Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
// Licensed under the MIT license.

import android.content.ContentResolver;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.graphics.Rect;
import android.media.ExifInterface;
import android.net.Uri;
import android.provider.MediaStore;
import java.io.IOException;
import java.io.InputStream;

public class Main {
    private static final int IMAGE_MAX_SIDE_LENGTH = 1280;

    public static Bitmap loadSizeLimitedBitmapFromUri(Uri imageUri, ContentResolver contentResolver) {
        try {
            // Load the image into InputStream.
            InputStream imageInputStream = contentResolver.openInputStream(imageUri);

            // For saving memory, only decode the image meta and get the side length.
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = true;
            Rect outPadding = new Rect();
            BitmapFactory.decodeStream(imageInputStream, outPadding, options);

            // Calculate shrink rate when loading the image into memory.
            int maxSideLength = options.outWidth > options.outHeight ? options.outWidth : options.outHeight;
            options.inSampleSize = 1;
            options.inSampleSize = calculateSampleSize(maxSideLength, IMAGE_MAX_SIDE_LENGTH);
            options.inJustDecodeBounds = false;
            imageInputStream.close();

            // Load the bitmap and resize it to the expected size length
            imageInputStream = contentResolver.openInputStream(imageUri);
            Bitmap bitmap = BitmapFactory.decodeStream(imageInputStream, outPadding, options);
            maxSideLength = bitmap.getWidth() > bitmap.getHeight() ? bitmap.getWidth() : bitmap.getHeight();
            double ratio = IMAGE_MAX_SIDE_LENGTH / (double) maxSideLength;
            if (ratio < 1) {
                bitmap = Bitmap.createScaledBitmap(bitmap, (int) (bitmap.getWidth() * ratio),
                        (int) (bitmap.getHeight() * ratio), false);
            }

            return rotateBitmap(bitmap, getImageRotationAngle(imageUri, contentResolver));
        } catch (Exception e) {
            return null;
        }
    }

    private static int calculateSampleSize(int maxSideLength, int expectedMaxImageSideLength) {
        int inSampleSize = 1;

        while (maxSideLength > 2 * expectedMaxImageSideLength) {
            maxSideLength /= 2;
            inSampleSize *= 2;
        }

        return inSampleSize;
    }

    private static Bitmap rotateBitmap(Bitmap bitmap, int angle) {
        // If the rotate angle is 0, then return the original image, else return the rotated image
        if (angle != 0) {
            Matrix matrix = new Matrix();
            matrix.postRotate(angle);
            return Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
        } else {
            return bitmap;
        }
    }

    private static int getImageRotationAngle(Uri imageUri, ContentResolver contentResolver) throws IOException {
        int angle = 0;
        Cursor cursor = contentResolver.query(imageUri, new String[] { MediaStore.Images.ImageColumns.ORIENTATION },
                null, null, null);
        if (cursor != null) {
            if (cursor.getCount() == 1) {
                cursor.moveToFirst();
                angle = cursor.getInt(0);
            }
            cursor.close();
        } else {
            ExifInterface exif = new ExifInterface(imageUri.getPath());
            int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);

            switch (orientation) {
            case ExifInterface.ORIENTATION_ROTATE_270:
                angle = 270;
                break;
            case ExifInterface.ORIENTATION_ROTATE_180:
                angle = 180;
                break;
            case ExifInterface.ORIENTATION_ROTATE_90:
                angle = 90;
                break;
            default:
                break;
            }
        }
        return angle;
    }
}