Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Apache License 

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

public class Main {

    public static Bitmap ReadBitmapBySD(String path, int screenWidth, int screenHight) {
        try {
            if (path == null) {
                return null;
            }
            BitmapFactory.Options opts = new BitmapFactory.Options();
            opts.inJustDecodeBounds = true;
            BitmapFactory.decodeFile(path, opts);

            opts.inSampleSize = computeSampleSize(opts, -1, screenWidth * screenHight);
            opts.inJustDecodeBounds = false;
            try {
                Bitmap bmp = BitmapFactory.decodeFile(path, opts);
                return bmp;
            } catch (OutOfMemoryError err) {
            }
        } catch (Exception e) {
            return null;
        }
        return null;
    }

    private 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 == -1) ? 1 : (int) Math.ceil(Math.sqrt(w * h / maxNumOfPixels));
        int upperBound = (minSideLength == -1) ? 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 == -1) && (minSideLength == -1)) {
            return 1;
        } else if (minSideLength == -1) {
            return lowerBound;
        } else {
            return upperBound;
        }
    }
}