Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import java.io.File;

import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.os.Build;
import android.text.TextUtils;

public class Main {
    private static final int UNCONSTRAINED = -1;

    @SuppressWarnings("deprecation")
    public static int[] getBitmapSize(File file, int targetWidth, int targetHeight) {
        if (null != file && file.exists() && file.isFile() && file.canRead()) {
            String path = file.getAbsolutePath();
            Options opts = new Options();
            if (targetWidth > 0 && targetHeight > 0) {
                opts.inJustDecodeBounds = true;
                BitmapFactory.decodeFile(path, opts);
                opts.inSampleSize = computeSampleSize(opts, Math.min(targetWidth, targetHeight),
                        targetWidth * targetHeight);
                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
                    opts.inInputShareable = true;
                    opts.inPurgeable = true;
                }
            }
            BitmapFactory.decodeFile(path, opts);
            return new int[] { opts.outWidth, opts.outHeight };
        }
        return null;
    }

    public static int[] getBitmapSize(String path, int targetWidth, int targetHeight) {
        if (TextUtils.isEmpty(path)) {
            return null;
        }
        if (path.matches("^\\w+$")) {
            return null;
        }
        return getBitmapSize(new File(path), targetWidth, targetHeight);
    }

    public static int computeSampleSize(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(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;
        }
    }
}