ente/lib/ui/backup_folder_selection_page.dart

import 'dart:ui';

import 'package:flutter/material.dart';
import 'package:implicitly_animated_reorderable_list/implicitly_animated_reorderable_list.dart';
import 'package:implicitly_animated_reorderable_list/transitions.dart';
import 'package:photos/core/configuration.dart';
import 'package:photos/core/event_bus.dart';
import 'package:photos/db/files_db.dart';
import 'package:photos/events/backup_folders_updated_event.dart';
import 'package:photos/models/file.dart';
import 'package:photos/ui/common_elements.dart';
import 'package:photos/ui/loading_widget.dart';
import 'package:photos/ui/thumbnail_widget.dart';

class BackupFolderSelectionPage extends StatefulWidget {
  final bool shouldSelectAll;
  final String buttonText;

  const BackupFolderSelectionPage({
    @required this.buttonText,
    this.shouldSelectAll = false,
    Key key,
  }) : super(key: key);

  @override
  _BackupFolderSelectionPageState createState() =>
      _BackupFolderSelectionPageState();
}

class _BackupFolderSelectionPageState extends State<BackupFolderSelectionPage> {
  final Set<String> _allFolders = Set<String>();
  Set<String> _selectedFolders = Set<String>();
  List<File> _latestFiles;

  @override
  void initState() {
    _selectedFolders = Configuration.instance.getPathsToBackUp();
    FilesDB.instance.getLatestLocalFiles().then((files) {
      setState(() {
        _latestFiles = files;
        for (final file in _latestFiles) {
          _allFolders.add(file.deviceFolder);
        }
        if (widget.shouldSelectAll) {
          _selectedFolders.addAll(_allFolders);
        }
      });
    });
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("select folders to backup")),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          Padding(
            padding: EdgeInsets.all(12),
          ),
          Padding(
            padding: const EdgeInsets.only(left: 32, right: 32),
            child: Text(
              "the selected folders will be end-to-end encrypted and backed up",
              style: TextStyle(
                color: Colors.white.withOpacity(0.36),
                fontSize: 14,
                height: 1.3,
              ),
              textAlign: TextAlign.center,
            ),
          ),
          Padding(
            padding: EdgeInsets.all(6),
          ),
          GestureDetector(
              behavior: HitTestBehavior.translucent,
              child: Padding(
                padding: const EdgeInsets.fromLTRB(6, 6, 64, 6),
                child: Align(
                  alignment: Alignment.centerRight,
                  child: Text(
                    _selectedFolders.length == _allFolders.length
                        ? "unselect all"
                        : "select all",
                    textAlign: TextAlign.right,
                    style: TextStyle(
                      fontSize: 12,
                      color: Colors.white.withOpacity(0.8),
                    ),
                  ),
                ),
              ),
              onTap: () {
                final hasSelectedAll =
                    _selectedFolders.length == _allFolders.length;
                // Flip selection
                if (hasSelectedAll) {
                  _selectedFolders.clear();
                } else {
                  _selectedFolders.addAll(_allFolders);
                }
                _latestFiles.sort((first, second) {
                  return first.deviceFolder.compareTo(second.deviceFolder);
                });
                setState(() {});
              }),
          Expanded(child: _getFolders()),
          Padding(
            padding: EdgeInsets.all(20),
          ),
          Hero(
            tag: "select_folders",
            child: Container(
              padding: EdgeInsets.only(left: 60, right: 60, bottom: 32),
              child: button(
                widget.buttonText,
                fontSize: 18,
                onPressed: _selectedFolders.length == 0
                    ? null
                    : () async {
                        await Configuration.instance
                            .setPathsToBackUp(_selectedFolders);
                        Bus.instance.fire(BackupFoldersUpdatedEvent());
                        Navigator.of(context).pop();
                      },
                padding: EdgeInsets.fromLTRB(60, 20, 60, 20),
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _getFolderList() {
    Widget child;
    if (_latestFiles != null) {
      final foldersWidget = _getFolders();
      final scrollController = ScrollController();
      child = Scrollbar(
        isAlwaysShown: true,
        controller: scrollController,
        child: SingleChildScrollView(
          controller: scrollController,
          child: Container(
            padding: EdgeInsets.only(right: 4),
            child: foldersWidget,
          ),
        ),
      );
    } else {
      child = loadWidget;
    }
    return Container(
      padding: EdgeInsets.only(left: 40, right: 40),
      child: child,
    );
  }

  Widget _getFolders() {
    if (_latestFiles == null) {
      return Container();
    }
    _sortFiles();
    final scrollController = ScrollController();
    return Container(
      padding: EdgeInsets.only(left: 40, right: 40),
      child: Scrollbar(
        controller: scrollController,
        isAlwaysShown: true,
        child: Padding(
          padding: const EdgeInsets.only(right: 4),
          child: ImplicitlyAnimatedReorderableList<File>(
            controller: scrollController,
            items: _latestFiles,
            areItemsTheSame: (oldItem, newItem) =>
                oldItem.deviceFolder == newItem.deviceFolder,
            onReorderFinished: (item, from, to, newItems) {
              setState(() {
                _latestFiles
                  ..clear()
                  ..addAll(newItems);
              });
            },
            itemBuilder: (context, itemAnimation, file, index) {
              return Reorderable(
                key: ValueKey(file),
                builder: (context, dragAnimation, inDrag) {
                  final t = dragAnimation.value;
                  final elevation = lerpDouble(0, 8, t);
                  final color = Color.lerp(
                      Colors.white, Colors.white.withOpacity(0.8), t);
                  return SizeFadeTransition(
                    sizeFraction: 0.7,
                    curve: Curves.easeInOut,
                    animation: itemAnimation,
                    child: Material(
                      color: color,
                      elevation: elevation,
                      type: MaterialType.transparency,
                      child: _getFileItem(file),
                    ),
                  );
                },
              );
            },
          ),
        ),
      ),
    );
  }

  Padding _getFileItem(File file) {
    final isSelected = _selectedFolders.contains(file.deviceFolder);
    return Padding(
      padding: const EdgeInsets.only(bottom: 1, right: 4),
      child: Container(
        decoration: BoxDecoration(
          border: Border.all(
            color: Colors.black,
          ),
          borderRadius: BorderRadius.all(
            Radius.circular(10),
          ),
          color: isSelected
              ? Color.fromRGBO(16, 32, 32, 1)
              : Color.fromRGBO(8, 18, 18, 0.4),
        ),
        padding: EdgeInsets.fromLTRB(20, 16, 20, 16),
        child: InkWell(
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Container(
                child: Expanded(
                  child: Row(
                    children: [
                      _getThumbnail(file),
                      Padding(padding: EdgeInsets.all(10)),
                      Expanded(
                        child: Text(
                          file.deviceFolder,
                          style: TextStyle(fontSize: 16, height: 1.5),
                          overflow: TextOverflow.clip,
                        ),
                      ),
                    ],
                  ),
                ),
              ),
              Checkbox(
                value: isSelected,
                onChanged: (value) {
                  if (value) {
                    _selectedFolders.add(file.deviceFolder);
                  } else {
                    _selectedFolders.remove(file.deviceFolder);
                  }
                  setState(() {});
                },
              ),
            ],
          ),
          onTap: () {
            final value = !_selectedFolders.contains(file.deviceFolder);
            if (value) {
              _selectedFolders.add(file.deviceFolder);
            } else {
              _selectedFolders.remove(file.deviceFolder);
            }
            setState(() {});
          },
        ),
      ),
    );
  }

  void _sortFiles() {
    _latestFiles.sort((first, second) {
      if (_selectedFolders.contains(first) &&
          _selectedFolders.contains(second)) {
        return first.deviceFolder.compareTo(second.deviceFolder);
      } else if (_selectedFolders.contains(first.deviceFolder)) {
        return -1;
      } else if (_selectedFolders.contains(second.deviceFolder)) {
        return 1;
      }
      return first.deviceFolder.compareTo(second.deviceFolder);
    });
  }

  Widget _getThumbnail(File file) {
    return ClipRRect(
      borderRadius: BorderRadius.circular(4.0),
      child: Container(
        child: ThumbnailWidget(
          file,
          shouldShowSyncStatus: false,
          key: Key("backup_selection_widget" + file.tag()),
        ),
        height: 60,
        width: 60,
      ),
    );
  }
}