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Nested RecyclerView load second item with lag

I'm trying to make Recyclerview like Shareit app. It uses sticky header and something like Cardview. I searched and found somethings for implementing sticky header with itemdecoration and it's okay. But for Cardview part, I tried to make nested Recyclerview but performance was so bad, Because using two vertical Recyclerview is not good at all. Is there any better way to achieve this?
The problem with performance is for when i scroll down. It makes lag on creating second item in parent Recyclerview.
AppheaderAdapter:
#Override
public AppHeaderAdapter.HeaderHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
final View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_media_header, parent, false);
HeaderHolder headerHolder = new HeaderHolder(view);
return headerHolder;
}
class HeaderHolder extends RecyclerView.ViewHolder { //story
final ImageView arrow;
final TextView tarikh;
final TextView tedad;
final CheckBox tick;
final RecyclerView item_recyc;
HeaderHolder(View itemView) {
super(itemView);
arrow = itemView.findViewById(R.id.header_arrow);
tarikh = itemView.findViewById(R.id.header_tarikh);
tedad = itemView.findViewById(R.id.header_tedad);
tick = itemView.findViewById(R.id.header_tick);
item_recyc = itemView.findViewById(R.id.header_recyc);
}
}
#Override
public void onBindViewHolder(#NonNull AppHeaderAdapter.HeaderHolder headerHolder, int position) {
final AppHeader appHeader = appHeaders.get(position);
...
GridLayoutManager gridLayoutManager = new GridLayoutManager(context, span);
gridLayoutManager.setRecycleChildrenOnDetach(true);
headerHolder.item_recyc.setLayoutManager(gridLayoutManager);
headerHolder.item_recyc.setNestedScrollingEnabled(false);
AppItemAdapter adapter = new AppItemAdapter(context, appHeader.getAppList(), fr_parent, width);
headerHolder.item_recyc.swapAdapter(adapter, true);
...
}
item_media_header.xml:
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/header_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:background="#drawable/so_round_so_white"
app:cardCornerRadius="10dp"
app:cardElevation="5dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/header_arrow"
android:layout_width="30dp"
android:layout_height="30dp"
android:padding="8dp"
android:src="#drawable/header_arrow"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/header_tarikh"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="#dimen/fragment_file"
android:textStyle="bold"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toRightOf="#id/header_arrow"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/header_tedad"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="2dp"
android:textColor="#AAAAAA"
android:textSize="#dimen/fragment_file"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toRightOf="#id/header_tarikh"
app:layout_constraintTop_toTopOf="parent" />
<CheckBox
android:id="#+id/header_tick"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="10dp"
android:button="#null"
android:clickable="false"
android:drawableRight="#drawable/file_checkbox"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/header_recyc"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
</androidx.cardview.widget.CardView>
EDIT 1:
I find that just first Cardview is loaded and second one is not loaded until I scroll to end of first one and then load second CardView item and it lags because of second RecyclerView.
I found that Shareit use previous created adapter and just change its internal datalist, So i do that, but still has lag on second item.
Edite 2:
I use one time created adapter on all RecyclerView but still has lag.
Edit 3:
It's a known bug that innerRecyclerView load all items at first and that cause my lag too. because inner Recyclerview is inside NestedScrollView (RV) and it loads all content.Using constant height doesn't work, But I'll update question if I find something better.

You can achieve this with ConstraintLayout and Flow.
EDIT: Sorry, I just realised I wrote everything in Kotlin. If you cannot understand something I can try to translate it to Java.
xml:
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/constraintLayout"
...>
<androidx.constraintlayout.helper.widget.Flow
android:id="#+id/flow"
app:flow_wrapMode="aligned"
app:flow_horizontalStyle="spread_inside"
app:flow_maxElementsWrap="4"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
Adding of items:
val constraintLayout = itemView.findViewById(R.id.constraintLayout)
val flow = itemView.findViewById(R.id.flow)
val items // items given to the viewHolder to display
val layoutInflater = LayoutInflater.from(context)
items.forEach { item ->
val view = // create item view, e.g. DataBinding, ...
view.id = ViewCompat.generateViewId()
constraintLayout.addView(root)
flow.addView(root)
}
}
// if there are less than 4 items you have to add invisible dummy items. Otherwise, the alignment will look different for these ViewHolders
if(items.size>=4) return
for (i in 0..(4-items.size)) {
val view = // create dummy view
view.id = ViewCompat.generateViewId()
constraintLayout.addView(root)
flow.addView(root)
}

So far, Using vertical RV inside vertical RV has bug. Because of inner RV make long height and outer RV has no idea of this, So it create just first Item, but all items in inner RV. using all solution on Stack O.F. had no effect!

ListView, API calls and onScrollListener

I'm developing an Android app for an online blog that retrieves data from its API (the company made it so I could use it in it, so it can be modified).
The app shows a ListView with n blog entries on load. The thing is I've spent the last three days searching for a way to add a Previous/Next button at the bottom of said ListView, just to finally give up and try another way.
I've seen apps update and append contents pulled from a server to a list (not sure which type) while the user scrolls up and down on it.
Is this possible? If so, how can it be done?
Any revealing piece of information, example (as simple as it may be) or help would be much appreciated!
EXTRA INFO
I'm loading the ListView in a LinearLineout, which is called in the onCreate method.
content_main.xml
<LinearLayout 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"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context="com.company.myApp.MainActivity"
tools:showIn="#layout/app_bar_main"
tools:layout_editor_absoluteY="81dp"
tools:layout_editor_absoluteX="0dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ListView
android:id="#+id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:background="#color/myGrey"
android:scrollbars="none"
android:visibility="visible" />
</LinearLayout>
</LinearLayout>
I also use a custom adapter to fill the ListView with the data retrieved. This data is retrieved by a custom class and stored in a List and that list is then passed as a parameter to the method I use to set such adapter.
public class AdaptadorPosts extends ArrayAdapter {
public AdaptadorPosts(Context context, List objects) {
super(context, 0, objects);
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View v = convertView;
if (null == convertView) {
v = inflater.inflate(R.layout.lista_posts, parent, false);
}
TextView titulo = (TextView)v.findViewById(R.id.titulo);
TextView resumen = (TextView)v.findViewById(R.id.resumen);
TextView fecha = (TextView)v.findViewById(R.id.fecha);
TextView autor = (TextView)v.findViewById(R.id.autor);
Post item = (Post) getItem(position);
titulo.setText(Html.fromHtml(item.getTitulo()));
if(item.getResumen().isEmpty() || item.getResumen().equals(null)) {
resumen.setText("¡No hay resumen!");
} else {
resumen.setText(Html.fromHtml(item.getResumen()));
}
fecha.setText(Html.fromHtml(item.getFecha()));
autor.setText(Html.fromHtml(item.getAutor().getNombre()));
return v;
}
}

If I understand correctly you want to:
Add a Prev/Next button on the bottom of your screen
You have endless content which you want to show dynamically
The first can be easily achieved by using RelativeLayout and for the second you should use RecyclerView.
For your layout you can use something like this:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/light_gray">
<android.support.v7.widget.RecyclerView
android:id="#+id/lv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:scrollbars="none"
android:visibility="visible"/>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:src="#drawable/btn_prev"/>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:src="#drawable/btn_next"/>
</RelativeLayout>
If you want your buttons to be directly below the list, you can attach them by using android:layout_below="#id/lv" and removing android:layout_alignParentBottom="true"
The Android RecyclerView displays a given number of items (e.x. 10) and preloads some of the next and previous items. It's ideal for endless lists. If you want to add items to it dynamically, you need to do that in the adapter by adding the item to the list and calling the notifyItemInserted(int position) method.

Strange behavior of the RecyclerView

I have the following code for example.
MainActivity.java
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
List<String> names = new ArrayList<>();
names.add("one");
names.add("two");
names.add("three");
names.add("four");
names.add("five");
names.add("six");
names.add("seven");
names.add("eight");
names.add("nine");
names.add("ten");
RecyclerView rv = (RecyclerView) findViewById(R.id.rv);
LinearLayoutManager llm = new LinearLayoutManager(this);
rv.setLayoutManager(llm);
RvAdapter adapter = new RvAdapter(names);
rv.setAdapter(adapter);
}
}
RvAdapter.java
public class RvAdapter extends RecyclerView.Adapter<RvAdapter.PersonViewHolder> {
public static final String TAG = RvAdapter.class.getSimpleName();
List<String> persons;
RvAdapter(List<String> persons) {
this.persons = persons;
}
#Override
public RvAdapter.PersonViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.item, parent, false);
return new PersonViewHolder(v);
}
#Override
public void onBindViewHolder(RvAdapter.PersonViewHolder holder, int position) {
holder.name.setText(persons.get(position));
Log.d(TAG, "onBindViewHolder: " + position);
}
#Override
public int getItemCount() {
return persons.size();
}
public static class PersonViewHolder extends RecyclerView.ViewHolder {
CardView cv;
TextView name;
PersonViewHolder(View itemView) {
super(itemView);
cv = (CardView) itemView.findViewById(R.id.cv);
name = (TextView) itemView.findViewById(R.id.name);
}
}
}
activity_main.xml
<?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"
tools:context="com.example.mrmayhem.myapplication.MainActivity">
<android.support.v7.widget.RecyclerView
android:id="#+id/rv"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
</RelativeLayout>
item.xml
<?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="wrap_content"
android:padding="16dp">
<android.support.v7.widget.CardView
android:id="#+id/cv"
android:layout_width="match_parent"
android:layout_height="200dp">
<TextView
android:id="#+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</android.support.v7.widget.CardView>
</LinearLayout>
It works so good and correct. When I scroll through the list I get successive messages from Adapter one by one in Logs: "onBindViewHolder: " + position. But my problem in next. When i try add some View above the RecyclerView, as shown in the code below. Adapter displays all calls of the method onBindViewHolder simultaneously. Wrap the RecyclerView in activity_main.xml by the next code.
activity_main.xml (with header)
<?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"
tools:context="com.example.mrmayhem.myapplication.MainActivity">
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HEADER" />
<android.support.v7.widget.RecyclerView
android:id="#+id/rv"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
</RelativeLayout>

RecyclerView is a ListView. It will only display the items that you can currently see, reusing parts as you scroll.
Now you wrap the RecyclerView in a LinearLayout within a NestedScrollView, what happens?
A NestedScrollView needs to know the size of the LinearLayout to handle the scrolling.
How does the LinearLayout know how long it should be, without knowing the RecyclerViews total length? It doesn't.
So the recyclerView gets completely inflated, all views at once, all in a long line. No recycling, no reuse. This is the phenomenon you experience.
Now the LinearLayout can properly tell the NestedScrollView it's height (the total height of the TextView and all the items of the RecyclerView) and the NestedScrollView can handle the scrolling.
This is why nested scrolling is always a bad idea. If possible, try to move your TextView as an item into the RecyclerView and get rid of the wrapping NestedScrollview.
e.g. as seen here: Is there an addHeaderView equivalent for RecyclerView?
Another option would be to remove the recyclerview from the scroll view and put it below. The header would not scroll then, though.

Unless you have a good reason to have a NestedScrollView in your hierarchy, you could achieve a TextView on top with a RecyclerView below with just this layout code:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
tools:context="com.example.mrmayhem.myapplication.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HEADER" />
<android.support.v7.widget.RecyclerView
android:id="#+id/rv"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
</LinearLayout>

CardView in fragment is invisible

I have a main activity (ActivityMain.java) that I would like to use to navigate between four fragments. In one of these fragments, I'm attempting to place a CardView in conjunction with a RecyclerView to create a vertical list of cards. However, so far I've been unable to get any of the cards to display when I run the app. The CardView will display perfectly in Android Studio's design preview, but when an actual device/emulator is used it disappears.
I've tried to manually set the visibility of the CardView through Java, but it continued to stay invisible. I believe that the fragment's layout could be covering the CardView's layout, but I'm still very new to Android development so I'm not completely sure what the problem could be.
Below I've pasted the classes and XML files that are likely to be associated with my problem.
AdapterMainFeed.java
public class AdapterMainFeed extends RecyclerView.Adapter<AdapterMainFeed.ViewHolderMainFeed> {
private ArrayList<Article> listArticlesMain = new ArrayList<>();
private LayoutInflater inflater;
public AdapterMainFeed(Context context) {
inflater = LayoutInflater.from(context);
}
public void setArticlesMain(ArrayList<Article> listArticlesMain) {
this.listArticlesMain = listArticlesMain;
notifyDataSetChanged();
}
#Override
public ViewHolderMainFeed onCreateViewHolder(ViewGroup container, int i) {
View layout = inflater.inflate(R.layout.view_main_feed, container, false);
Article article1 = new Article("asdf", "ghj", "klm", new Date(0));
Article article2 = new Article("sdfg", "hjk", "lmn", new Date(0));
Article article3 = new Article("dfgh", "jkl", "mno", new Date(0));
listArticlesMain.add(article1);
listArticlesMain.add(article2);
listArticlesMain.add(article3);
return new ViewHolderMainFeed(layout);
}
#Override
public void onBindViewHolder(ViewHolderMainFeed viewHolderMainFeed, int i) {
Article currentArticle = listArticlesMain.get(i);
viewHolderMainFeed.articleTitle.setText(currentArticle.getTitle());
viewHolderMainFeed.articleAuthor.setText(currentArticle.getAuthor());
viewHolderMainFeed.articleWebsite.setText(currentArticle.getWebsite());
DateFormat formatter = DateFormat.getDateTimeInstance();
final String timePosted = formatter.format(currentArticle.getTimePosted());
viewHolderMainFeed.articleTime.setText(timePosted);
}
#Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
#Override
public int getItemCount() {
return listArticlesMain.size();
}
static class ViewHolderMainFeed extends RecyclerView.ViewHolder {
TextView articleTitle;
TextView articleAuthor;
TextView articleWebsite;
TextView articleTime;
public ViewHolderMainFeed(View itemView) {
super(itemView);
articleTitle = (TextView) itemView.findViewById(R.id.mainArticleTitle);
articleAuthor = (TextView) itemView.findViewById(R.id.mainArticleAuthor);
articleWebsite = (TextView) itemView.findViewById(R.id.mainArticleWebsite);
articleTime = (TextView) itemView.findViewById(R.id.mainArticleTime);
}
}
}
view_main_feed.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="8dp"
tools:context="com.convergeapp.converge.ActivityMain">
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
card_view:cardCornerRadius="7dp"
card_view:cardBackgroundColor="#color/colorPurpleSeance"
android:id="#+id/mainArticleCard"
android:layout_width="match_parent"
android:layout_height="300dp"
android:padding="8dp"
android:clickable="true">
<RelativeLayout
android:id="#+id/mainArticleLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp">
<TextView
android:id="#+id/mainArticleTitle"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"/>
<TextView
android:id="#+id/mainArticleAuthor"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_below="#id/mainArticleTitle"/>
<TextView
android:id="#+id/mainArticleWebsite"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_below="#+id/mainArticleTime"/>
<TextView
android:id="#+id/mainArticleTime"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"/>
</RelativeLayout>
</android.support.v7.widget.CardView>
</RelativeLayout>

After playing around with some changes, I finally discovered the solution. What I did was add the Article objects to the list in the main fragment's onCreateView method. Additionally, I instantiated CardView in the ViewHolder, though that didn't help me see the cards initially.
So, if you're ever in a similar predicament and can't figure out the solution, try to actually create the objects before setting them.

You need to call notifyDataSetChanged(); inside onCreateViewHolder after adding the new articles so that the itemcount is updated

Create a ListView with selectable rows/change background color of ListView rows when clicked

Problem
I'm trying to create a ListView with selectable items. I want to be able to click on an item in the ListView and have the item change color in the list, and then go on and do something else with the data from the row.
I'm using a SimpleAdapter.
How do I make it so that when I tap on a row, it turns a different color, and then when I tap on a different row, the new row is selected and changed to a new color, and the old row changes back to normal?
Code
Here is my code so far. The DBTools class is has all of the data that I want to be displayed in my ListView organized and taken care of. The getAllReceivers() method returns an ArrayList of HashMap<String, String>s that have all of my data.
MainActivity.java:
public class MainActivity extends ListActivity {
DBTools dbTools = new DBTools(this);
ArrayList<HashMap<String, String>> receiverList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().hide();
setContentView(R.layout.activity_main);
receiverList = dbTools.getAllReceivers();
dbTools.close();
ListView listView = getListView();
if(receiverList.size() != 0) {
SimpleAdapter adapter = new SimpleAdapter(MainActivity.this,receiverList, R.layout.receiver_entry, new String[] {"receiverId","receiverName", "fullPath"}, new int[] {R.id.receiverId, R.id.receiverName, R.id.fullPath});
setListAdapter(adapter);
}
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TableRow
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/black" >
<TextView
android:id="#+id/titleTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:text="My List" />
</TableRow>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/black"
android:id="#android:id/list" />
</TableLayout>
receiver_entry.xml
<?xml version="1.0" encoding="utf-8"?>
<TableRow xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/tableRow" >
<TextView
android:id="#+id/receiverId"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<TextView
android:id="#+id/receiverName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Robotronics" />
<TextView
android:id="#+id/fullPath"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="123.45.678.910:8088/robtrox/find" />
</TableRow>

Solution
The solution to this problem is very simple. We need to add an OnItemClickListener to our ListView to listen for clicks and respond accordingly.
So, in the onCreate() method, once you've made sure that you set of data isn't empty, you're going to want to Override the onItemClick() method to listen for the click and change the color. You're also going to want to keep track of which item you selected for the later steps, so add public int selectionId = -1; at the top of your class. Furthermore, you'll need to let the ListAdapter know that you changed something by calling ((SimpleAdapter) getListAdapter()).notifyDataSetChanged().
if(receiverList.size() != 0) {
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int index, long id) {
view.setBackgroundColor(Color.RED);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
selectionId = Integer.valueOf(receiverIdTextView.getText().toString());
((SimpleAdapter) getListAdapter()).notifyDataSetChanged();
}
});
SimpleAdapter adapter = getNewAdapter();
setListAdapter(adapter);
}
Great! Now we have a working system that will change the color of the row that you tap. But we're not done yet. We need to make sure that the previous selection changes back to the normal color.
For this, we are going to use override the SimpleAdapter's getView() method, which is called everytime the ListView goes to draw the items being displayed in it.
It only actually displays the items it needs to - the ones that you can see. It does not render the ones above or below your screen. So if you have 200 items in a ListView, only 5 or 6, depending on the size of your screen and the size of the items, are being rendered at a time.
To override the getView() method, go up to where you initialize the adapter and change the code to this:
SimpleAdapter adapter = new SimpleAdapter(MainActivity.this,receiverList, R.layout.receiver_entry, new String[] { "receiverId","receiverName", "fullPath"}, new int[] {R.id.receiverId, R.id.receiverName, R.id.fullPath}) {
#Override
public View getView (int position, View convertView, ViewGroup parent) {
View view = super.getView(position, convertView, parent);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
if(receiverIdTextView.getText().toString().equals(String.valueOf(selectionId))) {
view.setBackgroundColor(Color.RED);
} else {
view.setBackgroundColor(Color.WHITE);
}
return view;
}
};
Every time one of the rows is drawn, since the getView() will get called, the ListView will check if the current view has the id of row you selected. If it doesn't, it'll change the background color to white. If it does, it'll change the background color to red.
And voila! That's it! Now you are setting the background color to red when you click on an item in the ListView.
Final Code
MainActivity.java:
public class MainActivity extends ListActivity {
DBTools dbTools = new DBTools(this);
ArrayList<HashMap<String, String>> receiverList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().hide();
setContentView(R.layout.activity_main);
receiverList = dbTools.getAllReceivers();
dbTools.close();
ListView listView = getListView();
if(receiverList.size() != 0) {
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int index, long id) {
view.setBackgroundColor(Color.RED);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
selectionId = Integer.valueOf(receiverIdTextView.getText().toString());
((SimpleAdapter) getListAdapter()).notifyDataSetChanged();
}
});
SimpleAdapter adapter = new SimpleAdapter(MainActivity.this,receiverList, R.layout.receiver_entry, new String[] { "receiverId","receiverName", "fullPath"}, new int[] {R.id.receiverId, R.id.receiverName, R.id.fullPath}) {
#Override
public View getView (int position, View convertView, ViewGroup parent) {
View view = super.getView(position, convertView, parent);
TextView receiverIdTextView = (TextView) view.findViewById(R.id.receiverId);
if(receiverIdTextView.getText().toString().equals(String.valueOf(selectionId))) {
view.setBackgroundColor(Color.RED);
} else {
view.setBackgroundColor(Color.WHITE);
}
return view;
}
};
setListAdapter(adapter);
}
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TableRow
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#android:color/black" >
<TextView
android:id="#+id/titleTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:text="My List" />
</TableRow>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/black"
android:id="#android:id/list" />
</TableLayout>
receiver_entry.xml
<?xml version="1.0" encoding="utf-8"?>
<TableRow xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="#+id/tableRow" >
<TextView
android:id="#+id/receiverId"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<TextView
android:id="#+id/receiverName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Robotronics" />
<TextView
android:id="#+id/fullPath"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="123.45.678.910:8088/robtrox/find" />
</TableRow>