How to generate Bitmap?

Question

I want to write a android receipt program by writing text, setLogo and image into Bitmap. I had search through internet but non of them are relevant to what I'm try to achieve. Is there anyway for me to make it?

My receipt output format is as below:

 _____________
| *********** |
| *  Logo   * | 
| *********** |
| Date        |
| Amount      |
| Card No     |
|             |
| Signature   |
|_____________|

For your information, my purpose is let user review the receipt before terminal print out the receipt. In printReceipt function will do all the generate receipt bitmap job and printPreview function will to set the bitmap into imageView.

Example in real world:- Supermarket receipt, the data will keep increase when we buy a lot of goods, and I'm try to write those data into bitmap and print it out or send through email.

Answer 1

I guess you have written the wrong heading. If you want to design a Receipt then you have to design it using the XML Layout Design. For your receipt I have this design.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:padding="16dp"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">


    <ImageView
            android:id="@+id/imageview"
            android:layout_centerHorizontal="true"
            android:background="@mipmap/ic_launcher"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>

    <TableLayout
            android:stretchColumns="*"
            android:layout_marginTop="20dp"
            android:layout_below="@id/imageview"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

        <TableRow>

            <TextView
                    android:textAppearance="@style/TextAppearance.AppCompat.Large"
                    android:text="Date"
            />

            <TextView
                    android:id="@+id/text_view_date"
                    android:textAppearance="@style/TextAppearance.AppCompat.Large"
                    tools:text="14/06/2019"
            />

        </TableRow>

        <TableRow>

            <TextView
                    android:textAppearance="@style/TextAppearance.AppCompat.Large"
                    android:text="Amount"
            />

            <TextView
                    android:id="@+id/text_view_amount"
                    android:textAppearance="@style/TextAppearance.AppCompat.Large"
                    tools:text="$120"
            />

        </TableRow>

        <TableRow>

            <TextView
                    android:textAppearance="@style/TextAppearance.AppCompat.Large"
                    android:text="Card Number"
            />

            <TextView
                    android:id="@+id/text_view_card_number"
                    android:textAppearance="@style/TextAppearance.AppCompat.Large"
                    tools:text="4587 8983 7456 2233"
            />

        </TableRow>

        <TableRow>

            <TextView
                    android:textAppearance="@style/TextAppearance.AppCompat.Large"
                    android:text="Signature"
            />

            <ImageView
                    android:background="@mipmap/ic_launcher"
            />

        </TableRow>


    </TableLayout>

</RelativeLayout>

This XML you will see like this

Now you can add the values to your textviews. And then if you want to convert this screen into a Bitmap you can take the screenshot.

Hope this helps.

Answer 2

You can convert the layout view directly to a bitmap using below code.

View v = printPreviewLayout;
Bitmap bmp = Bitmap.createBitmap(v.getWidth(), v.getHeight(), Bitmap.Config.ARGB_8888);

Canvas c = new Canvas(bmp);
v.draw(c);

try{
    File file =  new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "Image_" + System.currentTimeMillis() + ".png");
    FileOutputStream out = new FileOutputStream(file);
    bmp.compress(Bitmap.CompressFormat.PNG, 90, out);
    out.close();
    MediaScannerConnection.scanFile(mContext, new String[] { file.toString() }, null,new MediaScannerConnection.OnScanCompletedListener() {
        public void onScanCompleted(String path, Uri uri) {
            Log.i("ExternalStorage", "Scanned " + path + ":");
            Log.i("ExternalStorage", "-> uri=" + uri);
        }
   });
   Toast.makeText(mContext, "Image downloaded to"+file.toString(), Toast.LENGTH_LONG).show();
}

This will draw a bitmap of printPreviewLayout view.

Answer 3

You can turn your View into a Bitmap.

From the answer here Android Convert view to BitMap

private Bitmap createBitmapFromView(Context context, View view) {
        DisplayMetrics displayMetrics = new DisplayMetrics();
        ((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        view.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

        view.measure(displayMetrics.widthPixels, displayMetrics.heightPixels);
        view.layout(0, 0, displayMetrics.widthPixels, displayMetrics.heightPixels);
        view.buildDrawingCache();
        Bitmap bitmap = Bitmap.createBitmap(view.getMeasuredWidth(), view.getMeasuredHeight(), Bitmap.Config.ARGB_8888);

        Canvas canvas = new Canvas(bitmap);
        view.draw(canvas);

        return bitmap;
    }

But if you really want to create a Bitmap from scratch. Here is a library that can draw text and image into an image data(byte array) which you can turn into a Bitmap. Graphics 2D. Here's a basic usage of it Convert text content to Image