BitMapFromViewsWithoutDisplaying.java

    private Bitmap generateReceiptBitmap(ArrayList<PrinterDatum> data) {
        ReceiptViewAdapter adapter = new ReceiptViewAdapter();
        RecyclerView rv = new RecyclerView(mActivity);
        rv.setLayoutManager(new LinearLayoutManager(mActivity, LinearLayoutManager.VERTICAL, false));
        rv.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT));
        rv.setAdapter(adapter);
        adapter.setData(data);

        return loadBitmapFromView(rv);
    }

    public Bitmap loadBitmapFromView(View v) {
        int spec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        v.measure(spec, spec);
        v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());
        Bitmap b = Bitmap.createBitmap(v.getMeasuredWidth(), v.getMeasuredWidth(),
                Bitmap.Config.ARGB_8888);
        Canvas c = new Canvas(b);
        c.translate((-v.getScrollX()), (-v.getScrollY()));
        v.draw(c);

        return b;
    }

     public Bitmap loadBitMapFromRecyclerView(RecyclerView view) {
        ReceiptViewAdapter adapter = (ReceiptViewAdapter) view.getAdapter();
        Bitmap result = null;
        if (adapter != null) {
            int size = adapter.getItemCount();
            int height = 0;
            int width = 0;
            final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
            final int cacheSize = maxMemory / 8;

            LruCache<String, Bitmap> bmCache = new LruCache<>(cacheSize);
            for (int i = 0; i < size; i++) {
                BaseRecyclerAdapter.ViewHolder holder = adapter.createHolder(view, adapter.getItemViewType(i));
                adapter.onBindViewHolder(holder, i);
                int spec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
                holder.itemView.setDrawingCacheEnabled(true);
                holder.itemView.measure(spec, spec);
                holder.itemView.layout(0, 0, holder.itemView.getMeasuredWidth(), holder.itemView.getMeasuredHeight());
                holder.itemView.buildDrawingCache();
                Bitmap bmDrawingCache = Bitmap.createBitmap(holder.itemView.getDrawingCache());
                if (bmDrawingCache != null) {
                    bmCache.put(String.valueOf(i), bmDrawingCache);
                }
                holder.itemView.setDrawingCacheEnabled(false);
                holder.itemView.destroyDrawingCache();

                height += holder.itemView.getMeasuredHeight();
                width = (width == 0 || width < holder.itemView.getMeasuredWidth())
                        ? holder.itemView.getMeasuredWidth()
                        : width;
            }

            result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
            Canvas bigCanvas = new Canvas(result);
            bigCanvas.drawColor(Color.WHITE);

            Paint p = new Paint();
            int h = 0;
            for (int i = 0; i < size; i++) {
                Bitmap bm = bmCache.get(String.valueOf(i));
                bigCanvas.drawBitmap(bm, 0f, h, p);
                h += bm.getHeight();
                bm.recycle();
            }

            bmCache.evictAll();
        }

        return result;
    }

    private static class ReceiptViewAdapter extends BaseRecyclerAdapter<PrinterDatum, BaseRecyclerAdapter.ViewHolder<PrinterDatum>> {
        private final static int TYPE_TEXT = 1;
        private final static int QRCODE = 2;
        private final static int LINEFEED = 3;
        private final static int LOGO = 4;

        @Override
        public int getItemViewType(int position) {
            PrinterDatum item = mData.get(position);
            if (item.printerDataType == PrinterDatum.PrinterDataType.TEXT) {
                return TYPE_TEXT;
            }
            if (item.printerDataType == PrinterDatum.PrinterDataType.LOGO) {
                return LOGO;
            }

            return 1;
        }

        @Override
        public BaseRecyclerAdapter.ViewHolder createHolder(ViewGroup parent, int viewType) {
            switch (viewType) {
                case TYPE_TEXT:
                    return TextViewHolder.create(parent.getContext());
                case LOGO:
                    return LogoViewHolder.create(parent.getContext());
                default:
                    return null;
            }
        }

        static class TextViewHolder extends BaseRecyclerAdapter.ViewHolder<PrinterDatum> {
            private RobotoTextView mTextView;

            public static TextViewHolder create(Context context) {
                View v = LayoutInflater.from(context).inflate(R.layout.com_garena_cyberpay_app_activity_wifi_printer_item_text, null);
                return new TextViewHolder(v);
            }

            private TextViewHolder(View itemView) {
                super(itemView);
                mTextView = itemView.findViewById(R.id.cp_row_text);
            }

            @Override
            public void bindData(PrinterDatum data, int position) {
                mTextView.setText(data.data);
            }
        }

        static class LogoViewHolder extends BaseRecyclerAdapter.ViewHolder<PrinterDatum> {
            private final Context mContext;
            private ImageView mImageView;

            public static LogoViewHolder create(Context context) {
                View v = LayoutInflater.from(context).inflate(R.layout.com_garena_cyberpay_app_activity_wifi_printer_item_logo, null);
                return new LogoViewHolder(v, context);
            }

            private LogoViewHolder(View itemView, Context context) {
                super(itemView);
                mContext = context;
                mImageView = itemView.findViewById(R.id.cp_row_image);
            }

            @Override
            public void bindData(PrinterDatum data, int position) {
                try {
                    InputStream is = mContext.getAssets().open(data.data + ".png");
                    Drawable d = Drawable.createFromStream(is, null);
                    mImageView.setImageDrawable(d);
                } catch (IOException e) {
                    Sentry.e(e);
                }
            }
        }
    }