BaseAdapterDecorator.java

/*
 * Copyright 2013 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 external.ListviewAnimations;

import external.ListviewAnimations.view.DynamicListView;
import external.ListviewAnimations.view.DynamicListView.Swappable;
import android.database.DataSetObserver;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.SectionIndexer;

/**
 * A decorator class that enables decoration of an instance of the BaseAdapter
 * class. 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, DynamicListView.Swappable {

    protected final BaseAdapter mDecoratedBaseAdapter;

    private AbsListView mListView;

    private boolean mIsParentHorizontalScrollContainer;
    private int mResIdTouchChild;

    public BaseAdapterDecorator(BaseAdapter baseAdapter) {
        mDecoratedBaseAdapter = baseAdapter;
    }

    public void setAbsListView(AbsListView listView) {
        mListView = listView;

        if (mDecoratedBaseAdapter instanceof BaseAdapterDecorator) {
            ((BaseAdapterDecorator) mDecoratedBaseAdapter)
                    .setAbsListView(listView);
        }

        if (mListView instanceof DynamicListView) {
            DynamicListView dynListView = (DynamicListView) mListView;
            dynListView
                    .setIsParentHorizontalScrollContainer(mIsParentHorizontalScrollContainer);
            dynListView.setDynamicTouchChild(mResIdTouchChild);
        }
    }

    public AbsListView getAbsListView() {
        return mListView;
    }

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

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

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

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

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

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

    @Override
    public int getItemViewType(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(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
            mDecoratedBaseAdapter.notifyDataSetChanged();
        }
    }

    /**
     * Helper function if you want to force notifyDataSetChanged()
     * 
     * @param force
     */
    public void notifyDataSetChanged(Boolean force) {
        if ((force) || (!(mDecoratedBaseAdapter instanceof ArrayAdapter<?>))) {
            // leads to an infinite loop when trying because ArrayAdapter
            // triggers notifyDataSetChanged itself
            mDecoratedBaseAdapter.notifyDataSetChanged();
        }
    }

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

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

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

    @Override
    public int getPositionForSection(int section) {
        if (mDecoratedBaseAdapter instanceof SectionIndexer) {
            return ((SectionIndexer) mDecoratedBaseAdapter)
                    .getPositionForSection(section);
        }
        return 0;
    }

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

    @Override
    public Object[] getSections() {
        if (mDecoratedBaseAdapter instanceof SectionIndexer) {
            return ((SectionIndexer) mDecoratedBaseAdapter).getSections();
        }
        return null;
    }

    public BaseAdapter getDecoratedBaseAdapter() {
        return mDecoratedBaseAdapter;
    }

    @Override
    public void swapItems(int positionOne, int positionTwo) {
        if (mDecoratedBaseAdapter instanceof Swappable) {
            ((Swappable) mDecoratedBaseAdapter).swapItems(positionOne,
                    positionTwo);
        }
    }

    /**
     * If the adapter's list-view is hosted inside a parent(/grand-parent/etc)
     * that can scroll horizontally, horizontal swipes won't work, because the
     * parent will prevent touch-events from reaching the list-view. Call this
     * method with the value 'true' to fix this behavior. Note that this will
     * prevent the parent from scrolling horizontally when the user touches
     * anywhere in a list-item.
     * 
     * @param isParentHorizontalScrollContainer
     */
    public void setIsParentHorizontalScrollContainer(
            boolean isParentHorizontalScrollContainer) {
        mIsParentHorizontalScrollContainer = isParentHorizontalScrollContainer;
        if (mListView instanceof DynamicListView) {
            DynamicListView dynListView = (DynamicListView) mListView;
            dynListView
                    .setIsParentHorizontalScrollContainer(mIsParentHorizontalScrollContainer);
        }
    }

    public boolean isParentHorizontalScrollContainer() {
        return mIsParentHorizontalScrollContainer;
    }

    /**
     * If the adapter's list-view is hosted inside a parent(/grand-parent/etc)
     * that can scroll horizontally, horizontal swipes won't work, because the
     * parent will prevent touch-events from reaching the list-view. If a
     * list-item view has a child with the given resource-ID, the user can still
     * swipe the list-item by touching that child. If the user touches an area
     * outside that child (but inside the list-item view), then the swipe will
     * not happen and the parent will do its job instead (scrolling
     * horizontally).
     * 
     * @param childResId The resource-ID of the list-items' child that the user
     *            should touch to be able to swipe the list-items.
     */
    public void setTouchChild(int childResId) {
        mResIdTouchChild = childResId;
        if (mListView instanceof DynamicListView) {
            DynamicListView dynListView = (DynamicListView) mListView;
            dynListView.setDynamicTouchChild(mResIdTouchChild);
        }
    }

    public int getTouchChild() {
        return mResIdTouchChild;
    }
}