Main.java Source code

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Here is the source code for Main.java

Source

//package com.java2s;
/*
 * Copyright 2016 Dmitry Brant.
    
 * 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.
 */

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

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

public class Main {
    public static Bitmap loadMpoBitmapFromFile(File file, long offset, int maxWidth, int maxHeight)
            throws IOException {
        // First, decode the width and height of the image, so that we know how much to scale
        // it down when loading it into our ImageView (so we don't need to do a huge allocation).
        BitmapFactory.Options opts = new BitmapFactory.Options();
        InputStream fs = null;
        try {
            fs = new BufferedInputStream(new FileInputStream(file));
            fs.skip(offset);
            opts.inJustDecodeBounds = true;
            BitmapFactory.decodeStream(fs, null, opts);
        } finally {
            if (fs != null) {
                try {
                    fs.close();
                } catch (IOException e) {
                    // don't worry
                }
            }
        }
        int scale = 1;
        if (opts.outHeight > maxHeight || opts.outWidth > maxWidth) {
            scale = (int) Math.pow(2, (int) Math
                    .round(Math.log(maxWidth / (double) Math.max(opts.outHeight, opts.outWidth)) / Math.log(0.5)));
        }
        if ((opts.outHeight <= 0) || (opts.outWidth <= 0)) {
            return null;
        }
        // Decode the image for real, but now with a sampleSize.
        // We have to reopen the file stream, and re-skip to the correct offset, since
        // FileInputStream doesn't support reset().
        Bitmap bmp = null;
        fs = null;
        try {
            fs = new BufferedInputStream(new FileInputStream(file));
            fs.skip(offset);
            BitmapFactory.Options opts2 = new BitmapFactory.Options();
            opts2.inSampleSize = scale;
            bmp = BitmapFactory.decodeStream(fs, null, opts2);
        } finally {
            if (fs != null) {
                try {
                    fs.close();
                } catch (IOException e) {
                    // don't worry
                }
            }
        }
        return bmp;
    }
}