Develop Reference

Expand all list items in custom ListView (android)

I am using a normal ListView (mItemsList) with expandable animation (from this tutorial). It works, when I click on list item it expands and shows details for this item.
mItemsList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, final View view, int position, long id) {
View details = view.findViewById(R.id.details);
// Creating the expand animation for the item
ExpandAnimation expandAni = new ExpandAnimation(details, 500);
// Start the animation on the toolbar
details.startAnimation(expandAni);
}
});
I created a showDetails button and I want to expand all list items after clicking the button, but I am completely lost. Code below doesn't work
mShowDetailsButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
for (int i = 0; i < mItemsList.getAdapter().getCount(); i++) {
View details= v.findViewById(R.id.details);
details.startAnimation(new ExpandAnimation(details, 500));
}
}
});
Could you help me?
Here's my list_item xml file

Maybe do the similar approach like the following to automatically click item one by one to open all listciew.
mShowDetailsButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
for (int i = 0; i < mItemsList.getAdapter().getCount(); i++) {
listView.performItemClick(
getViewByPosition(i),
i,
listView.getAdapter().getItemId(i));
}
}
});
//the listview getChildAt only return the view(item) that is visible,
//therefore add a function to get invisible view together
public View getViewByPosition(int position) {
int firstItemPosition = listView.getFirstVisiblePosition();
int lastItemPosition = firstItemPosition + listView.getChildCount() - 1;
if (position < firstItemPosition || position > lastItemPosition ) {//is invisible
return listView.getAdapter().getView(position, null, listView);
} else {
int childIndex = position - firstItemPosition;//is visible
return listView.getChildAt(childIndex);
}
}
The one you do is not work as the view is refering the mShowDetailsButton ,but not mItemsList. Thus, you cannot findViewof id R.id.details.
mShowDetailsButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {//<-- this view not referring to mItemsList
}
});

How to highlight the first row of RecyclerView by default and then remove highlight as and when other rows are selected?

I am trying to load a list in RecyclerView and show the first row of the list as selected. I have achieved it using the following code:
#Override
public void onBindViewHolder(NavigationDrawerAdapter.ViewHolder holder, final int position) {
if (!mNavClassrooms.get(position).equals("")) {
holder.mTextViewClassroom.setText(mNavClassrooms.get(position)); // Setting the Text with the array of our Titles
holder.mRelLayClassroom.setSelected(mSelectedItems.get(position, false));
/*
The following code was written to make the first item in the Classroom list as selected.
It leads to the item always being selected and hence has been commented out.
*/
if(position == 0 && intOldSelectedItem == -1){
holder.mRelLayClassroom.setSelected(mSelectedItems.get(position, true));
intOldSelectedItem = 0;
mSelectedView = holder.mRelLayClassroom.getChildAt(position);
mSelectedItems.put(position, true);
}
else{
holder.mRelLayClassroom.setSelected(mSelectedItems.get(position, false));
}
} else {
holder.mTextViewClassroom.setText("No classes found");
holder.mTextViewClassroom.setPadding(40, 0, 0, 0);
}
holder.mRelLayClassroom.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
mSharedPreferences = mContext.getSharedPreferences(Constants.AAPREFERENCES, Context.MODE_PRIVATE);
String strClassroomValue = mNavClassrooms.get(position);
int strClassroomName = mNavClassroomNames.get(position);
SharedPreferences.Editor editor = mSharedPreferences.edit();
editor.putString(Constants.CLASSROOM_VALUE, strClassroomValue);
editor.putInt(Constants.CLASSROOM_NAME, strClassroomName);
editor.commit();
/*
We are storing the position of the selected row in the SparseBooleanArray.
We delete it in case another row has been selected.
*/
if (mSelectedItems.get(position, false)) {
/*
Do nothing
*/
} else {
mSelectedItems.put(position, true);
/*
Making sure that the delete code is called only if some view is selected
*/
if (mSelectedView != null) {
mSelectedView.setSelected(false);
mSelectedItems.delete(intOldSelectedItem);
view.setSelected(false);
}
mSelectedView = view;
intOldSelectedItem = position;
view.setSelected(true);
}
}
However, now the first row stays selected always. I am unable to deselect it. I cannot seem to get this working.
I referred to the following answer to achieve most of this functionlaity.
https://stackoverflow.com/a/29984220/2186220
Any help will be appreciated.

I'm not answering your question by posting a fixed version of your onBindViewHolder method since it's kinda hard to understand and we don't know how the rest of your adapter looks like. So following a RecyclerView Adapter which does what you want: Selecting the first row by default and deselecting it once a other row is selected.
public class Adapter extends RecyclerView.Adapter<Adapter.ViewHolder> {
// ... other fields
// default selection position is the first one
private int selectedPosition = 0;
// ... constructor etc.
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
if(position == selectedPosition){
holder.itemView.setSelected(true);
} else {
holder.itemView.setSelected(false);
}
// Actual selection / deselection logic
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
int currentPosition = holder.getLayoutPosition();
if(selectedPosition != currentPosition){
// Temporarily save the last selected position
int lastSelectedPosition = selectedPosition;
// Save the new selected position
selectedPosition = currentPosition;
// update the previous selected row
notifyItemChanged(lastSelectedPosition);
// select the clicked row
holder.itemView.setSelected(true);
}
}
});
// other adapter code
}
// other adapter stuff like onCreateViewHolder, getItemCount, ViewHolder etc.
}
Note: I guess there's no need to use a SparseBooleanArray so simply remove it and replace it with the int field used in the example above.

Initialize your
int intOldSelectedItem=0 and keep one boolean isVisible= false;
And do it as below:
if (holder.getPosition() == intOldSelectedItem) {
if (isVisible) {
//background for selected item
} else {
//background for unselected item
}
} else {
//background for unselected item
}
holder.mRelLayClassroom.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (intOldSelectedItem== holder.getPosition()) {
isVisible = !isVisible;
} else {
if (intOldSelectedItem!= 0) {
isVisible = false;
notifyItemChanged(intOldSelectedItem);
}
isVisible = true;
}
intOldSelectedItem= holder.getPosition();
notifyItemChanged(intOldSelectedItem);
}
});
I hope it might help you.

Add background selector to your ViewHolder layout.
Create your selector handler something like this:
public class SingleSelector {
private View oldVIew;
public void setSelection(View newView) {
if (oldVIew == null) {
newView.setSelected(true);
oldVIew = newView;
} else {
oldVIew.setSelected(false);
newView.setSelected(true);
oldVIew = newView;
}
}
}
Set default selection when you need it:
#Override
public void onBindViewHolder(SimpleViewHolder holder, int position) {
if (position == 0) {
singleSelector.setSelection(holder.itemView);
}
}
In your ViewHolder add listener to itemView and pass it to the handler:
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
singleSelector.setSelection(itemView);
}
});

using notifyItemRemoved or notifyDataSetChanged with RecyclerView in Android

I am creating a list of cards to display using the RecyclerView, where each card has a button to remove that card from the list.
When i use notifyItemRemoved() to remove the card in the RecyclerView, it removes the item and animates fine but the data in the list is not updated correctly.
If instead of that, i switch to the notifyDataSetChanged() then the items in list are removed and updated correctly, but then the cards dont animate.
Does someone has any experience in using the notifyItemRemoved() and know why it behaves differently than notifyDataSetChanged?
Here is some peiece of code that i am using:
private List<DetectedIssue> issues = new ArrayList<DetectedIssue>();
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
if(position >0){
RiskViewHolder riskHolder = (RiskViewHolder)holder;
final int index = position - 1;
final DetectedIssue anIssue = issues.get(index);
riskHolder.button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
int index = issues.indexOf(anIssue);
issues.remove(anIssue);
notifyItemRemoved(index);
//notifyDataSetChanged();
} catch (SQLException e) {
e.printStackTrace();
}
}
});
}
}
#Override
public int getItemCount() {
return (issues.size()+1);
}

Use notifyItemRangeChanged(position, getItemCount()); after notifyItemRemoved(position);
You don't need to use index, just use position. See code below.
private List<DetectedIssue> issues = new ArrayList<DetectedIssue>();
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
if(position >0){
RiskViewHolder riskHolder = (RiskViewHolder)holder;
riskHolder.button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
issues.remove(position);
notifyItemRemoved(position);
//this line below gives you the animation and also updates the
//list items after the deleted item
notifyItemRangeChanged(position, getItemCount());
} catch (SQLException e) {
e.printStackTrace();
}
}
});
}
}
#Override
public int getItemCount() {
return issues.size();
}

Tried
public void removeItem(int position) {
this.taskLists.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, getItemCount() - position);
}
and working like a charm.

my mistake ,
notifyItemChanged(position) is helpless,the item of position can be removed ,and the item of position+1 is fine,but the items start from position+2,you will get an Exception, please use notifyItemRangeChanged(position,getItemCount());
after notifyItemRemoved(position);
like this:
public void removeData(int position) {
yourdatalist.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position,getItemCount());
}

Use this it is working perfectly.
issues.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, issues.size());

As #pskink suggested it was supposed to be (index+1) in my case with notifyItemRemoved(index+1), probably because i am reserving the top index i.e. position=0 for a header.

**my solution looks like this**
this way is unnecessary to use the heavy method:
//notifyItemRangeChanged(xx,xx)
/**
*
* recyclerView的item中的某一个view,获取其最外层的viewParent，也就是item对应的layout在adapter中的position
*
* #param recyclerView
* #param view：can be the deep one inside the item,or the item itself .
* #return
*/
public static int getParentAdapterPosition(RecyclerView recyclerView, View view, int parentId) {
if (view.getId() == parentId)
return recyclerView.getChildAdapterPosition(view);
View viewGroup = (View) view.getParent();
if (viewGroup != null && viewGroup.getId() == parentId) {
return recyclerView.getChildAdapterPosition(viewGroup);
}
//recursion
return getParentAdapterPosition(recyclerView, viewGroup, parentId);
}
//wherever you set the clickListener .
holder.setOnClickListener(R.id.rLayout_device_item, deviceItemClickListener);
holder.setOnLongClickListener(R.id.rLayout_device_item, deviceItemLongClickListener);
#Override
public boolean onLongClick(View v) {
final int position = ViewUtils.getParentAdapterPosition(rVDevicesList, v, R.id.rLayout_device_item);
return true;
}

In my case I use Content Provider and a Custom RecyclerView Adapter with Cursor. This line of code is where you notify:
getContext().getContentResolver().notifyChange(uri, null);
Assuming In your recyclerView adapter (Delete Button):
Uri currentUri = ContentUris.withAppendedId(DatabaseContract.ToDoEntry.CONTENT_URI_TODO, id);
int rowsDeleted = mContext.getContentResolver().delete(currentUri, null, null);
if (rowsDeleted == 0) {
Log.d(TAG, "onClick: Delete failed");
} else {
Log.d(TAG, "onClick: Delete Successful");
}
And in your Database Provider:
case TODO_ID:
selection = DatabaseContract.ToDoEntry._ID + "=?";
selectionArgs = new String[] {String.valueOf(ContentUris.parseId(uri))};
rowsDeleted = database.delete(DatabaseContract.ToDoEntry.TODO_TABLE_NAME, selection, selectionArgs);
if (rowsDeleted != 0){
getContext().getContentResolver().notifyChange(uri, null);
}
return rowsDeleted;

You can use getAdapterPosition() from the RecyclerView.ViewHolder
getLayoutPosition() provides the exact position of item in the layout and code is
holder.removeButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//Position for remove
int modPosition= holder.getAdapterPosition();
//remove item from dataset
numbers.remove(modPosition);
//remove item from recycler view
if(numbers.isEmpty())
notifyDataSetChanged ()
else
notifyItemRemoved(modPosition);
}
});

Expandable list with RecyclerView?

It's possible to use expandable list items with new RecyclerView? Like ExpandableListView?

This is simple to do with the stock LayoutManagers, it all depends on how you manage your adapter.
When you want to expand a section you just add new items to your adapter after the header. Remember to call notifyItemRangeInserted when you do this. To collapse a section you simply remove the relevant items, and call notifyItemRangeRemoved(). For any data changes that are appropriately notified, the recycler view will animate the views. When adding items, an area to be filled with the new items is made, with the new items fading in. Removal is the opposite. All you need to do besides the adapter stuff is to style your views to convey the logical structure to the user.
Update: Ryan Brooks has now written an article on how to do this.

Get the sample code implementation from here
Set ValueAnimator inside onClick of ViewHolder
#Override
public void onClick(final View view) {
if (mOriginalHeight == 0) {
mOriginalHeight = view.getHeight();
}
ValueAnimator valueAnimator;
if (!mIsViewExpanded) {
mIsViewExpanded = true;
valueAnimator = ValueAnimator.ofInt(mOriginalHeight, mOriginalHeight + (int) (mOriginalHeight * 1.5));
} else {
mIsViewExpanded = false;
valueAnimator = ValueAnimator.ofInt(mOriginalHeight + (int) (mOriginalHeight * 1.5), mOriginalHeight);
}
valueAnimator.setDuration(300);
valueAnimator.setInterpolator(new LinearInterpolator());
valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
public void onAnimationUpdate(ValueAnimator animation) {
Integer value = (Integer) animation.getAnimatedValue();
view.getLayoutParams().height = value.intValue();
view.requestLayout();
}
});
valueAnimator.start();
}
Here is the final code
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private TextView mFriendName;
private int mOriginalHeight = 0;
private boolean mIsViewExpanded = false;
public ViewHolder(RelativeLayout v) {
super(v);
mFriendName = (TextView) v.findViewById(R.id.friendName);
v.setOnClickListener(this);
}
#Override
public void onClick(final View view) {
if (mOriginalHeight == 0) {
mOriginalHeight = view.getHeight();
}
ValueAnimator valueAnimator;
if (!mIsViewExpanded) {
mIsViewExpanded = true;
valueAnimator = ValueAnimator.ofInt(mOriginalHeight, mOriginalHeight + (int) (mOriginalHeight * 1.5));
} else {
mIsViewExpanded = false;
valueAnimator = ValueAnimator.ofInt(mOriginalHeight + (int) (mOriginalHeight * 1.5), mOriginalHeight);
}
valueAnimator.setDuration(300);
valueAnimator.setInterpolator(new LinearInterpolator());
valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
public void onAnimationUpdate(ValueAnimator animation) {
Integer value = (Integer) animation.getAnimatedValue();
view.getLayoutParams().height = value.intValue();
view.requestLayout();
}
});
valueAnimator.start();
}
}

https://github.com/gabrielemariotti/cardslib
This library has an implementation of an expandable list with a recyclerview (refer to the demo app under "CardViewNative" --> "List, Grid, and RecyclerView" --> "Expandable cards"). It also has a lot of other cool combinations of cards/lists.

Someone complained about that the above mentioned solution is not usable with a listview as expandable content. But there's a simple solution: create a listview and fill this listview manually with your rows.
Solution for the lazy ones: there's a simple solution if you don't want to change your code to much. Just manually use your adapter to create views and add them to the LinearLayout.
Here's the example:
if (mIsExpanded)
{
// llExpandable... is the expandable nested LinearLayout
llExpandable.removeAllViews();
final ArrayAdapter<?> adapter = ... // create your adapter as if you would use it for a ListView
for (int i = 0; i < adapter.getCount(); i++)
{
View item = adapter.getView(i, null, null);
// if you want the item to be selectable as if it would be in a default ListView, then you can add following code as well:
item.setBackgroundResource(Functions.getThemeReference(context, android.R.attr.selectableItemBackground));
item.setTag(i);
item.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// item would be retrieved with:
// adapter.getItem((Integer)v.getTag())
}
});
llExpandable.addView(item);
}
ExpandUtils.expand(llExpandable, null, 500);
}
else
{
ExpandUtils.collapse(llExpandable, null, 500);
}
helper functions: getThemeReference
public static int getThemeReference(Context context, int attribute)
{
TypedValue typeValue = new TypedValue();
context.getTheme().resolveAttribute(attribute, typeValue, false);
if (typeValue.type == TypedValue.TYPE_REFERENCE)
{
int ref = typeValue.data;
return ref;
}
else
{
return -1;
}
}
helper class: ExpandUtils
Kavin Varnan postet already how to animate a layout...
But if you want to use my class, feel free to do so, I posted a gist: https://gist.github.com/MichaelFlisar/738dfa03a1579cc7338a

You can use ExpandableLayout that like a smooth expand/collapse animation CheckBox, so you can use it as CheckBox in ListView and RecyclerView.
https://github.com/KyoSherlock/ExpandableLayout

This is the sample code for what is mentioned by #TonicArtos to add and remove Items and to animate it while doing, this is taken from RecyclerView Animations and GitHub sample
1) Add Listener inside your onCreateViewHolder() to register for onClick
2) Create your custom OnClickListener inside your Adapter
private View.OnClickListener mItemListener = new View.OnClickListener() {
#Override
public void onClick(View v) {
TextView tv = (TextView) v.findViewById(R.id.tvItems);
String selected = tv.getText().toString();
boolean checked = itemsList.get(recyclerView.getChildAdapterPosition(v)).isChecked();
switch (selected){
case "Item1":
if(checked){
deleteItem(v);
itemsList.get(recyclerView.getChildAdapterPosition(v)).setChecked(false);
}else {
addItem(v);
itemsList.get(recyclerView.getChildAdapterPosition(v)).setChecked(true);
}
break;
case "Item2":
if(checked){
deleteItem(v);
itemsList.get(recyclerView.getChildAdapterPosition(v)).setChecked(false);
}else {
addItem(v);
itemsList.get(recyclerView.getChildAdapterPosition(v)).setChecked(true);
}
break;
default:
//In my case I have checkList in subItems,
//checkItem(v);
break;
}
}
};
3) Add your addItem() and deleteItem()
private void addItem(View view){
int position = recyclerView.getChildLayoutPosition(view);
if (position != RecyclerView.NO_POSITION){
navDrawItems.add(position+1,new mObject());
navDrawItems.add(position+2,new mObject());
notifyItemRangeInserted(position+1,2);
}
}
private void deleteItem(View view) {
int position = recyclerView.getChildLayoutPosition(view);
if (position != RecyclerView.NO_POSITION) {
navDrawItems.remove(position+2);
navDrawItems.remove(position+1);
notifyItemRangeRemoved(position+1,2);
}
}
4) If your RecyclerViewAdapter is not in the same Activity as Recycler View, pass instance of recyclerView to the Adapter while creating
5) itemList is a ArrayList of type mObject which helps maintain states of item (Open/Close) , name, type of Item(subItems/mainItem) and set Theme based on values
public class mObject{
private String label;
private int type;
private boolean checked;
}

Swapping two rows in ArrayAdapter

I've created a ListView that in each row has a button with UP and DOWN arrow. Pressing these buttons makes the row to be shifted one position up or down.
I've achieved it by implementing OnClickListener for both buttons in a the override method getView. It works as it should however I fill bad with that cuz it seems to be highly memory consuming and lots of code is doubled.
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
View rowView = inflater.inflate(R.layout.row_layout, parent, false);
TextView textView = (TextView) rowView.findViewById(R.id.label);
CheckBox checkBox = (CheckBox) rowView.findViewById(R.id.checkbox);
checkBoxes.add(position, checkBox);
String address = this.getItem(position).getAddress();
String tokenizedAddress = tokenizeAddress(address);
textView.setText(tokenizedAddress);
ImageButton buttonUp = (ImageButton)rowView.findViewById(R.id.button_up);
ImageButton buttonDown = (ImageButton)rowView.findViewById(R.id.button_down);
buttonUp.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
ListAdapter adapter = ListAdapter.this;
if(position != 0 ){
GameTask current = adapter.getItem(position);
ArrayList<GameTask> list = new ArrayList<GameTask>();
for( int i = 0; i < adapter.getCount(); i++ )
list.add(adapter.getItem(i));
list.remove(position);
list.add(position-1, current);
adapter.clear();
for( int i = 0; i < list.size(); i++ ){
adapter.add(list.get(i));
}
adapter.notifyDataSetChanged();
}
}
});
buttonDown.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
ListAdapter adapter = ListAdapter.this;
if(position != adapter.getCount()-1 ){
GameTask current = adapter.getItem(position);
ArrayList<GameTask> list = new ArrayList<GameTask>();
for( int i = 0; i < adapter.getCount(); i++ )
list.add(adapter.getItem(i));
list.remove(position);
list.add(position+1, current);
adapter.clear();
for( int i = 0; i < list.size(); i++ ){
adapter.add(list.get(i));
}
adapter.notifyDataSetChanged();
}
}
});
return rowView;
}
Both listeners do almost the same, the only difference is the condition and the value of shifting +1/-1. I was wondering about creating the inner class implementing OnClickListener in the extended ArrayAdapter class however, I have no idea, how I could then pass the position of the row clicked to this inner class.

Instead of adding and removing elements from your ArrayList, you can better implement Collections.swap(List list, int firstElementIndex, int secondElementIndex) it would be much easier as you don't have to iterate through the whole Collection. A simple example for the same can be found here.

You could make a method that would be used by both buttonUp and buttonDown. This method could take as a parameter the type of action that was pressed (UP/DOWN), and the position of item in ListView, and then call this method in both of your click listener passing the appropriate action.
Example:
// 2 new constants
private static final int UP = 0;
private static final int DOWN = 1;
// Based on "type", increment or decrement the position.
private void changeRow(int type, int position){
if(type==UP){
position=position-1;
}else if(type==DOWN){
position=position+1;
}
// ........
// Then in your "for" cicle you specify:
list.add(position, current);
// ........
}
Then in the onClick() method of buttonUp you specify:
changeRow(UP, position);
and for buttonDown:
changeRow(DOWN, position);

This can be easily achieved
The way to do this is to store the data to be displayed in an List
Then when the user clicks the up or down arrow
Swap the references of data items which are shifting position using Collections.swap(List, int, int)
Then call notifyDataSetChanged on the adapter