Gradle dependencies
compile group: 'androidx.leanback', name: 'leanback', version: '1.2.0-alpha02'
- groupId: androidx.leanback
- artifactId: leanback
- version: 1.2.0-alpha02
Artifact androidx.leanback:leanback:1.2.0-alpha02 it located at Google repository (https://maven.google.com/)
Androidx artifact mapping:
androidx.leanback:leanback com.android.support:leanback-v17
Androidx class mapping:
androidx.leanback.widget.ItemBridgeAdapter android.support.v17.leanback.widget.ItemBridgeAdapter
Overview
Bridge from Presenter to . Public to allow use by third
party Presenters.
Summary
Methods |
---|
public void | clear()
Clears the adapter. |
public FacetProvider | getFacetProvider(int type)
|
public abstract int | getItemCount()
Returns the total number of items in the data set held by the adapter. |
public long | getItemId(int position)
Return the stable ID for the item at position . |
public int | getItemViewType(int position)
Return the view type of the item at position for the purposes
of view recycling. |
public java.util.ArrayList<Presenter> | getPresenterMapper()
Returns the presenter mapper array. |
public ItemBridgeAdapter.Wrapper | getWrapper()
Returns the ItemBridgeAdapter.Wrapper. |
protected void | onAddPresenter(Presenter presenter, int type)
Called when presenter is added to Adapter. |
protected void | onAttachedToWindow(ItemBridgeAdapter.ViewHolder viewHolder)
Called when ViewHolder has been attached to window. |
protected void | onBind(ItemBridgeAdapter.ViewHolder viewHolder)
Called when ViewHolder has been bound to data. |
public abstract void | onBindViewHolder(RecyclerView.ViewHolder holder, int position)
Called by RecyclerView to display the data at the specified position. |
public void | onBindViewHolder(RecyclerView.ViewHolder holder, int position, java.util.List<java.lang.Object> payloads)
Called by RecyclerView to display the data at the specified position. |
protected void | onCreate(ItemBridgeAdapter.ViewHolder viewHolder)
Called when ViewHolder is created. |
public final RecyclerView.ViewHolder | onCreateViewHolder(ViewGroup parent, int viewType)
that assigned in
Presenter.onCreateViewHolder(ViewGroup) may be chained, user should never change
after that. |
protected void | onDetachedFromWindow(ItemBridgeAdapter.ViewHolder viewHolder)
Called when ViewHolder has been detached from window. |
public boolean | onFailedToRecycleView(RecyclerView.ViewHolder holder)
Called by the RecyclerView if a ViewHolder created by this Adapter cannot be recycled
due to its transient state. |
protected void | onUnbind(ItemBridgeAdapter.ViewHolder viewHolder)
Called when ViewHolder has been unbound from data. |
public void | onViewAttachedToWindow(RecyclerView.ViewHolder holder)
Called when a view created by this adapter has been attached to a window. |
public void | onViewDetachedFromWindow(RecyclerView.ViewHolder holder)
Called when a view created by this adapter has been detached from its window. |
public void | onViewRecycled(RecyclerView.ViewHolder holder)
Called when a view created by this adapter has been recycled. |
public void | setAdapter(ObjectAdapter adapter)
Sets the ObjectAdapter. |
public void | setAdapterListener(ItemBridgeAdapter.AdapterListener listener)
Sets the AdapterListener. |
public void | setPresenter(PresenterSelector presenterSelector)
Changes Presenter that creates and binds the view. |
public void | setPresenterMapper(java.util.ArrayList<Presenter> presenters)
Sets the presenter mapper array. |
public void | setWrapper(ItemBridgeAdapter.Wrapper wrapper)
Sets the ItemBridgeAdapter.Wrapper. |
from RecyclerView.Adapter<VH> | bindViewHolder, createViewHolder, findRelativeAdapterPositionIn, getStateRestorationPolicy, hasObservers, hasStableIds, notifyDataSetChanged, notifyItemChanged, notifyItemChanged, notifyItemInserted, notifyItemMoved, notifyItemRangeChanged, notifyItemRangeChanged, notifyItemRangeInserted, notifyItemRangeRemoved, notifyItemRemoved, onAttachedToRecyclerView, onDetachedFromRecyclerView, registerAdapterDataObserver, setHasStableIds, setStateRestorationPolicy, unregisterAdapterDataObserver |
from java.lang.Object | clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructors
public
ItemBridgeAdapter()
Methods
Sets the ObjectAdapter.
Changes Presenter that creates and binds the view.
Parameters:
presenterSelector: Presenter that creates and binds the view.
Sets the ItemBridgeAdapter.Wrapper.
Returns the ItemBridgeAdapter.Wrapper.
Clears the adapter.
public void
setPresenterMapper(java.util.ArrayList<Presenter> presenters)
Sets the presenter mapper array.
public java.util.ArrayList<Presenter>
getPresenterMapper()
Returns the presenter mapper array.
public abstract int
getItemCount()
Returns the total number of items in the data set held by the adapter.
Returns:
The total number of items in this adapter.
public int
getItemViewType(int position)
Return the view type of the item at position
for the purposes
of view recycling.
The default implementation of this method returns 0, making the assumption of
a single view type for the adapter. Unlike ListView adapters, types need not
be contiguous. Consider using id resources to uniquely identify item view types.
Parameters:
position: position to query
Returns:
integer value identifying the type of the view needed to represent the item at
position
. Type codes need not be contiguous.
protected void
onAddPresenter(
Presenter presenter, int type)
Called when presenter is added to Adapter.
Called when ViewHolder is created.
Called when ViewHolder has been bound to data.
Called when ViewHolder has been unbound from data.
Called when ViewHolder has been attached to window.
Called when ViewHolder has been detached from window.
that assigned in
Presenter.onCreateViewHolder(ViewGroup) may be chained, user should never change
after that.
Sets the AdapterListener.
Called by RecyclerView to display the data at the specified position. This method should
update the contents of the RecyclerView.ViewHolder.itemView to reflect the item at the given
position.
Note that unlike , RecyclerView will not call this method
again if the position of the item changes in the data set unless the item itself is
invalidated or the new position cannot be determined. For this reason, you should only
use the position
parameter while acquiring the related data item inside
this method and should not keep a copy of it. If you need the position of an item later
on (e.g. in a click listener), use RecyclerView.ViewHolder.getBindingAdapterPosition() which
will have the updated adapter position.
Override RecyclerView.Adapter instead if Adapter can
handle efficient partial bind.
Parameters:
holder: The ViewHolder which should be updated to represent the contents of the
item at the given position in the data set.
position: The position of the item within the adapter's data set.
public void
onBindViewHolder(
RecyclerView.ViewHolder holder, int position, java.util.List<java.lang.Object> payloads)
Called by RecyclerView to display the data at the specified position. This method
should update the contents of the RecyclerView.ViewHolder.itemView to reflect the item at
the given position.
Note that unlike , RecyclerView will not call this method
again if the position of the item changes in the data set unless the item itself is
invalidated or the new position cannot be determined. For this reason, you should only
use the position
parameter while acquiring the related data item inside
this method and should not keep a copy of it. If you need the position of an item later
on (e.g. in a click listener), use RecyclerView.ViewHolder.getBindingAdapterPosition() which
will have the updated adapter position.
Partial bind vs full bind:
The payloads parameter is a merge list from RecyclerView.Adapter.notifyItemChanged(int, Object) or
RecyclerView.Adapter.notifyItemRangeChanged(int, int, Object). If the payloads list is not empty,
the ViewHolder is currently bound to old data and Adapter may run an efficient partial
update using the payload info. If the payload is empty, Adapter must run a full bind.
Adapter should not assume that the payload passed in notify methods will be received by
onBindViewHolder(). For example when the view is not attached to the screen, the
payload in notifyItemChange() will be simply dropped.
Parameters:
holder: The ViewHolder which should be updated to represent the contents of the
item at the given position in the data set.
position: The position of the item within the adapter's data set.
payloads: A non-null list of merged payloads. Can be empty list if requires full
update.
Called when a view created by this adapter has been recycled.
A view is recycled when a RecyclerView.LayoutManager decides that it no longer
needs to be attached to its parent RecyclerView. This can be because it has
fallen out of visibility or a set of cached views represented by views still
attached to the parent RecyclerView. If an item view has large or expensive data
bound to it such as large bitmaps, this may be a good place to release those
resources.
RecyclerView calls this method right before clearing ViewHolder's internal data and
sending it to RecycledViewPool. This way, if ViewHolder was holding valid information
before being recycled, you can call RecyclerView.ViewHolder.getBindingAdapterPosition() to get
its adapter position.
Parameters:
holder: The ViewHolder for the view being recycled
Called by the RecyclerView if a ViewHolder created by this Adapter cannot be recycled
due to its transient state. Upon receiving this callback, Adapter can clear the
animation(s) that effect the View's transient state and return true
so that
the View can be recycled. Keep in mind that the View in question is already removed from
the RecyclerView.
In some cases, it is acceptable to recycle a View although it has transient state. Most
of the time, this is a case where the transient state will be cleared in
RecyclerView.Adapter call when View is rebound to a new position.
For this reason, RecyclerView leaves the decision to the Adapter and uses the return
value of this method to decide whether the View should be recycled or not.
Note that when all animations are created by RecyclerView.ItemAnimator, you
should never receive this callback because RecyclerView keeps those Views as children
until their animations are complete. This callback is useful when children of the item
views create animations which may not be easy to implement using an RecyclerView.ItemAnimator.
You should never fix this issue by calling
holder.itemView.setHasTransientState(false);
unless you've previously called
holder.itemView.setHasTransientState(true);
. Each
View.setHasTransientState(true)
call must be matched by a
View.setHasTransientState(false)
call, otherwise, the state of the View
may become inconsistent. You should always prefer to end or cancel animations that are
triggering the transient state instead of handling it manually.
Parameters:
holder: The ViewHolder containing the View that could not be recycled due to its
transient state.
Returns:
True if the View should be recycled, false otherwise. Note that if this method
returns true
, RecyclerView will ignore the transient state of
the View and recycle it regardless. If this method returns false
,
RecyclerView will check the View's transient state again before giving a final decision.
Default implementation returns false.
Called when a view created by this adapter has been attached to a window.
This can be used as a reasonable signal that the view is about to be seen
by the user. If the adapter previously freed any resources in
onViewDetachedFromWindow
those resources should be restored here.
Parameters:
holder: Holder of the view being attached
Called when a view created by this adapter has been detached from its window.
Becoming detached from the window is not necessarily a permanent condition;
the consumer of an Adapter's views may choose to cache views offscreen while they
are not visible, attaching and detaching them as appropriate.
Parameters:
holder: Holder of the view being detached
public long
getItemId(int position)
Return the stable ID for the item at position
. If RecyclerView.Adapter.hasStableIds()
would return false this method should return RecyclerView.NO_ID. The default implementation
of this method returns RecyclerView.NO_ID.
Parameters:
position: Adapter position to query
Returns:
the stable ID of the item at position
Source
/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package androidx.leanback.widget;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
/**
* Bridge from {@link Presenter} to {@link RecyclerView.Adapter}. Public to allow use by third
* party Presenters.
*/
public class ItemBridgeAdapter extends RecyclerView.Adapter implements FacetProviderAdapter {
static final String TAG = "ItemBridgeAdapter";
static final boolean DEBUG = false;
/**
* Interface for listening to ViewHolder operations.
*/
public static class AdapterListener {
public void onAddPresenter(Presenter presenter, int type) {
}
public void onCreate(ViewHolder viewHolder) {
}
public void onBind(ViewHolder viewHolder) {
}
public void onBind(ViewHolder viewHolder, List payloads) {
onBind(viewHolder);
}
public void onUnbind(ViewHolder viewHolder) {
}
public void onAttachedToWindow(ViewHolder viewHolder) {
}
public void onDetachedFromWindow(ViewHolder viewHolder) {
}
}
/**
* Interface for wrapping a view created by a Presenter into another view.
* The wrapper must be the immediate parent of the wrapped view.
*/
public static abstract class Wrapper {
public abstract View createWrapper(View root);
public abstract void wrap(View wrapper, View wrapped);
}
private ObjectAdapter mAdapter;
Wrapper mWrapper;
private PresenterSelector mPresenterSelector;
FocusHighlightHandler mFocusHighlight;
private AdapterListener mAdapterListener;
private ArrayList<Presenter> mPresenters = new ArrayList<Presenter>();
static final class ChainingFocusChangeListener implements View.OnFocusChangeListener {
final View.OnFocusChangeListener mChainedListener;
boolean mHasWrapper;
FocusHighlightHandler mFocusHighlight;
ChainingFocusChangeListener(View.OnFocusChangeListener chainedListener,
boolean hasWrapper, FocusHighlightHandler focusHighlight) {
mChainedListener = chainedListener;
mHasWrapper = hasWrapper;
mFocusHighlight = focusHighlight;
}
void update(boolean hasWrapper, FocusHighlightHandler focusHighlight) {
mHasWrapper = hasWrapper;
mFocusHighlight = focusHighlight;
}
@Override
public void onFocusChange(View view, boolean hasFocus) {
if (DEBUG) {
Log.v(TAG, "onFocusChange " + hasFocus + " " + view
+ " mFocusHighlight" + mFocusHighlight);
}
if (mHasWrapper) {
view = (View) view.getParent();
}
mFocusHighlight.onItemFocused(view, hasFocus);
if (mChainedListener != null) {
mChainedListener.onFocusChange(view, hasFocus);
}
}
}
/**
* ViewHolder for the ItemBridgeAdapter.
*/
public static class ViewHolder extends RecyclerView.ViewHolder implements FacetProvider {
final Presenter mPresenter;
final Presenter.ViewHolder mHolder;
Object mItem;
Object mExtraObject;
/**
* Get {@link Presenter}.
*/
public final Presenter getPresenter() {
return mPresenter;
}
/**
* Get {@link Presenter.ViewHolder}.
*/
public final Presenter.ViewHolder getViewHolder() {
return mHolder;
}
/**
* Get currently bound object.
*/
public final Object getItem() {
return mItem;
}
/**
* Get extra object associated with the view. Developer can attach
* any customized UI object in addition to {@link Presenter.ViewHolder}.
* A typical use case is attaching an animator object.
*/
public final Object getExtraObject() {
return mExtraObject;
}
/**
* Set extra object associated with the view. Developer can attach
* any customized UI object in addition to {@link Presenter.ViewHolder}.
* A typical use case is attaching an animator object.
*/
public void setExtraObject(Object object) {
mExtraObject = object;
}
@Override
public Object getFacet(Class<?> facetClass) {
return mHolder.getFacet(facetClass);
}
ViewHolder(Presenter presenter, View view, Presenter.ViewHolder holder) {
super(view);
mPresenter = presenter;
mHolder = holder;
}
}
private ObjectAdapter.DataObserver mDataObserver = new ObjectAdapter.DataObserver() {
@Override
public void onChanged() {
ItemBridgeAdapter.this.notifyDataSetChanged();
}
@Override
public void onItemRangeChanged(int positionStart, int itemCount) {
ItemBridgeAdapter.this.notifyItemRangeChanged(positionStart, itemCount);
}
@Override
public void onItemRangeChanged(int positionStart, int itemCount, Object payload) {
ItemBridgeAdapter.this.notifyItemRangeChanged(positionStart, itemCount, payload);
}
@Override
public void onItemRangeInserted(int positionStart, int itemCount) {
ItemBridgeAdapter.this.notifyItemRangeInserted(positionStart, itemCount);
}
@Override
public void onItemRangeRemoved(int positionStart, int itemCount) {
ItemBridgeAdapter.this.notifyItemRangeRemoved(positionStart, itemCount);
}
@Override
public void onItemMoved(int fromPosition, int toPosition) {
ItemBridgeAdapter.this.notifyItemMoved(fromPosition, toPosition);
}
};
public ItemBridgeAdapter(ObjectAdapter adapter, PresenterSelector presenterSelector) {
setAdapter(adapter);
mPresenterSelector = presenterSelector;
}
public ItemBridgeAdapter(ObjectAdapter adapter) {
this(adapter, null);
}
public ItemBridgeAdapter() {
}
/**
* Sets the {@link ObjectAdapter}.
*/
public void setAdapter(ObjectAdapter adapter) {
if (adapter == mAdapter) {
return;
}
if (mAdapter != null) {
mAdapter.unregisterObserver(mDataObserver);
}
mAdapter = adapter;
if (mAdapter == null) {
notifyDataSetChanged();
return;
}
mAdapter.registerObserver(mDataObserver);
if (hasStableIds() != mAdapter.hasStableIds()) {
setHasStableIds(mAdapter.hasStableIds());
}
notifyDataSetChanged();
}
/**
* Changes Presenter that creates and binds the view.
*
* @param presenterSelector Presenter that creates and binds the view.
*/
public void setPresenter(PresenterSelector presenterSelector) {
mPresenterSelector = presenterSelector;
notifyDataSetChanged();
}
/**
* Sets the {@link Wrapper}.
*/
public void setWrapper(Wrapper wrapper) {
mWrapper = wrapper;
}
/**
* Returns the {@link Wrapper}.
*/
public Wrapper getWrapper() {
return mWrapper;
}
void setFocusHighlight(FocusHighlightHandler listener) {
mFocusHighlight = listener;
if (DEBUG) Log.v(TAG, "setFocusHighlight " + mFocusHighlight);
}
/**
* Clears the adapter.
*/
public void clear() {
setAdapter(null);
}
/**
* Sets the presenter mapper array.
*/
public void setPresenterMapper(ArrayList<Presenter> presenters) {
mPresenters = presenters;
}
/**
* Returns the presenter mapper array.
*/
public ArrayList<Presenter> getPresenterMapper() {
return mPresenters;
}
@Override
public int getItemCount() {
return mAdapter != null ? mAdapter.size() : 0;
}
@Override
public int getItemViewType(int position) {
PresenterSelector presenterSelector = mPresenterSelector != null
? mPresenterSelector : mAdapter.getPresenterSelector();
Object item = mAdapter.get(position);
Presenter presenter = presenterSelector.getPresenter(item);
int type = mPresenters.indexOf(presenter);
if (type < 0) {
mPresenters.add(presenter);
type = mPresenters.indexOf(presenter);
if (DEBUG) Log.v(TAG, "getItemViewType added presenter " + presenter + " type " + type);
onAddPresenter(presenter, type);
if (mAdapterListener != null) {
mAdapterListener.onAddPresenter(presenter, type);
}
}
return type;
}
/**
* Called when presenter is added to Adapter.
*/
protected void onAddPresenter(Presenter presenter, int type) {
}
/**
* Called when ViewHolder is created.
*/
protected void onCreate(ViewHolder viewHolder) {
}
/**
* Called when ViewHolder has been bound to data.
*/
protected void onBind(ViewHolder viewHolder) {
}
/**
* Called when ViewHolder has been unbound from data.
*/
protected void onUnbind(ViewHolder viewHolder) {
}
/**
* Called when ViewHolder has been attached to window.
*/
protected void onAttachedToWindow(ViewHolder viewHolder) {
}
/**
* Called when ViewHolder has been detached from window.
*/
protected void onDetachedFromWindow(ViewHolder viewHolder) {
}
/**
* {@link View.OnFocusChangeListener} that assigned in
* {@link Presenter#onCreateViewHolder(ViewGroup)} may be chained, user should never change
* {@link View.OnFocusChangeListener} after that.
*/
@Override
public final RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (DEBUG) Log.v(TAG, "onCreateViewHolder viewType " + viewType);
Presenter presenter = mPresenters.get(viewType);
Presenter.ViewHolder presenterVh;
View view;
if (mWrapper != null) {
view = mWrapper.createWrapper(parent);
presenterVh = presenter.onCreateViewHolder(parent);
mWrapper.wrap(view, presenterVh.view);
} else {
presenterVh = presenter.onCreateViewHolder(parent);
view = presenterVh.view;
}
ViewHolder viewHolder = new ViewHolder(presenter, view, presenterVh);
onCreate(viewHolder);
if (mAdapterListener != null) {
mAdapterListener.onCreate(viewHolder);
}
View presenterView = viewHolder.mHolder.view;
View.OnFocusChangeListener currentListener = presenterView.getOnFocusChangeListener();
if (mFocusHighlight != null) {
// update or create ChainingFocusChangeListener
if (currentListener instanceof ChainingFocusChangeListener) {
((ChainingFocusChangeListener) currentListener).update(
/* hasWrapper= */ mWrapper != null, mFocusHighlight);
} else {
presenterView.setOnFocusChangeListener(new ChainingFocusChangeListener(
currentListener, /* hasWrapper= */ mWrapper != null, mFocusHighlight));
}
mFocusHighlight.onInitializeView(view);
} else {
// restore chained listener
if (currentListener instanceof ChainingFocusChangeListener) {
presenterView.setOnFocusChangeListener(
((ChainingFocusChangeListener) currentListener).mChainedListener);
}
}
return viewHolder;
}
/**
* Sets the AdapterListener.
*/
public void setAdapterListener(AdapterListener listener) {
mAdapterListener = listener;
}
@Override
public final void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (DEBUG) Log.v(TAG, "onBindViewHolder position " + position);
ViewHolder viewHolder = (ViewHolder) holder;
viewHolder.mItem = mAdapter.get(position);
viewHolder.mPresenter.onBindViewHolder(viewHolder.mHolder, viewHolder.mItem);
onBind(viewHolder);
if (mAdapterListener != null) {
mAdapterListener.onBind(viewHolder);
}
}
@Override
@SuppressWarnings("unchecked")
public final void onBindViewHolder(RecyclerView.ViewHolder holder, int position,
List payloads) {
if (DEBUG) Log.v(TAG, "onBindViewHolder position " + position);
ViewHolder viewHolder = (ViewHolder) holder;
viewHolder.mItem = mAdapter.get(position);
viewHolder.mPresenter.onBindViewHolder(viewHolder.mHolder, viewHolder.mItem, payloads);
onBind(viewHolder);
if (mAdapterListener != null) {
mAdapterListener.onBind(viewHolder, payloads);
}
}
@Override
public final void onViewRecycled(RecyclerView.ViewHolder holder) {
ViewHolder viewHolder = (ViewHolder) holder;
viewHolder.mPresenter.onUnbindViewHolder(viewHolder.mHolder);
onUnbind(viewHolder);
if (mAdapterListener != null) {
mAdapterListener.onUnbind(viewHolder);
}
viewHolder.mItem = null;
}
@Override
public final boolean onFailedToRecycleView(RecyclerView.ViewHolder holder) {
onViewRecycled(holder);
return false;
}
@Override
public final void onViewAttachedToWindow(RecyclerView.ViewHolder holder) {
ViewHolder viewHolder = (ViewHolder) holder;
onAttachedToWindow(viewHolder);
if (mAdapterListener != null) {
mAdapterListener.onAttachedToWindow(viewHolder);
}
viewHolder.mPresenter.onViewAttachedToWindow(viewHolder.mHolder);
}
@Override
public final void onViewDetachedFromWindow(RecyclerView.ViewHolder holder) {
ViewHolder viewHolder = (ViewHolder) holder;
viewHolder.mPresenter.onViewDetachedFromWindow(viewHolder.mHolder);
onDetachedFromWindow(viewHolder);
if (mAdapterListener != null) {
mAdapterListener.onDetachedFromWindow(viewHolder);
}
}
@Override
public long getItemId(int position) {
return mAdapter.getId(position);
}
@Override
public FacetProvider getFacetProvider(int type) {
return mPresenters.get(type);
}
}