blob: 7d54c354fa06d886b2219c363ae9bb488e74f473 [file] [log] [blame]
// 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 'dart:math' as math;
import 'package:flutter/foundation.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';
import 'checkbox.dart';
import 'colors.dart';
import 'constants.dart';
import 'debug.dart';
import 'divider.dart';
import 'dropdown.dart';
import 'icons.dart';
import 'ink_well.dart';
import 'material.dart';
import 'theme.dart';
import 'theme_data.dart';
import 'tooltip.dart';
/// Signature for [DataColumn.onSort] callback.
typedef DataColumnSortCallback = void Function(int columnIndex, bool ascending);
/// Column configuration for a [DataTable].
///
/// One column configuration must be provided for each column to
/// display in the table. The list of [DataColumn] objects is passed
/// as the `columns` argument to the [new DataTable] constructor.
@immutable
class DataColumn {
/// Creates the configuration for a column of a [DataTable].
///
/// The [label] argument must not be null.
const DataColumn({
@required this.label,
this.tooltip,
this.numeric = false,
this.onSort,
}) : assert(label != null);
/// The column heading.
///
/// Typically, this will be a [Text] widget. It could also be an
/// [Icon] (typically using size 18), or a [Row] with an icon and
/// some text.
///
/// By default, this widget will only occupy the minimal space. If you want
/// it to take the entire remaining space, e.g. when you want to use [Center],
/// you can wrap it with an [Expanded].
///
/// The label should not include the sort indicator.
final Widget label;
/// The column heading's tooltip.
///
/// This is a longer description of the column heading, for cases
/// where the heading might have been abbreviated to keep the column
/// width to a reasonable size.
final String tooltip;
/// Whether this column represents numeric data or not.
///
/// The contents of cells of columns containing numeric data are
/// right-aligned.
final bool numeric;
/// Called when the user asks to sort the table using this column.
///
/// If null, the column will not be considered sortable.
///
/// See [DataTable.sortColumnIndex] and [DataTable.sortAscending].
final DataColumnSortCallback onSort;
bool get _debugInteractive => onSort != null;
}
/// Row configuration and cell data for a [DataTable].
///
/// One row configuration must be provided for each row to
/// display in the table. The list of [DataRow] objects is passed
/// as the `rows` argument to the [new DataTable] constructor.
///
/// The data for this row of the table is provided in the [cells]
/// property of the [DataRow] object.
@immutable
class DataRow {
/// Creates the configuration for a row of a [DataTable].
///
/// The [cells] argument must not be null.
const DataRow({
this.key,
this.selected = false,
this.onSelectChanged,
@required this.cells,
}) : assert(cells != null);
/// Creates the configuration for a row of a [DataTable], deriving
/// the key from a row index.
///
/// The [cells] argument must not be null.
DataRow.byIndex({
int index,
this.selected = false,
this.onSelectChanged,
@required this.cells,
}) : assert(cells != null),
key = ValueKey<int>(index);
/// A [Key] that uniquely identifies this row. This is used to
/// ensure that if a row is added or removed, any stateful widgets
/// related to this row (e.g. an in-progress checkbox animation)
/// remain on the right row visually.
///
/// If the table never changes once created, no key is necessary.
final LocalKey key;
/// Called when the user selects or unselects a selectable row.
///
/// If this is not null, then the row is selectable. The current
/// selection state of the row is given by [selected].
///
/// If any row is selectable, then the table's heading row will have
/// a checkbox that can be checked to select all selectable rows
/// (and which is checked if all the rows are selected), and each
/// subsequent row will have a checkbox to toggle just that row.
///
/// A row whose [onSelectChanged] callback is null is ignored for
/// the purposes of determining the state of the "all" checkbox,
/// and its checkbox is disabled.
final ValueChanged<bool> onSelectChanged;
/// Whether the row is selected.
///
/// If [onSelectChanged] is non-null for any row in the table, then
/// a checkbox is shown at the start of each row. If the row is
/// selected (true), the checkbox will be checked and the row will
/// be highlighted.
///
/// Otherwise, the checkbox, if present, will not be checked.
final bool selected;
/// The data for this row.
///
/// There must be exactly as many cells as there are columns in the
/// table.
final List<DataCell> cells;
bool get _debugInteractive => onSelectChanged != null || cells.any((DataCell cell) => cell._debugInteractive);
}
/// The data for a cell of a [DataTable].
///
/// One list of [DataCell] objects must be provided for each [DataRow]
/// in the [DataTable], in the [new DataRow] constructor's `cells`
/// argument.
@immutable
class DataCell {
/// Creates an object to hold the data for a cell in a [DataTable].
///
/// The first argument is the widget to show for the cell, typically
/// a [Text] or [DropdownButton] widget; this becomes the [child]
/// property and must not be null.
///
/// If the cell has no data, then a [Text] widget with placeholder
/// text should be provided instead, and then the [placeholder]
/// argument should be set to true.
const DataCell(
this.child, {
this.placeholder = false,
this.showEditIcon = false,
this.onTap,
}) : assert(child != null);
/// A cell that has no content and has zero width and height.
static final DataCell empty = DataCell(Container(width: 0.0, height: 0.0));
/// The data for the row.
///
/// Typically a [Text] widget or a [DropdownButton] widget.
///
/// If the cell has no data, then a [Text] widget with placeholder
/// text should be provided instead, and [placeholder] should be set
/// to true.
///
/// {@macro flutter.widgets.child}
final Widget child;
/// Whether the [child] is actually a placeholder.
///
/// If this is true, the default text style for the cell is changed
/// to be appropriate for placeholder text.
final bool placeholder;
/// Whether to show an edit icon at the end of the cell.
///
/// This does not make the cell actually editable; the caller must
/// implement editing behavior if desired (initiated from the
/// [onTap] callback).
///
/// If this is set, [onTap] should also be set, otherwise tapping
/// the icon will have no effect.
final bool showEditIcon;
/// Called if the cell is tapped.
///
/// If non-null, tapping the cell will call this callback. If
/// null, tapping the cell will attempt to select the row (if
/// [DataRow.onSelectChanged] is provided).
final VoidCallback onTap;
bool get _debugInteractive => onTap != null;
}
/// A material design data table.
///
/// {@youtube 560 315 https://www.youtube.com/watch?v=ktTajqbhIcY}
///
/// Displaying data in a table is expensive, because to lay out the
/// table all the data must be measured twice, once to negotiate the
/// dimensions to use for each column, and once to actually lay out
/// the table given the results of the negotiation.
///
/// For this reason, if you have a lot of data (say, more than a dozen
/// rows with a dozen columns, though the precise limits depend on the
/// target device), it is suggested that you use a
/// [PaginatedDataTable] which automatically splits the data into
/// multiple pages.
///
/// {@tool dartpad --template=stateless_widget_scaffold}
///
/// This sample shows how to display a [DataTable] with three columns: name, age, and
/// role. The columns are defined by three [DataColumn] objects. The table
/// contains three rows of data for three example users, the data for which
/// is defined by three [DataRow] objects.
///
/// ![](https://flutter.github.io/assets-for-api-docs/assets/material/data_table.png)
///
/// ```dart
/// Widget build(BuildContext context) {
/// return DataTable(
/// columns: const <DataColumn>[
/// DataColumn(
/// label: Text(
/// 'Name',
/// style: TextStyle(fontStyle: FontStyle.italic),
/// ),
/// ),
/// DataColumn(
/// label: Text(
/// 'Age',
/// style: TextStyle(fontStyle: FontStyle.italic),
/// ),
/// ),
/// DataColumn(
/// label: Text(
/// 'Role',
/// style: TextStyle(fontStyle: FontStyle.italic),
/// ),
/// ),
/// ],
/// rows: const <DataRow>[
/// DataRow(
/// cells: <DataCell>[
/// DataCell(Text('Sarah')),
/// DataCell(Text('19')),
/// DataCell(Text('Student')),
/// ],
/// ),
/// DataRow(
/// cells: <DataCell>[
/// DataCell(Text('Janine')),
/// DataCell(Text('43')),
/// DataCell(Text('Professor')),
/// ],
/// ),
/// DataRow(
/// cells: <DataCell>[
/// DataCell(Text('William')),
/// DataCell(Text('27')),
/// DataCell(Text('Associate Professor')),
/// ],
/// ),
/// ],
/// );
/// }
/// ```
///
/// {@end-tool}
// TODO(ianh): Also suggest [ScrollingDataTable] once we have it.
///
/// See also:
///
/// * [DataColumn], which describes a column in the data table.
/// * [DataRow], which contains the data for a row in the data table.
/// * [DataCell], which contains the data for a single cell in the data table.
/// * [PaginatedDataTable], which shows part of the data in a data table and
/// provides controls for paging through the remainder of the data.
/// * <https://material.io/design/components/data-tables.html>
class DataTable extends StatelessWidget {
/// Creates a widget describing a data table.
///
/// The [columns] argument must be a list of as many [DataColumn]
/// objects as the table is to have columns, ignoring the leading
/// checkbox column if any. The [columns] argument must have a
/// length greater than zero and must not be null.
///
/// The [rows] argument must be a list of as many [DataRow] objects
/// as the table is to have rows, ignoring the leading heading row
/// that contains the column headings (derived from the [columns]
/// argument). There may be zero rows, but the rows argument must
/// not be null.
///
/// Each [DataRow] object in [rows] must have as many [DataCell]
/// objects in the [DataRow.cells] list as the table has columns.
///
/// If the table is sorted, the column that provides the current
/// primary key should be specified by index in [sortColumnIndex], 0
/// meaning the first column in [columns], 1 being the next one, and
/// so forth.
///
/// The actual sort order can be specified using [sortAscending]; if
/// the sort order is ascending, this should be true (the default),
/// otherwise it should be false.
DataTable({
Key key,
@required this.columns,
this.sortColumnIndex,
this.sortAscending = true,
this.onSelectAll,
this.dataRowHeight = kMinInteractiveDimension,
this.headingRowHeight = 56.0,
this.horizontalMargin = 24.0,
this.columnSpacing = 56.0,
this.showCheckboxColumn = true,
this.dividerThickness = 1.0,
@required this.rows,
}) : assert(columns != null),
assert(columns.isNotEmpty),
assert(sortColumnIndex == null || (sortColumnIndex >= 0 && sortColumnIndex < columns.length)),
assert(sortAscending != null),
assert(dataRowHeight != null),
assert(headingRowHeight != null),
assert(horizontalMargin != null),
assert(columnSpacing != null),
assert(showCheckboxColumn != null),
assert(rows != null),
assert(!rows.any((DataRow row) => row.cells.length != columns.length)),
assert(dividerThickness != null && dividerThickness >= 0),
_onlyTextColumn = _initOnlyTextColumn(columns),
super(key: key);
/// The configuration and labels for the columns in the table.
final List<DataColumn> columns;
/// The current primary sort key's column.
///
/// If non-null, indicates that the indicated column is the column
/// by which the data is sorted. The number must correspond to the
/// index of the relevant column in [columns].
///
/// Setting this will cause the relevant column to have a sort
/// indicator displayed.
///
/// When this is null, it implies that the table's sort order does
/// not correspond to any of the columns.
final int sortColumnIndex;
/// Whether the column mentioned in [sortColumnIndex], if any, is sorted
/// in ascending order.
///
/// If true, the order is ascending (meaning the rows with the
/// smallest values for the current sort column are first in the
/// table).
///
/// If false, the order is descending (meaning the rows with the
/// smallest values for the current sort column are last in the
/// table).
final bool sortAscending;
/// Invoked when the user selects or unselects every row, using the
/// checkbox in the heading row.
///
/// If this is null, then the [DataRow.onSelectChanged] callback of
/// every row in the table is invoked appropriately instead.
///
/// To control whether a particular row is selectable or not, see
/// [DataRow.onSelectChanged]. This callback is only relevant if any
/// row is selectable.
final ValueSetter<bool> onSelectAll;
/// The height of each row (excluding the row that contains column headings).
///
/// This value defaults to kMinInteractiveDimension to adhere to the Material
/// Design specifications.
final double dataRowHeight;
/// The height of the heading row.
///
/// This value defaults to 56.0 to adhere to the Material Design specifications.
final double headingRowHeight;
/// The horizontal margin between the edges of the table and the content
/// in the first and last cells of each row.
///
/// When a checkbox is displayed, it is also the margin between the checkbox
/// the content in the first data column.
///
/// This value defaults to 24.0 to adhere to the Material Design specifications.
final double horizontalMargin;
/// The horizontal margin between the contents of each data column.
///
/// This value defaults to 56.0 to adhere to the Material Design specifications.
final double columnSpacing;
/// {@template flutter.material.dataTable.showCheckboxColumn}
/// Whether the widget should display checkboxes for selectable rows.
///
/// If true, a [CheckBox] will be placed at the beginning of each row that is
/// selectable. However, if [DataRow.onSelectChanged] is not set for any row,
/// checkboxes will not be placed, even if this value is true.
///
/// If false, all rows will not display a [CheckBox].
/// {@endtemplate}
final bool showCheckboxColumn;
/// The data to show in each row (excluding the row that contains
/// the column headings).
///
/// Must be non-null, but may be empty.
final List<DataRow> rows;
// Set by the constructor to the index of the only Column that is
// non-numeric, if there is exactly one, otherwise null.
final int _onlyTextColumn;
static int _initOnlyTextColumn(List<DataColumn> columns) {
int result;
for (int index = 0; index < columns.length; index += 1) {
final DataColumn column = columns[index];
if (!column.numeric) {
if (result != null)
return null;
result = index;
}
}
return result;
}
bool get _debugInteractive {
return columns.any((DataColumn column) => column._debugInteractive)
|| rows.any((DataRow row) => row._debugInteractive);
}
static final LocalKey _headingRowKey = UniqueKey();
void _handleSelectAll(bool checked) {
if (onSelectAll != null) {
onSelectAll(checked);
} else {
for (final DataRow row in rows) {
if ((row.onSelectChanged != null) && (row.selected != checked))
row.onSelectChanged(checked);
}
}
}
static const double _sortArrowPadding = 2.0;
static const double _headingFontSize = 12.0;
static const Duration _sortArrowAnimationDuration = Duration(milliseconds: 150);
static const Color _grey100Opacity = Color(0x0A000000); // Grey 100 as opacity instead of solid color
static const Color _grey300Opacity = Color(0x1E000000); // Dark theme variant is just a guess.
/// The width of the divider that appears between [TableRow]s.
///
/// Must be non-null and greater than or equal to zero.
/// This value defaults to 1.0.
final double dividerThickness;
Widget _buildCheckbox({
Color color,
bool checked,
VoidCallback onRowTap,
ValueChanged<bool> onCheckboxChanged,
}) {
Widget contents = Semantics(
container: true,
child: Padding(
padding: EdgeInsetsDirectional.only(start: horizontalMargin, end: horizontalMargin / 2.0),
child: Center(
child: Checkbox(
activeColor: color,
value: checked,
onChanged: onCheckboxChanged,
),
),
),
);
if (onRowTap != null) {
contents = TableRowInkWell(
onTap: onRowTap,
child: contents,
);
}
return TableCell(
verticalAlignment: TableCellVerticalAlignment.fill,
child: contents,
);
}
Widget _buildHeadingCell({
BuildContext context,
EdgeInsetsGeometry padding,
Widget label,
String tooltip,
bool numeric,
VoidCallback onSort,
bool sorted,
bool ascending,
}) {
List<Widget> arrowWithPadding() {
return onSort == null ? const <Widget>[] : <Widget>[
_SortArrow(
visible: sorted,
down: sorted ? ascending : null,
duration: _sortArrowAnimationDuration,
),
const SizedBox(width: _sortArrowPadding),
];
}
label = Row(
textDirection: numeric ? TextDirection.rtl : null,
children: <Widget>[
label,
...arrowWithPadding(),
],
);
label = Container(
padding: padding,
height: headingRowHeight,
alignment: numeric ? Alignment.centerRight : AlignmentDirectional.centerStart,
child: AnimatedDefaultTextStyle(
style: TextStyle(
// TODO(ianh): font family should match Theme; see https://github.com/flutter/flutter/issues/3116
fontWeight: FontWeight.w500,
fontSize: _headingFontSize,
height: math.min(1.0, headingRowHeight / _headingFontSize),
color: (Theme.of(context).brightness == Brightness.light)
? ((onSort != null && sorted) ? Colors.black87 : Colors.black54)
: ((onSort != null && sorted) ? Colors.white : Colors.white70),
),
softWrap: false,
duration: _sortArrowAnimationDuration,
child: label,
),
);
if (tooltip != null) {
label = Tooltip(
message: tooltip,
child: label,
);
}
// TODO(dkwingsmt): Only wrap Inkwell if onSort != null. Blocked by
// https://github.com/flutter/flutter/issues/51152
label = InkWell(
onTap: onSort,
child: label,
);
return label;
}
Widget _buildDataCell({
BuildContext context,
EdgeInsetsGeometry padding,
Widget label,
bool numeric,
bool placeholder,
bool showEditIcon,
VoidCallback onTap,
VoidCallback onSelectChanged,
}) {
final bool isLightTheme = Theme.of(context).brightness == Brightness.light;
if (showEditIcon) {
const Widget icon = Icon(Icons.edit, size: 18.0);
label = Expanded(child: label);
label = Row(
textDirection: numeric ? TextDirection.rtl : null,
children: <Widget>[ label, icon ],
);
}
label = Container(
padding: padding,
height: dataRowHeight,
alignment: numeric ? Alignment.centerRight : AlignmentDirectional.centerStart,
child: DefaultTextStyle(
style: TextStyle(
// TODO(ianh): font family should be Roboto; see https://github.com/flutter/flutter/issues/3116
fontSize: 13.0,
color: isLightTheme
? (placeholder ? Colors.black38 : Colors.black87)
: (placeholder ? Colors.white38 : Colors.white70),
),
child: IconTheme.merge(
data: IconThemeData(
color: isLightTheme ? Colors.black54 : Colors.white70,
),
child: DropdownButtonHideUnderline(child: label),
),
),
);
if (onTap != null) {
label = InkWell(
onTap: onTap,
child: label,
);
} else if (onSelectChanged != null) {
label = TableRowInkWell(
onTap: onSelectChanged,
child: label,
);
}
return label;
}
@override
Widget build(BuildContext context) {
assert(!_debugInteractive || debugCheckHasMaterial(context));
final ThemeData theme = Theme.of(context);
final BoxDecoration _kSelectedDecoration = BoxDecoration(
border: Border(bottom: Divider.createBorderSide(context, width: dividerThickness)),
// The backgroundColor has to be transparent so you can see the ink on the material
color: (Theme.of(context).brightness == Brightness.light) ? _grey100Opacity : _grey300Opacity,
);
final BoxDecoration _kUnselectedDecoration = BoxDecoration(
border: Border(bottom: Divider.createBorderSide(context, width: dividerThickness)),
);
final bool displayCheckboxColumn = showCheckboxColumn && rows.any((DataRow row) => row.onSelectChanged != null);
final bool allChecked = displayCheckboxColumn && !rows.any((DataRow row) => row.onSelectChanged != null && !row.selected);
final List<TableColumnWidth> tableColumns = List<TableColumnWidth>(columns.length + (displayCheckboxColumn ? 1 : 0));
final List<TableRow> tableRows = List<TableRow>.generate(
rows.length + 1, // the +1 is for the header row
(int index) {
return TableRow(
key: index == 0 ? _headingRowKey : rows[index - 1].key,
decoration: index > 0 && rows[index - 1].selected ? _kSelectedDecoration
: _kUnselectedDecoration,
children: List<Widget>(tableColumns.length),
);
},
);
int rowIndex;
int displayColumnIndex = 0;
if (displayCheckboxColumn) {
tableColumns[0] = FixedColumnWidth(horizontalMargin + Checkbox.width + horizontalMargin / 2.0);
tableRows[0].children[0] = _buildCheckbox(
color: theme.accentColor,
checked: allChecked,
onCheckboxChanged: _handleSelectAll,
);
rowIndex = 1;
for (final DataRow row in rows) {
tableRows[rowIndex].children[0] = _buildCheckbox(
color: theme.accentColor,
checked: row.selected,
onRowTap: () => row.onSelectChanged != null ? row.onSelectChanged(!row.selected) : null ,
onCheckboxChanged: row.onSelectChanged,
);
rowIndex += 1;
}
displayColumnIndex += 1;
}
for (int dataColumnIndex = 0; dataColumnIndex < columns.length; dataColumnIndex += 1) {
final DataColumn column = columns[dataColumnIndex];
double paddingStart;
if (dataColumnIndex == 0 && displayCheckboxColumn) {
paddingStart = horizontalMargin / 2.0;
} else if (dataColumnIndex == 0 && !displayCheckboxColumn) {
paddingStart = horizontalMargin;
} else {
paddingStart = columnSpacing / 2.0;
}
double paddingEnd;
if (dataColumnIndex == columns.length - 1) {
paddingEnd = horizontalMargin;
} else {
paddingEnd = columnSpacing / 2.0;
}
final EdgeInsetsDirectional padding = EdgeInsetsDirectional.only(
start: paddingStart,
end: paddingEnd,
);
if (dataColumnIndex == _onlyTextColumn) {
tableColumns[displayColumnIndex] = const IntrinsicColumnWidth(flex: 1.0);
} else {
tableColumns[displayColumnIndex] = const IntrinsicColumnWidth();
}
tableRows[0].children[displayColumnIndex] = _buildHeadingCell(
context: context,
padding: padding,
label: column.label,
tooltip: column.tooltip,
numeric: column.numeric,
onSort: column.onSort != null ? () => column.onSort(dataColumnIndex, sortColumnIndex != dataColumnIndex || !sortAscending) : null,
sorted: dataColumnIndex == sortColumnIndex,
ascending: sortAscending,
);
rowIndex = 1;
for (final DataRow row in rows) {
final DataCell cell = row.cells[dataColumnIndex];
tableRows[rowIndex].children[displayColumnIndex] = _buildDataCell(
context: context,
padding: padding,
label: cell.child,
numeric: column.numeric,
placeholder: cell.placeholder,
showEditIcon: cell.showEditIcon,
onTap: cell.onTap,
onSelectChanged: () => row.onSelectChanged != null ? row.onSelectChanged(!row.selected) : null,
);
rowIndex += 1;
}
displayColumnIndex += 1;
}
return Table(
columnWidths: tableColumns.asMap(),
children: tableRows,
);
}
}
/// A rectangular area of a Material that responds to touch but clips
/// its ink splashes to the current table row of the nearest table.
///
/// Must have an ancestor [Material] widget in which to cause ink
/// reactions and an ancestor [Table] widget to establish a row.
///
/// The [TableRowInkWell] must be in the same coordinate space (modulo
/// translations) as the [Table]. If it's rotated or scaled or
/// otherwise transformed, it will not be able to describe the
/// rectangle of the row in its own coordinate system as a [Rect], and
/// thus the splash will not occur. (In general, this is easy to
/// achieve: just put the [TableRowInkWell] as the direct child of the
/// [Table], and put the other contents of the cell inside it.)
class TableRowInkWell extends InkResponse {
/// Creates an ink well for a table row.
const TableRowInkWell({
Key key,
Widget child,
GestureTapCallback onTap,
GestureTapCallback onDoubleTap,
GestureLongPressCallback onLongPress,
ValueChanged<bool> onHighlightChanged,
}) : super(
key: key,
child: child,
onTap: onTap,
onDoubleTap: onDoubleTap,
onLongPress: onLongPress,
onHighlightChanged: onHighlightChanged,
containedInkWell: true,
highlightShape: BoxShape.rectangle,
);
@override
RectCallback getRectCallback(RenderBox referenceBox) {
return () {
RenderObject cell = referenceBox;
AbstractNode table = cell.parent;
final Matrix4 transform = Matrix4.identity();
while (table is RenderObject && table is! RenderTable) {
final RenderObject parentBox = table as RenderObject;
parentBox.applyPaintTransform(cell, transform);
assert(table == cell.parent);
cell = parentBox;
table = table.parent;
}
if (table is RenderTable) {
final TableCellParentData cellParentData = cell.parentData as TableCellParentData;
assert(cellParentData.y != null);
final Rect rect = table.getRowBox(cellParentData.y);
// The rect is in the table's coordinate space. We need to change it to the
// TableRowInkWell's coordinate space.
table.applyPaintTransform(cell, transform);
final Offset offset = MatrixUtils.getAsTranslation(transform);
if (offset != null)
return rect.shift(-offset);
}
return Rect.zero;
};
}
@override
bool debugCheckContext(BuildContext context) {
assert(debugCheckHasTable(context));
return super.debugCheckContext(context);
}
}
class _SortArrow extends StatefulWidget {
const _SortArrow({
Key key,
this.visible,
this.down,
this.duration,
}) : super(key: key);
final bool visible;
final bool down;
final Duration duration;
@override
_SortArrowState createState() => _SortArrowState();
}
class _SortArrowState extends State<_SortArrow> with TickerProviderStateMixin {
AnimationController _opacityController;
Animation<double> _opacityAnimation;
AnimationController _orientationController;
Animation<double> _orientationAnimation;
double _orientationOffset = 0.0;
bool _down;
static final Animatable<double> _turnTween = Tween<double>(begin: 0.0, end: math.pi)
.chain(CurveTween(curve: Curves.easeIn));
@override
void initState() {
super.initState();
_opacityAnimation = CurvedAnimation(
parent: _opacityController = AnimationController(
duration: widget.duration,
vsync: this,
),
curve: Curves.fastOutSlowIn,
)
..addListener(_rebuild);
_opacityController.value = widget.visible ? 1.0 : 0.0;
_orientationController = AnimationController(
duration: widget.duration,
vsync: this,
);
_orientationAnimation = _orientationController.drive(_turnTween)
..addListener(_rebuild)
..addStatusListener(_resetOrientationAnimation);
if (widget.visible)
_orientationOffset = widget.down ? 0.0 : math.pi;
}
void _rebuild() {
setState(() {
// The animations changed, so we need to rebuild.
});
}
void _resetOrientationAnimation(AnimationStatus status) {
if (status == AnimationStatus.completed) {
assert(_orientationAnimation.value == math.pi);
_orientationOffset += math.pi;
_orientationController.value = 0.0; // TODO(ianh): This triggers a pointless rebuild.
}
}
@override
void didUpdateWidget(_SortArrow oldWidget) {
super.didUpdateWidget(oldWidget);
bool skipArrow = false;
final bool newDown = widget.down ?? _down;
if (oldWidget.visible != widget.visible) {
if (widget.visible && (_opacityController.status == AnimationStatus.dismissed)) {
_orientationController.stop();
_orientationController.value = 0.0;
_orientationOffset = newDown ? 0.0 : math.pi;
skipArrow = true;
}
if (widget.visible) {
_opacityController.forward();
} else {
_opacityController.reverse();
}
}
if ((_down != newDown) && !skipArrow) {
if (_orientationController.status == AnimationStatus.dismissed) {
_orientationController.forward();
} else {
_orientationController.reverse();
}
}
_down = newDown;
}
@override
void dispose() {
_opacityController.dispose();
_orientationController.dispose();
super.dispose();
}
static const double _arrowIconBaselineOffset = -1.5;
static const double _arrowIconSize = 16.0;
@override
Widget build(BuildContext context) {
return Opacity(
opacity: _opacityAnimation.value,
child: Transform(
transform: Matrix4.rotationZ(_orientationOffset + _orientationAnimation.value)
..setTranslationRaw(0.0, _arrowIconBaselineOffset, 0.0),
alignment: Alignment.center,
child: Icon(
Icons.arrow_downward,
size: _arrowIconSize,
color: (Theme.of(context).brightness == Brightness.light) ? Colors.black87 : Colors.white70,
),
),
);
}
}