Main.java Source code

Java tutorial

Introduction

Here is the source code for Main.java

Source

//package com.java2s;

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

import java.io.FileDescriptor;

public class Main {
    public static Bitmap decodeSampledBitmapFromFileDescriptor(FileDescriptor stream, int reqWidth, int reqHeight) {

        // First decode with inJustDecodeBounds=true to check dimensions
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        options.inPurgeable = true;
        BitmapFactory.decodeFileDescriptor(stream, null, options);

        if (options.outHeight > 0 && options.outWidth > 0) {
            // Calculate inSampleSize
            options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

            // Decode bitmap with inSampleSize set
            options.inJustDecodeBounds = false;
            return BitmapFactory.decodeFileDescriptor(stream, null, options);
        } else {
            return null;
        }
    }

    public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
        // Raw height and width of image
        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = 1;

        if (height > reqHeight || width > reqWidth) {

            final int halfHeight = height / 2;
            final int halfWidth = width / 2;

            // Calculate the largest inSampleSize value that is a power of 2 and keeps both
            // height and width larger than the requested height and width.
            while ((halfHeight / inSampleSize) > reqHeight && (halfWidth / inSampleSize) > reqWidth) {
                inSampleSize *= 2;
            }
        }

        return inSampleSize;
    }
}