com.roger.quickviewpage.ImageGridFragment.java Source code

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Here is the source code for com.roger.quickviewpage.ImageGridFragment.java

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/*
 * Copyright (C) 2012 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.
 */

package com.roger.quickviewpage;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import com.roger.quickviewpage.imagecache.Images;

import com.roger.quickviewpage.imagecache.ImageCache.ImageCacheParams;
import com.roger.quickviewpage.imagecache.ImageWorker;
import com.roger.quickviewpage.imagecache.ImageWorker.OnImageLoadedListener;
import com.roger.quickviewpage.imagecache.Utils;

/**
 * The main fragment that powers the ImageGridActivity screen. Fairly straight
 * forward GridView implementation with the key addition being the ImageWorker
 * class w/ImageCache to load children asynchronously, keeping the UI nice and
 * smooth and caching thumbnails for quick retrieval. The cache is retained over
 * configuration changes like orientation change so the images are populated
 * quickly as the user rotates the device.
 */
public class ImageGridFragment extends Fragment implements AdapterView.OnItemClickListener {
    private static final String TAG = "ImageGridFragment";

    private ImageAdapter mAdapter;
    private ImageWorker mImageWorker;

    /**
     * Empty constructor as per the Fragment documentation
     */
    public ImageGridFragment() {
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mAdapter = new ImageAdapter(getActivity(), Images.imageUrls);

        ImageCacheParams cacheParams = new ImageCacheParams();
        cacheParams.reqWidth = getResources().getDisplayMetrics().widthPixels / 5;
        cacheParams.reqHeight = (int) (cacheParams.reqWidth * 1.5);
        cacheParams.loadingResId = R.drawable.empty_photo;
        // cacheParams.clearDiskCacheOnStart = true;
        cacheParams.memCacheSize = (1024 * 1024 * Utils.getMemoryClass(getActivity())) / 2;
        // cacheParams.clearDiskCacheOnStart = true;
        mImageWorker = ImageWorker.newInstance(getActivity());
        mImageWorker.addParams(TAG, cacheParams);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        final View v = inflater.inflate(R.layout.image_grid_fragment, container, false);
        final GridView mGridView = (GridView) v.findViewById(R.id.gridView);
        mGridView.setAdapter(mAdapter);
        mGridView.setOnItemClickListener(this);

        return v;
    }

    @Override
    public void onResume() {
        super.onResume();
        mImageWorker.setOnScreen(TAG, true);
        mAdapter.notifyDataSetChanged();
    }

    @Override
    public void onPause() {
        super.onPause();
        mImageWorker.setOnScreen(TAG, false);
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
        final Intent i = new Intent(getActivity(), ImageDetailActivity.class);
        i.putExtra(ImageDetailActivity.EXTRA_IMAGE, (int) id);
        startActivity(i);
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        inflater.inflate(R.menu.main_menu, menu);
    }

    /**
     * The main adapter that backs the GridView. This is fairly standard except
     * the number of columns in the GridView is used to create a fake top row of
     * empty views as we use a transparent ActionBar and don't want the real top
     * row of images to start off covered by it.
     */
    private class ImageAdapter extends BaseAdapter {

        private final Activity mContext;
        private GridView.LayoutParams mImageViewLayoutParams;
        String[] imageUrls;

        public ImageAdapter(Activity context, String[] imageUrls) {
            super();
            mContext = context;
            this.imageUrls = imageUrls;
            int width = (int) ((context.getResources().getDisplayMetrics().widthPixels / 3) * 1.5);
            mImageViewLayoutParams = new GridView.LayoutParams(LayoutParams.FILL_PARENT, width);
        }

        @Override
        public int getCount() {
            // Size of adapter + number of columns for top empty row
            return imageUrls.length;
        }

        @Override
        public Object getItem(int position) {
            return imageUrls[position];
        }

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

        @Override
        public View getView(int position, View convertView, ViewGroup container) {

            // Now handle the main ImageView thumbnails

            ImageView imageView;
            if (convertView == null) { // if it's not recycled, instantiate and
                // initialize
                imageView = new ImageView(mContext);
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                imageView.setLayoutParams(mImageViewLayoutParams);
            } else { // Otherwise re-use the converted view
                imageView = (ImageView) convertView;
            }

            Log.e("ad", "position ==  " + position);
            mImageWorker.loadBitmap(imageUrls[position], imageView, null);

            // Finally load the image asynchronously into the ImageView, this
            // also takes care of
            // setting a placeholder image while the background thread runs

            return imageView;
        }

    }
}