Android Hub 4 you : the free android programming tutorial: October 2015

Hello Friends,

Today I am going to share code for how to create android fragment and how to handle back stack. Have a look at below code or you can download full code from GIT server.

1)LoginActivity.java-

package com.androidhub4you.fragmentdemo;

import android.content.Intent;

import android.os.Bundle;

import android.support.v7.app.ActionBarActivity;

import android.view.View;

public class LoginActivity extends ActionBarActivity {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_login);

findViewById(R.id.button__activity_main).setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

Intent mIntent=new Intent(LoginActivity.this,MainActivity.class);

startActivity(mIntent);

}

});

}

2)activity_login.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=".MainActivity">

<TextView

android:layout_width="wrap_content"

android:text="Login Activity"

android:textSize="26sp"

android:textStyle="bold"

android:layout_marginTop="20dp"

android:layout_centerHorizontal="true"

android:layout_height="wrap_content" />

<TextView

android:layout_above="@+id/button__activity_main"

android:layout_width="match_parent"

android:text="(From Login Activity we will open Main Activity and inside Main Activity we will add Main Fragment in container)"

android:textSize="18sp"

android:textStyle="bold"

android:gravity="center"

android:layout_marginBottom="50dp"

android:layout_centerHorizontal="true"

android:layout_height="wrap_content" />

<Button

android:id="@+id/button__activity_main"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:paddingBottom="15dp"

android:text="Open Main Activity"

android:textSize="20sp"

android:layout_centerInParent="true"

android:paddingTop="15dp" />

</RelativeLayout>

 3)MainActivity.java-


package com.androidhub4you.fragmentdemo;

import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;


/**
 * Manish Srivastava
 */

public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Log.v("<<main activity>>", "<<screen>>");

        //display home back button
        ActionBar actionBar = getSupportActionBar();
        actionBar.setDisplayShowHomeEnabled(true);
        actionBar.setDisplayHomeAsUpEnabled(true);

        //In side Create method of MainActivity we will add main fragment
        FragmentTransaction transaction = getFragmentManager().beginTransaction();
        FragmentMain fragmentMain = new FragmentMain();
        transaction.addToBackStack("fragmentMain");
        transaction.replace(R.id.container, fragmentMain);
        transaction.commit();

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                handleBackStack();
                break;
            case R.id.action_settings:
                //do nothing
                break;

        }
        return super.onOptionsItemSelected(item);
    }

    //handle back stack from hardware back button and top action bar home back button
    public boolean handleBackStack() {
        //on back press check the count of fragment in stack
        int count = getFragmentManager().getBackStackEntryCount();
        Log.v("<<Fragment in stack>>",String.valueOf(count));
        if (count == 1) {
            //if count is 0 then finish main activity
            finish();
        }else {
            //else remove one fragment from the stack
            FragmentTransaction transaction = getFragmentManager().beginTransaction();
            getFragmentManager().popBackStackImmediate();
            transaction.commit();
        }
        return true;
    }

    //set action bar title name
    public void setActionBarTitle(String title) {
       getSupportActionBar().setTitle(title);
    }
    //handle the hardware back press
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(keyCode==KeyEvent.KEYCODE_BACK){
            handleBackStack();
            return  true;
        }
        return super.onKeyDown(keyCode, event);
    }
}



4)activity_main.xml-

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <FrameLayout
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

5)FragmentMain.java-

package com.androidhub4you.fragmentdemo;

import android.app.FragmentTransaction;
import android.os.Bundle;
import android.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

/**
 * Manish Srivastava
 */
public class FragmentMain extends Fragment {


    public FragmentMain() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_main, container, false);
        final Button mButtonFragmentMain=(Button)view.findViewById(R.id.button__fragment_main);

        Log.v("<< main fragment>>","<<screen>>");

        mButtonFragmentMain.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //call the child fragment
                FragmentTransaction transaction = getFragmentManager().beginTransaction();
                FragmentChild fragmentChild = new FragmentChild();
                transaction.addToBackStack("fragmentChild");
                transaction.replace(R.id.container, fragmentChild);
                transaction.commit();

            }
        });

        //call the main activity set tile method
        ((MainActivity)getActivity()).setActionBarTitle("Home Fragment");

        return view;
    }
}

6)fragment_main.xml-

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    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">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="20dp"
        android:text="Main Fragment Screen"
        android:textSize="26sp"
        android:textStyle="bold" />

    <Button
        android:id="@+id/button__fragment_main"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:paddingBottom="15dp"
        android:paddingTop="15dp"
        android:text="Open Child Fragment"
        android:textSize="20sp" />
</RelativeLayout>

7)FragmentChild.java-

package com.androidhub4you.fragmentdemo;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

/**
 * Manish Srivastava
 */
public class FragmentChild extends Fragment {


    public FragmentChild() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_child, container, false);

        //call the main activity set tile method
        ((MainActivity)getActivity()).setActionBarTitle("Child Fragment");


        return view;
    }
}

8)fragment_child.xml-

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    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">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="Child Fragment Screen"
        android:textSize="26sp"
        android:textStyle="bold" />
</RelativeLayout>

DOWNLOAD FULL CODE

Thanks!

Manish

Android Hub 4 you : the free android programming tutorial

Pages

Sunday, October 18, 2015

Android Fragmnet Example code with full stack maintain | Fragment demo application | Simple Fragment example with action bar back button stack handle