ThumbnailCreator.java

/*
    Open Manager, an open source file manager for the Android system
    Copyright (C) 2009, 2010, 2011  Joe Berria <nexesdevelopment@gmail.com>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package gem.kevin.util;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Handler;
import android.os.Message;

import java.lang.ref.SoftReference;
import java.util.HashMap;
import java.util.ArrayList;
import java.io.File;

public class ThumbnailCreator extends Thread {
    private int mWidth;
    private int mHeight;
    private SoftReference<Bitmap> mThumb;
    private static HashMap<String, Bitmap> mCacheMap = null;
    private ArrayList<String> mFiles;
    private String mDir;
    private Handler mHandler;
    private boolean mStop = false;

    public ThumbnailCreator(int width, int height) {
        mHeight = height;
        mWidth = width;

        if (mCacheMap == null)
            mCacheMap = new HashMap<String, Bitmap>();
    }

    public Bitmap isBitmapCached(String name) {
        return mCacheMap.get(name);
    }

    public void setCancelThumbnails(boolean stop) {
        mStop = stop;
    }

    public void createNewThumbnail(ArrayList<String> files, String dir,
            Handler handler) {
        this.mFiles = files;
        this.mDir = dir;
        this.mHandler = handler;
    }

    @Override
    public void run() {
        int len = mFiles.size();

        for (int i = 0; i < len; i++) {
            if (mStop) {
                mStop = false;
                mFiles = null;
                return;
            }
            final File file = new File(mDir + "/" + mFiles.get(i));

            if (isImageFile(file.getName())) {
                long len_kb = file.length() / 1024;

                BitmapFactory.Options options = new BitmapFactory.Options();
                options.outWidth = mWidth;
                options.outHeight = mHeight;

                if (len_kb > 1000 && len_kb < 5000) {
                    options.inSampleSize = 32;
                    options.inPurgeable = true;
                    mThumb = new SoftReference<Bitmap>(
                            BitmapFactory.decodeFile(file.getPath(), options));

                } else if (len_kb >= 5000) {
                    options.inSampleSize = 32;
                    options.inPurgeable = true;
                    mThumb = new SoftReference<Bitmap>(
                            BitmapFactory.decodeFile(file.getPath(), options));

                } else if (len_kb <= 1000) {
                    options.inPurgeable = true;
                    mThumb = new SoftReference<Bitmap>(
                            Bitmap.createScaledBitmap(
                                    BitmapFactory.decodeFile(file.getPath()),
                                    mWidth, mHeight, false));
                }

                mCacheMap.put(file.getPath(), mThumb.get());

                mHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        Message msg = mHandler.obtainMessage();
                        msg.obj = mThumb.get();
                        msg.sendToTarget();
                    }
                });
            }
        }
    }

    private boolean isImageFile(String file) {
        String ext = file.substring(file.lastIndexOf(".") + 1);

        if (ext.equalsIgnoreCase("png") || ext.equalsIgnoreCase("jpg")
                || ext.equalsIgnoreCase("jpeg") || ext.equalsIgnoreCase("gif")
                || ext.equalsIgnoreCase("bmp") || ext.equalsIgnoreCase("tiff")
                || ext.equalsIgnoreCase("tif"))
            return true;

        return false;
    }
}