session_shells/ermine/utils/lib/src/dialogs/dialogs.dart

// Copyright 2021 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// TODO(http://fxbug.dev/107480): Resolve lint issues and reenable analysis for file
// ignore_for_file: deprecated_member_use

import 'package:ermine_utils/ermine_utils.dart';
import 'package:flutter/material.dart';
import 'package:mobx/mobx.dart';

/// Displays dialogs sequentially.
class Dialogs extends StatelessWidget {
  /// List of [DialogInfo] to show dialogs sequenctially one after another.
  final List<DialogInfo> dialogs;

  /// Callback when the last dialog has been dismissed.
  final VoidCallback? onClose;

  const Dialogs(this.dialogs, {this.onClose});

  @override
  Widget build(BuildContext context) {
    // Display queued up dialogs if none are being displayed currently.
    if (!Navigator.canPop(context)) {
      WidgetsBinding.instance.addPostFrameCallback((_) {
        _showAllDialogs(context);
      });
    }
    return Offstage();
  }

  // Shows all dialogs sequentially.
  void _showAllDialogs(BuildContext context, [int index = 0]) async {
    if (index >= dialogs.length) {
      runInAction(() {
        dialogs.clear();
        onClose?.call();
      });
      return;
    }
    final _formState = GlobalKey<FormState>();
    bool validate() => _formState.currentState?.validate() ?? false;

    final dialog = dialogs[index];
    final result = await showDialog<String?>(
        context: context,
        builder: (context) {
          return LayoutBuilder(builder: (context, constraints) {
            final screenWidth = constraints.maxWidth;
            final sideMargin = dialog.width != null
                ? ((screenWidth - dialog.width!) / 2)
                    .clamp(40.0, screenWidth)
                    .toDouble()
                : 240.0;
            return Form(
              key: _formState,
              child: AlertDialog(
                title: _titleFromDialogInfo(dialog),
                content: _contentFromDialogInfo(dialog),
                actions: [
                  for (final label in dialog.actions)
                    if (label == dialog.defaultAction)
                      ElevatedButton(
                        autofocus: dialog is AlertDialogInfo,
                        child: Text(label.toUpperCase()),
                        onPressed: () {
                          if (validate()) {
                            _formState.currentState?.save();
                            Navigator.pop(context, label);
                          }
                        },
                      )
                    else
                      OutlinedButton(
                        child: Text(label.toUpperCase()),
                        onPressed: () => Navigator.pop(context, label),
                      )
                ],
                insetPadding: EdgeInsets.symmetric(horizontal: sideMargin),
                titlePadding: EdgeInsets.fromLTRB(40, 40, 40, 24),
                contentPadding: EdgeInsets.fromLTRB(40, 0, 40, 24),
                actionsPadding: EdgeInsets.only(right: 40, bottom: 24),
                titleTextStyle: Theme.of(context).textTheme.headline5,
              ),
            );
          });
        });
    if (result != null) {
      dialog.onAction?.call(result);
    }
    dialog.onClose?.call();

    _showAllDialogs(context, index + 1);
  }

  Widget? _titleFromDialogInfo(DialogInfo info) {
    switch (info.runtimeType) {
      case AlertDialogInfo:
      case CheckboxDialogInfo:
        if (info.title == null) return null;
        return Text(info.title!);
      default:
        return null;
    }
  }

  Widget? _contentFromDialogInfo(DialogInfo info) {
    switch (info.runtimeType) {
      case AlertDialogInfo:
        final dialog = info as AlertDialogInfo;
        return dialog.body != null ? Text(dialog.body!) : null;
      case CheckboxDialogInfo:
        final dialog = info as CheckboxDialogInfo;
        return CheckboxPrompt(dialog);
      case PasswordDialogInfo:
        final dialog = info as PasswordDialogInfo;
        return PasswordPrompt(dialog);
      default:
        return null;
    }
  }
}