how to take a screenshot through a floating widget in any activity in android

Question

I know there is same question on SO and I also know that question has one answer with two downvotes.

Here is what I'm doing to take a screenshot

 private Bitmap takeScreenshot(){
        View rootView = findViewById(android.R.id.content).getRootView();
        rootView.setDrawingCacheEnabled(true);
        return rootView.getDrawingCache();
    }

    public void saveBitmap(Bitmap bitmap) {
        File imagePath = new File(Environment.getExternalStorageDirectory() + "/screenshot.png");
        FileOutputStream fos;
        try {
            fos = new FileOutputStream(imagePath);
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos);
            fos.flush();
            fos.close();
        } catch (FileNotFoundException e) {
            Log.e("GREC", e.getMessage(), e);
        } catch (IOException e) {
            Log.e("GREC", e.getMessage(), e);
        }
    }

I'm using these two methods to capture the screen, well it does work but only when the user is in the app but I'm using a floating widget and want to capture the screen where ever the user is in his phone just like a normal screenshot.

And I'm also recording the screen, which is what the app is about, so I may say that media projection is already in use.

How can I achieve this any idea or suggestions anything