Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 *    Copyright (C) 2010 Stewart Gateley <birbeck@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/>.
 */

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

import android.util.Log;

public class Main {
    public static final int UNCONSTRAINED = -1;
    private static final String TAG = "BitmapUtil";

    /**
     * Make a bitmap from a given Uri.
     *
     * @param uri
     */
    public static Bitmap makeBitmap(int minSideLength, int maxNumOfPixels, String pathName,
            BitmapFactory.Options options) {
        try {
            if (options == null)
                options = new BitmapFactory.Options();

            options.inJustDecodeBounds = true;
            BitmapFactory.decodeFile(pathName, options);
            if (options.mCancel || options.outWidth == -1 || options.outHeight == -1) {
                return null;
            }

            options.inSampleSize = computeSampleSize(options, minSideLength, maxNumOfPixels);
            options.inJustDecodeBounds = false;
            //options.inDither = false;
            //options.inPreferredConfig = Bitmap.Config.ARGB_8888;
            return BitmapFactory.decodeFile(pathName, options);
        } catch (OutOfMemoryError ex) {
            Log.e(TAG, "Got oom exception ", ex);
            return null;
        }
    }

    public static int computeSampleSize(BitmapFactory.Options options, int minSideLength, int maxNumOfPixels) {
        int initialSize = computeInitialSampleSize(options, minSideLength, maxNumOfPixels);

        int roundedSize;
        if (initialSize <= 8) {
            roundedSize = 1;
            while (roundedSize < initialSize) {
                roundedSize <<= 1;
            }
        } else {
            roundedSize = (initialSize + 7) / 8 * 8;
        }

        return roundedSize;
    }

    private static int computeInitialSampleSize(BitmapFactory.Options options, int minSideLength,
            int maxNumOfPixels) {
        double w = options.outWidth;
        double h = options.outHeight;

        int lowerBound = (maxNumOfPixels == UNCONSTRAINED) ? 1 : (int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels));
        int upperBound = (minSideLength == UNCONSTRAINED) ? 128
                : (int) Math.min(Math.floor(w / minSideLength), Math.floor(h / minSideLength));

        if (upperBound < lowerBound) {
            // return the larger one when there is no overlapping zone.
            return lowerBound;
        }

        if ((maxNumOfPixels == UNCONSTRAINED) && (minSideLength == UNCONSTRAINED)) {
            return 1;
        } else if (minSideLength == UNCONSTRAINED) {
            return lowerBound;
        } else {
            return upperBound;
        }
    }
}