android activity stack- back navigation

Question

I am developing an app which has a home screen consisting of list view(Home Activity).User clicks on list item and new activity is started named as Topic.This activity also consist of list view. Home is set as parent activity for Topic.

Now in Topic class i am again calling Topic class using intent.

So a user clicks on a list item in Home activity,which opens a new Topic activity.User again clicks on list item ,and another new activity Topic is created,so we are at rd level. My app is working fine till here, but as Parent for Topic is Home,so as soon as i press back or up button,irrespective of where i am in my app,it is always the Home class which opens.

How to handle this so that all user can traverse back to each activity.

The code is given below:

Home.java

package com.example.guninder.home;

 import android.app.ListActivity;
 import android.app.ProgressDialog;
 import android.content.Intent;
 import android.support.v4.widget.DrawerLayout;
 import android.support.v7.app.ActionBar;
 import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;

import java.util.List;

import static android.widget.AdapterView.*;


public class Home extends AppCompatActivity implements FetchDataListener {
private ProgressDialog dialog;
private ListView HomeListview;
private DrawerLayout home_drawer_layout;
private ListView Menu_option_list;
private String[] Menu_list;
private ActionBarDrawerToggle drawerToggle;
private ApplicationAdaptor adapter;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);
    HomeListview = (ListView) findViewById(R.id.listView1);
    itemClickListener(HomeListview);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setHomeButtonEnabled(true);

    Menu_list = getResources().getStringArray(R.array.Menu_options);
    home_drawer_layout = (DrawerLayout) findViewById(R.id.home_drawable);
    Menu_option_list = (ListView) findViewById(R.id.home_menu_option);
    Menu_option_list.setAdapter(new ArrayAdapter<>(this, android.R.layout.simple_expandable_list_item_1, Menu_list));
    // home_Toolbar.setNavigationIcon(R.drawable.ic_drawer);
    drawerToggle = new ActionBarDrawerToggle(this, home_drawer_layout, R.string.drawer_open, R.string.drawer_close) {
        @Override
        public void onDrawerOpened(View drawerView) {
            super.onDrawerOpened(drawerView);
        }

        @Override
        public void onDrawerClosed(View drawerView) {
            super.onDrawerClosed(drawerView);
        }

    };
    drawerToggle.setDrawerIndicatorEnabled(true);
    home_drawer_layout.setDrawerListener(drawerToggle);
    initView();


}

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

private void initView() {
    // show progress dialog
    dialog = ProgressDialog.show(this, "", "Loading...");

  // String url = "http://dexterous.comuv.com/connect.php";
    String url = "http://192.168.0.25/connect.php";

    FetchDataTask task = new FetchDataTask(this);
    task.execute(url,null);
}

@Override
public void onFetchComplete(List<Application> data) {
    // dismiss the progress dialog
    if (dialog != null) dialog.dismiss();
    // create new adapter
    adapter = new ApplicationAdaptor(this, data);
    HomeListview.setAdapter(adapter);
    // set the adapter to list
    //setListAdapter(adapter);
}

public void onPostCreate(Bundle savedInstanceState){
    super.onPostCreate(savedInstanceState);
    drawerToggle.syncState();
}

@Override
public void onFetchFailure(String msg) {
    // dismiss the progress dialog
    if (dialog != null) dialog.dismiss();
    // show failure message
    Toast.makeText(this, msg, Toast.LENGTH_LONG).show();
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }
    if(drawerToggle.onOptionsItemSelected(item)){
        return true;
    }

    return super.onOptionsItemSelected(item);
}

public void itemClickListener(final ListView HomeListview) {
    HomeListview.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            Application app = adapter.getItem(position);

            Intent intent = new Intent(Home.this, Topic.class);
            intent.putExtra("topic_name",app.getTitle());
            intent.putExtra("topic_id", app.getTopic_id());
            intent.putExtra("Content", app.getParentContent());
            Toast toast=Toast.makeText(Home.this,app.getParentContent(),Toast.LENGTH_LONG);
            startActivity(intent);
        }
    });
}


}

Topic.java

 package com.example.guninder.home;

import android.app.ProgressDialog;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.method.ScrollingMovementMethod;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.List;

public class Topic extends AppCompatActivity implements FetchDataListener {
String topicName, ParentContent;
int topic_id;
//TextView txv;
ProgressDialog Topicdialog;
ListView topiclistView;
ApplicationAdaptor tAdaptor;
TextView txv;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_topic);
    Bundle extras = getIntent().getExtras();
    if (extras == null) {
        topicName = null;
    }
    topicName = extras.getString("topic_name");
    topic_id = extras.getInt("topic_id");
    ParentContent = extras.getString("Content");
    txv = (TextView) findViewById(R.id.content);
    txv.setMovementMethod(ScrollingMovementMethod.getInstance());
    if (ParentContent.isEmpty()) {
        txv.setVisibility(txv.GONE);
    } else {
        txv.setText(ParentContent);
    }

    setTitle(topicName);
    topiclistView = (ListView) findViewById(R.id.topiclistView1);
    itemClickListener(topiclistView);
    topicinitView();


}
@Override
public void onPause(){
    super.onPause();
}

public void onResume(){
    super.onResume();
}

private void topicinitView() {
    // show progress dialog
    Topicdialog = ProgressDialog.show(this, "", "Loading...");

   // String url = "http://dexterous.comuv.com/Topic.php";
    String url = "http://192.168.0.25/Topic.php";

    FetchDataTask task = new FetchDataTask(this);
    task.execute(url, String.valueOf(topic_id));
}

@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_topic, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@Override
public void onFetchComplete(List<Application> data) {
    if (Topicdialog != null) Topicdialog.dismiss();
    // create new adapter
    tAdaptor = new ApplicationAdaptor(this, data);
    topiclistView.setAdapter(tAdaptor);
    // set the adapter to list
    //setListAdapter(adapter);

}

@Override
public void onFetchFailure(String msg) {
    // dismiss the progress dialog
    if (Topicdialog != null) Topicdialog.dismiss();
    // show failure message
    Toast.makeText(this, msg, Toast.LENGTH_LONG).show();
}


public void itemClickListener(final ListView TopicListview) {
    TopicListview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            Application app = tAdaptor.getItem(position);
            if (app.getChildExist()) {
                Intent intent = new Intent(Topic.this, Topic.class);
                intent.putExtra("topic_name", app.getTitle());
                intent.putExtra("topic_id", app.getTopic_id());
                intent.putExtra("Content", app.getParentContent());
               // Toast toast = Toast.makeText(Topic.this,    app.getTopic_id(), Toast.LENGTH_LONG);
                //toast.show();
                startActivity(intent);
                finish();
            }


        }
    });
}
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.guninder.home" >

    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".Home"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".Topic"
            android:label="@string/title_activity_topic"
            android:parentActivityName=".Home" >
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.example.guninder.home.Home" />
        </activity>
        <activity
            android:name=".SetNotification"
            android:label="@string/title_activity_set_notification"
            android:theme="@android:style/Theme.Dialog" >
        </activity>
    </application>

    </manifest>

Please help.Thanks in advance

Answer 1

Comment finish() inside the listitem click in topic class. it will solve your problem.