SetupWizardLibrary/library/recyclerview/src/com/android/setupwizardlib/view/HeaderRecyclerView.java
Aurimas Liutikas 4860e4ee48 Migrate setup-wizard-lib to androidx.
Test: make setup-wizard-lib
Bug: 76692459
Change-Id: I40171e973d442b1a1815e9e7d7c2cc984cb38bac
2018-04-18 17:26:19 -07:00

278 lines
9.5 KiB
Java

/*
* Copyright (C) 2015 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 com.android.setupwizardlib.view;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Build;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
import android.widget.FrameLayout;
import androidx.recyclerview.widget.RecyclerView;
import com.android.setupwizardlib.DividerItemDecoration;
import com.android.setupwizardlib.R;
/**
* A RecyclerView that can display a header item at the start of the list. The header can be set by
* {@code app:suwHeader} in XML. Note that the header will not be inflated until a layout manager
* is set.
*/
public class HeaderRecyclerView extends RecyclerView {
private static class HeaderViewHolder extends ViewHolder
implements DividerItemDecoration.DividedViewHolder {
HeaderViewHolder(View itemView) {
super(itemView);
}
@Override
public boolean isDividerAllowedAbove() {
return false;
}
@Override
public boolean isDividerAllowedBelow() {
return false;
}
}
/**
* An adapter that can optionally add one header item to the RecyclerView.
*
* @param <CVH> Type of the content view holder. i.e. view holder type of the wrapped adapter.
*/
public static class HeaderAdapter<CVH extends ViewHolder>
extends RecyclerView.Adapter<ViewHolder> {
private static final int HEADER_VIEW_TYPE = Integer.MAX_VALUE;
private RecyclerView.Adapter<CVH> mAdapter;
private View mHeader;
private final AdapterDataObserver mObserver = new AdapterDataObserver() {
@Override
public void onChanged() {
notifyDataSetChanged();
}
@Override
public void onItemRangeChanged(int positionStart, int itemCount) {
if (mHeader != null) {
positionStart++;
}
notifyItemRangeChanged(positionStart, itemCount);
}
@Override
public void onItemRangeInserted(int positionStart, int itemCount) {
if (mHeader != null) {
positionStart++;
}
notifyItemRangeInserted(positionStart, itemCount);
}
@Override
public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
if (mHeader != null) {
fromPosition++;
toPosition++;
}
// Why is there no notifyItemRangeMoved?
for (int i = 0; i < itemCount; i++) {
notifyItemMoved(fromPosition + i, toPosition + i);
}
}
@Override
public void onItemRangeRemoved(int positionStart, int itemCount) {
if (mHeader != null) {
positionStart++;
}
notifyItemRangeRemoved(positionStart, itemCount);
}
};
public HeaderAdapter(RecyclerView.Adapter<CVH> adapter) {
mAdapter = adapter;
mAdapter.registerAdapterDataObserver(mObserver);
setHasStableIds(mAdapter.hasStableIds());
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// Returning the same view (mHeader) results in crash ".. but view is not a real child."
// The framework creates more than one instance of header because of "disappear"
// animations applied on the header and this necessitates creation of another header
// view to use after the animation. We work around this restriction by returning an
// empty FrameLayout to which the header is attached using #onBindViewHolder method.
if (viewType == HEADER_VIEW_TYPE) {
FrameLayout frameLayout = new FrameLayout(parent.getContext());
FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(
FrameLayout.LayoutParams.MATCH_PARENT,
FrameLayout.LayoutParams.WRAP_CONTENT);
frameLayout.setLayoutParams(params);
return new HeaderViewHolder(frameLayout);
} else {
return mAdapter.onCreateViewHolder(parent, viewType);
}
}
@Override
@SuppressWarnings("unchecked") // Non-header position always return type CVH
public void onBindViewHolder(ViewHolder holder, int position) {
if (mHeader != null) {
position--;
}
if (holder instanceof HeaderViewHolder) {
if (mHeader == null) {
throw new IllegalStateException("HeaderViewHolder cannot find mHeader");
}
if (mHeader.getParent() != null) {
((ViewGroup) mHeader.getParent()).removeView(mHeader);
}
FrameLayout mHeaderParent = (FrameLayout) holder.itemView;
mHeaderParent.addView(mHeader);
} else {
mAdapter.onBindViewHolder((CVH) holder, position);
}
}
@Override
public int getItemViewType(int position) {
if (mHeader != null) {
position--;
}
if (position < 0) {
return HEADER_VIEW_TYPE;
}
return mAdapter.getItemViewType(position);
}
@Override
public int getItemCount() {
int count = mAdapter.getItemCount();
if (mHeader != null) {
count++;
}
return count;
}
@Override
public long getItemId(int position) {
if (mHeader != null) {
position--;
}
if (position < 0) {
return Long.MAX_VALUE;
}
return mAdapter.getItemId(position);
}
public void setHeader(View header) {
mHeader = header;
}
public RecyclerView.Adapter<CVH> getWrappedAdapter() {
return mAdapter;
}
}
private View mHeader;
private int mHeaderRes;
public HeaderRecyclerView(Context context) {
super(context);
init(null, 0);
}
public HeaderRecyclerView(Context context, AttributeSet attrs) {
super(context, attrs);
init(attrs, 0);
}
public HeaderRecyclerView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(attrs, defStyleAttr);
}
private void init(AttributeSet attrs, int defStyleAttr) {
final TypedArray a = getContext().obtainStyledAttributes(attrs,
R.styleable.SuwHeaderRecyclerView, defStyleAttr, 0);
mHeaderRes = a.getResourceId(R.styleable.SuwHeaderRecyclerView_suwHeader, 0);
a.recycle();
}
@Override
public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
// Decoration-only headers should not count as an item for accessibility, adjust the
// accessibility event to account for that.
final int numberOfHeaders = mHeader != null ? 1 : 0;
event.setItemCount(event.getItemCount() - numberOfHeaders);
event.setFromIndex(Math.max(event.getFromIndex() - numberOfHeaders, 0));
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
event.setToIndex(Math.max(event.getToIndex() - numberOfHeaders, 0));
}
}
/**
* Gets the header view of this RecyclerView, or {@code null} if there are no headers.
*/
public View getHeader() {
return mHeader;
}
/**
* Set the view to use as the header of this recycler view.
* Note: This must be called before setAdapter.
*/
public void setHeader(View header) {
mHeader = header;
}
@Override
public void setLayoutManager(LayoutManager layout) {
super.setLayoutManager(layout);
if (layout != null && mHeader == null && mHeaderRes != 0) {
// Inflating a child view requires the layout manager to be set. Check here to see if
// any header item is specified in XML and inflate them.
final LayoutInflater inflater = LayoutInflater.from(getContext());
mHeader = inflater.inflate(mHeaderRes, this, false);
}
}
@Override
@SuppressWarnings("rawtypes,unchecked") // RecyclerView.setAdapter uses raw type :(
public void setAdapter(Adapter adapter) {
if (mHeader != null && adapter != null) {
final HeaderAdapter headerAdapter = new HeaderAdapter(adapter);
headerAdapter.setHeader(mHeader);
adapter = headerAdapter;
}
super.setAdapter(adapter);
}
}