packages/flutter/lib/src/cupertino/form_section.dart - external/github.com/flutter/flutter - Git at Google

 // Copyright 2014 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/widgets.dart';

 import 'colors.dart';

 // Standard header margin, determined from SwiftUI's Forms in iOS 14.2 SDK.
 const EdgeInsetsDirectional _kDefaultHeaderMargin =
     EdgeInsetsDirectional.fromSTEB(20.0, 16.0, 20.0, 10.0);

 // Standard footer margin, determined from SwiftUI's Forms in iOS 14.2 SDK.
 const EdgeInsetsDirectional _kDefaultFooterMargin =
     EdgeInsetsDirectional.fromSTEB(20.0, 0.0, 20.0, 10.0);

 // Used for iOS "Inset Grouped" margin, determined from SwiftUI's Forms in
 // iOS 14.2 SDK.
 const EdgeInsetsDirectional _kDefaultInsetGroupedRowsMargin =
     EdgeInsetsDirectional.fromSTEB(20.0, 0.0, 20.0, 10.0);

 // Used for iOS "Inset Grouped" border radius, estimated from SwiftUI's Forms in
 // iOS 14.2 SDK.
 // TODO(edrisian): This should be a rounded rectangle once that shape is added.
 const BorderRadius _kDefaultInsetGroupedBorderRadius =
     BorderRadius.all(Radius.circular(10.0));

 // Used to differentiate the edge-to-edge section with the centered section.
 enum _CupertinoFormSectionType { base, insetGrouped }

 /// An iOS-style form section.
 ///
 /// The base constructor for [CupertinoFormSection] constructs an
 /// edge-to-edge style section which includes an iOS-style header, rows,
 /// the dividers between rows, and borders on top and bottom of the rows.
 ///
 /// The [CupertinoFormSection.insetGrouped] constructor creates a round-edged and
 /// padded section that is commonly seen in notched-displays like iPhone X and
 /// beyond. Creates an iOS-style header, rows, and the dividers
 /// between rows. Does not create borders on top and bottom of the rows.
 ///
 /// The [header] parameter sets the form section header. The section header lies
 /// above the [children] rows, with margins that match the iOS style.
 ///
 /// The [footer] parameter sets the form section footer. The section footer
 /// lies below the [children] rows.
 ///
 /// The [children] parameter is required and sets the list of rows shown in
 /// the section. The [children] parameter takes a list, as opposed to a more
 /// efficient builder function that lazy builds, because forms are intended to
 /// be short in row count. It is recommended that only [CupertinoFormRow] and
 /// [CupertinoTextFormFieldRow] widgets be included in the [children] list in
 /// order to retain the iOS look.
 ///
 /// The [margin] parameter sets the spacing around the content area of the
 /// section encapsulating [children].
 ///
 /// The [decoration] parameter sets the decoration around [children].
 /// If null, defaults to [CupertinoColors.secondarySystemGroupedBackground].
 /// If null, defaults to 10.0 circular radius when constructing with
 /// [CupertinoFormSection.insetGrouped]. Defaults to zero radius for the
 /// standard [CupertinoFormSection] constructor.
 ///
 /// The [backgroundColor] parameter sets the background color behind the section.
 /// If null, defaults to [CupertinoColors.systemGroupedBackground].
 ///
 /// {@macro flutter.material.Material.clipBehavior}
 class CupertinoFormSection extends StatelessWidget {
   /// Creates a section that mimics standard iOS forms.
   ///
   /// The base constructor for [CupertinoFormSection] constructs an
   /// edge-to-edge style section which includes an iOS-style header,
   /// rows, the dividers between rows, and borders on top and bottom of the rows.
   ///
   /// The [header] parameter sets the form section header. The section header
   /// lies above the [children] rows, with margins that match the iOS style.
   ///
   /// The [footer] parameter sets the form section footer. The section footer
   /// lies below the [children] rows.
   ///
   /// The [children] parameter is required and sets the list of rows shown in
   /// the section. The [children] parameter takes a list, as opposed to a more
   /// efficient builder function that lazy builds, because forms are intended to
   /// be short in row count. It is recommended that only [CupertinoFormRow] and
   /// [CupertinoTextFormFieldRow] widgets be included in the [children] list in
   /// order to retain the iOS look.
   ///
   /// The [margin] parameter sets the spacing around the content area of the
   /// section encapsulating [children], and defaults to zero padding.
   ///
   /// The [decoration] parameter sets the decoration around [children].
   /// If null, defaults to [CupertinoColors.secondarySystemGroupedBackground].
   /// If null, defaults to 10.0 circular radius when constructing with
   /// [CupertinoFormSection.insetGrouped]. Defaults to zero radius for the
   /// standard [CupertinoFormSection] constructor.
   ///
   /// The [backgroundColor] parameter sets the background color behind the
   /// section. If null, defaults to [CupertinoColors.systemGroupedBackground].
   ///
   /// {@macro flutter.material.Material.clipBehavior}
   const CupertinoFormSection({
     Key? key,
     required this.children,
     this.header,
     this.footer,
     this.margin = EdgeInsets.zero,
     this.backgroundColor = CupertinoColors.systemGroupedBackground,
     this.decoration,
     this.clipBehavior = Clip.none,
   })  : _type = _CupertinoFormSectionType.base,
         assert(children.length > 0),
         super(key: key);

   /// Creates a section that mimics standard "Inset Grouped" iOS forms.
   ///
   /// The [CupertinoFormSection.insetGrouped] constructor creates a round-edged and
   /// padded section that is commonly seen in notched-displays like iPhone X and
   /// beyond. Creates an iOS-style header, rows, and the dividers
   /// between rows. Does not create borders on top and bottom of the rows.
   ///
   /// The [header] parameter sets the form section header. The section header
   /// lies above the [children] rows, with margins that match the iOS style.
   ///
   /// The [footer] parameter sets the form section footer. The section footer
   /// lies below the [children] rows.
   ///
   /// The [children] parameter is required and sets the list of rows shown in
   /// the section. The [children] parameter takes a list, as opposed to a more
   /// efficient builder function that lazy builds, because forms are intended to
   /// be short in row count. It is recommended that only [CupertinoFormRow] and
   /// [CupertinoTextFormFieldRow] widgets be included in the [children] list in
   /// order to retain the iOS look.
   ///
   /// The [margin] parameter sets the spacing around the content area of the
   /// section encapsulating [children], and defaults to the standard
   /// notched-style iOS form padding.
   ///
   /// The [decoration] parameter sets the decoration around [children].
   /// If null, defaults to [CupertinoColors.secondarySystemGroupedBackground].
   /// If null, defaults to 10.0 circular radius when constructing with
   /// [CupertinoFormSection.insetGrouped]. Defaults to zero radius for the
   /// standard [CupertinoFormSection] constructor.
   ///
   /// The [backgroundColor] parameter sets the background color behind the
   /// section. If null, defaults to [CupertinoColors.systemGroupedBackground].
   ///
   /// {@macro flutter.material.Material.clipBehavior}
   const CupertinoFormSection.insetGrouped({
     Key? key,
     required this.children,
     this.header,
     this.footer,
     this.margin = _kDefaultInsetGroupedRowsMargin,
     this.backgroundColor = CupertinoColors.systemGroupedBackground,
     this.decoration,
     this.clipBehavior = Clip.none,
   })  : _type = _CupertinoFormSectionType.insetGrouped,
         assert(children.length > 0),
         super(key: key);

   final _CupertinoFormSectionType _type;

   /// Sets the form section header. The section header lies above the
   /// [children] rows.
   final Widget? header;

   /// Sets the form section footer. The section footer lies below the
   /// [children] rows.
   final Widget? footer;

   /// Margin around the content area of the section encapsulating [children].
   ///
   /// Defaults to zero padding if constructed with standard
   /// [CupertinoFormSection] constructor. Defaults to the standard notched-style
   /// iOS margin when constructing with [CupertinoFormSection.insetGrouped].
   final EdgeInsetsGeometry margin;

   /// The list of rows in the section.
   ///
   /// This takes a list, as opposed to a more efficient builder function that
   /// lazy builds, because forms are intended to be short in row count. It is
   /// recommended that only [CupertinoFormRow] and [CupertinoTextFormFieldRow]
   /// widgets be included in the [children] list in order to retain the iOS look.
   final List<Widget> children;

   /// Sets the decoration around [children].
   ///
   /// If null, background color defaults to
   /// [CupertinoColors.secondarySystemGroupedBackground].
   ///
   /// If null, border radius defaults to 10.0 circular radius when constructing
   /// with [CupertinoFormSection.insetGrouped]. Defaults to zero radius for the
   /// standard [CupertinoFormSection] constructor.
   final BoxDecoration? decoration;

   /// Sets the background color behind the section.
   ///
   /// Defaults to [CupertinoColors.systemGroupedBackground].
   final Color backgroundColor;

   /// {@macro flutter.material.Material.clipBehavior}
   ///
   /// Defaults to [Clip.none], and must not be null.
   final Clip clipBehavior;

   @override
   Widget build(BuildContext context) {
     final Color dividerColor = CupertinoColors.separator.resolveFrom(context);
     final double dividerHeight = 1.0 / MediaQuery.of(context).devicePixelRatio;

     // Long divider is used for wrapping the top and bottom of rows.
     // Only used in _CupertinoFormSectionType.base mode
     final Widget longDivider = Container(
       color: dividerColor,
       height: dividerHeight,
     );

     // Short divider is used between rows.
     // The value of the starting inset (15.0) is determined using SwiftUI's Form
     // separators in the iOS 14.2 SDK.
     final Widget shortDivider = Container(
       margin: const EdgeInsetsDirectional.only(start: 15.0),
       color: dividerColor,
       height: dividerHeight,
     );

     // We construct childrenWithDividers as follows:
     // Insert a short divider between all rows.
     // If it is a `_CupertinoFormSectionType.base` type, add a long divider
     // to the top and bottom of the rows.
     assert(children.isNotEmpty);

     final List<Widget> childrenWithDividers = <Widget>[];

     if (_type == _CupertinoFormSectionType.base) {
       childrenWithDividers.add(longDivider);
     }

     children.sublist(0, children.length - 1).forEach((Widget widget) {
       childrenWithDividers.add(widget);
       childrenWithDividers.add(shortDivider);
     });

     childrenWithDividers.add(children.last);
     if (_type == _CupertinoFormSectionType.base) {
       childrenWithDividers.add(longDivider);
     }

     final BorderRadius childrenGroupBorderRadius;
     switch (_type) {
       case _CupertinoFormSectionType.insetGrouped:
         childrenGroupBorderRadius = _kDefaultInsetGroupedBorderRadius;
         break;
       case _CupertinoFormSectionType.base:
         childrenGroupBorderRadius = BorderRadius.zero;
         break;
     }

     // Refactored the decorate children group in one place to avoid repeating it
     // twice down bellow in the returned widget.
     final DecoratedBox decoratedChildrenGroup = DecoratedBox(
       decoration: decoration ?? BoxDecoration(
         color: CupertinoDynamicColor.resolve(
           decoration?.color ?? CupertinoColors.secondarySystemGroupedBackground,
           context,
         ),
         borderRadius: childrenGroupBorderRadius,
       ),
       child: Column(
         children: childrenWithDividers,
       ),
     );

     return DecoratedBox(
       decoration: BoxDecoration(
         color: CupertinoDynamicColor.resolve(backgroundColor, context),
       ),
       child: Column(
         children: <Widget>[
           if (header != null)
             Align(
               alignment: AlignmentDirectional.centerStart,
               child: DefaultTextStyle(
                 style: TextStyle(
                   fontSize: 13.0,
                   color: CupertinoColors.secondaryLabel.resolveFrom(context),
                 ),
                 child: Padding(
                   padding: _kDefaultHeaderMargin,
                   child: header,
                 ),
               ),
             ),
           Padding(
             padding: margin,
             child: clipBehavior == Clip.none
               ? decoratedChildrenGroup
               : ClipRRect(
                   borderRadius: childrenGroupBorderRadius,
                   clipBehavior: clipBehavior,
                   child: decoratedChildrenGroup,
                 ),
           ),
           if (footer != null)
             Align(
               alignment: AlignmentDirectional.centerStart,
               child: DefaultTextStyle(
                 style: TextStyle(
                   fontSize: 13.0,
                   color: CupertinoColors.secondaryLabel.resolveFrom(context),
                 ),
                 child: Padding(
                   padding: _kDefaultFooterMargin,
                   child: footer,
                 ),
               ),
             ),
         ],
       ),
     );
   }
 }
	// Copyright 2014 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/widgets.dart';

	import 'colors.dart';

	// Standard header margin, determined from SwiftUI's Forms in iOS 14.2 SDK.
	const EdgeInsetsDirectional _kDefaultHeaderMargin =
	EdgeInsetsDirectional.fromSTEB(20.0, 16.0, 20.0, 10.0);

	// Standard footer margin, determined from SwiftUI's Forms in iOS 14.2 SDK.
	const EdgeInsetsDirectional _kDefaultFooterMargin =
	EdgeInsetsDirectional.fromSTEB(20.0, 0.0, 20.0, 10.0);

	// Used for iOS "Inset Grouped" margin, determined from SwiftUI's Forms in
	// iOS 14.2 SDK.
	const EdgeInsetsDirectional _kDefaultInsetGroupedRowsMargin =
	EdgeInsetsDirectional.fromSTEB(20.0, 0.0, 20.0, 10.0);

	// Used for iOS "Inset Grouped" border radius, estimated from SwiftUI's Forms in
	// iOS 14.2 SDK.
	// TODO(edrisian): This should be a rounded rectangle once that shape is added.
	const BorderRadius _kDefaultInsetGroupedBorderRadius =
	BorderRadius.all(Radius.circular(10.0));

	// Used to differentiate the edge-to-edge section with the centered section.
	enum _CupertinoFormSectionType { base, insetGrouped }

	/// An iOS-style form section.
	///
	/// The base constructor for [CupertinoFormSection] constructs an
	/// edge-to-edge style section which includes an iOS-style header, rows,
	/// the dividers between rows, and borders on top and bottom of the rows.
	///
	/// The [CupertinoFormSection.insetGrouped] constructor creates a round-edged and
	/// padded section that is commonly seen in notched-displays like iPhone X and
	/// beyond. Creates an iOS-style header, rows, and the dividers
	/// between rows. Does not create borders on top and bottom of the rows.
	///
	/// The [header] parameter sets the form section header. The section header lies
	/// above the [children] rows, with margins that match the iOS style.
	///
	/// The [footer] parameter sets the form section footer. The section footer
	/// lies below the [children] rows.
	///
	/// The [children] parameter is required and sets the list of rows shown in
	/// the section. The [children] parameter takes a list, as opposed to a more
	/// efficient builder function that lazy builds, because forms are intended to
	/// be short in row count. It is recommended that only [CupertinoFormRow] and
	/// [CupertinoTextFormFieldRow] widgets be included in the [children] list in
	/// order to retain the iOS look.
	///
	/// The [margin] parameter sets the spacing around the content area of the
	/// section encapsulating [children].
	///
	/// The [decoration] parameter sets the decoration around [children].
	/// If null, defaults to [CupertinoColors.secondarySystemGroupedBackground].
	/// If null, defaults to 10.0 circular radius when constructing with
	/// [CupertinoFormSection.insetGrouped]. Defaults to zero radius for the
	/// standard [CupertinoFormSection] constructor.
	///
	/// The [backgroundColor] parameter sets the background color behind the section.
	/// If null, defaults to [CupertinoColors.systemGroupedBackground].
	///
	/// {@macro flutter.material.Material.clipBehavior}
	class CupertinoFormSection extends StatelessWidget {
	/// Creates a section that mimics standard iOS forms.
	///
	/// The base constructor for [CupertinoFormSection] constructs an
	/// edge-to-edge style section which includes an iOS-style header,
	/// rows, the dividers between rows, and borders on top and bottom of the rows.
	///
	/// The [header] parameter sets the form section header. The section header
	/// lies above the [children] rows, with margins that match the iOS style.
	///
	/// The [footer] parameter sets the form section footer. The section footer
	/// lies below the [children] rows.
	///
	/// The [children] parameter is required and sets the list of rows shown in
	/// the section. The [children] parameter takes a list, as opposed to a more
	/// efficient builder function that lazy builds, because forms are intended to
	/// be short in row count. It is recommended that only [CupertinoFormRow] and
	/// [CupertinoTextFormFieldRow] widgets be included in the [children] list in
	/// order to retain the iOS look.
	///
	/// The [margin] parameter sets the spacing around the content area of the
	/// section encapsulating [children], and defaults to zero padding.
	///
	/// The [decoration] parameter sets the decoration around [children].
	/// If null, defaults to [CupertinoColors.secondarySystemGroupedBackground].
	/// If null, defaults to 10.0 circular radius when constructing with
	/// [CupertinoFormSection.insetGrouped]. Defaults to zero radius for the
	/// standard [CupertinoFormSection] constructor.
	///
	/// The [backgroundColor] parameter sets the background color behind the
	/// section. If null, defaults to [CupertinoColors.systemGroupedBackground].
	///
	/// {@macro flutter.material.Material.clipBehavior}
	const CupertinoFormSection({
	Key? key,
	required this.children,
	this.header,
	this.footer,
	this.margin = EdgeInsets.zero,
	this.backgroundColor = CupertinoColors.systemGroupedBackground,
	this.decoration,
	this.clipBehavior = Clip.none,
	}) : _type = _CupertinoFormSectionType.base,
	assert(children.length > 0),
	super(key: key);

	/// Creates a section that mimics standard "Inset Grouped" iOS forms.
	///
	/// The [CupertinoFormSection.insetGrouped] constructor creates a round-edged and
	/// padded section that is commonly seen in notched-displays like iPhone X and
	/// beyond. Creates an iOS-style header, rows, and the dividers
	/// between rows. Does not create borders on top and bottom of the rows.
	///
	/// The [header] parameter sets the form section header. The section header
	/// lies above the [children] rows, with margins that match the iOS style.
	///
	/// The [footer] parameter sets the form section footer. The section footer
	/// lies below the [children] rows.
	///
	/// The [children] parameter is required and sets the list of rows shown in
	/// the section. The [children] parameter takes a list, as opposed to a more
	/// efficient builder function that lazy builds, because forms are intended to
	/// be short in row count. It is recommended that only [CupertinoFormRow] and
	/// [CupertinoTextFormFieldRow] widgets be included in the [children] list in
	/// order to retain the iOS look.
	///
	/// The [margin] parameter sets the spacing around the content area of the
	/// section encapsulating [children], and defaults to the standard
	/// notched-style iOS form padding.
	///
	/// The [decoration] parameter sets the decoration around [children].
	/// If null, defaults to [CupertinoColors.secondarySystemGroupedBackground].
	/// If null, defaults to 10.0 circular radius when constructing with
	/// [CupertinoFormSection.insetGrouped]. Defaults to zero radius for the
	/// standard [CupertinoFormSection] constructor.
	///
	/// The [backgroundColor] parameter sets the background color behind the
	/// section. If null, defaults to [CupertinoColors.systemGroupedBackground].
	///
	/// {@macro flutter.material.Material.clipBehavior}
	const CupertinoFormSection.insetGrouped({
	Key? key,
	required this.children,
	this.header,
	this.footer,
	this.margin = _kDefaultInsetGroupedRowsMargin,
	this.backgroundColor = CupertinoColors.systemGroupedBackground,
	this.decoration,
	this.clipBehavior = Clip.none,
	}) : _type = _CupertinoFormSectionType.insetGrouped,
	assert(children.length > 0),
	super(key: key);

	final _CupertinoFormSectionType _type;

	/// Sets the form section header. The section header lies above the
	/// [children] rows.
	final Widget? header;

	/// Sets the form section footer. The section footer lies below the
	/// [children] rows.
	final Widget? footer;

	/// Margin around the content area of the section encapsulating [children].
	///
	/// Defaults to zero padding if constructed with standard
	/// [CupertinoFormSection] constructor. Defaults to the standard notched-style
	/// iOS margin when constructing with [CupertinoFormSection.insetGrouped].
	final EdgeInsetsGeometry margin;

	/// The list of rows in the section.
	///
	/// This takes a list, as opposed to a more efficient builder function that
	/// lazy builds, because forms are intended to be short in row count. It is
	/// recommended that only [CupertinoFormRow] and [CupertinoTextFormFieldRow]
	/// widgets be included in the [children] list in order to retain the iOS look.
	final List<Widget> children;

	/// Sets the decoration around [children].
	///
	/// If null, background color defaults to
	/// [CupertinoColors.secondarySystemGroupedBackground].
	///
	/// If null, border radius defaults to 10.0 circular radius when constructing
	/// with [CupertinoFormSection.insetGrouped]. Defaults to zero radius for the
	/// standard [CupertinoFormSection] constructor.
	final BoxDecoration? decoration;

	/// Sets the background color behind the section.
	///
	/// Defaults to [CupertinoColors.systemGroupedBackground].
	final Color backgroundColor;

	/// {@macro flutter.material.Material.clipBehavior}
	///
	/// Defaults to [Clip.none], and must not be null.
	final Clip clipBehavior;

	@override
	Widget build(BuildContext context) {
	final Color dividerColor = CupertinoColors.separator.resolveFrom(context);
	final double dividerHeight = 1.0 / MediaQuery.of(context).devicePixelRatio;

	// Long divider is used for wrapping the top and bottom of rows.
	// Only used in _CupertinoFormSectionType.base mode
	final Widget longDivider = Container(
	color: dividerColor,
	height: dividerHeight,
	);

	// Short divider is used between rows.
	// The value of the starting inset (15.0) is determined using SwiftUI's Form
	// separators in the iOS 14.2 SDK.
	final Widget shortDivider = Container(
	margin: const EdgeInsetsDirectional.only(start: 15.0),
	color: dividerColor,
	height: dividerHeight,
	);

	// We construct childrenWithDividers as follows:
	// Insert a short divider between all rows.
	// If it is a `_CupertinoFormSectionType.base` type, add a long divider
	// to the top and bottom of the rows.
	assert(children.isNotEmpty);

	final List<Widget> childrenWithDividers = <Widget>[];

	if (_type == _CupertinoFormSectionType.base) {
	childrenWithDividers.add(longDivider);
	}

	children.sublist(0, children.length - 1).forEach((Widget widget) {
	childrenWithDividers.add(widget);
	childrenWithDividers.add(shortDivider);
	});

	childrenWithDividers.add(children.last);
	if (_type == _CupertinoFormSectionType.base) {
	childrenWithDividers.add(longDivider);
	}

	final BorderRadius childrenGroupBorderRadius;
	switch (_type) {
	case _CupertinoFormSectionType.insetGrouped:
	childrenGroupBorderRadius = _kDefaultInsetGroupedBorderRadius;
	break;
	case _CupertinoFormSectionType.base:
	childrenGroupBorderRadius = BorderRadius.zero;
	break;
	}

	// Refactored the decorate children group in one place to avoid repeating it
	// twice down bellow in the returned widget.
	final DecoratedBox decoratedChildrenGroup = DecoratedBox(
	decoration: decoration ?? BoxDecoration(
	color: CupertinoDynamicColor.resolve(
	decoration?.color ?? CupertinoColors.secondarySystemGroupedBackground,
	context,
	),
	borderRadius: childrenGroupBorderRadius,
	),
	child: Column(
	children: childrenWithDividers,
	),
	);

	return DecoratedBox(
	decoration: BoxDecoration(
	color: CupertinoDynamicColor.resolve(backgroundColor, context),
	),
	child: Column(
	children: <Widget>[
	if (header != null)
	Align(
	alignment: AlignmentDirectional.centerStart,
	child: DefaultTextStyle(
	style: TextStyle(
	fontSize: 13.0,
	color: CupertinoColors.secondaryLabel.resolveFrom(context),
	),
	child: Padding(
	padding: _kDefaultHeaderMargin,
	child: header,
	),
	),
	),
	Padding(
	padding: margin,
	child: clipBehavior == Clip.none
	? decoratedChildrenGroup
	: ClipRRect(
	borderRadius: childrenGroupBorderRadius,
	clipBehavior: clipBehavior,
	child: decoratedChildrenGroup,
	),
	),
	if (footer != null)
	Align(
	alignment: AlignmentDirectional.centerStart,
	child: DefaultTextStyle(
	style: TextStyle(
	fontSize: 13.0,
	color: CupertinoColors.secondaryLabel.resolveFrom(context),
	),
	child: Padding(
	padding: _kDefaultFooterMargin,
	child: footer,
	),
	),
	),
	],
	),
	);
	}
	}