dashboard/lib/widgets/filter_property_sheet.dart - mirrors/cocoon - Git at Google

 // Copyright 2020 The Flutter 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:flutter/foundation.dart';
 import 'package:flutter/material.dart';

 /// Bridge between the [FilterPropertySheet] and a filter object that has a number of
 /// properties by which it filters lists. The [sheetLayout] provides both the properties
 /// to be displayed and edited and also a suggestion for their layout.
 abstract class FilterPropertySource extends Listenable {
   /// The list of properties exposed by the filter for editing.
   List<FilterPropertyNode> get sheetLayout;
 }

 /// The base class for all elements in a [FilterPropertySheet]. Most of the nodes will
 /// be value properties, but some may be layout nodes.
 ///
 /// @see [ValueFilterProperty], [FilterPropertyGroup]
 abstract class FilterPropertyNode {
   /// The descriptive name of the property or layout group as will be displayed
   /// in the [FilterPropertySheet].
   String? get label;
 }

 /// The abstract base class of all valued properties, useful for both displaying them
 /// in and editing them from a [FilterPropertySheet] and methods to make them useful
 /// as the actual storage for the properties in a filter object. A filter object then
 /// becomes mostly a list of these properties along with methods to combine them into
 /// predicates for filtering data in a dashboard or other list.
 ///
 /// @see [RegExpFilterProperty], [BoolFilterProperty]
 abstract class ValueFilterProperty<T> extends ValueListenable<T> with FilterPropertyNode {
   ValueFilterProperty({required this.fieldName, this.label});

   /// The name of the field represented by this property, used to import and export
   /// the property values via maps.
   final String fieldName;

   @override
   final String? label;

   /// The value of the property converted to a [String] useful for importing and
   /// exporting the values via maps and JSON files.
   String get stringValue;
   set stringValue(String newValue);

   /// Whether the property is set to its default value.
   bool get isDefault;

   /// Resets this property to its default value;
   void reset();

   List<VoidCallback>? _listeners;

   @override
   void addListener(VoidCallback listener) {
     _listeners ??= <VoidCallback>[];
     _listeners!.add(listener);
   }

   @override
   void removeListener(VoidCallback listener) {
     _listeners?.remove(listener);
   }

   /// Notify all listeners that the value of the property has changed.
   void notifyListeners() {
     if (_listeners != null) {
       for (final VoidCallback listener in _listeners!) {
         listener();
       }
     }
   }
 }

 /// A class used to represent a Regular Expression property in the filter object.
 class RegExpFilterProperty extends ValueFilterProperty<String?> {
   RegExpFilterProperty({required super.fieldName, super.label, String? value, bool caseSensitive = true})
       : _value = value,
         _caseSensitive = caseSensitive;

   String? _value;
   final bool _caseSensitive;
   @override
   String? get value => _value;
   set value(String? newValue) {
     if (newValue == '') {
       newValue = null;
     }
     if (_value != newValue) {
       _value = newValue;
       _regExp = null;
       notifyListeners();
     }
     newValue ??= '';
     if (_controller != null && _controller!.text != newValue) {
       _controller!.text = newValue;
       // The listener callback should nop
     }
   }

   TextEditingController? _controller;
   TextEditingController? get controller {
     if (_controller == null) {
       _controller = TextEditingController(text: stringValue);
       _controller!.addListener(() {
         value = _controller!.text;
       });
     }
     return _controller;
   }

   @override
   String get stringValue => _value ?? '';

   @override
   set stringValue(String newValue) => value = newValue;

   @override
   bool get isDefault => _value == null;

   @override
   void reset() => value = null;

   /// The value of this property as a [RegExp] object, useful for matching its pattern
   /// against candidate values in the list being filtered.
   RegExp? _regExp;
   RegExp? get regExp => _regExp ??= _value == null ? null : RegExp(_value!, caseSensitive: _caseSensitive);
   set regExp(RegExp? newRegExp) => value = newRegExp == null || newRegExp.pattern == '' ? null : newRegExp.pattern;

   /// True iff the value, interpreted as a regular expression, matches the candidate [String].
   bool matches(String candidate) => regExp?.hasMatch(candidate) ?? true;
 }

 /// A class used to represent a boolean property in the filter object.
 class BoolFilterProperty extends ValueFilterProperty<bool?> {
   BoolFilterProperty({required super.fieldName, super.label, bool value = true})
       : _value = value,
         _defaultValue = value;

   bool? _value;
   final bool? _defaultValue;

   @override
   bool? get value => _value;
   set value(bool? newValue) {
     if (_value != newValue) {
       _value = newValue;
       notifyListeners();
     }
   }

   @override
   String get stringValue => _value.toString();

   @override
   set stringValue(String newValue) {
     if (newValue == 'true' || newValue == 't') {
       value = true;
     } else if (newValue == 'false' || newValue == 'f') {
       value = false;
     } else {
       throw 'Unrecognized bool value: $newValue';
     }
   }

   @override
   bool get isDefault => value == _defaultValue;

   @override
   void reset() => value = _defaultValue;
 }

 /// A class used to enclose a group of other [BoolFilterProperty] properties to be
 /// presented in a more compact format in the property sheet.
 class BoolFilterPropertyGroup extends FilterPropertyNode {
   BoolFilterPropertyGroup({this.label, this.members});

   @override
   final String? label;

   /// The boolean property members of this group.
   final List<BoolFilterProperty>? members;
 }

 /// A [Widget] used to display the values of the properties of a filter object and to allow
 /// a user to edit those properties. The changes are recorded in new filter objects using the
 /// [FilterPropertySource.copyWithMap] method and communicated back to the app live via
 /// modifying the value of the [filterNotifier].
 ///
 /// If an optional [onClose] callback is supplied, this sheet will include its own close control
 /// and notify the creator when it is closed via the callback. Otherwise the creator is
 /// responsible for the lifecycle of this sheet.
 class FilterPropertySheet extends StatefulWidget {
   const FilterPropertySheet(this.propertySource, {this.onClose, super.key});

   /// The notifier object used to get the initial value of the filter properties and to
   /// send back new filter objects with modified values as the user edits the fields.
   final FilterPropertySource? propertySource;

   /// The optional callback for when the close field on the sheet is used to close the
   /// sheet. This [Widget] will only implement its own close box if this callback is non-null.
   final Function()? onClose;

   @override
   State createState() => FilterPropertySheetState();
 }

 class FilterPropertySheetState extends State<FilterPropertySheet> {
   @override
   void initState() {
     super.initState();

     widget.propertySource!.addListener(_update);
   }

   @override
   void dispose() {
     widget.propertySource!.removeListener(_update);

     super.dispose();
   }

   static const TextStyle _labelStyle = TextStyle(
     fontSize: 16.0,
     fontWeight: FontWeight.normal,
     fontStyle: FontStyle.normal,
     decoration: TextDecoration.none,
   );

   void _update() {
     setState(() {});
   }

   Widget _pad(Widget child, Alignment alignment) {
     return Container(
       padding: const EdgeInsets.all(5.0),
       alignment: alignment,
       child: child,
     );
   }

   TableRow _makeRow(String label, Widget editable) {
     return TableRow(
       children: <Widget>[
         _pad(Text(label, style: _labelStyle), Alignment.centerRight),
         _pad(editable, Alignment.centerLeft),
       ],
     );
   }

   TableRow _makeTextFilterRow(RegExpFilterProperty property) {
     return _makeRow(
       property.label!,
       TextField(
         autofocus: true,
         controller: property.controller,
         decoration: const InputDecoration(
           hintText: '(JavaScript regular expression)',
         ),
         onChanged: (String value) => property.value = value,
       ),
     );
   }

   TableRow _makeBoolRow(BoolFilterProperty property) {
     return _makeRow(
       property.label!,
       Checkbox(
         value: property.value,
         onChanged: (bool? newValue) => property.value = newValue,
       ),
     );
   }

   Widget _makeLoneCheckbox(BoolFilterProperty property) {
     return Row(
       mainAxisSize: MainAxisSize.min,
       children: <Widget>[
         Text(property.label!, style: _labelStyle),
         Checkbox(
           value: property.value,
           onChanged: (bool? newValue) => property.value = newValue,
         ),
       ],
     );
   }

   TableRow _makeTableRow(FilterPropertyNode property) {
     if (property is RegExpFilterProperty) {
       return _makeTextFilterRow(property);
     }
     if (property is BoolFilterProperty) {
       return _makeBoolRow(property);
     }
     if (property is BoolFilterPropertyGroup) {
       return _makeRow(
         property.label!,
         Wrap(
           children: property.members!.map<Widget>(_makeLoneCheckbox).toList(),
         ),
       );
     }
     throw 'unrecognized FilterProperty: $property';
   }

   @override
   Widget build(BuildContext context) {
     return Stack(
       children: <Widget>[
         if (widget.onClose != null)
           Positioned(
             child: TextButton(
               onPressed: widget.onClose,
               child: const Icon(Icons.close),
             ),
           ),
         Table(
           defaultVerticalAlignment: TableCellVerticalAlignment.middle,
           columnWidths: const <int, TableColumnWidth>{
             0: IntrinsicColumnWidth(),
             1: FixedColumnWidth(300.0),
           },
           children: widget.propertySource!.sheetLayout.map(_makeTableRow).toList(),
         ),
       ],
     );
   }
 }
	// Copyright 2020 The Flutter 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:flutter/foundation.dart';
	import 'package:flutter/material.dart';

	/// Bridge between the [FilterPropertySheet] and a filter object that has a number of
	/// properties by which it filters lists. The [sheetLayout] provides both the properties
	/// to be displayed and edited and also a suggestion for their layout.
	abstract class FilterPropertySource extends Listenable {
	/// The list of properties exposed by the filter for editing.
	List<FilterPropertyNode> get sheetLayout;
	}

	/// The base class for all elements in a [FilterPropertySheet]. Most of the nodes will
	/// be value properties, but some may be layout nodes.
	///
	/// @see [ValueFilterProperty], [FilterPropertyGroup]
	abstract class FilterPropertyNode {
	/// The descriptive name of the property or layout group as will be displayed
	/// in the [FilterPropertySheet].
	String? get label;
	}

	/// The abstract base class of all valued properties, useful for both displaying them
	/// in and editing them from a [FilterPropertySheet] and methods to make them useful
	/// as the actual storage for the properties in a filter object. A filter object then
	/// becomes mostly a list of these properties along with methods to combine them into
	/// predicates for filtering data in a dashboard or other list.
	///
	/// @see [RegExpFilterProperty], [BoolFilterProperty]
	abstract class ValueFilterProperty<T> extends ValueListenable<T> with FilterPropertyNode {
	ValueFilterProperty({required this.fieldName, this.label});

	/// The name of the field represented by this property, used to import and export
	/// the property values via maps.
	final String fieldName;

	@override
	final String? label;

	/// The value of the property converted to a [String] useful for importing and
	/// exporting the values via maps and JSON files.
	String get stringValue;
	set stringValue(String newValue);

	/// Whether the property is set to its default value.
	bool get isDefault;

	/// Resets this property to its default value;
	void reset();

	List<VoidCallback>? _listeners;

	@override
	void addListener(VoidCallback listener) {
	_listeners ??= <VoidCallback>[];
	_listeners!.add(listener);
	}

	@override
	void removeListener(VoidCallback listener) {
	_listeners?.remove(listener);
	}

	/// Notify all listeners that the value of the property has changed.
	void notifyListeners() {
	if (_listeners != null) {
	for (final VoidCallback listener in _listeners!) {
	listener();
	}
	}
	}
	}

	/// A class used to represent a Regular Expression property in the filter object.
	class RegExpFilterProperty extends ValueFilterProperty<String?> {
	RegExpFilterProperty({required super.fieldName, super.label, String? value, bool caseSensitive = true})
	: _value = value,
	_caseSensitive = caseSensitive;

	String? _value;
	final bool _caseSensitive;
	@override
	String? get value => _value;
	set value(String? newValue) {
	if (newValue == '') {
	newValue = null;
	}
	if (_value != newValue) {
	_value = newValue;
	_regExp = null;
	notifyListeners();
	}
	newValue ??= '';
	if (_controller != null && _controller!.text != newValue) {
	_controller!.text = newValue;
	// The listener callback should nop
	}
	}

	TextEditingController? _controller;
	TextEditingController? get controller {
	if (_controller == null) {
	_controller = TextEditingController(text: stringValue);
	_controller!.addListener(() {
	value = _controller!.text;
	});
	}
	return _controller;
	}

	@override
	String get stringValue => _value ?? '';

	@override
	set stringValue(String newValue) => value = newValue;

	@override
	bool get isDefault => _value == null;

	@override
	void reset() => value = null;

	/// The value of this property as a [RegExp] object, useful for matching its pattern
	/// against candidate values in the list being filtered.
	RegExp? _regExp;
	RegExp? get regExp => _regExp ??= _value == null ? null : RegExp(_value!, caseSensitive: _caseSensitive);
	set regExp(RegExp? newRegExp) => value = newRegExp == null \|\| newRegExp.pattern == '' ? null : newRegExp.pattern;

	/// True iff the value, interpreted as a regular expression, matches the candidate [String].
	bool matches(String candidate) => regExp?.hasMatch(candidate) ?? true;
	}

	/// A class used to represent a boolean property in the filter object.
	class BoolFilterProperty extends ValueFilterProperty<bool?> {
	BoolFilterProperty({required super.fieldName, super.label, bool value = true})
	: _value = value,
	_defaultValue = value;

	bool? _value;
	final bool? _defaultValue;

	@override
	bool? get value => _value;
	set value(bool? newValue) {
	if (_value != newValue) {
	_value = newValue;
	notifyListeners();
	}
	}

	@override
	String get stringValue => _value.toString();

	@override
	set stringValue(String newValue) {
	if (newValue == 'true' \|\| newValue == 't') {
	value = true;
	} else if (newValue == 'false' \|\| newValue == 'f') {
	value = false;
	} else {
	throw 'Unrecognized bool value: $newValue';
	}
	}

	@override
	bool get isDefault => value == _defaultValue;

	@override
	void reset() => value = _defaultValue;
	}

	/// A class used to enclose a group of other [BoolFilterProperty] properties to be
	/// presented in a more compact format in the property sheet.
	class BoolFilterPropertyGroup extends FilterPropertyNode {
	BoolFilterPropertyGroup({this.label, this.members});

	@override
	final String? label;

	/// The boolean property members of this group.
	final List<BoolFilterProperty>? members;
	}

	/// A [Widget] used to display the values of the properties of a filter object and to allow
	/// a user to edit those properties. The changes are recorded in new filter objects using the
	/// [FilterPropertySource.copyWithMap] method and communicated back to the app live via
	/// modifying the value of the [filterNotifier].
	///
	/// If an optional [onClose] callback is supplied, this sheet will include its own close control
	/// and notify the creator when it is closed via the callback. Otherwise the creator is
	/// responsible for the lifecycle of this sheet.
	class FilterPropertySheet extends StatefulWidget {
	const FilterPropertySheet(this.propertySource, {this.onClose, super.key});

	/// The notifier object used to get the initial value of the filter properties and to
	/// send back new filter objects with modified values as the user edits the fields.
	final FilterPropertySource? propertySource;

	/// The optional callback for when the close field on the sheet is used to close the
	/// sheet. This [Widget] will only implement its own close box if this callback is non-null.
	final Function()? onClose;

	@override
	State createState() => FilterPropertySheetState();
	}

	class FilterPropertySheetState extends State<FilterPropertySheet> {
	@override
	void initState() {
	super.initState();

	widget.propertySource!.addListener(_update);
	}

	@override
	void dispose() {
	widget.propertySource!.removeListener(_update);

	super.dispose();
	}

	static const TextStyle _labelStyle = TextStyle(
	fontSize: 16.0,
	fontWeight: FontWeight.normal,
	fontStyle: FontStyle.normal,
	decoration: TextDecoration.none,
	);

	void _update() {
	setState(() {});
	}

	Widget _pad(Widget child, Alignment alignment) {
	return Container(
	padding: const EdgeInsets.all(5.0),
	alignment: alignment,
	child: child,
	);
	}

	TableRow _makeRow(String label, Widget editable) {
	return TableRow(
	children: <Widget>[
	_pad(Text(label, style: _labelStyle), Alignment.centerRight),
	_pad(editable, Alignment.centerLeft),
	],
	);
	}

	TableRow _makeTextFilterRow(RegExpFilterProperty property) {
	return _makeRow(
	property.label!,
	TextField(
	autofocus: true,
	controller: property.controller,
	decoration: const InputDecoration(
	hintText: '(JavaScript regular expression)',
	),
	onChanged: (String value) => property.value = value,
	),
	);
	}

	TableRow _makeBoolRow(BoolFilterProperty property) {
	return _makeRow(
	property.label!,
	Checkbox(
	value: property.value,
	onChanged: (bool? newValue) => property.value = newValue,
	),
	);
	}

	Widget _makeLoneCheckbox(BoolFilterProperty property) {
	return Row(
	mainAxisSize: MainAxisSize.min,
	children: <Widget>[
	Text(property.label!, style: _labelStyle),
	Checkbox(
	value: property.value,
	onChanged: (bool? newValue) => property.value = newValue,
	),
	],
	);
	}

	TableRow _makeTableRow(FilterPropertyNode property) {
	if (property is RegExpFilterProperty) {
	return _makeTextFilterRow(property);
	}
	if (property is BoolFilterProperty) {
	return _makeBoolRow(property);
	}
	if (property is BoolFilterPropertyGroup) {
	return _makeRow(
	property.label!,
	Wrap(
	children: property.members!.map<Widget>(_makeLoneCheckbox).toList(),
	),
	);
	}
	throw 'unrecognized FilterProperty: $property';
	}

	@override
	Widget build(BuildContext context) {
	return Stack(
	children: <Widget>[
	if (widget.onClose != null)
	Positioned(
	child: TextButton(
	onPressed: widget.onClose,
	child: const Icon(Icons.close),
	),
	),
	Table(
	defaultVerticalAlignment: TableCellVerticalAlignment.middle,
	columnWidths: const <int, TableColumnWidth>{
	0: IntrinsicColumnWidth(),
	1: FixedColumnWidth(300.0),
	},
	children: widget.propertySource!.sheetLayout.map(_makeTableRow).toList(),
	),
	],
	);
	}
	}