Code of the illustration:
mLinearLayoutManager = new LinearLayoutManager(this);
mLinearLayoutManager.setReverseLayout(true);
mLinearLayoutManager.setStackFromEnd(true);
mMessageRecyclerView.setLayoutManager(mLinearLayoutManager);
How can I add new items (in my case, messages) to the bottom of Recycler View and still keep the "gravity" of the view to the top?
So, what works now is the following:
What doesn't work:
Try removing these two lines or setting them false
layoutManager.setReverseLayout(true);
layoutManager.setStackFromEnd(true);
setStackFromEnd
will set the view to show the last element, the layout direction will remain the same whereas setReverseLayout
will change the order of the elements added by the Adapter.
Try using this to move your RecyclerView
and EditText
up when keyboard appears
<activity name="YourActivity"
android:windowSoftInputMode="stateHidden|adjustResize">
//stateHidden -> keyboard is hidden when you first open the activity
//adjustResize -> this will adjust the layout resize option
...
</activity>
in AndroidManifest.xml
.
To hook the RecyclerView at top
<android.support.v7.widget.RecyclerView
android:id="@+id/messageRecyclerViewRep"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_below="@+id/linearLayout3"
android:layout_marginLeft="36dp"
android:scrollbars="vertical" />
To put the recyclerView at bottom first and push it up as the keyboard pops up.
<LinearLayout
android:id="@+id/recyclerContainer"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@+id/linearLayout3"
android:layout_above="@+id/linearLayout"
android:gravity="bottom">
<android.support.v7.widget.RecyclerView
android:id="@+id/messageRecyclerViewRep"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="36dp"
android:scrollbars="vertical" />
</LinearLayout>
To scroll the recyclerView to bottom when keyboard pops up ie when the recycler view's layout is changed ( You can do the same thing on Edit Text active or focused or clicked or something like that. I've done it on recycler view's layout change. )
recyclerView.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
@Override
public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
if (bottom < oldBottom) {
recyclerView.postDelayed(new Runnable() {
@Override
public void run() {
recyclerView.smoothScrollToPosition(mAdapter.getItemCount());
}
}, 100);
}
}
});
setReverseLayout(true) this will reverse the item traversal & layout order.The first item will come to end not view or content.
setStackFromEnd(true) this will fill the recycler list content starting from the bottom of the view.
Need to setStackFromEnd(true)
not setReverseLayout(true)
And in XML Recyclerview height should be match_parent
Below i have given working code.
activity 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="match_parent"
android:orientation="vertical">
<Button
android:id="@+id/btnAdd"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Add" />
<android.support.v7.widget.RecyclerView
android:id="@+id/rcList"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="true" />
</LinearLayout>
list item xml layout
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginRight="20dp"
android:gravity="center_vertical">
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content" android:textSize="23sp"
android:layout_height="wrap_content" android:textColor="#4a4883"
android:text="Test Text" />
</FrameLayout>
Adapter class
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.ViewHolder> {
private static final String TAG = "CustomAdapter";
private ArrayList<String> mDataSet;
private int size = 0;
public static class ViewHolder extends RecyclerView.ViewHolder {
private final TextView textView;
public ViewHolder(View v) {
super(v);
v.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d(TAG, "Element " + getAdapterPosition() + " clicked.");
}
});
textView = (TextView) v.findViewById(R.id.textView);
}
public TextView getTextView() {
return textView;
}
}
public CustomAdapter(ArrayList<String> dataSet) {
mDataSet = dataSet;
if (mDataSet != null && !mDataSet.isEmpty()) {
size = mDataSet.size();
}
}
public void refreshData(String add) {
if (!TextUtils.isEmpty(add)) {
mDataSet.add(add);
size = mDataSet.size();
notifyDataSetChanged();
}
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
// Create a new view.
View v = LayoutInflater.from(viewGroup.getContext())
.inflate(R.layout.list_item, viewGroup, false);
return new ViewHolder(v);
}
@Override
public void onBindViewHolder(ViewHolder viewHolder, final int position) {
Log.d(TAG, "Element " + position + " set.");
viewHolder.getTextView().setText(mDataSet.get(position));
}
@Override
public int getItemCount() {
return size;
}
}
Activity class
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
protected CustomAdapter mAdapter;
protected LinearLayoutManager mLayoutManager;
protected ArrayList<String> listString = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRecyclerView = (RecyclerView) findViewById(R.id.rcList);
mLayoutManager = new LinearLayoutManager(this);
mLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
/**
*setStackFromEnd true will fill the content(list item) from the bottom of the view
*/
mLayoutManager.setStackFromEnd(true);
mLayoutManager.setReverseLayout(true);
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
findViewById(R.id.btnAdd).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int temp = mAdapter.getItemCount() + 1;
mAdapter.refreshData("Test text " + temp);
mRecyclerView.smoothScrollToPosition(mAdapter.getItemCount());
}
});
mAdapter = new CustomAdapter(listString);
mRecyclerView.setAdapter(mAdapter);
}
}
The simplest way to achieve this would be to load the elements into the Recyclerview in the reverse order to how they are entered in the Firebase Database.
@Override
public void onBindViewHolder(ViewHolder viewHolder, final int position) {
Log.d(TAG, "Element " + position + " set.");
viewHolder.getTextView().setText(mDataSet.get(getItemCount() - 1 -position));
}
What this would do is that the item which is inserted last will get displayed at bottom since you are loading the items from top. No need for any change in any of the XMLs or any other code.
I had same issues with Recylerview not resizing itself when the keyboard pops up and therefore I resorted to this method.
All the best!!
I have implemented and here is my Implementation using FirebaseRecyclerView you need to set this setStackFromEnd=true
and setReverseLayout=true
Recycler View Holder
public class TestingFirebaseHolder extends RecyclerView.ViewHolder {
private TextView mTextView;
private TextView mTextView2;
public TestingFirebaseHolder(View itemView) {
super(itemView);
mTextView = itemView.findViewById(R.id.textViewTesting);
mTextView2 = itemView.findViewById(R.id.textViewTesting2);
}
public void setTextView(String text,String text2)
{
mTextView.setText(text);
mTextView2.setText(text2);
}
}
Testing Class
public class TestingUser {
public String UserName;
public String mUid;
public TestingUser() {
}
public TestingUser(String userName, String uid) {
UserName = userName;
mUid = uid;
}
}
Activity Code
private EditText mEditText;
private RecyclerView mRecyclerView;
private FirebaseRecyclerAdapter<TestingUser,TestingFirebaseHolder> mAdapter;
private FirebaseUser mUser;
private DatabaseReference mReference;
mEditText = findViewById(R.id.testingEditText);
mRecyclerView = findViewById(R.id.hello_rec);
mUser = FirebaseAuth.getInstance().getCurrentUser();
mReference = FirebaseDatabase.getInstance().getReference();
LinearLayoutManager ll = new LinearLayoutManager(this);
ll.setReverseLayout(true); // set this
ll.setStackFromEnd(true); // set this
mRecyclerView.setLayoutManager(ll);
Query query = mReference.child("Testing").child(mUser.getUid()).orderByValue();
mAdapter = new FirebaseRecyclerAdapter<TestingUser, TestingFirebaseHolder>(
TestingUser.class,R.layout.testing_recycler_layout,TestingFirebaseHolder.class,query
) {
@Override
protected void populateViewHolder(TestingFirebaseHolder viewHolder, TestingUser model, int position) {
viewHolder.setTextView(model.mUid,model.UserName);
}
};
mRecyclerView.setAdapter(mAdapter);
public void buttonClick(View view) {
if(!mEditText.getText().toString().isEmpty())
{
TestingUser user = new TestingUser("Salman",mEditText.getText().toString());
mReference.child("Testing").child(mUser.getUid()).push().setValue(user);
mEditText.setText("");
}
}
Result is link
Try this, it works for me.
mLinearLayoutManager = new LinearLayoutManager(this);
mLinearLayoutManager.stackFromEnd(true)
mLinearLayoutManager.isSmoothScrollbarEnabled(true)
mMessageRecyclerView.setLayoutManager(mLinearLayoutManager);
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