Develop Reference

Issues with Listview in a Fragment in Android

I have a ListView in a ListFragment and in the code I wrote a code that says when an item of listview is clicked, open another activity.
The problem is when I click on an item, nothing happens!
This code works fine in an Activity, but not in a Fragment.
Code:
ListView lv = (ListView) v.findViewById(android.R.id.list);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String pid = ((TextView) view.findViewById(R.id.pid)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getActivity().getApplicationContext(),
EditProductActivity.class);
// sending pid to next activity
in.putExtra(TAG_PID, pid);
// starting new activity and expecting some response back
startActivity(in);
}
});
I replaced this code :
ListView lv = (ListView) v.findViewById(android.R.id.list);
with :
ListView lv = getListView();
Because it was giving me
content view not yet created
in logcat.
All the code:
package rappage.rapfarsi.media.appteam;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.StrictMode;
import android.support.annotation.Nullable;
import android.support.v4.app.ListFragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class tab1 extends ListFragment {
static final String url_all_products = "http://aliak.xzn.ir/rap/get_all_products.php";
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> productsList;
// url to get all products list
final String TAG_SUCCESS = "success";
final String TAG_PRODUCTS = "products";
final String TAG_PID = "pid";
final String TAG_NAME = "name";
// JSON Node names
// products JSONArray
JSONArray products = null;
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.tab_1, container, false);
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
// Get listview
ListView lv = (ListView) v.findViewById(android.R.id.list);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String pid = ((TextView) view.findViewById(R.id.pid)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getActivity().getApplicationContext(),
EditProductActivity.class);
// sending pid to next activity
in.putExtra(TAG_PID, pid);
// starting new activity and expecting some response back
startActivity(in);
}
});
return v;
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Loading products. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_PID);
String name = c.getString(TAG_NAME);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_PID, id);
map.put(TAG_NAME, name);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
Intent i = new Intent(getActivity().getApplicationContext(),
Main.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
getActivity().runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
getActivity(), productsList,
R.layout.list_item, new String[] { TAG_PID,
TAG_NAME},
new int[] { R.id.pid, R.id.name });
// updating listview
setListAdapter(adapter);
}
});
}
}
}
I hope you can help me....thanks

Extending from ListFragment you only have to redefine this method:
#Override
public void onListItemClick(ListView l, View v, int position, long id) {
//Handle click event
}
Instead of getting the list and setting its onItemClickListener

how to speed up my android app

I have recently developed an android app, which is parsing the xml links, whenever i use the app it responds very slowly, because each time i open the app and navigate the pages on the app, it parse it then give the data,
is there any way so that i could speed up the app, i have searched for it on google, but have not got any idea, it stated to use the volley library, but no result as i am unable to use that,
plz help guys if anyone has any option , is there any way that i could parse the link and store it into the cache and then retrive from there..
package com.stepupup.pm;
import info.stepupup.tabswipe.R;
import java.util.ArrayList;
import java.util.HashMap;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import android.content.Context;
import android.content.Intent;
import android.graphics.Typeface;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
public class Cricket extends ListFragment {
static final String URL = "http://www.statenewsonline.com/category/sports/cricket/feed";
// XML node keys
static final String KEY_ITEM = "item"; // parent node
static final String KEY_NAME = "title";
static final String KEY_COST = "link";
static final String KEY_DESC = "content:encoded";
static final String KEY_PUB = "pubDate";
Context context;
Typeface font;
String nam,cost,desc,ti,cdesc,lnk1;
TextView t1;;
TextView t2,t3,t5,t15;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.cricket, container, false);
font=Typeface.createFromAsset(getActivity().getAssets(), "DroidHindi.ttf");
return rootView;
}
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL); // getting XML
Document doc = parser.getDomElement(xml); // getting DOM element
NodeList nl = doc.getElementsByTagName(KEY_ITEM);
// looping through all item nodes <item>
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
// adding each child node to HashMap key => value
map.put(KEY_NAME, (parser.getValue(e, KEY_NAME)));
map.put(KEY_COST, parser.getValue(e, KEY_COST));
map.put(KEY_DESC, parser.getValue(e, KEY_DESC));
map.put(KEY_PUB, parser.getValue(e, KEY_PUB));
// map.put(KEY_CDESC, parser.getValue(e, KEY_CDESC));
// adding HashList to ArrayList
menuItems.add(map);
}
ListAdapter adapter = new SimpleAdapter(getActivity(), menuItems,
R.layout.list_item,
new String[] { KEY_NAME, KEY_DESC,KEY_COST}, new int[] {
R.id.name1, R.id.description, R.id.link1}){
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewGroup view = (ViewGroup) super.getView(position, convertView, parent);
if(convertView == null) Cricket.setAppFont(view, font);
t1=(TextView)view.findViewById(R.id.name1);
t1.setTypeface(font);
t2=((TextView)view.findViewById(R.id.description));
t2.setTypeface(font);
t15=(TextView)view.findViewById(R.id.link1);
t15.setTypeface(font);
return view;
}
};
setListAdapter(adapter);
// selecting single ListView item
ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
t1=(TextView)view.findViewById(R.id.name1);
nam=t1.getText().toString();
t2=((TextView)view.findViewById(R.id.description));
desc = t2.getText().toString();
t15=(TextView)view.findViewById(R.id.link1);
lnk1=t15.getText().toString();
// cost = ((TextView) view.findViewById(R.id.cost)).getText().toString();
ti = ((TextView) view.findViewById(R.id.time)).getText().toString();
// Starting new intent
Intent in = new Intent(getActivity(), SingleMenuItemActivity.class);
in.putExtra(KEY_NAME, nam);
in.putExtra(KEY_COST, lnk1);
in.putExtra(KEY_DESC, desc);
in.putExtra(KEY_PUB, ti);
startActivity(in);
}
});
}
protected static void setAppFont(ViewGroup view, Typeface font2) {
// TODO Auto-generated method stub
}
}
and the folllwing is my xml file..
<?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"
android:orientation="vertical"
android:background="#ffffff" >
<ListView
android:id="#android:id/list"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</ListView>
</LinearLayout>

Android Documentation says,
We recommend XmlPullParser, which is an efficient and maintainable way
to parse XML on Android. Historically Android has had two
implementations of this interface:
KXmlParser via XmlPullParserFactory.newPullParser().
ExpatPullParser, via Xml.newPullParser().
You can find a good example in that page. Don't forget to use Async task and do that network related stuff in background. Good luck!

One obvious problem with your code is that you do network request on the UI thread, here:
public void onActivityCreated(Bundle savedInstanceState) {
...
String xml = parser.getXmlFromUrl(URL); // getting XML
...
}
I don't know where XMLParser is coming from, but, just from the method's name, it is downloading something from the network. You should never do such things on the UI thread. Instead, this should be done on the background thread, and the results should be delivered on the UI thread.
Now which exactly mechanism to use for that is up to you. There are lots of options, with different advantages and trade-offs. AsyncTask mechanism was already mentioned, and it indeed might be an appropriate solution (but not always). Other possibilities are RxJava, RoboSpice, Guava's ListenableFutures, etc.

How to make parsed list items open new class

I have a custom list adapter that reads in data from a xml file that is hosted online, each one is for a different article. My question is how do I make each list item open a different corresponding article? The articles will be hosted online.
Thank you in advance.
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import java.util.ArrayList;
import java.util.HashMap;
public class CustomizedListView extends Fragment { // All static variables
// XML node keys
static final String KEY_SONG = "song"; // parent node
static final String KEY_ID = "id";
static final String KEY_ARTIST = "artist";
static final String KEY_DURATION = "duration";
static final String KEY_THUMB_URL = "thumb_url";
ListView list;
LazyAdapter adapter;
ArrayList<HashMap<String, String>> songsList;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.news, container, false);
songsList = new ArrayList<HashMap<String, String>>();
list=(ListView) rootView.findViewById(R.id.list);
new RetrieveXML().execute(URL);
// Getting adapter by passing xml data ArrayList
// Click event for single list row XMLParser parser = new XMLParser();
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
}
});
return rootView;
}
class RetrieveXML extends AsyncTask<String, Void, String> {
private Exception exception;
XMLParser parser = new XMLParser();
protected String doInBackground(String... urls) {
try {
return parser.getXmlFromUrl(urls[0]);
} catch (Exception e) {
this.exception = e;
return null;
}
}
protected void onPostExecute(String xml) {
Document doc = parser.getDomElement(xml); // getting DOM element
NodeList nl = doc.getElementsByTagName(KEY_SONG);
// looping through all song nodes <song>
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
// adding each child node to HashMap key => value
map.put(KEY_ID, parser.getValue(e, KEY_ID));
map.put(KEY_ARTIST, parser.getValue(e, KEY_ARTIST));
map.put(KEY_DURATION, parser.getValue(e, KEY_DURATION));
map.put(KEY_THUMB_URL, parser.getValue(e, KEY_ID));
map.put(KEY_THUMB_URL, parser.getValue(e, KEY_THUMB_URL));
// adding HashList to ArrayList
songsList.add(map);
}
adapter=new LazyAdapter(getActivity(), songsList);
list.setAdapter(adapter);
}
}
}

You have implemented:
onItemClick()
In this you get the position of item in the list as parameter. here you can write a switch case to accomplish your task. This function gets triggered when any listitem is clicked.
Something like this you can do:
private string[] mArticles={
"abc",
"def",
"ghi",
"jkl"
};
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
openArticle(mArticles[position]);
}
While creating the string array keep appropriate artile link for each item position.

Class extending fragment and listview

I am trying to create a tab using fragments which will display a list of entries after parsing a xml page. But I am unable to extend listactivity int the tab class as it already extends fragments.I have tried implementing listfragments but it is giving me an error on ListAdapter adapter = new SimpleAdapter saying "The constructor SimpleAdapter(Protab1, ArrayList>, int, String[], int[]) is undefined".Could you please help me out.
package com.example.pro1;
import java.util.ArrayList;
import java.util.HashMap;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import android.annotation.TargetApi;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListAdapter;
import android.widget.SimpleAdapter;
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
public class Protab1 extends ListFragment {
// All static variables
static final String URL = "http://api.androidhive.info/pizza/?format=xml";
// XML node keys
static final String KEY_ITEM = "item"; // parent node
static final String KEY_ID = "id";
static final String KEY_NAME = "name";
static final String KEY_COST = "cost";
static final String KEY_DESC = "description";
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.protab1, container, false);
ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL); // getting XML
Document doc = parser.getDomElement(xml); // getting DOM element
NodeList nl = doc.getElementsByTagName(KEY_ITEM);
// looping through all item nodes <item>
for (int i = 0; i < nl.getLength(); i++) {
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element) nl.item(i);
// adding each child node to HashMap key => value
map.put(KEY_ID, parser.getValue(e, KEY_ID));
map.put(KEY_NAME, parser.getValue(e, KEY_NAME));
map.put(KEY_COST, "Rs." + parser.getValue(e, KEY_COST));
map.put(KEY_DESC, parser.getValue(e, KEY_DESC));
// adding HashList to ArrayList
menuItems.add(map);
}
// Adding menuItems to ListView
ListAdapter adapter = new SimpleAdapter(this, menuItems,
R.layout.list_item,
new String[] { KEY_NAME, KEY_DESC, KEY_COST }, new int[] {
R.id.name, R.id.desciption, R.id.cost });
setListAdapter(adapter);
}
}

Try using this.getActivity() instead of this as first parameter of the SimpleAdapter. The first parameter takes a Context object, but since a ListFragment (or any Fragment) does not extend Context, it will not work.

Android OnItemClickListener in list view not working

I'm have made a tab activity which works fine when i click on specific tab i extend the list activity and am also getting the list view but i'm not able to make the items in list clickable. code:
package com.infra.android.views;
import java.util.ArrayList;
import java.util.HashMap;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import android.app.ListActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
public class TopNewsActivity extends ListActivity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listplaceholder);
ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();
String xml = XMLfunctions.getTopNewsXML();
Document doc = XMLfunctions.XMLfromString(xml);
int numResults = XMLfunctions.numResults(doc);
if((numResults <= 0)){
Toast.makeText(TopNewsActivity.this, "No Result Found", Toast.LENGTH_LONG).show();
finish();
}
NodeList nodes = doc.getElementsByTagName("result");
for (int i = 0; i < nodes.getLength(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
Element e = (Element)nodes.item(i);
map.put("id", XMLfunctions.getValue(e, "id"));
map.put("title", XMLfunctions.getValue(e, "title"));
mylist.add(map);
}
ListAdapter adapter = new SimpleAdapter(this, mylist , R.layout.main, new String[] { "title"}, new int[] { R.id.item_title});
setListAdapter(adapter);
final ListView lv = getListView();
lv.setTextFilterEnabled(true);
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
#SuppressWarnings("unchecked")
HashMap<String, String> o = (HashMap<String, String>) lv.getItemAtPosition(position);
Toast.makeText(TopNewsActivity.this, "ID '" + o.get("id") + "' was clicked.", Toast.LENGTH_LONG).show();
}
});
}
}
when i click on the item it should probably give the id of the clicked item but it is not working.

For ListView,
ListView lv = (ListView) findViewById(R.id.ContainlistItems);
lv.setItemsCanFocus(false);
and In XML file, make sure that for Textview inside list item set focusable false
android:focusable="false"
android:focusableInTouchMode="false"

u can use
#Override
protected void onListItemClick(ListView l, View v, int position, long id) {
// TODO Auto-generated method stub
super.onListItemClick(l, v, position, id);
}

Try this:
lvlList = (ListView)findViewById(R.id.lvlList);
lvlList.setOnItemClickListener(new OnItemClickListener()
{
#Override
public void onItemClick(AdapterView<?> a, View v,int position, long id)
{
Toast.makeText(getBaseContext(), "Click", Toast.LENGTH_LONG).show();
}
});
You have missed the #Override.

There are problems in android with showing dialogs and toasts in subactivities, so your code have to work fine but to make toast try this:
Toast.makeText(TopNewsActivity.this.getParent(), "ID '" + o.get("id") + "' was clicked.", Toast.LENGTH_LONG).show();

The problem is that in your adapter you inflate the main layout for every list item. That should be changed to an itemrenderer's layout.
Since you already have the solution for this question here, you should mark it solved either by accepting any of these answers, or by answering it yourself with the above link.

I battled with this for some time before I figured out that areAllItemsEnabled and isEnabled in my costum ListAdapter where set to false.