First wrong button text in View Headers in night theme. https://redmine.stoutner...

[PrivacyBrowserAndroid.git] / app / src / main / java / com / stoutner / privacybrowser / dialogs / EditBookmarkFolderDatabaseViewDialog.kt

/*
 * Copyright 2016-2024 Soren Stoutner <soren@stoutner.com>.
 *
 * This file is part of Privacy Browser Android <https://www.stoutner.com/privacy-browser-android>.
 *
 * Privacy Browser Android 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.
 *
 * Privacy Browser Android 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 Privacy Browser Android.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.stoutner.privacybrowser.dialogs

import android.app.Dialog
import android.content.Context
import android.content.DialogInterface
import android.database.Cursor
import android.database.MatrixCursor
import android.database.MergeCursor
import android.graphics.Bitmap
import android.graphics.BitmapFactory
import android.net.Uri
import android.os.Bundle
import android.text.Editable
import android.text.TextWatcher
import android.view.KeyEvent
import android.view.View
import android.view.WindowManager
import android.widget.AdapterView
import android.widget.Button
import android.widget.EditText
import android.widget.ImageView
import android.widget.LinearLayout
import android.widget.RadioButton
import android.widget.Spinner
import android.widget.TextView

import androidx.activity.result.contract.ActivityResultContracts
import androidx.appcompat.app.AlertDialog
import androidx.appcompat.content.res.AppCompatResources
import androidx.core.content.ContextCompat
import androidx.core.graphics.drawable.toBitmap
import androidx.cursoradapter.widget.ResourceCursorAdapter
import androidx.fragment.app.DialogFragment
import androidx.preference.PreferenceManager

import com.google.android.material.snackbar.Snackbar

import com.stoutner.privacybrowser.R
import com.stoutner.privacybrowser.activities.HOME_FOLDER_DATABASE_ID
import com.stoutner.privacybrowser.activities.HOME_FOLDER_ID
import com.stoutner.privacybrowser.helpers.BOOKMARK_NAME
import com.stoutner.privacybrowser.helpers.DISPLAY_ORDER
import com.stoutner.privacybrowser.helpers.FAVORITE_ICON
import com.stoutner.privacybrowser.helpers.FOLDER_ID
import com.stoutner.privacybrowser.helpers.ID
import com.stoutner.privacybrowser.helpers.PARENT_FOLDER_ID
import com.stoutner.privacybrowser.helpers.BookmarksDatabaseHelper

import java.io.ByteArrayOutputStream

// Define the class constants.
private const val DATABASE_ID = "A"
private const val FAVORITE_ICON_BYTE_ARRAY = "B"

class EditBookmarkFolderDatabaseViewDialog : DialogFragment() {
    companion object {
        fun folderDatabaseId(databaseId: Int, favoriteIconBitmap: Bitmap): EditBookmarkFolderDatabaseViewDialog {
            // Create a favorite icon byte array output stream.
            val favoriteIconByteArrayOutputStream = ByteArrayOutputStream()

            // Convert the favorite icon to a PNG and place it in the byte array output stream.  `0` is for lossless compression (the only option for a PNG).
            favoriteIconBitmap.compress(Bitmap.CompressFormat.PNG, 0, favoriteIconByteArrayOutputStream)

            // Convert the byte array output stream to a byte array.
            val favoriteIconByteArray = favoriteIconByteArrayOutputStream.toByteArray()

            // Create an arguments bundle.
            val argumentsBundle = Bundle()

            // Store the variables in the bundle.
            argumentsBundle.putInt(DATABASE_ID, databaseId)
            argumentsBundle.putByteArray(FAVORITE_ICON_BYTE_ARRAY, favoriteIconByteArray)

            // Create a new instance of the dialog.
            val editBookmarkFolderDatabaseViewDialog = EditBookmarkFolderDatabaseViewDialog()

            // Add the arguments bundle to the dialog.
            editBookmarkFolderDatabaseViewDialog.arguments = argumentsBundle

            // Return the new dialog.
            return editBookmarkFolderDatabaseViewDialog
        }
    }

    private val browseActivityResultLauncher = registerForActivityResult(ActivityResultContracts.GetContent()) { imageUri: Uri? ->
        // Only do something if the user didn't press back from the file picker.
        if (imageUri != null) {
            // Get a handle for the content resolver.
            val contentResolver = requireContext().contentResolver

            // Get the image MIME type.
            val mimeType = contentResolver.getType(imageUri)

            // Decode the image according to the type.
            if (mimeType == "image/svg+xml") {  // The image is an SVG.
                // Display a snackbar.
                Snackbar.make(customIconImageView, getString(R.string.cannot_use_svg), Snackbar.LENGTH_LONG).show()
            } else {  // The image is not an SVG.
                // Get an input stream for the image URI.
                val inputStream = contentResolver.openInputStream(imageUri)

                // Get the bitmap from the URI.
                // `ImageDecoder.decodeBitmap` can't be used, because when running `Drawable.toBitmap` later the `Software rendering doesn't support hardware bitmaps` error message might be produced.
                var imageBitmap = BitmapFactory.decodeStream(inputStream)

                // Scale the image down if it is greater than 64 pixels in either direction.
                if ((imageBitmap != null) && ((imageBitmap.height > 128) || (imageBitmap.width > 128)))
                    imageBitmap = Bitmap.createScaledBitmap(imageBitmap, 128, 128, true)

                // Display the new custom favorite icon.
                customIconImageView.setImageBitmap(imageBitmap)

                // Select the custom icon radio button.
                customIconLinearLayout.performClick()
            }
        }
    }

    // Declare the class views.
    private lateinit var currentIconRadioButton: RadioButton
    private lateinit var customIconLinearLayout: LinearLayout
    private lateinit var customIconImageView: ImageView
    private lateinit var displayOrderEditText: EditText
    private lateinit var nameEditText: EditText
    private lateinit var parentFolderSpinner: Spinner
    private lateinit var saveButton: Button

    // Declare the class variables.
    private lateinit var currentFolderName: String
    private lateinit var editBookmarkFolderDatabaseViewListener: EditBookmarkFolderDatabaseViewListener

    // Declare the class variables.
    private var currentDisplayOrder: Int = 0
    private var currentParentFolderDatabaseIdInt: Int = 0

    // The public interface is used to send information back to the parent activity.
    interface EditBookmarkFolderDatabaseViewListener {
        fun saveBookmarkFolder(dialogFragment: DialogFragment, selectedFolderDatabaseId: Int)
    }

    override fun onAttach(context: Context) {
        // Run the default commands.
        super.onAttach(context)

        // Get a handle for edit bookmark database view listener from the launching context.
        editBookmarkFolderDatabaseViewListener = context as EditBookmarkFolderDatabaseViewListener
    }

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        // Get a handle for the arguments.
        val arguments = requireArguments()

        // Get the variables from the arguments.
        val folderDatabaseId = arguments.getInt(DATABASE_ID)
        val favoriteIconByteArray = arguments.getByteArray(FAVORITE_ICON_BYTE_ARRAY)!!

        // Convert the favorite icon byte array to a bitmap.
        val favoriteIconBitmap = BitmapFactory.decodeByteArray(favoriteIconByteArray, 0, favoriteIconByteArray.size)

        // Initialize the bookmarks database helper.
        val bookmarksDatabaseHelper = BookmarksDatabaseHelper(requireContext())

        // Get a cursor with the selected bookmark.
        val folderCursor = bookmarksDatabaseHelper.getBookmark(folderDatabaseId)

        // Move the cursor to the first position.
        folderCursor.moveToFirst()

        // Use an alert dialog builder to create the alert dialog.
        val dialogBuilder = AlertDialog.Builder(requireContext(), R.style.PrivacyBrowserAlertDialog)

        // Set the title.
        dialogBuilder.setTitle(R.string.edit_folder)

        // Set the icon.
        dialogBuilder.setIcon(R.drawable.folder)

        // Set the view.
        dialogBuilder.setView(R.layout.edit_bookmark_folder_databaseview_dialog)

        // Set the cancel button listener.  Using `null` as the listener closes the dialog without doing anything else.
        dialogBuilder.setNegativeButton(R.string.cancel, null)

        // Set the save button listener.
        dialogBuilder.setPositiveButton(R.string.save) { _: DialogInterface?, _: Int ->
            // Return the dialog fragment to the parent activity.
            editBookmarkFolderDatabaseViewListener.saveBookmarkFolder(this, folderDatabaseId)
        }

        // Create an alert dialog from the alert dialog builder.
        val alertDialog = dialogBuilder.create()

        // Get a handle for the shared preferences.
        val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(requireContext())

        // Get the screenshot preference.
        val allowScreenshots = sharedPreferences.getBoolean(getString(R.string.allow_screenshots_key), false)

        // Disable screenshots if not allowed.
        if (!allowScreenshots) {
            alertDialog.window!!.addFlags(WindowManager.LayoutParams.FLAG_SECURE)
        }

        // The alert dialog must be shown before items in the layout can be modified.
        alertDialog.show()

        // Get handles for the views in the alert dialog.
        val databaseIdTextView = alertDialog.findViewById<TextView>(R.id.folder_database_id_textview)!!
        val folderIdTextView = alertDialog.findViewById<TextView>(R.id.folder_id_textview)!!
        val currentIconLinearLayout = alertDialog.findViewById<LinearLayout>(R.id.current_icon_linearlayout)!!
        currentIconRadioButton = alertDialog.findViewById(R.id.current_icon_radiobutton)!!
        val currentIconImageView = alertDialog.findViewById<ImageView>(R.id.current_icon_imageview)!!
        val defaultFolderIconLinearLayout = alertDialog.findViewById<LinearLayout>(R.id.default_folder_icon_linearlayout)!!
        val defaultFolderIconRadioButton = alertDialog.findViewById<RadioButton>(R.id.default_folder_icon_radiobutton)!!
        val webpageFavoriteIconLinearLayout = alertDialog.findViewById<LinearLayout>(R.id.webpage_favorite_icon_linearlayout)!!
        val webpageFavoriteIconRadioButton = alertDialog.findViewById<RadioButton>(R.id.webpage_favorite_icon_radiobutton)!!
        val webpageFavoriteIconImageView = alertDialog.findViewById<ImageView>(R.id.webpage_favorite_icon_imageview)!!
        customIconLinearLayout = alertDialog.findViewById(R.id.custom_icon_linearlayout)!!
        val customIconRadioButton = alertDialog.findViewById<RadioButton>(R.id.custom_icon_radiobutton)!!
        customIconImageView = alertDialog.findViewById(R.id.custom_icon_imageview)!!
        val browseButton = alertDialog.findViewById<Button>(R.id.browse_button)!!
        nameEditText = alertDialog.findViewById(R.id.folder_name_edittext)!!
        parentFolderSpinner = alertDialog.findViewById(R.id.parent_folder_spinner)!!
        displayOrderEditText = alertDialog.findViewById(R.id.display_order_edittext)!!
        saveButton = alertDialog.getButton(AlertDialog.BUTTON_POSITIVE)

        // Get the current favorite icon byte array from the cursor.
        val currentIconByteArray = folderCursor.getBlob(folderCursor.getColumnIndexOrThrow(FAVORITE_ICON))

        // Convert the byte array to a bitmap beginning at the first byte and ending at the last.
        val currentIconBitmap = BitmapFactory.decodeByteArray(currentIconByteArray, 0, currentIconByteArray.size)

        // Get the current folder values.
        currentFolderName = folderCursor.getString(folderCursor.getColumnIndexOrThrow(BOOKMARK_NAME))
        currentDisplayOrder = folderCursor.getInt(folderCursor.getColumnIndexOrThrow(DISPLAY_ORDER))
        val currentParentFolderIdLong = folderCursor.getLong(folderCursor.getColumnIndexOrThrow(PARENT_FOLDER_ID))
        val currentFolderIdLong = folderCursor.getLong(folderCursor.getColumnIndexOrThrow(FOLDER_ID))

        // Populate the views.
        databaseIdTextView.text = folderDatabaseId.toString()
        folderIdTextView.text = currentFolderIdLong.toString()
        currentIconImageView.setImageBitmap(currentIconBitmap)
        webpageFavoriteIconImageView.setImageBitmap(favoriteIconBitmap)
        customIconImageView.setImageBitmap(AppCompatResources.getDrawable(requireContext(), R.drawable.folder)!!.toBitmap(128, 128, Bitmap.Config.ARGB_8888))
        nameEditText.setText(currentFolderName)

        // Define an array of matrix cursor column names.
        val matrixCursorColumnNames = arrayOf(ID, BOOKMARK_NAME, PARENT_FOLDER_ID)

        // Create a matrix cursor.
        val matrixCursor = MatrixCursor(matrixCursorColumnNames)

        // Add `Home Folder` to the matrix cursor.
        matrixCursor.addRow(arrayOf(HOME_FOLDER_DATABASE_ID, getString(R.string.home_folder), HOME_FOLDER_ID))

        // Create a list of folder IDs.
        val currentAndSubfolderIds = mutableListOf<Long>()

        // Add the current folder ID to the list.
        currentAndSubfolderIds.add(currentFolderIdLong)

        // Get a long array of all the subfolders IDs.
        val subfolderIdLongList = getListOfSubfolderIds(currentFolderIdLong, bookmarksDatabaseHelper)

        // Add the subfolder IDs to the list.
        for (subfolderId in subfolderIdLongList)
            currentAndSubfolderIds.add(subfolderId)

        // Get a cursor with the list of all the folders except for those specified..
        val foldersCursor = bookmarksDatabaseHelper.getFoldersExcept(currentAndSubfolderIds)

        // Combine the matrix cursor and the folders cursor.
        val combinedFoldersCursor = MergeCursor(arrayOf(matrixCursor, foldersCursor))

        // Create a resource cursor adapter for the spinner.
        val foldersCursorAdapter: ResourceCursorAdapter = object: ResourceCursorAdapter(context, R.layout.databaseview_spinner_item, combinedFoldersCursor, 0) {
            override fun bindView(view: View, context: Context, cursor: Cursor) {
                // Get handles for the spinner views.
                val subfolderSpacerTextView = view.findViewById<TextView>(R.id.subfolder_spacer_textview)
                val folderIconImageView = view.findViewById<ImageView>(R.id.folder_icon_imageview)
                val folderNameTextView = view.findViewById<TextView>(R.id.folder_name_textview)

                // Populate the subfolder spacer if it is not null (the spinner is open).
                if (subfolderSpacerTextView != null) {
                    // Indent subfolders.
                    if (cursor.getLong(cursor.getColumnIndexOrThrow(PARENT_FOLDER_ID)) != HOME_FOLDER_ID) {  // The folder is not in the home folder.
                        // Get the subfolder spacer.
                        subfolderSpacerTextView.text = bookmarksDatabaseHelper.getSubfolderSpacer(cursor.getLong(cursor.getColumnIndexOrThrow(FOLDER_ID)))
                    } else {  // The folder is in the home folder.
                        // Reset the subfolder spacer.
                        subfolderSpacerTextView.text = ""
                    }
                }

                // Set the folder icon according to the type.
                if (combinedFoldersCursor.position == 0) {  // Set the `Home Folder` icon.
                    // Set the gray folder image.  `ContextCompat` must be used until the minimum API >= 21.
                    folderIconImageView.setImageDrawable(ContextCompat.getDrawable(context, R.drawable.folder_gray))
                } else {  // Set a user folder icon.
                    // Get the folder icon byte array.
                    val folderIconByteArray = cursor.getBlob(cursor.getColumnIndexOrThrow(FAVORITE_ICON))

                    // Convert the byte array to a bitmap beginning at the first byte and ending at the last.
                    val folderIconBitmap = BitmapFactory.decodeByteArray(folderIconByteArray, 0, folderIconByteArray.size)

                    // Set the folder icon.
                    folderIconImageView.setImageBitmap(folderIconBitmap)
                }

                // Set the folder name.
                folderNameTextView.text = cursor.getString(cursor.getColumnIndexOrThrow(BOOKMARK_NAME))
            }
        }

        // Set the folders cursor adapter drop drown view resource.
        foldersCursorAdapter.setDropDownViewResource(R.layout.databaseview_spinner_dropdown_items)

        // Set the parent folder spinner adapter.
        parentFolderSpinner.adapter = foldersCursorAdapter

        // Select the current folder in the spinner if the bookmark isn't in the home folder.
        if (currentParentFolderIdLong != HOME_FOLDER_ID) {
            // Get the database ID of the parent folder as a long.
            val parentFolderDatabaseIdLong = bookmarksDatabaseHelper.getFolderDatabaseId(currentParentFolderIdLong).toLong()

            // Initialize the parent folder position and the iteration variable.
            var parentFolderPosition = 0
            var i = 0

            // Find the parent folder position in the folders cursor adapter.
            do {
                if (foldersCursorAdapter.getItemId(i) == parentFolderDatabaseIdLong) {
                    // Store the current position for the parent folder.
                    parentFolderPosition = i
                } else {
                    // Try the next entry.
                    i++
                }
                // Stop when the parent folder position is found or all the items in the folders cursor adapter have been checked.
            } while (parentFolderPosition == 0 && i < foldersCursorAdapter.count)

            // Select the parent folder in the spinner.
            parentFolderSpinner.setSelection(parentFolderPosition)
        }

        // Store the current folder database ID.
        currentParentFolderDatabaseIdInt = parentFolderSpinner.selectedItemId.toInt()

        // Populate the display order edit text.
        displayOrderEditText.setText(folderCursor.getInt(folderCursor.getColumnIndexOrThrow(DISPLAY_ORDER)).toString())

        // Set the radio button listeners.  These perform a click on the linear layout, which contains the necessary logic.
        currentIconRadioButton.setOnClickListener { currentIconLinearLayout.performClick() }
        defaultFolderIconRadioButton.setOnClickListener { defaultFolderIconLinearLayout.performClick() }
        webpageFavoriteIconRadioButton.setOnClickListener { webpageFavoriteIconLinearLayout.performClick() }
        customIconRadioButton.setOnClickListener { customIconLinearLayout.performClick() }

        // Set the current icon linear layout click listener.
        currentIconLinearLayout.setOnClickListener {
            // Check the current icon radio button.
            currentIconRadioButton.isChecked = true

            // Uncheck the other radio buttons.
            defaultFolderIconRadioButton.isChecked = false
            webpageFavoriteIconRadioButton.isChecked = false
            customIconRadioButton.isChecked = false

            // Update the save button.
            updateSaveButton()
        }

        // Set the default icon linear layout click listener.
        defaultFolderIconLinearLayout.setOnClickListener {
            // Check the default icon radio button.
            defaultFolderIconRadioButton.isChecked = true

            // Uncheck the other radio buttons.
            currentIconRadioButton.isChecked = false
            webpageFavoriteIconRadioButton.isChecked = false
            customIconRadioButton.isChecked = false

            // Update the save button.
            updateSaveButton()
        }

        // Set the webpage favorite icon linear layout click listener.
        webpageFavoriteIconLinearLayout.setOnClickListener {
            // Check the webpage favorite icon radio button.
            webpageFavoriteIconRadioButton.isChecked = true

            // Uncheck the other radio buttons.
            currentIconRadioButton.isChecked = false
            defaultFolderIconRadioButton.isChecked = false
            customIconRadioButton.isChecked = false

            // Update the save button.
            updateSaveButton()
        }

        // Set the custom icon linear layout click listener.
        customIconLinearLayout.setOnClickListener {
            // Check the current icon radio button.
            customIconRadioButton.isChecked = true

            // Uncheck the other radio buttons.
            currentIconRadioButton.isChecked = false
            defaultFolderIconRadioButton.isChecked = false
            webpageFavoriteIconRadioButton.isChecked = false

            // Update the save button.
            updateSaveButton()
        }

        browseButton.setOnClickListener {
            // Open the file picker.
            browseActivityResultLauncher.launch("image/*")
        }

        // Update the save button if the bookmark name changes.
        nameEditText.addTextChangedListener(object: TextWatcher {
            override fun beforeTextChanged(charSequence: CharSequence?, start: Int, count: Int, after: Int) {
                // Do nothing.
            }

            override fun onTextChanged(charSequence: CharSequence?, start: Int, before: Int, count: Int) {
                // Do nothing.
            }

            override fun afterTextChanged(editable: Editable?) {
                // Update the save button.
                updateSaveButton()
            }
        })

        // Wait to set the on item selected listener until the spinner has been inflated.  Otherwise the dialog will crash on restart.
        parentFolderSpinner.post {
            // Update the save button if the parent folder changes.
            parentFolderSpinner.onItemSelectedListener = object: AdapterView.OnItemSelectedListener {
                override fun onItemSelected(parent: AdapterView<*>, view: View, position: Int, id: Long) {
                    // Update the save button.
                    updateSaveButton()
                }

                override fun onNothingSelected(parent: AdapterView<*>) {
                    // Do nothing.
                }
            }
        }

        // Update the save button if the display order changes.
        displayOrderEditText.addTextChangedListener(object: TextWatcher {
            override fun beforeTextChanged(charSequence: CharSequence?, start: Int, count: Int, after: Int) {
                // Do nothing.
            }

            override fun onTextChanged(charSequence: CharSequence?, start: Int, before: Int, count: Int) {
                // Do nothing.
            }

            override fun afterTextChanged(editable: Editable?) {
                // Update the save button.
                updateSaveButton()
            }
        })

        // Allow the enter key on the keyboard to save the bookmark from the bookmark name edit text.
        nameEditText.setOnKeyListener { _: View?, keyCode: Int, event: KeyEvent ->
            // Check the key code, event, and button status.
            if (event.action == KeyEvent.ACTION_DOWN && keyCode == KeyEvent.KEYCODE_ENTER && saveButton.isEnabled) {  // The enter key was pressed and the save button is enabled.
                // Trigger the listener and return the dialog fragment to the parent activity.
                editBookmarkFolderDatabaseViewListener.saveBookmarkFolder(this, folderDatabaseId)

                // Manually dismiss the alert dialog.
                alertDialog.dismiss()

                // Consume the event.
                return@setOnKeyListener true
            } else {  // If any other key was pressed, or if the save button is currently disabled, do not consume the event.
                return@setOnKeyListener false
            }
        }

        // Allow the enter key on the keyboard to save the bookmark from the display order edit text.
        displayOrderEditText.setOnKeyListener { _: View?, keyCode: Int, event: KeyEvent ->
            // Check the key code, event, and button status.
            if (event.action == KeyEvent.ACTION_DOWN && keyCode == KeyEvent.KEYCODE_ENTER && saveButton.isEnabled) {  // The enter key was pressed and the save button is enabled.
                // Trigger the listener and return the dialog fragment to the parent activity.
                editBookmarkFolderDatabaseViewListener.saveBookmarkFolder(this, folderDatabaseId)

                // Manually dismiss the alert dialog.
                alertDialog.dismiss()

                // Consume the event.
                return@setOnKeyListener true
            } else { // If any other key was pressed, or if the save button is currently disabled, do not consume the event.
                return@setOnKeyListener false
            }
        }

        // Initially disable the edit button.
        saveButton.isEnabled = false

        // Return the alert dialog.
        return alertDialog
    }

    private fun updateSaveButton() {
        // Get the values from the views.
        val newFolderName = nameEditText.text.toString()
        val newParentFolderDatabaseIdInt = parentFolderSpinner.selectedItemId.toInt()
        val newDisplayOrder = displayOrderEditText.text.toString()

        // Has the favorite icon changed?
        val iconChanged = !currentIconRadioButton.isChecked

        // Has the folder been renamed?
        val folderRenamed = (newFolderName != currentFolderName)

        // Has the parent folder changed?
        val parentFolderChanged = (newParentFolderDatabaseIdInt != currentParentFolderDatabaseIdInt)

        // Has the display order changed?
        val displayOrderChanged = (newDisplayOrder != currentDisplayOrder.toString())

        // Update the enabled status of the edit button.
        saveButton.isEnabled = (iconChanged || folderRenamed || parentFolderChanged || displayOrderChanged) && newFolderName.isNotBlank() && newDisplayOrder.isNotBlank()
    }

    private fun getListOfSubfolderIds(folderId: Long, bookmarksDatabaseHelper: BookmarksDatabaseHelper): List<Long> {
        // Create a subfolder long list.
        val subfolderIdLongList = mutableListOf<Long>()

        // Get a cursor with all the immediate subfolders.
        val subfoldersCursor = bookmarksDatabaseHelper.getSubfolderNamesAndFolderIds(folderId)

        // Populate the subfolder list.
        for (i in 0 until subfoldersCursor.count) {
            // Move the subfolder cursor to the current item.
            subfoldersCursor.moveToPosition(i)

            // Get the subfolder ID.
            val subfolderId = subfoldersCursor.getLong(subfoldersCursor.getColumnIndexOrThrow(FOLDER_ID))

            // Add the folder ID to the list.
            subfolderIdLongList.add(subfolderId)

            // Get a list of any subfolders of the subfolder.
            val nestedSubfolderIdList = getListOfSubfolderIds(subfolderId, bookmarksDatabaseHelper)

            // Add each of the subfolder IDs to the list.
            for (nestedSubfolderId in nestedSubfolderIdList)
                subfolderIdLongList.add(nestedSubfolderId)
        }

        // Return the list of subfolder IDs.
        return subfolderIdLongList
    }
}