
compile 'com.google.firebase:firebase-database:11.8.0'
}
apply plugin: 'com.google.gms.google-services'
Make sure you apply plugin: 'com.google.gms.google-services'
as above.
package com.tutorials.hp.firebasesimplegridview.m_Model;
public class Spacecraft {
String name;
public Spacecraft() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
Where we perform :
push()
and setValue()
methods.package com.tutorials.hp.firebasesimplegridview.m_FireBase;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseException;
import com.google.firebase.database.DatabaseReference;
import com.tutorials.hp.firebasesimplegridview.m_Model.Spacecraft;
import java.util.ArrayList;
public class FirebaseHelper {
DatabaseReference db;
Boolean saved=null;
ArrayList<String> spacecrafts=new ArrayList<>();
public FirebaseHelper(DatabaseReference db) {
this.db = db;
}
public Boolean save(Spacecraft spacecraft)
{
if(spacecraft==null)
{
saved=false;
}else
{
try
{
db.child("Spacecraft").push().setValue(spacecraft);
saved=true;
}catch (DatabaseException e)
{
e.printStackTrace();
saved=false;
}
}
return saved;
}
//RETRIEVE
public ArrayList<String> retrieve()
{
db.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
fetchData(dataSnapshot);
}
@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
fetchData(dataSnapshot);
}
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
return spacecrafts;
}
private void fetchData(DataSnapshot dataSnapshot)
{
spacecrafts.clear();
for (DataSnapshot ds:dataSnapshot.getChildren())
{
String name=ds.getValue(Spacecraft.class).getName();
spacecrafts.add(name);
}
}
}
package com.tutorials.hp.firebasesimplegridview;
import android.app.Dialog;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.GridView;
import android.widget.Toast;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.tutorials.hp.firebasesimplegridview.m_FireBase.FirebaseHelper;
import com.tutorials.hp.firebasesimplegridview.m_Model.Spacecraft;
public class MainActivity extends AppCompatActivity {
GridView gv;
ArrayAdapter<String> adapter;
DatabaseReference db;
FirebaseHelper helper;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
gv= (GridView) findViewById(R.id.gv);
//SETUP FIREBASE
db= FirebaseDatabase.getInstance().getReference();
helper=new FirebaseHelper(db);
//adapter
adapter=new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,helper.retrieve());
gv.setAdapter(adapter);
gv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(MainActivity.this, helper.retrieve().get(position), Toast.LENGTH_SHORT).show();
}
});
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
displayInputDialog();
}
});
}
private void displayInputDialog()
{
Dialog d=new Dialog(this);
d.setTitle("Save To Rirebase");
d.setContentView(R.layout.input_dialog);
final EditText nameEditTxt= (EditText) d.findViewById(R.id.nameEditText);
Button saveBtn= (Button) d.findViewById(R.id.saveBtn);
saveBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//GET DATA
String name=nameEditTxt.getText().toString();
//SET DATA
Spacecraft s=new Spacecraft();
s.setName(name);
//VALIDATE
if(name != null && name.length()>0)
{
if(helper.save(s))
{
nameEditTxt.setText("");
adapter=new ArrayAdapter<String>(MainActivity.this,android.R.layout.simple_list_item_1,helper.retrieve());
gv.setAdapter(adapter);
}
}else
{
Toast.makeText(MainActivity.this, "Name Cannot be empty", Toast.LENGTH_SHORT).show();
}
}
});
d.show();
}
}
Our main activity layout.
<?xml version="1.0" encoding="utf-8"?>
<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="com.tutorials.hp.firebasesimplegridview.MainActivity">
<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="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme.PopupOverlay" />
</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"
android:src="@android:drawable/ic_dialog_email" />
</android.support.design.widget.CoordinatorLayout>
This layout will be included into our activity_main.xml
.
We add our gridview which is our adapterview here.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.tutorials.hp.firebasesimplegridview.MainActivity"
tools:showIn="@layout/activity_main">
<GridView
android:id="@+id/gv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:numColumns="3" />
</RelativeLayout>
Basically our input form layout. Will be used to insert data into Firebase Database.
<?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">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_marginTop="?attr/actionBarSize"
android:orientation="vertical"
android:paddingLeft="15dp"
android:paddingRight="15dp"
android:paddingTop="20dp">
<android.support.design.widget.TextInputLayout
android:id="@+id/nameLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/nameEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:singleLine="true"
android:hint= "Name" />
</android.support.design.widget.TextInputLayout>
<Button android:id="@+id/saveBtn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Save"
android:clickable="true"
android:background="@color/colorAccent"
android:layout_marginTop="10dp"
android:textColor="@android:color/white"/>
</LinearLayout>
</LinearLayout>
Resource | Link |
---|---|
GitHub Browse | Browse |
GitHub Download Link | Download |
Video Tutorial | Video |
This is a Firebase example to help us explore how to work with multiple fields.
In a previous class we'd looked at saving and retrieving a single field, so let's see many fields in this example.
This is an android firebase gridview tutorial.We had actually done an android firebase tutorial earler with a GridView.However in that case we using a simple field.Well that's not terribly practical. How to save data to firebase,retrieve then show that data in a simple gridview.
No. | File | Major Responsibility |
---|---|---|
1. | Spacecraft.java | Represents a single Spacecraft and it's properties like name,propellant and description. |
2. | FirebaseHelper.java | This class has allows us perform Firebase CRUD operations. |
3. | CustomAdapter.java | Our adapter class |
4. | MainActivity.java | Our Master Activity. It shows the grid of Spacecrafts |
5. | activity_main.xml | Our Master Activity's layout. |
6. | content_main.xml | Our Master Activity's content detail. |
7. | input_dialog.xml | Our input dialog layout. |
8. | model.xml | Each GridView's grid model. |
9. | build.gradle(app) | We add Firebase dependencies here. |
Go ahead create you Firebase Database realtime in your Firebase account.
Then download the google.json
file and add it to your project at the app level:
Go to your build.gradle and add dependencies.You many use later verisons of Firbese than we used.Make sure you also apply the googleservices plugin:
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.3.0'
compile 'com.android.support:design:23.3.0'
compile 'com.android.support:cardview-v7:23.3.0'
compile 'com.google.firebase:firebase-core:9.0.2'
compile 'com.google.firebase:firebase-database:9.0.2'
}
apply plugin: 'com.google.gms.google-services'
Finally add internet permission in your AndroidManifest.xml as we will be accessing internet:
<manifest>
....
<uses-permission android:name="android.permission.INTERNET" />
....
</manifest>
Here are our layouts for this project:
<?xml version="1.0" encoding="utf-8"?>
<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="com.tutorials.hp.firebasegridviewmulti_items.MainActivity">
<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="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme.PopupOverlay" />
</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"
android:src="@android:drawable/ic_dialog_email" />
</android.support.design.widget.CoordinatorLayout>
This layout gets included in your activity_main.xml. We define our GridView here.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.tutorials.hp.firebasegridviewmulti_items.MainActivity"
tools:showIn="@layout/activity_main">
<GridView
android:id="@+id/gv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:numColumns="2" />
</RelativeLayout>
This in our input view. We have a couple of EditTexts and button to save data to Firebase.
This layout will be inflated into a Custom Dialog.
<?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">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_marginTop="?attr/actionBarSize"
android:orientation="vertical"
android:paddingLeft="15dp"
android:paddingRight="15dp"
android:paddingTop="50dp">
<android.support.design.widget.TextInputLayout
android:id="@+id/nameLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/nameEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:singleLine="true"
android:hint= "Name" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:id="@+id/propLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/propellantEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:singleLine="true"
android:hint= "Propellant" />
<android.support.design.widget.TextInputLayout
android:id="@+id/descLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/descEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:singleLine="true"
android:hint= "Description" />
</android.support.design.widget.TextInputLayout>
</android.support.design.widget.TextInputLayout>
<Button android:id="@+id/saveBtn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Save"
android:clickable="true"
android:background="@color/colorAccent"
android:layout_marginTop="40dp"
android:textColor="@android:color/white"/>
</LinearLayout>
</LinearLayout>
This layout will get inflated into GridView View items or grids.
Each grid is basically a CardView with several TextViews. Each Grid will represents a single Spacecraft object.
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_margin="10dp"
card_view:cardCornerRadius="5dp"
card_view:cardElevation="5dp"
android:layout_height="200dp">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Name"
android:id="@+id/nameTxt"
android:padding="10dp"
android:textColor="@color/colorAccent"
android:textStyle="bold"
android:layout_alignParentLeft="true"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Description....................."
android:lines="3"
android:id="@+id/descTxt"
android:padding="10dp"
android:layout_alignParentLeft="true"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Propellant"
android:textStyle="italic"
android:id="@+id/propellantTxt" />
</LinearLayout>
</android.support.v7.widget.CardView>
Well those are our layouts.
This is our data object class. Here's its responsibilities:
No. | Responsibility |
---|---|
1. | Represents a Single Spacecraft |
2. | Set Spacecraft properties: name,propellant and description. |
3. | Get Spacecraft properties: name,propellant and description. |
package com.tutorials.hp.firebasegridviewmulti_items.m_Model;
/*
* 1. OUR MODEL CLASS
*/
public class Spacecraft {
String name,propellant,description;
public Spacecraft() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPropellant() {
return propellant;
}
public void setPropellant(String propellant) {
this.propellant = propellant;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
This class allows us perform save and retrieve data to Firebase Realtime database.
No. | Responsibility |
---|---|
1. | Keep hold of three Objects: DatabaseReference,a Boolean saved value, and an ArrayList of Spacecrafts. |
2. | Obtain a DatabaseReference object via the constructor and Assign it to our local db data member. |
3. | Take a Spacecraft object and save it to Firebase this returning a Boolean indicating success or failure. |
4. | Loop through DataSnapshot children nodes obtaining all the Spacecraft objects from Firebase and fill our local arraylist with those objects. |
5. | Listen to Firebase Children mutation events like when a DataSnapshot child has been added, moved, removed, changed or cancelled. This allows us to fetch data in realtime. |
package com.tutorials.hp.firebasegridviewmulti_items.m_FireBase;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseException;
import com.google.firebase.database.DatabaseReference;
import com.tutorials.hp.firebasegridviewmulti_items.m_Model.Spacecraft;
import java.util.ArrayList;
/*
* 1.SAVE DATA TO FIREBASE
* 2. RETRIEVE
* 3.RETURN AN ARRAYLIST
*/
public class FirebaseHelper {
DatabaseReference db;
Boolean saved=null;
ArrayList<Spacecraft> spacecrafts=new ArrayList<>();
/*
PASS DATABASE REFRENCE
*/
public FirebaseHelper(DatabaseReference db) {
this.db = db;
}
//WRITE IF NOT NULL
public Boolean save(Spacecraft spacecraft)
{
if(spacecraft==null)
{
saved=false;
}else
{
try
{
db.child("Spacecraft").push().setValue(spacecraft);
saved=true;
}catch (DatabaseException e)
{
e.printStackTrace();
saved=false;
}
}
return saved;
}
//IMPLEMENT FETCH DATA AND FILL ARRAYLIST
private void fetchData(DataSnapshot dataSnapshot)
{
spacecrafts.clear();
for (DataSnapshot ds : dataSnapshot.getChildren())
{
Spacecraft spacecraft=ds.getValue(Spacecraft.class);
spacecrafts.add(spacecraft);
}
}
//READ BY HOOKING ONTO DATABASE OPERATION CALLBACKS
public ArrayList<Spacecraft> retrieve()
{
db.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
fetchData(dataSnapshot);
}
@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
fetchData(dataSnapshot);
}
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
return spacecrafts;
}
}
This is our adapter class. It derives from BaseAdapter.
No. | Responsibility |
---|---|
1. | This class will maintain a Context object that will be used to during layout inflation. Furthermore we declare an ArrayList of Spacecrafts that will be bound to our GridView. |
2. | Receive a Context and ArrayList of Spacecrafts from outside and assign them to our local instance fields. |
3. | Return data list count,Item and Item Identifier. |
4. | Inflate our model.xml layout and return it as a View when the getView() is called. |
package com.tutorials.hp.firebasegridviewmulti_items.m_UI;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import android.widget.Toast;
import com.tutorials.hp.firebasegridviewmulti_items.R;
import com.tutorials.hp.firebasegridviewmulti_items.m_Model.Spacecraft;
import java.util.ArrayList;
/*
* 1. where WE INFLATE OUR MODEL LAYOUT INTO VIEW ITEM
* 2. THEN BIND DATA
*/
public class CustomAdapter extends BaseAdapter {
Context c;
ArrayList<Spacecraft> spacecrafts;
public CustomAdapter(Context c, ArrayList<Spacecraft> spacecrafts) {
this.c = c;
this.spacecrafts = spacecrafts;
}
@Override
public int getCount() {
return spacecrafts.size();
}
@Override
public Object getItem(int position) {
return spacecrafts.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView==null)
{
convertView= LayoutInflater.from(c).inflate(R.layout.model,parent,false);
}
TextView nameTxt= (TextView) convertView.findViewById(R.id.nameTxt);
TextView propTxt= (TextView) convertView.findViewById(R.id.propellantTxt);
TextView descTxt= (TextView) convertView.findViewById(R.id.descTxt);
final Spacecraft s= (Spacecraft) this.getItem(position);
nameTxt.setText(s.getName());
propTxt.setText(s.getPropellant());
descTxt.setText(s.getDescription());
//ONITECLICK
convertView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(c,s.getName(),Toast.LENGTH_SHORT).show();
}
});
return convertView;
}
}
This is our MainActivity, our launcher activity.
No. | Responsibility |
---|---|
1. | It will maintain a couple of objects as instance fields including: DatabaseReference,FirebaseHelper,CustomAdapter, GridView and three EditTexts. |
2. | Define a method to instantiate our Dialog object, set it's title, set its ConteView and finally show it.This dialog is our input dialog with edittexts and save/retrieve buttons. |
3. | Search all the input widgets defined in input_dialog.xml and assign them to their respective instance objects.These include EditTexts and Buttons. |
4. | Listen to Save button click events, then obtain edittext values, assign those values to a Spacecraft object and with the help of FirebaseHelper instance send that object to Firebase realtime database. |
5. | Override the onCreate() method,call it's super equivalence. |
6. | Find Toolbar in our layout and use it as our actionbar. |
7. | Get FirebaseDatabase instance then it's reference and pass it to our FirebaseHelper constructor. |
8. | Instantiate CustomAdapter , find Gridview from our layout, then assign the adapter to the Gridview. |
9. | Listen to FAB button click event and show the input dialog. |
package com.tutorials.hp.firebasegridviewmulti_items;
import android.app.Dialog;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.GridView;
import android.widget.Toast;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.tutorials.hp.firebasegridviewmulti_items.m_FireBase.FirebaseHelper;
import com.tutorials.hp.firebasegridviewmulti_items.m_Model.Spacecraft;
import com.tutorials.hp.firebasegridviewmulti_items.m_UI.CustomAdapter;
/*
1.INITIALIZE FIREBASE DB
2.INITIALIZE UI
3.DATA INPUT
*/
public class MainActivity extends AppCompatActivity {
DatabaseReference db;
FirebaseHelper helper;
CustomAdapter adapter;
GridView gv;
EditText nameEditTxt,propTxt,descTxt;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
gv= (GridView) findViewById(R.id.gv);
//INITIALIZE FIREBASE DB
db= FirebaseDatabase.getInstance().getReference();
helper=new FirebaseHelper(db);
//ADAPTER
adapter=new CustomAdapter(this,helper.retrieve());
gv.setAdapter(adapter);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
displayInputDialog();
}
});
}
//DISPLAY INPUT DIALOG
private void displayInputDialog()
{
Dialog d=new Dialog(this);
d.setTitle("Save To Firebase");
d.setContentView(R.layout.input_dialog);
nameEditTxt= (EditText) d.findViewById(R.id.nameEditText);
propTxt= (EditText) d.findViewById(R.id.propellantEditText);
descTxt= (EditText) d.findViewById(R.id.descEditText);
Button saveBtn= (Button) d.findViewById(R.id.saveBtn);
//SAVE
saveBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//GET DATA
String name=nameEditTxt.getText().toString();
String propellant=propTxt.getText().toString();
String desc=descTxt.getText().toString();
//SET DATA
Spacecraft s=new Spacecraft();
s.setName(name);
s.setPropellant(propellant);
s.setDescription(desc);
//SIMPLE VALIDATION
if(name != null && name.length()>0)
{
//THEN SAVE
if(helper.save(s))
{
//IF SAVED CLEAR EDITXT
nameEditTxt.setText("");
propTxt.setText("");
descTxt.setText("");
adapter=new CustomAdapter(MainActivity.this,helper.retrieve());
gv.setAdapter(adapter);
}
}else
{
Toast.makeText(MainActivity.this, "Name Must Not Be Empty", Toast.LENGTH_SHORT).show();
}
}
});
d.show();
}
}
Resource | Link |
---|---|
GitHub Browse | Browse |
GitHub Download Link | Download |
This is an android firebase tutorial. The aim is to write, read and show data in a GridView.
User can then click a particular gridview item and move to a new activity transferring data over there.
This is an android firebase gridview tutorial. How to save data to firebase,retrieve then show that data in a custom gridview.
Let's go.
No. | File | Major Responsibility |
---|---|---|
1. | Spacecraft.java | Represents a single Spacecraft and it's properties like name,propellant and description. |
2. | FirebaseHelper.java | This class has allows us perform Firebase CRUD operations. |
3. | CustomAdapter.java | Our adapter class |
4. | DetailActivity.java | Our Detail Activity to show a single spacecraft's details. |
5. | MainActivity.java | Our Master Activity. It shows the grid of Spacecrafts |
6. | activity_main.xml | Our Master Activity's layout. |
7. | content_main.xml | Our Master Activity's content detail. |
8. | activity_detail.xml | Our Detail Activity's main layout. |
9. | content_detail.xml | Our Detail Activity's content layout. |
10. | input_dialog.xml | Our input dialog layout. |
11. | model.xml | Each GridView's grid model. |
Go ahead create you Firebase Database realtime in your Firebase account.
Then download the google.json
file and add it to your project at the app level:
In your dependencies add Firebase dependencies then apply the googleservices plugin as below:
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.3.0'
compile 'com.android.support:design:23.3.0'
compile 'com.android.support:cardview-v7:23.3.0'
compile 'com.google.firebase:firebase-core:9.0.2'
compile 'com.google.firebase:firebase-database:9.0.2'
}
apply plugin: 'com.google.gms.google-services'
Finally add internet permission in your AndroidManifest.xml as we will be accessing internet:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.tutorials.hp.firebasegridviewmdetail">
<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"
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>
<activity
android:name=".DetailActivity"
android:label="@string/title_activity_detail"
android:theme="@style/AppTheme.NoActionBar"></activity>
</application>
</manifest>
Go ahead create a SecondActivity that will be used as the Detail View.
It will display selected Spacecraft details.
We'll look at its source later. However note that it will add two XML layouts: activity_detail
and content_detail
to our layout resources.
Here are our layouts for this project:
This layout gets included in your activity_main.xml. We define our GridView here.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.tutorials.hp.firebasegridviewmdetail.MainActivity"
tools:showIn="@layout/activity_main">
<GridView
android:id="@+id/gv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:numColumns="2"
/>
</RelativeLayout>
Our SecondActivity's layout. Virtually the same as the activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<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="com.tutorials.hp.firebasegridviewmdetail.DetailActivity">
<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="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<include layout="@layout/content_detail" />
<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"
android:src="@android:drawable/ic_dialog_email" />
</android.support.design.widget.CoordinatorLayout>
The SecondActivity's content layout.
Will be included into the activity_detail.xml.
We add a CardView with an imageview and TextView that will be used to show the details of our Spacecraft.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.tutorials.hp.firebasegridviewmdetail.DetailActivity"
tools:showIn="@layout/activity_detail">
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_margin="5dp"
card_view:cardCornerRadius="10dp"
card_view:cardElevation="5dp"
android:layout_height="match_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:weightSum="1">
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="@+id/articleDetailImg"
android:layout_width="320dp"
android:layout_height="wrap_content"
android:paddingLeft="10dp"
android:layout_alignParentTop="true"
android:scaleType="centerCrop"
android:src="@drawable/spitzer" />
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/nameDetailTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:padding="5dp"
android:minLines="1"
android:textStyle="bold"
android:textColor="@color/colorAccent"
android:text="Title" />
<TextView
android:id="@+id/descDetailTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:padding="5dp"
android:textColor="#0f0f0f"
android:minLines="4"
android:text="Space craft details...." />
</LinearLayout>
</LinearLayout>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_marginTop="?attr/actionBarSize"
android:orientation="vertical"
android:paddingLeft="5dp"
android:paddingRight="5dp"
android:paddingTop="5dp">
<TextView
android:id="@+id/propellantDetailTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:padding="5dp"
android:minLines="1"
android:text="DATE" />
<TextView
android:id="@+id/linkDetailTxt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:padding="5dp"
android:textColor="@color/colorPrimaryDark"
android:textStyle="italic"
android:text="Link" />
</LinearLayout>
</LinearLayout>
</android.support.v7.widget.CardView>
</RelativeLayout>
This layout will be inflated into a dialog. Our input dialog.
Users can then perform CRUD via this 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">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_marginTop="?attr/actionBarSize"
android:orientation="vertical"
android:paddingLeft="15dp"
android:paddingRight="15dp"
android:paddingTop="50dp">
<android.support.design.widget.TextInputLayout
android:id="@+id/nameLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/nameEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:singleLine="true"
android:hint= "Name" />
</android.support.design.widget.TextInputLayout>
<android.support.design.widget.TextInputLayout
android:id="@+id/propLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/propellantEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:singleLine="true"
android:hint= "Propellant" />
<android.support.design.widget.TextInputLayout
android:id="@+id/descLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/descEditText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:singleLine="true"
android:hint= "Description" />
</android.support.design.widget.TextInputLayout>
</android.support.design.widget.TextInputLayout>
<Button android:id="@+id/saveBtn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Save"
android:clickable="true"
android:background="@color/colorAccent"
android:layout_marginTop="40dp"
android:textColor="@android:color/white"/>
</LinearLayout>
</LinearLayout>
Our GridView will have images and text from our Firebase. We therefore need to create a custom model layout for each Grid.
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_margin="10dp"
card_view:cardCornerRadius="5dp"
card_view:cardElevation="5dp"
android:layout_height="200dp">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Name"
android:id="@+id/nameTxt"
android:padding="10dp"
android:textColor="@color/colorAccent"
android:textStyle="bold"
android:layout_alignParentLeft="true"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Description....................."
android:lines="3"
android:id="@+id/descTxt"
android:padding="10dp"
android:layout_alignParentLeft="true"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Propellant"
android:textStyle="italic"
android:id="@+id/propellantTxt" />
</LinearLayout>
</android.support.v7.widget.CardView>
Android projects get written in Java so let's write some Java code for our Firebase project.
This is our data object class. Here's its responsibilities:
No. | Responsibility |
---|---|
1. | Represents a Single Spacecraft |
2. | Set Spacecraft properties: name,propellant and description. |
3. | Get Spacecraft properties: name,propellant and description. |
package com.tutorials.hp.firebasegridviewmdetail.m_Model;
/*
* 1. OUR MODEL CLASS
*/
public class Spacecraft {
String name,propellant,description;
public Spacecraft() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPropellant() {
return propellant;
}
public void setPropellant(String propellant) {
this.propellant = propellant;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
This class allows us perform save and retrieve data to Firebase Realtime database.
No. | Responsibility |
---|---|
1. | Keep hold of three Objects: DatabaseReference,a Boolean saved value, and an ArrayList of Spacecrafts. |
2. | Obtain a DatabaseReference object via the constructor and Assign it to our local db data member. |
3. | Take a Spacecraft object and save it to Firebase this returning a Boolean indicating success or failure. |
4. | Loop through DataSnapshot children nodes obtaining all the Spacecraft objects from Firebase and fill our local arraylist with those objects. |
5. | Listen to Firebase Children mutation events like when a DataSnapshot child has been added, moved, removed, changed or cancelled. This allows us to fetch data in realtime. |
package com.tutorials.hp.firebasegridviewmdetail.m_FireBase;
import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseException;
import com.google.firebase.database.DatabaseReference;
import com.tutorials.hp.firebasegridviewmdetail.m_Model.Spacecraft;
import java.util.ArrayList;
/*
* 1.SAVE DATA TO FIREBASE
* 2. RETRIEVE
* 3.RETURN AN ARRAYLIST
*/
public class FirebaseHelper {
DatabaseReference db;
Boolean saved=null;
ArrayList<Spacecraft> spacecrafts=new ArrayList<>();
public FirebaseHelper(DatabaseReference db) {
this.db = db;
}
//WRITE IF NOT NULL
public Boolean save(Spacecraft spacecraft)
{
if(spacecraft==null)
{
saved=false;
}else
{
try
{
db.child("Spacecraft").push().setValue(spacecraft);
saved=true;
}catch (DatabaseException e)
{
e.printStackTrace();
saved=false;
}
}
return saved;
}
//IMPLEMENT FETCH DATA AND FILL ARRAYLIST
private void fetchData(DataSnapshot dataSnapshot)
{
spacecrafts.clear();
for (DataSnapshot ds : dataSnapshot.getChildren())
{
Spacecraft spacecraft=ds.getValue(Spacecraft.class);
spacecrafts.add(spacecraft);
}
}
//READ BY HOOKING ONTO DATABASE OPERATION CALLBACKS
public ArrayList<Spacecraft> retrieve() {
db.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
fetchData(dataSnapshot);
}
@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
fetchData(dataSnapshot);
}
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
return spacecrafts;
}
}
This is our adapter class. It derives from BaseAdapter.
No. | Responsibility |
---|---|
1. | This class will maintain a Context object that will be used to during layout inflation. Furthermore we declare an ArrayList of Spacecrafts that will be bound to our GridView. |
2. | Receive a Context and ArrayList of Spacecrafts from outside and assign them to our local instance fields. |
3. | Return data list count,Item and Item Identifier. |
4. | Inflate our model.xml layout and return it as a View when the getView() is called. |
5. | Listen to the inflated View click event and open our Master activity. |
6. | Pass the clicked spacecraft's details to the Detail Activity. |
package com.tutorials.hp.firebasegridviewmdetail.m_UI;
import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import com.tutorials.hp.firebasegridviewmdetail.DetailActivity;
import com.tutorials.hp.firebasegridviewmdetail.R;
import com.tutorials.hp.firebasegridviewmdetail.m_Model.Spacecraft;
import java.util.ArrayList;
/*
* 1. where WE INFLATE OUR MODEL LAYOUT INTO VIEW ITEM
* 2. THEN BIND DATA
*/
public class CustomAdapter extends BaseAdapter {
Context c;
ArrayList<Spacecraft> spacecrafts;
public CustomAdapter(Context c, ArrayList<Spacecraft> spacecrafts) {
this.c = c;
this.spacecrafts = spacecrafts;
}
@Override
public int getCount() {
return spacecrafts.size();
}
@Override
public Object getItem(int position) {
return spacecrafts.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView==null)
{
convertView= LayoutInflater.from(c).inflate(R.layout.model,parent,false);
}
TextView nameTxt= (TextView) convertView.findViewById(R.id.nameTxt);
TextView propTxt= (TextView) convertView.findViewById(R.id.propellantTxt);
TextView descTxt= (TextView) convertView.findViewById(R.id.descTxt);
final Spacecraft s= (Spacecraft) this.getItem(position);
nameTxt.setText(s.getName());
propTxt.setText(s.getPropellant());
descTxt.setText(s.getDescription());
convertView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//OPEN DETAIL
openDetailActivity(s.getName(),s.getDescription(),s.getPropellant());
}
});
return convertView;
}
//OPEN DETAIL ACTIVITY
private void openDetailActivity(String...details)
{
Intent i=new Intent(c,DetailActivity.class);
i.putExtra("NAME_KEY",details[0]);
i.putExtra("DESC_KEY",details[1]);
i.putExtra("PROP_KEY",details[2]);
c.startActivity(i);
}
}
This is our DetailActivity. It will show the details of our Spacecraft.
Here's it's responsibilities and how it works:
No. | Responsibility |
---|---|
1. | Maintain three TextView objects as private instance fields that will be used to show Spacecraft details. |
2. | Override the onCreate() method. Call the super class version of onCreate() as well. |
3. | Inflate the activity_detail via the setContentView() to a View object and set it as the detail Activity's main UI. |
4. | Find the toolbar from activity_detail and set it as the actionbar of our SecondActivity. |
5. | Find TextViews defined in the content_detail.xml and assign them to our local TextView objects. |
6. | Retrieve the Intent assoicated with our SecondActivity via the getIntent() call. |
7. | Obtain name, description and propellant of our Spacecraft via the getExtras() method calls of our Intent.Then set those values to our TextView objects. |
package com.tutorials.hp.firebasegridviewmdetail;
import android.content.Intent;
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.widget.TextView;
public class DetailActivity extends AppCompatActivity {
TextView nameTxt,descTxt, propTxt;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_detail);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
nameTxt = (TextView) findViewById(R.id.nameDetailTxt);
descTxt= (TextView) findViewById(R.id.descDetailTxt);
propTxt = (TextView) findViewById(R.id.propellantDetailTxt);
//get intent
Intent i=this.getIntent();
//RECEIVE DATA
String name=i.getExtras().getString("NAME_KEY");
String desc=i.getExtras().getString("DESC_KEY");
String propellant=i.getExtras().getString("PROP_KEY");
//BIND DATA
nameTxt.setText(name);
descTxt.setText(desc);
propTxt.setText(propellant);
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();
}
});
}
}
This is our MainActivity. Our project has two activities and this is the main one. It will be the one launched when we launch our application.
It is also our Master View and will contain a grid of Spacecraft objects.
No. | Responsibility |
---|---|
1. | It will maintain a couple of objects as instance fields including: DatabaseReference,FirebaseHelper,CustomAdapter, GridView and three EditTexts. |
2. | Define a method to instantiate our Dialog object, set it's title, set its ConteView and finally show it.This dialog is our input dialog with edittexts and save/retrieve buttons. |
3. | Search all the input widgets defined in input_dialog.xml and assign them to their respective instance objects.These include EditTexts and Buttons. |
4. | Listen to Save button click events, then obtain edittext values, assign those values to a Spacecraft object and with the help of FirebaseHelper instance send that object to Firebase realtime database. |
5. | Override the onCreate() method,call it's super equivalence. |
6. | Find Toolbar in our layout and use it as our actionbar. |
7. | Get FirebaseDatabase instance then it's reference and pass it to our FirebaseHelper constructor. |
8. | Instantiate CustomAdapter , find Gridview from our layout, then assign the adapter to the Gridview. |
9. | Listen to FAB button click event and show the input dialog. |
package com.tutorials.hp.firebasegridviewmdetail;
import android.app.Dialog;
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.Button;
import android.widget.EditText;
import android.widget.GridView;
import android.widget.Toast;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.tutorials.hp.firebasegridviewmdetail.m_FireBase.FirebaseHelper;
import com.tutorials.hp.firebasegridviewmdetail.m_Model.Spacecraft;
import com.tutorials.hp.firebasegridviewmdetail.m_UI.CustomAdapter;
/*
1.INITIALIZE FIREBASE DB
2.INITIALIZE UI
3.DATA INPUT
*/
public class MainActivity extends AppCompatActivity {
DatabaseReference db;
FirebaseHelper helper;
CustomAdapter adapter;
GridView gv;
EditText nameEditTxt,propTxt,descTxt;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
gv= (GridView) findViewById(R.id.gv);
//INITIALIZE FIREBASE DB
db= FirebaseDatabase.getInstance().getReference();
helper=new FirebaseHelper(db);
//ADAPTER
adapter=new CustomAdapter(this,helper.retrieve());
gv.setAdapter(adapter);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
displayInputDialog();
}
});
}
//DISPLAY INPUT DIALOG
private void displayInputDialog()
{
Dialog d=new Dialog(this);
d.setTitle("Save To Firebase");
d.setContentView(R.layout.input_dialog);
nameEditTxt= (EditText) d.findViewById(R.id.nameEditText);
propTxt= (EditText) d.findViewById(R.id.propellantEditText);
descTxt= (EditText) d.findViewById(R.id.descEditText);
Button saveBtn= (Button) d.findViewById(R.id.saveBtn);
//SAVE
saveBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//GET DATA
String name=nameEditTxt.getText().toString();
String propellant=propTxt.getText().toString();
String desc=descTxt.getText().toString();
//SET DATA
Spacecraft s=new Spacecraft();
s.setName(name);
s.setPropellant(propellant);
s.setDescription(desc);
//SIMPLE VALIDATION
if(name != null && name.length()>0)
{
//THEN SAVE
if(helper.save(s))
{
//IF SAVED CLEAR EDITXT
nameEditTxt.setText("");
propTxt.setText("");
descTxt.setText("");
adapter=new CustomAdapter(MainActivity.this,helper.retrieve());
gv.setAdapter(adapter);
}
}else
{
Toast.makeText(MainActivity.this, "Name Must Not Be Empty", Toast.LENGTH_SHORT).show();
}
}
});
d.show();
}
}
Resource | Link |
---|---|
GitHub Browse | Browse |
GitHub Download Link | Download |
Video Tutorial | Video |