Add scan_area.xml and dedicated view.

/*

 * Copyright MURENA SAS 2024

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 *  along with this program.  If not, see <https://www.gnu.org/licenses/>.

 */

package net.sourceforge.opencamera.preview;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.drawable.Drawable;

import android.util.DisplayMetrics;

import android.view.View;

import androidx.core.content.ContextCompat;

import foundation.e.camera.R;

public class OverlayQRCodeView extends View {

    private Drawable qrcode;

    // Do not draw the additional resource if something goes wrong

    private boolean isValid = true;

    public OverlayQRCodeView(Context context) {

        super(context);

        init();

    }

    private void init() {

        qrcode = ContextCompat.getDrawable(this.getContext(), R.drawable.scan_area);

        DisplayMetrics displayMetrics =this.getContext().getResources().getDisplayMetrics();

        final int screenWidth = displayMetrics.widthPixels;

        final int screenHeight = displayMetrics.heightPixels;

        final int left = (screenWidth - qrcode.getIntrinsicWidth()) / 2;

        final int top = (screenHeight - qrcode.getIntrinsicHeight()) / 2;

        final int right = left + qrcode.getIntrinsicWidth();

        final int bottom = top + qrcode.getIntrinsicHeight();

        if (left<=0 || top<=0 || right<=0 || bottom<=0)

            isValid = false;

        else

            qrcode.setBounds(left, top, right, bottom);

    }

    @Override

    protected void onDraw(Canvas canvas) {

        super.onDraw(canvas);

        if (isValid)

            qrcode.draw(canvas);

    }

}

<vector xmlns:android="http://schemas.android.com/apk/res/android"

    android:width="192dp"

    android:height="192dp"

    android:viewportWidth="192"

    android:viewportHeight="192">

  <group>

    <clip-path

        android:pathData="M0,0h192v192h-192z"/>

    <path

        android:pathData="M0,21.33V48H13.33V22.33C13.33,17.36 17.36,13.33 22.33,13.33H48V0H21.33C9.6,0 0,9.6 0,21.33ZM13.33,144H0V170.67C0,182.4 9.6,192 21.33,192H48V178.67H22.33C17.36,178.67 13.33,174.64 13.33,169.67V144ZM178.67,169.67C178.67,174.64 174.64,178.67 169.67,178.67H144V192H170.67C182.4,192 192,182.4 192,170.67V144H178.67V169.67ZM170.67,0H144V13.33H169.67C174.64,13.33 178.67,17.36 178.67,22.33V48H192V21.33C192,9.6 182.4,0 170.67,0Z"

        android:fillColor="#ffffff"

        android:fillAlpha="0.8"/>

  </group>

</vector>