Database Users

How to prevent laggy scrolling ListView w ImageView-Items filled with cached images?

Hello community,
I've got a ListActivity in my app, which shows Views including TextViews, for showing artist, title and album information of some mp3-Files (queried by my cursor), and an ImageView, for showing an albumart => Similar to the Tracklist in the music app.
Here's the code for my custom SimpleCursorAdapter and it's binding to the ListView:
Code:
void setListAdapterOverride() {
String[] fromColumns = new String[] {
AudioColumns.ARTIST,
MediaColumns.TITLE,
AudioColumns.ALBUM,
AudioColumns.ALBUM_ID
};
int[] toColumns = new int[] {
R.id.tv_artist,
R.id.tv_title,
R.id.tv_album,
R.id.iv_albumArt
};
cursorAdapter = new customAdapter(getBaseContext(), R.layout.listviewitem, cursor, fromColumns, toColumns);
setListAdapter(cursorAdapter);
if (MyDebug.Log)
Log.d("Activity", "ListAdapter gesetzt");
}
class customAdapter extends SimpleCursorAdapter {
int layout;
Cursor cursor;
String[] from;
int[] to;
public customAdapter(Context context, int layout, Cursor c,
String[] from, int[] to) {
super(context, layout, c, from, to);
this.layout = layout;
this.cursor = c;
this.from = from;
this.to = to;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
if (row == null) {
LayoutInflater inflater = getLayoutInflater();
row = inflater.inflate(R.layout.listviewitem, parent, false);
if (MyDebug.Log)
Log.d("Activity", "Inflate");
}
cursor.moveToPosition(position);
TextView artist = (TextView) row.findViewById(to[0]);
TextView title = (TextView) row.findViewById(to[1]);
TextView album = (TextView) row.findViewById(to[2]);
ImageView albumArt = (ImageView) row.findViewById(to[3]);
artist.setText(cursor.getString(cursor.getColumnIndex(from[0])));
title.setText(cursor.getString(cursor.getColumnIndex(from[1])));
album.setText(cursor.getString(cursor.getColumnIndex(from[2])));
Cursor albumArtCursor = contentResolver.query(MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI, new String[] { MediaStore.Audio.Albums._ID, MediaStore.Audio.Albums.ALBUM_ART }, MediaStore.Audio.Albums._ID + "='" + cursor.getInt(cursor.getColumnIndex(from[3])) + "'", null, null);
albumArtCursor.moveToFirst();
String albumArtUri = albumArtCursor.getString(albumArtCursor.getColumnIndex(MediaStore.Audio.Albums.ALBUM_ART));
if (albumArtUri == null) albumArtUri = "default";
if (!imageCache.containsKey(albumArtUri)) {
Bitmap albumArtBitmap;
if (!albumArtUri.equals("default")) {
Options opts = new Options();
opts.inJustDecodeBounds = true;
BitmapFactory.decodeFile(albumArtUri, opts);
Integer[] bitmapSize = new Integer[] { opts.outWidth, opts.outHeight };
Integer scaleFactor = 1;
while ((bitmapSize[0]/2 > 50) && (bitmapSize[1]/2 > 50)) {
scaleFactor++;
bitmapSize[0] /= 2;
bitmapSize[1] /= 2;
}
opts = new Options();
opts.inSampleSize = scaleFactor;
albumArtBitmap = BitmapFactory.decodeFile(albumArtUri, opts);
} else {
albumArtBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_mp_song_list);
}
imageCache.put(albumArtUri, albumArtBitmap);
}
albumArt.setImageBitmap(imageCache.get(albumArtUri));
return row;
}
}
imageCache is a Hashmap<String, Bitmap> for caching the Bitmaps, so they don't have to be decoded from file again when they had been cached before.
In a former version of the code, I didn't have the imageCache, so the albumarts were decoded from file everytime a new row has been added. That slowed down ListView-scrolling. By adding the imageCache scrolling in ListView doesn't lag that much as before, but it's lagging a bit sometimes.
Can anyone help me to further optimize my code to completely prevent lagging when I scroll the ListView?
Thanks regards ChemDroid

Adding custom apps to an app switcher panel

I am currently working on an App Switcher with the ability to also add custom apps in the app switcher. So, I already got the recent apps loader built. This is the code for this part of the app:
Code:
public class Corners_RecentApps extends Activity {
private ArrayList<PanelItemDetail> rowItems = null;
private ListView listView;
private ArrayList<String> packageName = null;
private ArrayList<String> className = null;
[user=439709]@override[/user]
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
boolean rightpanel = getSharedPreferences(getPackageName() + "_preferences", Context.MODE_PRIVATE).getBoolean("panelpos_right", true);
if(rightpanel){
overridePendingTransition(R.anim.left_slide_in_fast, 0);
setContentView(R.layout.right_side_panel);
}
else
{
overridePendingTransition(R.anim.right_slide_in_fast, 0);
setContentView(R.layout.activity_left_side_panel);
}
ImageView imgbtn = (ImageView) findViewById(R.id.transparentbackground);
ImageView panelbg = (ImageView) findViewById(R.id.panelbackground);
listView = (ListView)findViewById(R.id.panelcontents);
packageName = new ArrayList<String>();
className = new ArrayList<String>();
ActivityManager am = (ActivityManager) this.getSystemService(ACTIVITY_SERVICE);
List<ActivityManager.RecentTaskInfo> tasks = am.getRecentTasks(30, 0);
rowItems = new ArrayList<PanelItemDetail>();
PackageManager pacMgr = getPackageManager();
for (ActivityManager.RecentTaskInfo recentTask : tasks) {
try {
rowItems.add(new PanelItemDetail(pacMgr.getApplicationIcon(recentTask.origActivity.getPackageName())));
packageName.add(recentTask.origActivity.getPackageName());
className.add(recentTask.origActivity.getClassName());
Log.d("#@#", "getPackageName = " + recentTask.origActivity.getPackageName());
Log.d("#@#", "getClassName = " + recentTask.origActivity.getClassName());
} catch (NameNotFoundException e) {
e.printStackTrace();
}
}
SharedPreferences myPreference = PreferenceManager.getDefaultSharedPreferences(this);
String itembg = myPreference.getString("itembg_list", "");
if(itembg.equals("defaults"))
{
PanelArrayAdapter adapter = new PanelArrayAdapter(this,R.layout.panelrow_default, rowItems);
listView.setAdapter(adapter);
}
else if(itembg.equals("dark"))
{
PanelArrayAdapter adapter = new PanelArrayAdapter(this,R.layout.panelrow_dark, rowItems);
listView.setAdapter(adapter);
}
else if(itembg.equals("light"))
{
PanelArrayAdapter adapter = new PanelArrayAdapter(this,R.layout.panelrow_light, rowItems);
listView.setAdapter(adapter);
}
else
{
PanelArrayAdapter adapter = new PanelArrayAdapter(this,R.layout.panelrow_none, rowItems);
listView.setAdapter(adapter);
}
listView.setOnItemClickListener(new OnItemClickListener() {
[user=439709]@override[/user]
public void onItemClick(AdapterView<?> parent, View view, int postion, long id) {
try{
boolean rightpanel = getSharedPreferences(getPackageName() + "_preferences", Context.MODE_PRIVATE).getBoolean("panelpos_right", true);
Intent taskintent = getPackageManager().getLaunchIntentForPackage(packageName.get(postion).toString());
startActivity(taskintent);
if(rightpanel){
overridePendingTransition(R.anim.right_slide_in, R.anim.zoom_out);
}
else
{
overridePendingTransition(R.anim.left_slide_in, R.anim.zoom_out);
}
finish();
}
catch (NullPointerException fail) {
Toast.makeText(getApplicationContext(), "!", Toast.LENGTH_SHORT).show();
}
}
});
SharedPreferences panelbgpref = PreferenceManager.getDefaultSharedPreferences(this);
String panelbgset = panelbgpref.getString("panelbg_list", "");
if(panelbgset.equals("light"))
{
panelbg.setImageResource(R.drawable.panelbg_light);
}
else
{
panelbg.setImageResource(R.drawable.panelbg);
}
imgbtn.setOnClickListener(new View.OnClickListener(){
[user=439709]@override[/user]
public void onClick(View v) {
if(v.getId() ==R.id.transparentbackground){
moveTaskToBack(true);
finish();
}
}
});
}
Now I want to let the users define in the app settings up to 3 own apps that should be shown on every moment.
How should I do that?
Thank you

Loading a new fragment from an OnClick set in asyncTask

I have a fragment, which contains a button that when pressed loads a new fragment. The new fragment runs an async task to populate a listview with data.
I am running into trouble, trying to load a new fragment from the onClick. The problem is I can not get the getFragmentManager();
My async task looks like this:
Code:
public class GetStyleStatisticsJSON extends AsyncTask<String, Void, String> {
Context c;
private ProgressDialog Dialog;
android.support.v4.app.Fragment Fragment_one;
public GetStyleStatisticsJSON(Context context)
{
c = context;
Dialog = new ProgressDialog(c);
}
@Override
protected String doInBackground(String... arg0) {
// TODO Auto-generated method stub
return readJSONFeed(arg0[0]);
}
protected void onPreExecute() {
Dialog.setMessage("Analyzing Statistics");
Dialog.setTitle("Loading");
Dialog.setCancelable(false);
Dialog.show();
}
protected void onPostExecute(String result){
//decode json here
try{
JSONArray jsonArray = new JSONArray(result);
//acces listview
ListView lv = (ListView) ((Activity) c).findViewById(R.id.yourStyleStatistics);
//make array list for beer
final List<StyleInfo> tasteList = new ArrayList<StyleInfo>();
for(int i = 0; i < jsonArray.length(); i++) {
String style = jsonArray.getJSONObject(i).getString("style");
String rate = jsonArray.getJSONObject(i).getString("rate");
String beerID = jsonArray.getJSONObject(i).getString("id");
int count = i + 1;
style = count + ". " + style;
//create object
StyleInfo tempTaste = new StyleInfo(style, rate, beerID);
//add to arraylist
tasteList.add(tempTaste);
//add items to listview
StyleInfoAdapter adapter1 = new StyleInfoAdapter(c ,R.layout.brewer_stats_listview, tasteList);
lv.setAdapter(adapter1);
//set up clicks
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
StyleInfo o=(StyleInfo)arg0.getItemAtPosition(arg2);
String bID = o.id;
//todo: add onclick for fragment to load
FragmentManager man= (Activity)c.getFragmentManager();
FragmentTransaction tran = man.beginTransaction();
Fragment_one = new StylePage2();
final Bundle bundle = new Bundle();
bundle.putString("beerIDSent", bID);
Fragment_one.setArguments(bundle);
tran.replace(R.id.main, Fragment_one);//tran.
tran.addToBackStack(null);
tran.commit();
}
});
}
}
catch(Exception e){
}
Dialog.dismiss();
}
public String readJSONFeed(String URL) {
StringBuilder stringBuilder = new StringBuilder();
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(URL);
try {
HttpResponse response = httpClient.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
InputStream inputStream = entity.getContent();
BufferedReader reader = new BufferedReader(
new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
stringBuilder.append(line);
}
inputStream.close();
} else {
Log.d("JSON", "Failed to download file");
}
} catch (Exception e) {
Log.d("readJSONFeed", e.getLocalizedMessage());
}
return stringBuilder.toString();
}
}
can not resolve method FragmentManager() is the error I am receiving

Hi,
To be able to call getFragmentManager() or getSupportFragmentManager() you'll need to use FragmentActivity, so what I would do is:
1. Make sure the activity that calls the asycTask is a FragmentActivity.
2. Pass this actvity to the asycTask.
Something like: (asyncTask method)
setActivity(Activity activity)
{
fm = activity.getFragmentManager();
}

mrsegev said:
Hi,
To be able to call getFragmentManager() or getSupportFragmentManager() you'll need to use FragmentActivity, so what I would do is:
1. Make sure the activity that calls the asycTask is a FragmentActivity.
2. Pass this actvity to the asycTask.
Something like: (asyncTask method)
setActivity(Activity activity)
{
fm = activity.getFragmentManager();
}
Click to expand...
Click to collapse
thats the problem, I launch the asyncTask from a fragment....

Oh! So you'll access your activity like this:
getActivity().getFragmentManager();

FC when using interface to launch new fragment form listView

I have an async task that loads a list view of items. I am currently trying to set the onClick to load a new fragment with an "id" that is being retrieved from the list item that is clicked. I have no errors in my code that the Android Studio shows me.
When I run the app and click on the item in the list view I get this FC:
02-13 19:49:56.813 20334-20334/com.beerportfolio.beerportfoliopro E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.NullPointerException
at com.beerportfolio.beerportfoliopro.ReadJSONResult$1.onItemClick(ReadJSONResult.java:140)
at android.widget.AdapterView.performItemClick(AdapterView.java:298)
at android.widget.AbsListView.performItemClick(AbsListView.java:1237)
at android.widget.ListView.performItemClick(ListView.java:4555)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:3037)
at android.widget.AbsListView$1.run(AbsListView.java:3724)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:5789)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:843)
at dalvik.system.NativeStart.main(Native Method)
02-13 19:50:42.112 20864-20870/? E/jdwp﹕ Failed sending reply to debugger: Broken pipe
line 140 in ReadJSONResult is:
listenerBeer.onArticleSelected(idToSend);
That line is part of this whole onClick:
//set up clicks
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@override
public void onItemClick(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
BeerData beerInfo = beerList.get(arg2);
String idToSend = beerInfo.beerId;
//todo: launch beer fragment
listenerBeer.onArticleSelected(idToSend);
}
});
All the code for ReadJSONResult is:
public class ReadJSONResult extends AsyncTask<String, Void, String> {
Context c;
private ProgressDialog Dialog;
public ReadJSONResult(Context context)
{
c = context;
Dialog = new ProgressDialog(c);
}
//code for on click
OnArticleSelectedListener listenerBeer;
public interface OnArticleSelectedListener{
public void onArticleSelected(String myString);
}
public void setOnArticleSelectedListener(OnArticleSelectedListener listener){
this.listenerBeer = listener;
}
//end code for onClick
@override
protected String doInBackground(String... arg0) {
// TODO Auto-generated method stub
return readJSONFeed(arg0[0]);
}
protected void onPreExecute() {
Dialog.setMessage("Searching Beer Cellar");
Dialog.setTitle("Loading");
Dialog.setCancelable(false);
Dialog.show();
}
protected void onPostExecute(String result){
//decode json here
try{
JSONObject json = new JSONObject(result);
//acces listview
ListView lv = (ListView) ((Activity) c).findViewById(android.R.id.list);
//make array list for beer
final List<BeerData> beerList = new ArrayList<BeerData>();
//get json items
for(int i = 0; i < json.getJSONArray("data").length(); i++) {
String beerId = GetBeerDataFromJSON(i,"id", json);
String beerName = GetBeerDataFromJSON(i,"name", json);
String beerDescription = GetBeerDataFromJSON(i,"description" , json);
String beerAbv = GetBeerDataFromJSON(i,"abv" , json);
String beerIbu = GetBeerDataFromJSON(i,"ibu" , json);
String beerIcon = GetBeerIconsFromJSON(i, "icon",json );
String beerMediumIcon = GetBeerIconsFromJSON(i, "medium",json );
String beerLargeIcon = GetBeerIconsFromJSON(i, "large",json );
String beerGlass = GetBeerGlassFromJSON(i, json );
String beerStyle = GetBeerStyleFromJSON(i,"name", json );
String beerStyleDescription = GetBeerStyleFromJSON(i,"description", json );
String beerBreweryId = GetBeerBreweryInfoFromJSON(i, "id", json );
String beerBreweryName = GetBeerBreweryInfoFromJSON(i, "name", json );
String beerBreweryDescription = GetBeerBreweryInfoFromJSON(i, "description", json );
String beerBreweryWebsite = GetBeerBreweryInfoFromJSON(i, "website", json );
//get long and latt
String beerBreweryLat = GetBeerBreweryLocationJSON(i, "longitude", json );
String beerBreweryLong = GetBeerBreweryLocationJSON(i, "latitude", json );
String beerBreweryYear = GetBeerBreweryInfoFromJSON(i, "established", json );
String beerBreweryIcon = GetBeerBreweryIconsFromJSON(i,"large",json);
//create beer object
BeerData thisBeer = new BeerData(beerName, beerId, beerDescription, beerAbv, beerIbu, beerIcon,
beerMediumIcon,beerLargeIcon, beerGlass, beerStyle, beerStyleDescription, beerBreweryId, beerBreweryName,
beerBreweryDescription, beerBreweryYear, beerBreweryWebsite,beerBreweryIcon, beerBreweryLat, beerBreweryLong);
//add beer to list
beerList.add(thisBeer);
}
//update listview
BeerSearchAdapter adapter1 = new BeerSearchAdapter(c ,R.layout.listview_item_row, beerList);
lv.setAdapter(adapter1);
//set up clicks
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@override
public void onItemClick(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
BeerData beerInfo = beerList.get(arg2);
String idToSend = beerInfo.beerId;
//todo: launch beer fragment
listenerBeer.onArticleSelected(idToSend);
}
});
}
catch(Exception e){
}
Dialog.dismiss();
}
//todo: all the get functions go here
private String GetBeerDataFromJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getString(whatIsTheKeyYouAreLookFor);
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get icons
private String GetBeerBreweryIconsFromJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONArray("breweries").getJSONObject(0).getJSONObject("images").getString(whatIsTheKeyYouAreLookFor);;
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get icons
private String GetBeerIconsFromJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONObject("labels").getString(whatIsTheKeyYouAreLookFor);
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get style information
private String GetBeerStyleFromJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONObject("style").getString(whatIsTheKeyYouAreLookFor);
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get location data
private String GetBeerBreweryLocationJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONArray("breweries").getJSONObject(0).getJSONArray("locations").getJSONObject(0).getString(whatIsTheKeyYouAreLookFor);
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get brewery information
//get style information
private String GetBeerBreweryInfoFromJSON(int position, String whatToGet, JSONObject json ) {
String whatIsTheKeyYouAreLookFor = whatToGet;
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONArray("breweries").getJSONObject(0).getString(whatIsTheKeyYouAreLookFor);
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
//get glass
private String GetBeerGlassFromJSON(int position, JSONObject json ) {
int whereInTheJSONArrayForLoopIsTheData = position;
String holder = "";
try{
holder = json.getJSONArray("data").getJSONObject(whereInTheJSONArrayForLoopIsTheData).getJSONObject("glass").getString("name");
} catch (JSONException e) {
holder = "N/A";
}
return holder;
}
public String readJSONFeed(String URL) {
StringBuilder stringBuilder = new StringBuilder();
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(URL);
try {
HttpResponse response = httpClient.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
InputStream inputStream = entity.getContent();
BufferedReader reader = new BufferedReader(
new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
stringBuilder.append(line);
}
inputStream.close();
} else {
Log.d("JSON", "Failed to download file");
}
} catch (Exception e) {
Log.d("readJSONFeed", e.getLocalizedMessage());
}
return stringBuilder.toString();
}
}
BeerSearchAdapter is:
public class BeerSearchAdapter extends ArrayAdapter<BeerData> {
Context context;
int layoutResourceId;
List<BeerData> data = null;
public BeerSearchAdapter(Context context, int layoutResourceId, List<BeerData> data) {
super(context, layoutResourceId, data);
this.layoutResourceId = layoutResourceId;
this.context = context;
this.data = data;
}
@override
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
beerHolder holder = null;
if(row == null)
{
LayoutInflater inflater = ((Activity)context).getLayoutInflater();
row = inflater.inflate(layoutResourceId, parent, false);
holder = new beerHolder();
holder.txtBrewery = (TextView)row.findViewById(R.id.beerBreweryNameList);
holder.txtTitle = (TextView)row.findViewById(R.id.beerNameList);
row.setTag(holder);
}
else
{
holder = (beerHolder)row.getTag();
}
BeerData beer = data.get(position);
holder.txtTitle.setText(beer.beerName);
holder.txtBrewery.setText(beer.beerBreweryName);
return row;
}
static class beerHolder
{
TextView txtBrewery;
TextView txtTitle;
}
}
My Search.java where the interface comes form is here:
public class Search extends Fragment implements SearchView.OnQueryTextListener, ReadJSONResult.OnArticleSelectedListener {
private ListView lv;
View v;
@override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
//set layout here
v = inflater.inflate(R.layout.activity_search, container, false);
setHasOptionsMenu(true);
getActivity().setTitle("Search");
//get user information
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getActivity());
String userName = prefs.getString("userName", null);
String userID = prefs.getString("userID", null);
//todo: code body goes here
// Inflate the layout for this fragment
return v;
}
@override
public void onCreateOptionsMenu (Menu menu, MenuInflater inflater) {
// Inflate the menu; this adds items to the action bar if it is present.
super.onCreateOptionsMenu(menu, inflater);
Log.d("click", "inside the on create");
//inflater.inflate(R.menu.main, menu);
SearchView searchView = (SearchView) menu.findItem(R.id.menu_search2).getActionView();
searchView.setIconified(false);
searchView.setOnQueryTextListener(this);
}
public boolean onQueryTextSubmit (String query) {
//toast query
//make json variables to fill
// url to make request
String url = "myURL";
try {
query = URLEncoder.encode(query, "UTF-8");
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String jsonUrl = url + query;
//todo: get json
new ReadJSONResult(getActivity()).execute(jsonUrl);
return false;
}
@override
public boolean onQueryTextChange(String newText) {
// TODO Auto-generated method stub
return false;
}
@override
public void onArticleSelected(String b){
//code to execute on click
Fragment Fragment_one;
FragmentManager man= getFragmentManager();
FragmentTransaction tran = man.beginTransaction();
//todo: set to beer fragment
Fragment_one = new StylePage2();
final Bundle bundle = new Bundle();
bundle.putString("beerIDSent", b);
Fragment_one.setArguments(bundle);
tran.replace(R.id.main, Fragment_one);//tran.
tran.addToBackStack(null);
tran.commit();
}
}
Let me know if you need any other code, I am stomped on this and could use a second pair of eyes. Thanks.

How do I implement a onscroll Listener to my listview?

I have a large data to load from JSON.
I have implemented a custom list view by following a tutorial, now since the data is huge I want it load as the user scrolls.
This is my LoadRestaurant class code which is inside the main activity.
Code:
class LoadRestaurants extends AsyncTask<String, String, String> {
//Show Progress Dialog
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(SearchAll.this);
pDialog.setMessage("Loading All Restaurants...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
protected String doInBackground(String... arg) {
//building parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
//Getting JSON from URL
String json = jsonParser.makeHttpRequest(URL_RESTAURANT_LIST, "GET", params);
//Log Cat Response Check
Log.d("Areas JSON: ", "> " + json);
try {
restaurants = new JSONArray(json);
if (restaurants != null) {
//loop through all restaurants
for (int i = 0; i < restaurants.length(); i++) {
JSONObject c = restaurants.getJSONObject(i);
//Storing each json object in the variable.
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String location = c.getString(TAG_LOCATION);
String rating = c.getString(TAG_RATING);
//Creating New Hashmap
HashMap<String, String> map = new HashMap<String, String>();
//adding each child node to Hashmap key
map.put(TAG_ID, id);
map.put(TAG_NAME, name);
map.put(TAG_LOCATION, location);
map.put(TAG_RATING, rating);
//adding HashList to ArrayList
restaurant_list.add(map);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url) {
//dismiss the dialog
pDialog.dismiss();
//Updating UI from the Background Thread
runOnUiThread(new Runnable() {
@Override
public void run() {
ListAdapter adapter = new SimpleAdapter(
SearchAll.this, restaurant_list,
R.layout.listview_restaurants, new String[]{
TAG_ID, TAG_NAME, TAG_LOCATION, TAG_RATING}, new int[]{
R.id.login_id, R.id.restaurant_name, R.id.address, R.id.rating});
setListAdapter(adapter);
ListView lv = getListView();
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// Bundle bundle = new Bundle();
Intent intent = new Intent(SearchAll.this, RestaurantProfile.class);
String loginId = ((TextView) view.findViewById(R.id.login_id)).getText().toString();
intent.putExtra("login_id", loginId);
startActivity(intent);
}
});
}
});
}
}
}
I want to load around 20 restaurants and then it auto loads another 20 as soon as user reaches the end of first 20.
There are lots of tutorials online but its confusing to implement.
Please help me out!

The custom ListView, support for automatic loading you can try https://github.com/chrisbanes/Android-PullToRefresh