package com.example.smart.oss.image;


import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
import android.widget.ImageView;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class UiDisplayer {

    private ImageView imageView;

    public void setImageView(ImageView imageView) {
        this.imageView = imageView;
    }

    //根据ImageView大小自动缩放图片
    public Bitmap autoResizeFromStream(InputStream stream) throws IOException {

        byte[] data;
        {
            ByteArrayOutputStream outStream = new ByteArrayOutputStream();
            byte[] buffer = new byte[1024];
            int len = 0;
            while ((len = stream.read(buffer)) != -1) {
                outStream.write(buffer, 0, len);
            }
            outStream.close();
            data = outStream.toByteArray();
            stream.close();
        }

        // First decode with inJustDecodeBounds=true to check dimensions
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeByteArray(data, 0, data.length, options);

        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, imageView.getWidth(), imageView.getHeight());
        Log.d("ImageHeight", String.valueOf(options.outHeight));
        Log.d("ImageWidth", String.valueOf(options.outWidth));
        Log.d("Height", String.valueOf(imageView.getWidth()));
        Log.d("Width", String.valueOf(imageView.getWidth()));
        options.inSampleSize = 4;

        Log.d("SampleSize", String.valueOf(options.inSampleSize));
        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;
        return BitmapFactory.decodeByteArray(data, 0, data.length, options);
    }


    //计算图片缩放比例
    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;
    }
}