/*
* 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 com.example.android.supportv7.widget;
import android.support.v4.util.ArrayMap;
import android.widget.CompoundButton;
import com.example.android.supportv7.R;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.view.MenuItemCompat;
import android.support.v7.widget.RecyclerView;
import android.util.DisplayMetrics;
import android.util.TypedValue;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CheckBox;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class AnimatedRecyclerView extends Activity {
private static final int SCROLL_DISTANCE = 80; // dp
private RecyclerView mRecyclerView;
private int mNumItemsAdded = 0;
ArrayList<String> mItems = new ArrayList<String>();
MyAdapter mAdapter;
boolean mAnimationsEnabled = true;
boolean mPredictiveAnimationsEnabled = true;
RecyclerView.ItemAnimator mCachedAnimator = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.animated_recycler_view);
ViewGroup container = (ViewGroup) findViewById(R.id.container);
mRecyclerView = new RecyclerView(this);
mCachedAnimator = mRecyclerView.getItemAnimator();
mRecyclerView.setLayoutManager(new MyLayoutManager(this));
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT));
for (int i = 0; i < 6; ++i) {
mItems.add("Item #" + i);
}
mAdapter = new MyAdapter(mItems);
mRecyclerView.setAdapter(mAdapter);
container.addView(mRecyclerView);
CheckBox enableAnimations = (CheckBox) findViewById(R.id.enableAnimations);
enableAnimations.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if (isChecked && mRecyclerView.getItemAnimator() == null) {
mRecyclerView.setItemAnimator(mCachedAnimator);
} else if (!isChecked && mRecyclerView.getItemAnimator() != null) {
mRecyclerView.setItemAnimator(null);
}
mAnimationsEnabled = isChecked;
}
});
CheckBox enablePredictiveAnimations =
(CheckBox) findViewById(R.id.enablePredictiveAnimations);
enablePredictiveAnimations.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
mPredictiveAnimationsEnabled = isChecked;
}
});
CheckBox enableChangeAnimations =
(CheckBox) findViewById(R.id.enableChangeAnimations);
enableChangeAnimations.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
mCachedAnimator.setSupportsChangeAnimations(isChecked);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
MenuItemCompat.setShowAsAction(menu.add("Layout"), MenuItemCompat.SHOW_AS_ACTION_IF_ROOM);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
mRecyclerView.requestLayout();
return super.onOptionsItemSelected(item);
}
public void checkboxClicked(View view) {
ViewGroup parent = (ViewGroup) view.getParent();
boolean selected = ((CheckBox) view).isChecked();
MyViewHolder holder = (MyViewHolder) mRecyclerView.getChildViewHolder(parent);
mAdapter.selectItem(holder, selected);
}
public void itemClicked(View view) {
ViewGroup parent = (ViewGroup) view;
MyViewHolder holder = (MyViewHolder) mRecyclerView.getChildViewHolder(parent);
mAdapter.toggleExpanded(holder);
mAdapter.notifyItemChanged(holder.getPosition());
}
public void deleteItem(View view) {
int numItems = mItems.size();
if (numItems > 0) {
for (int i = numItems - 1; i >= 0; --i) {
final String itemText = mItems.get(i);
boolean selected = mAdapter.mSelected.get(itemText);
if (selected) {
removeAtPosition(i);
}
}
}
}
private String generateNewText() {
return "Added Item #" + mNumItemsAdded++;
}
public void d1a2d3(View view) {
removeAtPosition(1);
addAtPosition(2, "Added Item #" + mNumItemsAdded++);
removeAtPosition(3);
}
private void removeAtPosition(int position) {
mItems.remove(position);
mAdapter.notifyItemRemoved(position);
}
private void addAtPosition(int position, String text) {
mItems.add(position, text);
mAdapter.mSelected.put(text, Boolean.FALSE);
mAdapter.mExpanded.put(text, Boolean.FALSE);
mAdapter.notifyItemInserted(position);
}
public void addDeleteItem(View view) {
addItem(view);
deleteItem(view);
}
public void deleteAddItem(View view) {
deleteItem(view);
addItem(view);
}
public void addItem(View view) {
addAtPosition(3, "Added Item #" + mNumItemsAdded++);
}
/**
* A basic ListView-style LayoutManager.
*/
class MyLayoutManager extends RecyclerView.LayoutManager {
private static final String TAG = "MyLayoutManager";
private int mFirstPosition;
private final int mScrollDistance;
public MyLayoutManager(Context c) {
final DisplayMetrics dm = c.getResources().getDisplayMetrics();
mScrollDistance = (int) (SCROLL_DISTANCE * dm.density + 0.5f);
}
@Override
public boolean supportsPredictiveItemAnimations() {
return mPredictiveAnimationsEnabled;
}
@Override
public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
int parentBottom = getHeight() - getPaddingBottom();
final View oldTopView = getChildCount() > 0 ? getChildAt(0) : null;
int oldTop = getPaddingTop();
if (oldTopView != null) {
oldTop = Math.min(oldTopView.getTop(), oldTop);
}
// Note that we add everything to the scrap, but we do not clean it up;
// that is handled by the RecyclerView after this method returns
detachAndScrapAttachedViews(recycler);
int top = oldTop;
int bottom = top;
final int left = getPaddingLeft();
final int right = getWidth() - getPaddingRight();
int count = state.getItemCount();
for (int i = 0; mFirstPosition + i < count && top < parentBottom; i++, top = bottom) {
View v = recycler.getViewForPosition(mFirstPosition + i);
RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) v.getLayoutParams();
addView(v);
measureChild(v, 0, 0);
bottom = top + v.getMeasuredHeight();
v.layout(left, top, right, bottom);
if (mPredictiveAnimationsEnabled && params.isItemRemoved()) {
parentBottom += v.getHeight();
}
}
if (mAnimationsEnabled && mPredictiveAnimationsEnabled && !state.isPreLayout()) {
// Now that we've run a full layout, figure out which views were not used
// (cached in previousViews). For each of these views, position it where
// it would go, according to its position relative to the visible
// positions in the list. This information will be used by RecyclerView to
// record post-layout positions of these items for the purposes of animating them
// out of view
View lastVisibleView = getChildAt(getChildCount() - 1);
if (lastVisibleView != null) {
RecyclerView.LayoutParams lastParams =
(RecyclerView.LayoutParams) lastVisibleView.getLayoutParams();
int lastPosition = lastParams.getViewPosition();
final List<RecyclerView.ViewHolder> previousViews = recycler.getScrapList();
count = previousViews.size();
for (int i = 0; i < count; ++i) {
View view = previousViews.get(i).itemView;
RecyclerView.LayoutParams params =
(RecyclerView.LayoutParams) view.getLayoutParams();
if (params.isItemRemoved()) {
continue;
}
int position = params.getViewPosition();
int newTop;
if (position < mFirstPosition) {
newTop = view.getHeight() * (position - mFirstPosition);
} else {
newTop = lastVisibleView.getTop() + view.getHeight() *
(position - lastPosition);
}
view.offsetTopAndBottom(newTop - view.getTop());
}
}
}
}
@Override
public RecyclerView.LayoutParams generateDefaultLayoutParams() {
return new RecyclerView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
}
@Override
public boolean canScrollVertically() {
return true;
}
@Override
public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler,
RecyclerView.State state) {
if (getChildCount() == 0) {
return 0;
}
int scrolled = 0;
final int left = getPaddingLeft();
final int right = getWidth() - getPaddingRight();
if (dy < 0) {
while (scrolled > dy) {
final View topView = getChildAt(0);
final int hangingTop = Math.max(-topView.getTop(), 0);
final int scrollBy = Math.min(scrolled - dy, hangingTop);
scrolled -= scrollBy;
offsetChildrenVertical(scrollBy);
if (mFirstPosition > 0 && scrolled > dy) {
mFirstPosition--;
View v = recycler.getViewForPosition(mFirstPosition);
addView(v, 0);
measureChild(v, 0, 0);
final int bottom = topView.getTop(); // TODO decorated top?
final int top = bottom - v.getMeasuredHeight();
v.layout(left, top, right, bottom);
} else {
break;
}
}
} else if (dy > 0) {
final int parentHeight = getHeight();
while (scrolled < dy) {
final View bottomView = getChildAt(getChildCount() - 1);
final int hangingBottom = Math.max(bottomView.getBottom() - parentHeight, 0);
final int scrollBy = -Math.min(dy - scrolled, hangingBottom);
scrolled -= scrollBy;
offsetChildrenVertical(scrollBy);
if (scrolled < dy && state.getItemCount() > mFirstPosition + getChildCount()) {
View v = recycler.getViewForPosition(mFirstPosition + getChildCount());
final int top = getChildAt(getChildCount() - 1).getBottom();
addView(v);
measureChild(v, 0, 0);
final int bottom = top + v.getMeasuredHeight();
v.layout(left, top, right, bottom);
} else {
break;
}
}
}
recycleViewsOutOfBounds(recycler);
return scrolled;
}
@Override
public View onFocusSearchFailed(View focused, int direction,
RecyclerView.Recycler recycler, RecyclerView.State state) {
final int oldCount = getChildCount();
if (oldCount == 0) {
return null;
}
final int left = getPaddingLeft();
final int right = getWidth() - getPaddingRight();
View toFocus = null;
int newViewsHeight = 0;
if (direction == View.FOCUS_UP || direction == View.FOCUS_BACKWARD) {
while (mFirstPosition > 0 && newViewsHeight < mScrollDistance) {
mFirstPosition--;
View v = recycler.getViewForPosition(mFirstPosition);
final int bottom = getChildAt(0).getTop(); // TODO decorated top?
addView(v, 0);
measureChild(v, 0, 0);
final int top = bottom - v.getMeasuredHeight();
v.layout(left, top, right, bottom);
if (v.isFocusable()) {
toFocus = v;
break;
}
}
}
if (direction == View.FOCUS_DOWN || direction == View.FOCUS_FORWARD) {
while (mFirstPosition + getChildCount() < state.getItemCount() &&
newViewsHeight < mScrollDistance) {
View v = recycler.getViewForPosition(mFirstPosition + getChildCount());
final int top = getChildAt(getChildCount() - 1).getBottom();
addView(v);
measureChild(v, 0, 0);
final int bottom = top + v.getMeasuredHeight();
v.layout(left, top, right, bottom);
if (v.isFocusable()) {
toFocus = v;
break;
}
}
}
return toFocus;
}
public void recycleViewsOutOfBounds(RecyclerView.Recycler recycler) {
final int childCount = getChildCount();
final int parentWidth = getWidth();
final int parentHeight = getHeight();
boolean foundFirst = false;
int first = 0;
int last = 0;
for (int i = 0; i < childCount; i++) {
final View v = getChildAt(i);
if (v.hasFocus() || (v.getRight() >= 0 && v.getLeft() <= parentWidth &&
v.getBottom() >= 0 && v.getTop() <= parentHeight)) {
if (!foundFirst) {
first = i;
foundFirst = true;
}
last = i;
}
}
for (int i = childCount - 1; i > last; i--) {
removeAndRecycleViewAt(i, recycler);
}
for (int i = first - 1; i >= 0; i--) {
removeAndRecycleViewAt(i, recycler);
}
if (getChildCount() == 0) {
mFirstPosition = 0;
} else {
mFirstPosition += first;
}
}
@Override
public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) {
if (positionStart < mFirstPosition) {
mFirstPosition += itemCount;
}
}
@Override
public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) {
if (positionStart < mFirstPosition) {
mFirstPosition -= itemCount;
}
}
}
class MyAdapter extends RecyclerView.Adapter {
private int mBackground;
List<String> mData;
ArrayMap<String, Boolean> mSelected = new ArrayMap<String, Boolean>();
ArrayMap<String, Boolean> mExpanded = new ArrayMap<String, Boolean>();
public MyAdapter(List<String> data) {
TypedValue val = new TypedValue();
AnimatedRecyclerView.this.getTheme().resolveAttribute(
R.attr.selectableItemBackground, val, true);
mBackground = val.resourceId;
mData = data;
for (String itemText : mData) {
mSelected.put(itemText, Boolean.FALSE);
mExpanded.put(itemText, Boolean.FALSE);
}
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
MyViewHolder h = new MyViewHolder(getLayoutInflater().inflate(R.layout.selectable_item,
null));
h.textView.setMinimumHeight(128);
h.textView.setFocusable(true);
h.textView.setBackgroundResource(mBackground);
return h;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
String itemText = mData.get(position);
((MyViewHolder) holder).textView.setText(itemText);
((MyViewHolder) holder).expandedText.setText("More text for the expanded version");
boolean selected = false;
if (mSelected.get(itemText) != null) {
selected = mSelected.get(itemText);
}
((MyViewHolder) holder).checkBox.setChecked(selected);
Boolean expanded = mExpanded.get(itemText);
if (expanded != null && expanded) {
((MyViewHolder) holder).expandedText.setVisibility(View.VISIBLE);
((MyViewHolder) holder).textView.setVisibility(View.GONE);
} else {
((MyViewHolder) holder).expandedText.setVisibility(View.GONE);
((MyViewHolder) holder).textView.setVisibility(View.VISIBLE);
}
}
@Override
public int getItemCount() {
return mData.size();
}
public void selectItem(String itemText, boolean selected) {
mSelected.put(itemText, selected);
}
public void selectItem(MyViewHolder holder, boolean selected) {
mSelected.put((String) holder.textView.getText(), selected);
}
public void toggleExpanded(MyViewHolder holder) {
String text = (String) holder.textView.getText();
mExpanded.put(text, !mExpanded.get(text));
}
}
static class MyViewHolder extends RecyclerView.ViewHolder {
public TextView expandedText;
public TextView textView;
public CheckBox checkBox;
public MyViewHolder(View v) {
super(v);
expandedText = (TextView) v.findViewById(R.id.expandedText);
textView = (TextView) v.findViewById(R.id.text);
checkBox = (CheckBox) v.findViewById(R.id.selected);
}
@Override
public String toString() {
return super.toString() + " \"" + textView.getText() + "\"";
}
}
}