flutter_barcode_reader/android/src/main/kotlin/com/apptreesoftware/barcodescan/BarcodeScannerActivity.kt

/*
 * ************************************************************************
 *  *
 *  * AppTree Software Inc CONFIDENTIAL
 *  * __________________
 *  *
 *  *  [2012] - [2016] AppTree Software Inc
 *  *  All Rights Reserved.
 *  *
 *  * NOTICE:  All information contained herein is, and remains
 *  * the property of AppTree Software Inc and its suppliers,
 *  * if any.  The intellectual and technical concepts contained
 *  * herein are proprietary to AppTree Software Inc
 *  * and its suppliers and may be covered by U.S. and Foreign Patents,
 *  * patents in process, and are protected by trade secret or copyright law.
 *  * Dissemination of this information or reproduction of this material
 *  * is strictly forbidden unless prior written permission is obtained
 *  * from AppTree Software Inc.
 *
 */

package com.apptreesoftware.barcodescan

import android.Manifest
import android.app.Activity
import android.content.Intent
import android.content.pm.PackageManager
import android.os.Bundle
import android.support.design.widget.Snackbar
import android.support.v4.app.ActivityCompat
import android.support.v4.content.ContextCompat
import android.view.Menu
import android.view.MenuItem
import com.google.zxing.Result
import me.dm7.barcodescanner.zxing.ZXingScannerView


class BarcodeScannerActivity : Activity(), ZXingScannerView.ResultHandler {

    lateinit var scannerView: me.dm7.barcodescanner.zxing.ZXingScannerView
    //lateinit var pressLightSnackBar: Snackbar

    companion object {
        val REQUEST_TAKE_PHOTO_CAMERA_PERMISSION = 100
        val TOGGLE_FLASH = 200

    }
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        title = ""
        scannerView = ZXingScannerView(this)
        scannerView.setAutoFocus(true)
        setContentView(scannerView)
//        pressLightSnackBar = Snackbar.make(scannerView, "Press Screen To Turn Light On",
//                                           Int.MAX_VALUE)
//        pressLightSnackBar.show()
    }

    override fun onCreateOptionsMenu(menu: Menu): Boolean {
        if (scannerView.flash) {
            val item = menu.add(0,
                                TOGGLE_FLASH, 0, "Flash Off")
            item.setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS)
        } else {
            val item = menu.add(0,
                                TOGGLE_FLASH, 0, "Flash On")
            item.setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS)
        }
        return super.onCreateOptionsMenu(menu)
    }

    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        if (item.itemId == TOGGLE_FLASH) {
            scannerView.flash = !scannerView.flash
            this.invalidateOptionsMenu()
            return true
        }
        return super.onOptionsItemSelected(item)
    }

    override fun onResume() {
        super.onResume()
        scannerView.setResultHandler(this)
        if (!requestCameraAccessIfNecessary()) {
            scannerView.startCamera()
        }
    }

    override fun onPause() {
        super.onPause()
        scannerView.stopCamera()
    }

    override fun handleResult(result: Result?) {
        val intent = Intent()
        intent.putExtra("SCAN_RESULT", result.toString())
        setResult(Activity.RESULT_OK, intent)
        finish()
    }

    private fun requestCameraAccessIfNecessary(): Boolean {
        val array = arrayOf(Manifest.permission.CAMERA)
        if (ContextCompat
            .checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.CAMERA)) {
                val snackbar = Snackbar.make(scannerView, "Grant access to the camera to enable barcode scanning.", Snackbar.LENGTH_INDEFINITE)
                snackbar.setAction("OK") {
                    ActivityCompat.requestPermissions(this,
                                            array,
                                                      REQUEST_TAKE_PHOTO_CAMERA_PERMISSION)
                }
                snackbar.show()
            } else {
                ActivityCompat.requestPermissions(this,
                                                  array,
                                                  REQUEST_TAKE_PHOTO_CAMERA_PERMISSION)
            }
            return true
        }
        return false
    }

    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>,
                                            grantResults: IntArray) {
        when (requestCode) {
            REQUEST_TAKE_PHOTO_CAMERA_PERMISSION -> {
                if (PermissionUtil.verifyPermissions(grantResults)) {
                    scannerView.startCamera()
                }
            }
        }
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
    }
}

object PermissionUtil {

    /**
     * Check that all given permissions have been granted by verifying that each entry in the
     * given array is of the value [PackageManager.PERMISSION_GRANTED].

     * @see Activity.onRequestPermissionsResult
     */
    fun verifyPermissions(grantResults: IntArray): Boolean {
        // At least one result must be checked.
        if (grantResults.size < 1) {
            return false
        }

        // Verify that each required permission has been granted, otherwise return false.
        for (result in grantResults) {
            if (result != PackageManager.PERMISSION_GRANTED) {
                return false
            }
        }
        return true
    }
}