BaseAdapterDecorator.java

/*
 * Copyright 2014 Niek Haarman
 *
 * 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.nhaarman.listviewanimations;

import android.database.DataSetObserver;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.SectionIndexer;

import com.nhaarman.listviewanimations.util.AbsListViewWrapper;
import com.nhaarman.listviewanimations.util.Insertable;
import com.nhaarman.listviewanimations.util.ListViewWrapper;
import com.nhaarman.listviewanimations.util.ListViewWrapperSetter;
import com.nhaarman.listviewanimations.util.Swappable;
import com.pan.simplepicture.annotations.NonNull;
import com.pan.simplepicture.annotations.Nullable;

/**
 * A decorator class that enables decoration of an instance of the
 * {@link BaseAdapter} class.
 * <p/>
 * Classes extending this class can override methods and provide extra
 * functionality before or after calling the super method.
 */
public abstract class BaseAdapterDecorator extends BaseAdapter implements
		SectionIndexer, Swappable, Insertable, ListViewWrapperSetter {

	/**
	 * The {@link android.widget.BaseAdapter} this {@code BaseAdapterDecorator}
	 * decorates.
	 */
	@NonNull
	private final BaseAdapter mDecoratedBaseAdapter;

	/**
	 * The {@link com.nhaarman.listviewanimations.util.ListViewWrapper}
	 * containing the ListView this {@code BaseAdapterDecorator} will be bound
	 * to.
	 */
	@Nullable
	private ListViewWrapper mListViewWrapper;

	/**
	 * Create a new {@code BaseAdapterDecorator}, decorating given
	 * {@link android.widget.BaseAdapter}.
	 * 
	 * @param baseAdapter
	 *            the {@code} BaseAdapter to decorate.
	 */
	protected BaseAdapterDecorator(@NonNull final BaseAdapter baseAdapter) {
		mDecoratedBaseAdapter = baseAdapter;
	}

	/**
	 * Returns the {@link android.widget.BaseAdapter} that this
	 * {@code BaseAdapterDecorator} decorates.
	 */
	@NonNull
	public BaseAdapter getDecoratedBaseAdapter() {
		return mDecoratedBaseAdapter;
	}

	/**
	 * Returns the root {@link android.widget.BaseAdapter} this
	 * {@code BaseAdapterDecorator} decorates.
	 */
	@NonNull
	protected BaseAdapter getRootAdapter() {
		BaseAdapter adapter = mDecoratedBaseAdapter;
		while (adapter instanceof BaseAdapterDecorator) {
			adapter = ((BaseAdapterDecorator) adapter)
					.getDecoratedBaseAdapter();
		}
		return adapter;
	}

	public void setAbsListView(@NonNull final AbsListView absListView) {
		setListViewWrapper(new AbsListViewWrapper(absListView));
	}

	/**
	 * Returns the {@link com.nhaarman.listviewanimations.util.ListViewWrapper}
	 * containing the ListView this {@code BaseAdapterDecorator} is bound to.
	 */
	@Nullable
	public ListViewWrapper getListViewWrapper() {
		return mListViewWrapper;
	}

	/**
	 * Alternative to {@link #setAbsListView(android.widget.AbsListView)}. Sets
	 * the {@link com.nhaarman.listviewanimations.util.ListViewWrapper} which
	 * contains the ListView this adapter will be bound to. Call this method
	 * before setting this adapter to the ListView. Also propagates to the
	 * decorated {@code BaseAdapter} if applicable.
	 */
	@Override
	public void setListViewWrapper(
			@NonNull final ListViewWrapper listViewWrapper) {
		mListViewWrapper = listViewWrapper;

		if (mDecoratedBaseAdapter instanceof ListViewWrapperSetter) {
			((ListViewWrapperSetter) mDecoratedBaseAdapter)
					.setListViewWrapper(listViewWrapper);
		}
	}

	@Override
	public int getCount() {
		return mDecoratedBaseAdapter.getCount();
	}

	@Override
	public Object getItem(final int position) {
		return mDecoratedBaseAdapter.getItem(position);
	}

	@Override
	public long getItemId(final int position) {
		return mDecoratedBaseAdapter.getItemId(position);
	}

	@Override
	@NonNull
	public View getView(final int position, @Nullable final View convertView,
			@NonNull final ViewGroup parent) {
		return mDecoratedBaseAdapter.getView(position, convertView, parent);
	}

	@Override
	public boolean areAllItemsEnabled() {
		return mDecoratedBaseAdapter.areAllItemsEnabled();
	}

	@Override
	@NonNull
	public View getDropDownView(final int position,
			@Nullable final View convertView, @NonNull final ViewGroup parent) {
		return mDecoratedBaseAdapter.getDropDownView(position, convertView,
				parent);
	}

	@Override
	public int getItemViewType(final int position) {
		return mDecoratedBaseAdapter.getItemViewType(position);
	}

	@Override
	public int getViewTypeCount() {
		return mDecoratedBaseAdapter.getViewTypeCount();
	}

	@Override
	public boolean hasStableIds() {
		return mDecoratedBaseAdapter.hasStableIds();
	}

	@Override
	public boolean isEmpty() {
		return mDecoratedBaseAdapter.isEmpty();
	}

	@Override
	public boolean isEnabled(final int position) {
		return mDecoratedBaseAdapter.isEnabled(position);
	}

	@Override
	public void notifyDataSetChanged() {
		if (!(mDecoratedBaseAdapter instanceof ArrayAdapter<?>)) {
			// fix #35 dirty trick !
			// leads to an infinite loop when trying because ArrayAdapter
			// triggers notifyDataSetChanged itself
			// TODO: investigate
			mDecoratedBaseAdapter.notifyDataSetChanged();
		}
	}

	/**
	 * Helper function if you want to force notifyDataSetChanged()
	 */
	@SuppressWarnings("UnusedDeclaration")
	public void notifyDataSetChanged(final boolean force) {
		if (force || !(mDecoratedBaseAdapter instanceof ArrayAdapter<?>)) {
			// leads to an infinite loop when trying because ArrayAdapter
			// triggers notifyDataSetChanged itself
			// TODO: investigate
			mDecoratedBaseAdapter.notifyDataSetChanged();
		}
	}

	@Override
	public void notifyDataSetInvalidated() {
		mDecoratedBaseAdapter.notifyDataSetInvalidated();
	}

	@Override
	public void registerDataSetObserver(@NonNull final DataSetObserver observer) {
		mDecoratedBaseAdapter.registerDataSetObserver(observer);
	}

	@Override
	public void unregisterDataSetObserver(
			@NonNull final DataSetObserver observer) {
		mDecoratedBaseAdapter.unregisterDataSetObserver(observer);
	}

	@Override
	public int getPositionForSection(final int sectionIndex) {
		int result = 0;
		if (mDecoratedBaseAdapter instanceof SectionIndexer) {
			result = ((SectionIndexer) mDecoratedBaseAdapter)
					.getPositionForSection(sectionIndex);
		}
		return result;
	}

	@Override
	public int getSectionForPosition(final int position) {
		int result = 0;
		if (mDecoratedBaseAdapter instanceof SectionIndexer) {
			result = ((SectionIndexer) mDecoratedBaseAdapter)
					.getSectionForPosition(position);
		}
		return result;
	}

	@Override
	@NonNull
	public Object[] getSections() {
		Object[] result = new Object[0];
		if (mDecoratedBaseAdapter instanceof SectionIndexer) {
			result = ((SectionIndexer) mDecoratedBaseAdapter).getSections();
		}
		return result;
	}

	@Override
	public void swapItems(final int positionOne, final int positionTwo) {
		if (mDecoratedBaseAdapter instanceof Swappable) {
			((Swappable) mDecoratedBaseAdapter).swapItems(positionOne,
					positionTwo);
		} else {
			Log.w("ListViewAnimations",
					"Warning: swapItems called on an adapter that does not implement Swappable!");
		}
	}

	@Override
	public void add(final int index, @NonNull final Object item) {
		if (mDecoratedBaseAdapter instanceof Insertable) {
			// noinspection rawtypes
			((Insertable) mDecoratedBaseAdapter).add(index, item);
		} else {
			Log.w("ListViewAnimations",
					"Warning: add called on an adapter that does not implement Insertable!");
		}
	}
}