/*
* Copyright (C) 2006 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.
*
* This ArrayList class is copied from android.widget.ArrayList and
* adjusted in three ways: 1) loading from resources is no longer supported,
* 2) a public method is added to allow replacing of the while list, and
* 3) it is made abstract, requiring to override getView (no more setting
* of the resource id to show)
*/
package com.ratebeer.android.gui.components.helpers;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Filter;
import android.widget.Filterable;
/**
* A ListAdapter that manages a ListView backed by an array of arbitrary
* objects. getView needs to be overridden to determine the view to show
* for an object in the list.
*/
public abstract class ArrayAdapter<T> extends BaseAdapter implements Filterable {
/**
* Contains the list of objects that represent the data of this ArrayAdapter.
* The content of this list is referred to as "the array" in the documentation.
*/
private List<T> mObjects;
/**
* Lock used to modify the content of {@link #mObjects}. Any write operation
* performed on the array should be synchronized on this lock. This lock is also
* used by the filter (see {@link #getFilter()} to make a synchronized copy of
* the original array of data.
*/
private final Object mLock = new Object();
/**
* Indicates whether or not {@link #notifyDataSetChanged()} must be called whenever
* {@link #mObjects} is modified.
*/
private boolean mNotifyOnChange = true;
private Context mContext;
private ArrayList<T> mOriginalValues;
private ArrayFilter mFilter;
/**
* Constructor
*
* @param context The current context.
*/
public ArrayAdapter(Context context) {
init(context, new ArrayList<T>());
}
/**
* Constructor
*
* @param context The current context.
* @param objects The objects to represent in the ListView.
*/
public ArrayAdapter(Context context, T[] objects) {
init(context, Arrays.asList(objects));
}
/**
* Constructor
*
* @param context The current context.
* @param objects The objects to represent in the ListView.
*/
public ArrayAdapter(Context context, List<T> objects) {
init(context, objects);
}
/**
* Adds the specified object at the end of the array.
*
* @param object The object to add at the end of the array.
*/
public void add(T object) {
if (mOriginalValues != null) {
synchronized (mLock) {
mOriginalValues.add(object);
if (mNotifyOnChange) notifyDataSetChanged();
}
} else {
mObjects.add(object);
if (mNotifyOnChange) notifyDataSetChanged();
}
}
/**
* Adds a collection of objects at the end of the array.
*
* @param object The collection to add at the end of the array.
*/
public void addAll(Collection<? extends T> object) {
if (mOriginalValues != null) {
synchronized (mLock) {
mOriginalValues.addAll(object);
if (mNotifyOnChange) notifyDataSetChanged();
}
} else {
mObjects.addAll(object);
if (mNotifyOnChange) notifyDataSetChanged();
}
}
/**
* Inserts the specified object at the specified index in the array.
*
* @param object The object to insert into the array.
* @param index The index at which the object must be inserted.
*/
public void insert(T object, int index) {
if (mOriginalValues != null) {
synchronized (mLock) {
mOriginalValues.add(index, object);
if (mNotifyOnChange) notifyDataSetChanged();
}
} else {
mObjects.add(index, object);
if (mNotifyOnChange) notifyDataSetChanged();
}
}
/**
* Removes the specified object from the array.
*
* @param object The object to remove.
*/
public void remove(T object) {
if (mOriginalValues != null) {
synchronized (mLock) {
mOriginalValues.remove(object);
}
} else {
mObjects.remove(object);
}
if (mNotifyOnChange) notifyDataSetChanged();
}
/**
* Remove all elements from the list.
*/
public void clear() {
if (mOriginalValues != null) {
synchronized (mLock) {
mOriginalValues.clear();
}
} else {
mObjects.clear();
}
if (mNotifyOnChange) notifyDataSetChanged();
}
/**
* Sorts the content of this adapter using the specified comparator.
*
* @param comparator The comparator used to sort the objects contained
* in this adapter.
*/
public void sort(Comparator<? super T> comparator) {
Collections.sort(mObjects, comparator);
if (mNotifyOnChange) notifyDataSetChanged();
}
/**
* Replaces the underlying list some other list and notifies a listening view.
*
* @param objects The new list of data objects,
*/
public void replace(List<T> objects) {
init(getContext(), objects);
if (mNotifyOnChange) notifyDataSetChanged();
}
/**
* {@inheritDoc}
*/
@Override
public void notifyDataSetChanged() {
super.notifyDataSetChanged();
mNotifyOnChange = true;
}
/**
* Control whether methods that change the list ({@link #add},
* {@link #insert}, {@link #remove}, {@link #clear}) automatically call
* {@link #notifyDataSetChanged}. If set to false, caller must
* manually call notifyDataSetChanged() to have the changes
* reflected in the attached view.
*
* The default is true, and calling notifyDataSetChanged()
* resets the flag to true.
*
* @param notifyOnChange if true, modifications to the list will
* automatically call {@link
* #notifyDataSetChanged}
*/
public void setNotifyOnChange(boolean notifyOnChange) {
mNotifyOnChange = notifyOnChange;
}
private void init(Context context, List<T> objects) {
mContext = context;
mObjects = objects;
}
/**
* Returns the context associated with this array adapter. The context is used
* to create views from the resource passed to the constructor.
*
* @return The Context associated with this adapter.
*/
public Context getContext() {
return mContext;
}
/**
* {@inheritDoc}
*/
public int getCount() {
return mObjects.size();
}
/**
* {@inheritDoc}
*/
public T getItem(int position) {
return mObjects.get(position);
}
/**
* Returns all objects in this adapter.
*
* @return The contained list of objects.
*/
public List<T> getAllItems() {
return mObjects;
}
/**
* Returns the position of the specified item in the array.
*
* @param item The item to retrieve the position of.
*
* @return The position of the specified item.
*/
public int getPosition(T item) {
return mObjects.indexOf(item);
}
/**
* {@inheritDoc}
*/
public long getItemId(int position) {
return position;
}
/**
* {@inheritDoc}
*/
public abstract View getView(int position, View convertView, ViewGroup parent);
/**
* {@inheritDoc}
*/
public Filter getFilter() {
if (mFilter == null) {
mFilter = new ArrayFilter();
}
return mFilter;
}
/**
* <p>An array filter constrains the content of the array adapter with
* a prefix. Each item that does not start with the supplied prefix
* is removed from the list.</p>
*/
private class ArrayFilter extends Filter {
@Override
protected FilterResults performFiltering(CharSequence prefix) {
FilterResults results = new FilterResults();
if (mOriginalValues == null) {
synchronized (mLock) {
mOriginalValues = new ArrayList<T>(mObjects);
}
}
if (prefix == null || prefix.length() == 0) {
synchronized (mLock) {
ArrayList<T> list = new ArrayList<T>(mOriginalValues);
results.values = list;
results.count = list.size();
}
} else {
String prefixString = prefix.toString().toLowerCase();
final ArrayList<T> values = mOriginalValues;
final int count = values.size();
final ArrayList<T> newValues = new ArrayList<T>(count);
for (int i = 0; i < count; i++) {
final T value = values.get(i);
final String valueText = value.toString().toLowerCase();
// First match against the whole, non-splitted value
if (valueText.startsWith(prefixString)) {
newValues.add(value);
} else {
final String[] words = valueText.split(" ");
final int wordCount = words.length;
for (int k = 0; k < wordCount; k++) {
if (words[k].startsWith(prefixString)) {
newValues.add(value);
break;
}
}
}
}
results.values = newValues;
results.count = newValues.size();
}
return results;
}
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
//noinspection unchecked
mObjects = (List<T>) results.values;
if (results.count > 0) {
notifyDataSetChanged();
} else {
notifyDataSetInvalidated();
}
}
}
}