Wrong size from Drawable.getIntrinsicWidth()

Question

I download image with this code:

ImageGetter imageGetter = new ImageGetter() {
    @Override
    public Drawable getDrawable(String source) {
        Drawable drawable = null;
        try {
            URL url = new URL(source);
            String path = Environment.getExternalStorageDirectory().getPath()+"/Android/data/com.my.pkg/"+url.getFile();
            File f=new File(path);
            if(!f.exists()) {
                URLConnection connection = url.openConnection();
                InputStream is = connection.getInputStream();

                f=new File(f.getParent());
                f.mkdirs();                 

                FileOutputStream os = new FileOutputStream(path);
                byte[] buffer = new byte[4096];
                int length;
                while ((length = is.read(buffer)) > 0) {
                    os.write(buffer, 0, length);
                }
                os.close();
                is.close();
            }
            drawable = Drawable.createFromPath(path);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (Throwable t) {
            t.printStackTrace();
        }
        if(drawable != null) {
            drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
        }
        return drawable;
    }
};

This image has size 20x20. But drawable.getIntrinsicWidth() and drawable.getIntrinsicHeight() return 27. And image looks larger. How I can fix it?

Answer 1

BitmapDrawable must scale bitmap to compensate for different screen densities.

If you need it to draw pixel-for-pixel, try setting Drawable's source density & target density to same value. To do this, you need slightly different objects to work with.

Instead of

drawable = Drawable.createFromPath(path);

use

Bitmap bmp = BitmapFactory.decodeFile(path);
DisplayMetrics dm = context.getResources().getDisplayMetrics();
bmp.setDensity(dm.densityDpi);
drawable = new BitmapDrawable(bmp, context.getResources());

If you don't have context (which you should), you can use application context, see e.g. Using Application context everywhere?

Since bitmap's density is set to resources' density, which is actual device's screen's density, it should draw without scaling.

Answer 2

I tried the code form the answer and did not work. So instead i used the code below and it worked fine.

     DisplayMetrics dm = context.getResources().getDisplayMetrics();

     Options options=new Options();
     options.inDensity=dm.densityDpi;
     options.inScreenDensity=dm.densityDpi;
     options.inTargetDensity=dm.densityDpi;      

     Bitmap bmp = BitmapFactory.decodeFile(path,options);
     drawable = new BitmapDrawable(bmp, context.getResources());