sky/sdk/lib/widgets/dialog.dart

// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:sky/theme/colors.dart' as colors;
import 'package:sky/widgets/basic.dart';
import 'package:sky/widgets/default_text_style.dart';
import 'package:sky/widgets/material.dart';
import 'package:sky/widgets/scrollable_viewport.dart';
import 'package:sky/widgets/theme.dart';

/// A material design dialog
///
/// <https://www.google.com/design/spec/components/dialogs.html>
class Dialog extends Component {
  Dialog({
    String key,
    this.title,
    this.content,
    this.actions,
    this.onDismiss
  }) : super(key: key);

  /// The (optional) title of the dialog is displayed in a large font at the top
  /// of the dialog.
  final Widget title;

  /// The (optional) content of the dialog is displayed in the center of the
  /// dialog in a lighter font.
  final Widget content;

  /// The (optional) set of actions that are displayed at the bottom of the
  /// dialog.
  final List<Widget> actions;

  /// An (optional) callback that is called when the dialog is dismissed.
  final Function onDismiss;

  Color get _color {
    switch (Theme.of(this).brightness) {
      case ThemeBrightness.light:
        return colors.white;
      case ThemeBrightness.dark:
        return colors.Grey[800];
    }
  }

  Widget build() {
    Container mask = new Container(
      decoration: const BoxDecoration(
        backgroundColor: const Color(0x7F000000)));

    List<Widget> children = new List<Widget>();

    if (title != null) {
      children.add(new Padding(
        padding: new EdgeDims(24.0, 24.0, content == null ? 20.0 : 0.0, 24.0),
        child: new DefaultTextStyle(
          style: Theme.of(this).text.title,
          child: title
        )
      ));
    }

    if (content != null) {
      children.add(new Padding(
        padding: const EdgeDims(20.0, 24.0, 24.0, 24.0),
        child: new DefaultTextStyle(
          style: Theme.of(this).text.subhead,
          child: content
        )
      ));
    }

    if (actions != null)
      children.add(new Flex(actions, justifyContent: FlexJustifyContent.end));

    return new Stack([
      new Listener(
        child: mask,
        onGestureTap: (_) => onDismiss()
      ),
      new Center(
        child: new Container(
          margin: new EdgeDims.symmetric(horizontal: 40.0, vertical: 24.0),
          child: new ConstrainedBox(
            constraints: new BoxConstraints(minWidth: 280.0),
            child: new Material(
              level: 4,
              color: _color,
              child: new ShrinkWrapWidth(
                child: new ScrollableBlock(children)
              )
            )
          )
        )
      )
    ]);
  }
}