com.lightydev.dk.widget.PagerCursorAdapter.java Source code

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Here is the source code for com.lightydev.dk.widget.PagerCursorAdapter.java

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/*
 * Copyright 2012-2014 Daniel Serdyukov
 *
 * 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.lightydev.dk.widget;

import android.content.Context;
import android.database.Cursor;
import android.database.DataSetObserver;
import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.ViewGroup;

/**
 * @author =Troy= <Daniel Serdyukov>
 */
public abstract class PagerCursorAdapter extends PagerAdapter {

    private final DataSetObserver mDataSetObserver = new DataSetObserver() {
        @Override
        public void onChanged() {
            onDataSetChanged();
        }
    };

    private final Context mContext;

    private Cursor mCursor;

    protected PagerCursorAdapter(Context context) {
        this(context, null);
    }

    protected PagerCursorAdapter(Context context, Cursor cursor) {
        super();
        mContext = context;
        mCursor = cursor;
    }

    public Cursor swapCursor(Cursor newCursor) {
        if (mCursor == newCursor) {
            return null;
        }
        final Cursor oldCursor = mCursor;
        if (oldCursor != null) {
            oldCursor.unregisterDataSetObserver(mDataSetObserver);
        }
        mCursor = newCursor;
        if (mCursor != null) {
            mCursor.registerDataSetObserver(mDataSetObserver);
        }
        notifyDataSetChanged();
        return oldCursor;
    }

    @Override
    public int getCount() {
        if (mCursor != null) {
            return mCursor.getCount();
        }
        return 0;
    }

    @Override
    public boolean isViewFromObject(View view, Object o) {
        return view.equals(o);
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        if (mCursor.moveToPosition(position)) {
            final View view = getItem(mContext, mCursor, container);
            container.addView(view);
            return view;
        }
        throw new IllegalStateException("couldn't move cursor to position " + position);
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView((View) object);
    }

    protected void onDataSetChanged() {
        notifyDataSetChanged();
    }

    protected abstract View getItem(Context context, Cursor cursor, ViewGroup parent);

}