com.espian.ticktock.oss.CursorPagerAdapter.java Source code

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Here is the source code for com.espian.ticktock.oss.CursorPagerAdapter.java

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/*
 * Copyright (C) 2013 Alex Curran.
 *
 * 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.espian.ticktock.oss;

import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.util.SparseArray;

import java.lang.ref.WeakReference;

public class CursorPagerAdapter<F extends Fragment> extends FragmentStatePagerAdapter {

    private final Class<F> fragmentClass;
    private final String[] projection;
    private final Class<? extends Fragment> emptyFragmentClass;
    private final SparseArray<WeakReference<F>> fragmentRefs = new SparseArray<WeakReference<F>>();
    private Cursor cursor;
    private boolean hasEmptyFragment = true;

    public CursorPagerAdapter(FragmentManager fm, Class<F> fragmentClass,
            Class<? extends Fragment> emptyFragmentClass, String[] projection, Cursor cursor) {
        super(fm);
        this.fragmentClass = fragmentClass;
        this.emptyFragmentClass = emptyFragmentClass;
        this.projection = projection;
        this.cursor = cursor;
        hasEmptyFragment = true;
    }

    @Override
    public Fragment getItem(int position) {
        if (cursor == null || cursor.getCount() == 0) {
            if (emptyFragmentClass != null) {
                try {
                    return emptyFragmentClass.newInstance();
                } catch (Exception ex) {
                    throw new RuntimeException(ex);
                }
            }
            return null;
        }

        if (fragmentRefs.get(position) != null && fragmentRefs.get(position).get() != null)
            return fragmentRefs.get(position).get();

        cursor.moveToPosition(position);
        F frag;
        try {
            frag = fragmentClass.newInstance();
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
        Bundle args = new Bundle();
        if (projection == null || projection.length == 0) {
            for (int i = 0; i < cursor.getColumnCount(); i++) {
                args.putString(cursor.getColumnName(i), cursor.getString(i));
            }
        } else {
            for (int i = 0; i < projection.length; ++i) {
                args.putString(projection[i], cursor.getString(i));
            }
        }
        frag.setArguments(args);
        fragmentRefs.put(position, new WeakReference<F>(frag));
        return frag;
    }

    @Override
    public int getCount() {
        if (hasEmptyFragment)
            return 1;
        if (cursor == null)
            return 0;
        else
            return cursor.getCount();
    }

    public void swapCursor(Cursor c) {
        if (cursor == c)
            return;

        this.cursor = c;
        notifyDataSetChanged();
    }

    public Cursor getCursor() {
        return cursor;
    }

}