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Recycler view not showing the views when a background color is setted

Hi I'm new to Android Studio, and I am trying to make a simple recycler view that contains a list of card view. The code runs just fine and every view is rendering fine when I run it, but then I decided to add background color to recycler view than everything just went wrong. The only thing I've changed is setting the background color of the recycler view. By the way, my recycler view lives in a fragment.
Here is what it looked like before I set the background color:
The xml file for the recycler view before change:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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.support.v7.widget.RecyclerView
android:id="#+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:listitem="#layout/recycler_view_item" />
</android.support.constraint.ConstraintLayout>
And here is what it looks like now, all I did is setting the background color of the recycler view:
Here is the new xml file:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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.support.v7.widget.RecyclerView
android:id="#+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/holo_green_dark"
tools:listitem="#layout/recycler_view_item" />
</android.support.constraint.ConstraintLayout>
My guess is that somehow the background color is covering my views?
By the way, I do notice an error occured in the logcat:
2018-12-21 22:02:05.515 20644-20644/com.steven97102gmail.todoassistant E/RecyclerView: No adapter attached; skipping layout
However, that error occurs even if I don't set the background, and it is working just fine.
Here is my class for frament:
public class RecycleFragment extends Fragment {
private RecyclerView recyclerView;
private RecyclerView.Adapter viewAdapter;
private RecyclerView.LayoutManager viewLayouManager;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.recyler_view, container, false);
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
// get and configure the recycle view
recyclerView = (RecyclerView) getActivity().findViewById(R.id.recycler_view);
recyclerView.setHasFixedSize(true);
// layout manager for recyler view
viewLayouManager = new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(viewLayouManager);
// creates the initial cards
ArrayList<CardItem> card_lists = new ArrayList<>();
for (int i = 0;i<=10;i++){
CardItem card = new CardItem("TODO"+i,"12/" + i);
card_lists.add(card);
}
// adapter for recycler view, initialize the recycler view
viewAdapter = new RecyclerAdapter(card_lists);
recyclerView.setAdapter(viewAdapter);
// test add a new item
card_lists.add(0,new CardItem("Test Insert","12/16"));
viewAdapter.notifyItemInserted(0);
}
}
Here is my class for recycler view's adapter:
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.RecyclerViewHolder> {
private ArrayList<CardItem> card_item_list;
// view holder is created from the recycler_card_item template
public static class RecyclerViewHolder extends RecyclerView.ViewHolder {
public TextView title_tv, date_tv;
public RecyclerViewHolder(LinearLayout layout) {
super(layout);
title_tv = layout.findViewById(R.id.card_item_title);
date_tv = layout.findViewById(R.id.card_item_date);
}
}
// take in a list of card items to initialize with
public RecyclerAdapter(ArrayList<CardItem> card_list) {
card_item_list = card_list;
}
#NonNull
#Override
// inflate and creates a viewholder objects, which is from the recycler care item template;
public RecyclerAdapter.RecyclerViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
// create a new card item
LinearLayout cardLayout = (LinearLayout) LayoutInflater.from(viewGroup.getContext())
.inflate(R.layout.recycler_card_item, viewGroup, false);
RecyclerViewHolder vh = new RecyclerViewHolder(cardLayout);
return vh;
}
#Override
// bind the CardItem class with the viewholder to complete the card
public void onBindViewHolder(#NonNull RecyclerViewHolder holder, int position) {
CardItem target_card = card_item_list.get(position);
holder.title_tv.setText(target_card.title);
holder.date_tv.setText(target_card.date);
}
#Override
public int getItemCount() {
return card_item_list.size();
}
}

In your code, you're trying to retrieve a recyclerview at Activity level:
recyclerView = (RecyclerView) getActivity().findViewById(R.id.recycler_view);
but the recyclerview is in your fragment. It is strange that you do not have any other errors, I would've expected the app to crash. Anyway, it should be solved in this way: change your onCreateView like this
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.recyler_view, container, false);
recyclerView = root.findViewById(R.id.recycler_view);
return root;
}
the previous line, the one that retrieved the recyclerview from the activity, is not needed anymore.

How can i get a button to add an item to an arraylist then to a listview in another fragment activity

I have a fixed tab layout with 3 tabs. I am trying to have a button in tab1 to add items into a listview in tab2 using ArrayList, both of them extends Fragment. The below code works only when the the activity extends Activity. Can anyone help me out with an answer to the fix of the problem.
I did some testing with an independent activity with a button that adds to listview inside that same activity layout, this is the one that works
MainActivty
public class MainActivity extends Activity {
private ListView LView;
ArrayList <String> arrayList = new ArrayList<String>();
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LView = (ListView) findViewById(R.id.listview);
}
public void sendToListView(View view) {
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, arrayList); //Sets the adapter to hold the List View
LView.setAdapter(adapter); //Adds to the List View
arrayList.add("Thursday");
}
}
activity_main
<?xml version="1.0" encoding="utf-8"?>
<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"
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/listview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/button"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="add"
android:onClick="sendToListView"
android:id="#+id/button"/>
</RelativeLayout>
This MainActivity extends Fragment and has an error when i try to implement the same operation
public class MainActivity extends Fragment implements View.OnClickListener {
private ListView LView;
ArrayList <String> arrayList = new ArrayList<String>();
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.activity_main,
container, false);
LView = (ListView) view.findViewById(R.id.listview);
return view;
}
#Override
public void onClick(View v) {
switch (v.getId()){
case R.id.button:
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, arrayList); //Here is the error
LView.setAdapter(adapter); //Adds to the List View
arrayList.add("Thursday");
break;
}
}
}
How can i get this working for Fragments, and how could i hve this operation be sent to the other Fragment activity tab and saved to SharedPreferences

I think it may have more to do with just your general methodology in your fragments. In your activity, you are using the XML to specify a method to run on click of a Button, which makes a whole lot of sense. In the fragment instead you are overriding the method onClick but not activating it by any means. Instead I would again define a button in your fragment XML and either findViewById in your fragment and add your on click method there instead of how you are currently doing it. Alternatively you could just add a onclick handler to the view inside of your fragment if you do indeed want the user to be able to click anywhere in your fragment.
Button yourFragmentButton = (Button) findViewById(R.id.yourFragementButtonId);
yourFragmentButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, arrayList);
//Sets the adapter to hold the List View
LView.setAdapter(adapter); //Adds to the List View
arrayList.add("Thursday");
}
});

You're confunsing the concepts of Activity and Fragment. Having a Fragment does not exclude the necessity for an underlying Activity, because every Fragment needs to be plugged on an Activity to be displayed as it is stated in the AndroidDevelopers:
A Fragment represents a behavior or a portion of user interface in an Activity
To see more on this: http://developer.android.com/guide/components/fragments.html .
But, even considering that you attached the fragment correctly and that you are using the right layout on it, you still need to do a few changes if you need to use a fragment here:
public class MyFragment extends Fragment implements View.OnClickListener {
private ListView LView;
ArrayList <String> arrayList = new ArrayList<String>();
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.activity_main,
container, false);
LView = (ListView) view.findViewById(R.id.listview);
Button myButton = view.findViewById(R.id.button);
myButton.setOnClickListener(this);
return view;
}
#Override
public void onClick(View v) {
switch (v.getId()){
case R.id.button:
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getContext(), android.R.layout.simple_list_item_1, arrayList); //Here is the error
LView.setAdapter(adapter); //Adds to the List View
arrayList.add("Thursday");
break;
}
}

Restore views in a fragment added programmatically

I have a single activity with a navigation drawer (the basic one provided by Eclipse new app wizard). I have a FrameLayout as a container for the different fragments of the app, which are replaced when selecting an item in the navigation drawer. They are also added to the BackStack.
These fragments contain a LinearLayout, which has some EditTexts and a Button. If the button is pressed, a new LinearLayout is created and a couple TextViews are added to it with the content of the EditTexts. The user can repeat this option more than once, so I cannot tell how many LinearLayouts I'll need, therefore I need to add them programmatically.
One of these fragments xml:
<LinearLayout
android:id="#+id/pen_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<LinearLayout
android:id="#+id/new_pen_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="#dimen/activity_vertical_margin"
android:background="#drawable/border"
android:orientation="vertical"
android:paddingBottom="#dimen/home_section_margin_bottom"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/home_section_margin_top" >
<EditText
android:id="#+id/new_pen_round"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="number"
android:hint="#string/new_pen_round_hint"
android:textSize="#dimen/normal_text_size" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="2" >
<Button
android:id="#+id/new_pen_cancel_button"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginRight="#dimen/new_item_button_margin_right"
android:layout_weight="1"
android:background="#drawable/button_bg"
android:paddingBottom="#dimen/new_item_button_padding_bottom"
android:paddingTop="#dimen/new_item_button_padding_top"
android:text="#string/new_item_cancel_button"
android:textSize="#dimen/normal_text_size" />
<Button
android:id="#+id/new_pen_insert_button"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginLeft="#dimen/new_item_button_margin_left"
android:layout_weight="1"
android:background="#drawable/button_bg"
android:paddingBottom="#dimen/new_item_button_padding_bottom"
android:paddingTop="#dimen/new_item_button_padding_top"
android:text="#string/new_pen_insert_button"
android:textSize="#dimen/normal_text_size" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
There are actually many other EditTexts but I removed them here to keep it short, the result is the same. It's java file:
public class PenaltiesFragment extends Fragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_penalties, container, false);
Button insertNewPen = (Button) view.findViewById(R.id.new_pen_insert_button);
insertNewPen.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
TextView round = (TextView) getActivity().findViewById(R.id.new_pen_round);
LinearLayout layout = (LinearLayout) getActivity().findViewById(R.id.pen_layout);
int numChilds = layout.getChildCount();
CustomPenaltyLayout penalty = new CustomPenaltyLayout(getActivity(), round.getText());
layout.addView(penalty, numChilds - 1);
}
});
return view;
}
}
I removed some useless methods, which are just the default ones. CustomPenaltyLayoutis a subclass of LinearLayout which I created, it just creates some TextViews and adds them to itself.
Everything works fine here. The user inserts data in the EditText, presses the Insert button and a new layout is created and added in the fragment.
What I want to achieve is: say that I open the navigation drawer and select another page, the fragment gets replaced and if I go back to this fragment (via navigation drawer or via Back button) I want the text, that the user added, to be still there.
I do not call PenaltiesFragment.newInstance() everytime I switch back to this fragment, I instead create the PenaltiesFragment object once and keep using that one. This is what I do:
Fragment fragment;
switch (newContent) {
// various cases
case PEN:
if(penFragment == null) // penFragment is a private field of the Main Activity
penFragment = PenaltiesFragment.newInstance();
fragment = penFragment;
break;
}
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.container, fragment)
.addToBackStack("fragment back")
.commit();
I understand that onCreateView() is called again when the fragment is reloaded, right? So that is probably why a new, blank fragment is what I see. But how do I get the inserted CustomPenaltyLayout back? I cannot create it in the onCreateView() method.

I found a solution to my problem. I replaced the default FrameLayout that Android automatically created as a container for my fragments, with a ViewPager, then created a FragmentPagerAdapter like this:
public static class MyAdapter extends FragmentPagerAdapter {
public MyAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
Fragment fragment;
switch (position) {
// ...other cases
case PEN:
fragment = PenaltiesFragment.newInstance();
break;
// ...other cases
}
return fragment;
}
#Override
public int getCount() {
return 6;
}
}
Then the only thing left to do to keep all the views at all times has been to add this line to my activity onCreate method.
mPager.setOffscreenPageLimit(5);
See the documentation for details on how this method works.
This way, though, I had to reimplement all the back button logic, but it's still simple, and this is how I did it: I create a java.util.Stack<Integer> object, add fragment numbers to it (except when you use the back button, see below), and override onBackPressed() to make it pop the last viewed fragment instead of using the back stack, when my history stack is not empty.
You want to avoid pushing elements on the Stack when you press the back button, otherwise you will get stuck between two fragments if you keep using the back button, instead of eventually exiting.
My code:
MyAdapter mAdapter;
ViewPager mPager;
Stack<Integer> pageHistory;
int currentPage;
boolean saveToHistory;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mAdapter = new MyAdapter(getSupportFragmentManager());
mPager = (ViewPager)findViewById(R.id.container);
mPager.setAdapter(mAdapter);
mPager.setOffscreenPageLimit(5);
pageHistory = new Stack<Integer>();
mPager.setOnPageChangeListener(new OnPageChangeListener() {
#Override
public void onPageSelected(int arg0) {
if(saveToHistory)
pageHistory.push(Integer.valueOf(currentPage));
}
#Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
#Override
public void onPageScrollStateChanged(int arg0) {
}
});
saveToHistory = true;
}
#Override
public void onBackPressed() {
if(pageHistory.empty())
super.onBackPressed();
else {
saveToHistory = false;
mPager.setCurrentItem(pageHistory.pop().intValue());
saveToHistory = true;
}
};

ListView OnItemLongClickListener() not triggered

I have a class that extends ListActivity where the list items respond to OnClick events. Adding an OnItemLongClickListener does not work. The onItemLongClick() function is not called (no log-output or Toast showing) but the normal OnClick() event is handled instead.
I want to display a contextual action bar upon long click. A minimum example using my code in a new project works fine. So my question is: What can possibly prevent the onItemLongClick() trigger from being triggered?
My minimum API is 11. I am also setting the listView to longClickable="true".
Activity code (selected functions):
public class EventListActivity extends ListActivity {
private ArrayList<Event> arrEvents = null;
private ArrayAdapter<Event> adpEvents = null;
private ActionMode mActionMode = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// only create list adapter and set it
arrEvents = new ArrayList<Event>();
adpEvents = new ArrayAdapter<Event>(this, android.R.layout.simple_list_item_activated_2, android.R.id.text1, arrEvents) {
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = super.getView(position, convertView, parent);
TextView text1 = (TextView) view.findViewById(android.R.id.text1);
TextView text2 = (TextView) view.findViewById(android.R.id.text2);
text1.setText(arrEvents.get(position).getTitle());
text2.setText(arrEvents.get(position).getDateTimeFormatted());
return view;
}
};
setListAdapter(adpEvents);
// add CAB to ListView
setupCAB();
}
#Override
protected void onResume() {
super.onResume();
// populate list and refresh adapter
createEventList();
adpEvents.notifyDataSetChanged();
// if list empty show emtpy msg, otherwise hide it
setContentView(R.layout.activity_event_list);
TextView empty = (TextView) findViewById(R.id.text_empty);
if(arrEvents.isEmpty()) {
empty.setVisibility(View.VISIBLE);
} else {
empty.setVisibility(View.GONE);
}
}
private void setupCAB() {
// Important: to select single mode
getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE);
getListView().setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
// Called when the user long-clicks an item on the list
#Override
public boolean onItemLongClick(AdapterView<?> parent, View row, int position, long rowid) {
Log.w("EventListActivity", "Long click detected!");
Toast.makeText(EventListActivity.this, "Long click detected!", Toast.LENGTH_SHORT).show();
if (mActionMode != null) {
return false;
}
// Important: to mark the editing row as activated
getListView().setItemChecked(position, true);
// Start the CAB using the ActionMode.Callback defined above
mActionMode = EventListActivity.this.startActionMode(mActionModeCallback);
return true;
}
});
}
private ActionMode.Callback mActionModeCallback = new ActionMode.Callback() {
// Called when the action mode is created; startActionMode() was called
#Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
// Inflate a menu resource providing context menu items
MenuInflater inflater = mode.getMenuInflater();
inflater.inflate(R.menu.event_context, menu);
return true;
}
// Called when the user enters the action mode
#Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
// Disable the list to avoid selecting other elements while editing one
EventListActivity.this.getListView().setEnabled(false);
return true; // Return false if nothing is done
}
// Called when the user selects a contextual menu item
#Override
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
switch (item.getItemId()) {
case R.id.mnu_share_event:
//TODO share event
mode.finish();
return true;
default:
return false;
}
}
// Called when the user exits the action mode
#Override
public void onDestroyActionMode(ActionMode mode) {
// Re-enable the list after edition
EventListActivity.this.getListView().setEnabled(true);
mActionMode = null;
}
};
}
activity_event_list.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=".EventListActivity" >
<TextView
android:id="#+id/text_empty"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="45dp"
android:text="#string/empty"
android:textAppearance="?android:attr/textAppearanceLarge"
android:visibility="gone" />
<ListView
android:id="#android:id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:longClickable="true" >
</ListView>
</RelativeLayout>

If you have buttons responding to onClick() events inside your listview, you need to set the following in the container holding those buttons:
android:descendantFocusability="blocksDescendants"
If what you have are textviews, the problem is slightly trickier. See this: Focusable EditText inside ListView

This answer does not solve user1's question but the symptoms were similar my problem (i.e. OnItemClickListener was getting called but OnItemLongClickListener was not). I'm posting my answer here in case anyone else stumbles on this question like I did when trying to solve my problem.
I was using a ListView inside a Fragment and implemented the listener methods:
public class MyFragment extends Fragment implements OnClickListener,
OnLongClickListener, OnItemClickListener, OnItemLongClickListener {
Here is the onItemClick method that was working fine:
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long rowId) {
Log.i("Chimee", "short click working");
}
And here is the onItemLongClick method that wasn't firing:
#Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position,
long rowId) {
Log.i("Chimee", "Long click working");
return false;
}
Of course the simple answer was that I forgot to setOnItemLongClickListener. I added it after the setOnItemClickListener that I had all along and then it worked fine.
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.my_fragment, container, false);
lvSuggestions = (ListView) v.findViewById(R.id.lvSuggestions);
lvSuggestions.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
lvSuggestions.setOnItemClickListener(this);
lvSuggestions.setOnItemLongClickListener(this); // Forgot this
...
}

When using a ListActivity or ListFragment there is no method you can override for the long-click, and getting access to the ListView is not possible in onCreateView(), since it is being controlled by the parent class.
So, to overcome this, I did this, since the getListView() command won't work until after the view is created:
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mRecipeListView = this.getListView();
mRecipeListView.setOnItemLongClickListener(new ListView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> arg0, View view, int position, long row_id) {
// Process the long-click
}
});
}

ListView row buttons: How do I create a custom Adapter that connects a View.OnClickListener to a button on each row of a ListView?

I want my ListView to contain buttons, but setting the button's xml property, onClick="myFunction" and then placing a public void myFunction(android.view.View view) method in the activity causes an NoSuchMethodException (the stack trace is null) to be thrown, as although the onclick listener is there, it doesn't fire myFunction(...) and cause the activity to close.
How do I create a custom Adapter that connects a View.OnClickListener to a button on each row of a ListView?
My ListView is created as follows...
[activity.java content..]
public void myFunction(android.view.View view)
{
//Do stuff
}
[activity.xml content..]
<LinearLayout xmlns:tools="http://schemas.android.com/tools" xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context=".FrmCustomerDetails" >
<ListView android:id="#+id/LstCustomerDetailsList" android:layout_width="fill_parent" android:layout_height="0dip" android:layout_weight="1" android:clickable="true" android:clipChildren="true" android:divider="#null" android:dividerHeight="0dp" android:fastScrollEnabled="true" android:footerDividersEnabled="false" android:headerDividersEnabled="false" android:requiresFadingEdge="vertical" android:smoothScrollbar="true" />
</LinearLayout>
[activity_row_item.xml content..]
<?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:id="#+id/Llt" android:layout_width="match_parent" android:layout_height="match_parent" >
<Button android:id="#+id/Btn" android:text="Click me" android:onClick="myFunction" />
</LinearLayout>

Here is how to create the custom Adapter, connecting View.OnClickListener to a ListView with a button per row...
1. Create a layout for a typical row
In this case, the row is composed of three view components:
name (EditText)
value (EditText:inputType="numberDecimal")
delete (Button)
Xml
pay_list_item.xml layout is as follows:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<EditText
android:id="#+id/pay_name"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="2"
android:hint="Name" />
<EditText
android:id="#+id/pay_value"
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:inputType="numberDecimal"
android:text="0.0" />
<Button
android:id="#+id/pay_removePay"
android:layout_width="100dp"
android:layout_height="fill_parent"
android:text="Remove Pay"
android:onClick="removePayOnClickHandler" />
</LinearLayout>
Note: the button has onClick handler defined in xml layout file, because we want to refer its action to a specific list item.
Doing this means that the handler will be implemented in Activity file and each button will know which list item it belongs to.
2. Create list item adapter
This is the java class that is the controller for pay_list_item.xml.
It keeps references for all of its views, and it also puts these references in tags, extending the ArrayAdapter interface.
The Adapter:
public class PayListAdapter extends ArrayAdapter<Payment> {
private List<Payment> items;
private int layoutResourceId;
private Context context;
public PayListAdapter(Context context, int layoutResourceId, List<Payment> items) {
super(context, layoutResourceId, items);
this.layoutResourceId = layoutResourceId;
this.context = context;
this.items = items;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
PaymentHolder holder = null;
LayoutInflater inflater = ((Activity) context).getLayoutInflater();
row = inflater.inflate(layoutResourceId, parent, false);
holder = new PaymentHolder();
holder.Payment = items.get(position);
holder.removePaymentButton = (ImageButton)row.findViewById(R.id.pay_removePay);
holder.removePaymentButton.setTag(holder.Payment);
holder.name = (TextView)row.findViewById(R.id.pay_name);
holder.value = (TextView)row.findViewById(R.id.pay_value);
row.setTag(holder);
setupItem(holder);
return row;
}
private void setupItem(PaymentHolder holder) {
holder.name.setText(holder.Payment.getName());
holder.value.setText(String.valueOf(holder.Payment.getValue()));
}
public static class PaymentHolder {
Payment Payment;
TextView name;
TextView value;
ImageButton removePaymentButton;
}
}
Here we list the Payment class items.
There are three most important elements here:
PayListAdapter constructor: sets some private fields and calls superclass constructor. It also gets the List of Payment objects. Its implementation is obligatory.
PaymentHolder: static class that holds references to all views that I have to set in this list item. I also keep the Payment object that references to this particular item in list. I set it as tag for ImageButton, that will help me to find the Payment item on list, that user wanted to remove
Overriden getView method: called by superclass. Its goal is to return the single List row. We create its fields and setup their values and store them in static holder. Holder then is put in row’s tag element. Note that there is a performance issue, as the row is being recreated each time it is displayed. I used to add some flag in holder like isCreated, and set it to true after row was already created. then you can add if statement and read tag’s holder instead of creating it from scratch.
Payment.java is quite simple as for now and it looks a bit like BasicNameValuePair:
public class Payment implements Serializable {
private String name = "";
private double value = 0;
public Payment(String name, double value) {
this.setName(name);
this.setValue(value);
}
...
}
There are additional gets and sets for each private field not shown.
3. Add ListView to the activity layout xml file
In its simpliest form, it will be enough to add this view to activity layout:
<ListView
android:id="#+id/EnterPays_PaysList"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
</ListView>
4. Set up adapter to this list view in Activity Java code
In order to display items in ListView you need to set up its adapter and map it to some other ArrayList of Payment objects (as I am extending an Array adapter here). Here is code that is responsible for binding adapter to editPersonData.getPayments() ArrayList:
PayListAdapter adapter = new PayListAdapter(AddNewPerson.this, R.layout.pay_list_item, editPersonData.getPayments());
ListView PaysListView = (ListView)findViewById(R.id.EnterPays_PaysList);
PaysListView.setAdapter(adapter);
5. Adding / removing items to ListView (and its adapter)
Adapter is handled just like any other ArrayList, so adding new element to it is as simple as:
Payment testPayment = new Payment("Test", 13);
adapter.add(testPayment);
adapter.remove(testPayment);
6. Handle Remove Payment button click event
In an activity’s code, where ListView is displayed, add public method that will handle remove button click action. The method name has to be exactly the same as it was in pay_list_item.xml:
android:onClick="removePayOnClickHandler"
The method body is as follows:
public void removePayOnClickHandler(View v) {
Payment itemToRemove = (Payment)v.getTag();
adapter.remove(itemToRemove);
}
The Payment object was stored in ImageButton’s Tag element. Now it is enough to read it from Tag, and remove this item from the adapter.
7. Incorporate remove confirmation dialog window
Probably you need also make sure that user intentionally pressed the remove button by asking him additional question in confirmation dialog.
Dialogue
a) Create dialog’s id constant
This is simply dialog’s ID. it should be unique among any other dialog window that is handled by current activity. I set it like that:
protected static final int DIALOG_REMOVE_CALC = 1;
protected static final int DIALOG_REMOVE_PERSON = 2;
b) Build dialog
I use this method to build dialog window:
private Dialog createDialogRemoveConfirm(final int dialogRemove) {
return new AlertDialog.Builder(getApplicationContext())
.setIcon(R.drawable.trashbin_icon)
.setTitle(R.string.calculation_dialog_remove_text)
.setPositiveButton(R.string.calculation_dialog_button_ok, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
handleRemoveConfirm(dialogRemove);
}
})
.setNegativeButton(R.string.calculation_dialog_button_cancel, null)
.create();
}
AlertDialog builder pattern is utilized here. I do not handle NegativeButton click action – by default the dialog is just being hidden. If dialog’s confirm button is clicked, my handleRemoveConfirm callback is called and action is performed based on dialog’s ID:
protected void handleRemoveConfirm(int dialogType) {
if(dialogType == DIALOG_REMOVE_PERSON){
calc.removePerson();
}else if(dialogType == DIALOG_REMOVE_CALC){
removeCalc();
}
}
c) Show Dialog
I show dialog after my remove button click. The showDialog(int) is Android’s Activity’s method:
OnClickListener removeCalcButtonClickListener = new OnClickListener() {
public void onClick(View v) {
showDialog(DIALOG_REMOVE_CALC);
}
};
the showDialog(int) method calls onCreateDialog (also defined in Activity’s class). Override it and tell your app what to do if the showDialog was requested:
#Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DIALOG_REMOVE_CALC:
return createDialogRemoveConfirm(DIALOG_REMOVE_CALC);
case DIALOG_REMOVE_PERSON:
return createDialogRemoveConfirm(DIALOG_REMOVE_PERSON);
}
}

Take a look at this blog post I wrote on exactly this matter:
Create custom ArrayAdapter
There are comments that explain every action I make in the adapter.
Here is the explanation in short:
So lets for example take a row where you want to place a CheckBox, ImageView
and a TextView while all of them are clickable. Meaning that you can click the
row it self for going to another Actvity for more details on the row, check its
CheckBox or press the ImageView to perform another operation.
So what you should do is:
1. First create an XML layout file for your ListView row:
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<CheckBox
android:id="#+id/cbCheckListItem"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp" />
<TextView
android:id="#+id/tvItemTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="item string" />
<ImageView
android:id="#+id/iStatus"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:clickable="true"
android:contentDescription="#drawable/ic_launcher"
android:src="#drawable/ic_launcher" />
</LinearLayout>
2. Second in your java code define a ViewHolder, a ViewHolder
is designed to hold the row views and that way operating more quickly:
static class ViewHolder
{
TextView title;
CheckBox checked;
ImageView changeRowStatus;
}
3. Now we have to define CustomArrayAdapter, using the array adapter
we can define precisely what is the desired output for each row based on the content of this
row or it’s position. We can do so by overriding the getView method:
private class CustomArrayAdapter extends ArrayAdapter<RowData>
{
private ArrayList<RowData> list;
//this custom adapter receives an ArrayList of RowData objects.
//RowData is my class that represents the data for a single row and could be anything.
public CustomArrayAdapter(Context context, int textViewResourceId, ArrayList<RowData> rowDataList)
{
//populate the local list with data.
super(context, textViewResourceId, rowDataList);
this.list = new ArrayList<RowData>();
this.list.addAll(rowDataList);
}
public View getView(final int position, View convertView, ViewGroup parent)
{
//creating the ViewHolder we defined earlier.
ViewHolder holder = new ViewHolder();)
//creating LayoutInflator for inflating the row layout.
LayoutInflater inflator = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
//inflating the row layout we defined earlier.
convertView = inflator.inflate(R.layout.row_item_layout, null);
//setting the views into the ViewHolder.
holder.title = (TextView) convertView.findViewById(R.id.tvItemTitle);
holder.changeRowStatus = (ImageView) convertView.findViewById(R.id.iStatus);
holder.changeRowStatus.setTag(position);
//define an onClickListener for the ImageView.
holder.changeRowStatus.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
Toast.makeText(activity, "Image from row " + position + " was pressed", Toast.LENGTH_LONG).show();
}
});
holder.checked = (CheckBox) convertView.findViewById(R.id.cbCheckListItem);
holder.checked.setTag(position);
//define an onClickListener for the CheckBox.
holder.checked.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
//assign check-box state to the corresponding object in list.
CheckBox checkbox = (CheckBox) v;
rowDataList.get(position).setChecked(checkbox.isChecked());
Toast.makeText(activity, "CheckBox from row " + position + " was checked", Toast.LENGTH_LONG).show();
}
});
//setting data into the the ViewHolder.
holder.title.setText(RowData.getName());
holder.checked.setChecked(RowData.isChecked());
//return the row view.
return convertView;
}
}
4. Now you need to set this adapter, as the adapter of your ListView.
this ListView can be created in java or using an XML file, in this case I’m using a list that was
defined in the XML file using the “list” id:
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_layout);
ListView list = (ListView)findViewById(R.id.list);
CustomArrayAdapter dataAdapter = new CustomArrayAdapter(this, R.id.tvItemTitle, rowDataList);
list.setAdapter(dataAdapter);
}
5. Finally if we want to be able to press the row it self and not only a certain view in it
we should assign an onItemClickListener to the ListView:
list.setOnItemClickListener(new OnItemClickListener()
{
public void onItemClick(AdapterView<?> parent, View view,int position, long id)
{
Toast.makeText(activity, "row " + position + " was pressed", Toast.LENGTH_LONG).show();
}
});

First, the way of adding listeners in xml using onClick="function" is deprecated. You need a ViewHolder class to link the button in the xml to your java code. Then you can implement onClickListener for that.

Inside your getView() implementation of CustomAdapter, you can try like below.
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.xxxxx, null);
holder = new ViewHolder();
holder.invite = (Button) convertView.findViewById(R.id.button);
} else {
holder = (ViewHolder) convertView.getTag();
}
final int pos = position;
holder.button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
handleClick(pos);
}
});
}
class ViewHolder {
Button button;
}