| // 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 'box.dart'; |
| import 'layer.dart'; |
| import 'layout_helper.dart'; |
| import 'object.dart'; |
| |
| /// How [Wrap] should align objects. |
| /// |
| /// Used both to align children within a run in the main axis as well as to |
| /// align the runs themselves in the cross axis. |
| enum WrapAlignment { |
| /// Place the objects as close to the start of the axis as possible. |
| /// |
| /// If this value is used in a horizontal direction, a [TextDirection] must be |
| /// available to determine if the start is the left or the right. |
| /// |
| /// If this value is used in a vertical direction, a [VerticalDirection] must be |
| /// available to determine if the start is the top or the bottom. |
| start, |
| |
| /// Place the objects as close to the end of the axis as possible. |
| /// |
| /// If this value is used in a horizontal direction, a [TextDirection] must be |
| /// available to determine if the end is the left or the right. |
| /// |
| /// If this value is used in a vertical direction, a [VerticalDirection] must be |
| /// available to determine if the end is the top or the bottom. |
| end, |
| |
| /// Place the objects as close to the middle of the axis as possible. |
| center, |
| |
| /// Place the free space evenly between the objects. |
| spaceBetween, |
| |
| /// Place the free space evenly between the objects as well as half of that |
| /// space before and after the first and last objects. |
| spaceAround, |
| |
| /// Place the free space evenly between the objects as well as before and |
| /// after the first and last objects. |
| spaceEvenly, |
| } |
| |
| /// Who [Wrap] should align children within a run in the cross axis. |
| enum WrapCrossAlignment { |
| /// Place the children as close to the start of the run in the cross axis as |
| /// possible. |
| /// |
| /// If this value is used in a horizontal direction, a [TextDirection] must be |
| /// available to determine if the start is the left or the right. |
| /// |
| /// If this value is used in a vertical direction, a [VerticalDirection] must be |
| /// available to determine if the start is the top or the bottom. |
| start, |
| |
| /// Place the children as close to the end of the run in the cross axis as |
| /// possible. |
| /// |
| /// If this value is used in a horizontal direction, a [TextDirection] must be |
| /// available to determine if the end is the left or the right. |
| /// |
| /// If this value is used in a vertical direction, a [VerticalDirection] must be |
| /// available to determine if the end is the top or the bottom. |
| end, |
| |
| /// Place the children as close to the middle of the run in the cross axis as |
| /// possible. |
| center, |
| |
| // TODO(ianh): baseline. |
| } |
| |
| class _RunMetrics { |
| _RunMetrics(this.mainAxisExtent, this.crossAxisExtent, this.childCount); |
| |
| final double mainAxisExtent; |
| final double crossAxisExtent; |
| final int childCount; |
| } |
| |
| /// Parent data for use with [RenderWrap]. |
| class WrapParentData extends ContainerBoxParentData<RenderBox> { |
| int _runIndex = 0; |
| } |
| |
| /// Displays its children in multiple horizontal or vertical runs. |
| /// |
| /// A [RenderWrap] lays out each child and attempts to place the child adjacent |
| /// to the previous child in the main axis, given by [direction], leaving |
| /// [spacing] space in between. If there is not enough space to fit the child, |
| /// [RenderWrap] creates a new _run_ adjacent to the existing children in the |
| /// cross axis. |
| /// |
| /// After all the children have been allocated to runs, the children within the |
| /// runs are positioned according to the [alignment] in the main axis and |
| /// according to the [crossAxisAlignment] in the cross axis. |
| /// |
| /// The runs themselves are then positioned in the cross axis according to the |
| /// [runSpacing] and [runAlignment]. |
| class RenderWrap extends RenderBox |
| with ContainerRenderObjectMixin<RenderBox, WrapParentData>, |
| RenderBoxContainerDefaultsMixin<RenderBox, WrapParentData> { |
| /// Creates a wrap render object. |
| /// |
| /// By default, the wrap layout is horizontal and both the children and the |
| /// runs are aligned to the start. |
| RenderWrap({ |
| List<RenderBox>? children, |
| Axis direction = Axis.horizontal, |
| WrapAlignment alignment = WrapAlignment.start, |
| double spacing = 0.0, |
| WrapAlignment runAlignment = WrapAlignment.start, |
| double runSpacing = 0.0, |
| WrapCrossAlignment crossAxisAlignment = WrapCrossAlignment.start, |
| TextDirection? textDirection, |
| VerticalDirection verticalDirection = VerticalDirection.down, |
| Clip clipBehavior = Clip.none, |
| }) : assert(direction != null), |
| assert(alignment != null), |
| assert(spacing != null), |
| assert(runAlignment != null), |
| assert(runSpacing != null), |
| assert(crossAxisAlignment != null), |
| assert(clipBehavior != null), |
| _direction = direction, |
| _alignment = alignment, |
| _spacing = spacing, |
| _runAlignment = runAlignment, |
| _runSpacing = runSpacing, |
| _crossAxisAlignment = crossAxisAlignment, |
| _textDirection = textDirection, |
| _verticalDirection = verticalDirection, |
| _clipBehavior = clipBehavior { |
| addAll(children); |
| } |
| |
| /// The direction to use as the main axis. |
| /// |
| /// For example, if [direction] is [Axis.horizontal], the default, the |
| /// children are placed adjacent to one another in a horizontal run until the |
| /// available horizontal space is consumed, at which point a subsequent |
| /// children are placed in a new run vertically adjacent to the previous run. |
| Axis get direction => _direction; |
| Axis _direction; |
| set direction (Axis value) { |
| assert(value != null); |
| if (_direction == value) |
| return; |
| _direction = value; |
| markNeedsLayout(); |
| } |
| |
| /// How the children within a run should be placed in the main axis. |
| /// |
| /// For example, if [alignment] is [WrapAlignment.center], the children in |
| /// each run are grouped together in the center of their run in the main axis. |
| /// |
| /// Defaults to [WrapAlignment.start]. |
| /// |
| /// See also: |
| /// |
| /// * [runAlignment], which controls how the runs are placed relative to each |
| /// other in the cross axis. |
| /// * [crossAxisAlignment], which controls how the children within each run |
| /// are placed relative to each other in the cross axis. |
| WrapAlignment get alignment => _alignment; |
| WrapAlignment _alignment; |
| set alignment (WrapAlignment value) { |
| assert(value != null); |
| if (_alignment == value) |
| return; |
| _alignment = value; |
| markNeedsLayout(); |
| } |
| |
| /// How much space to place between children in a run in the main axis. |
| /// |
| /// For example, if [spacing] is 10.0, the children will be spaced at least |
| /// 10.0 logical pixels apart in the main axis. |
| /// |
| /// If there is additional free space in a run (e.g., because the wrap has a |
| /// minimum size that is not filled or because some runs are longer than |
| /// others), the additional free space will be allocated according to the |
| /// [alignment]. |
| /// |
| /// Defaults to 0.0. |
| double get spacing => _spacing; |
| double _spacing; |
| set spacing (double value) { |
| assert(value != null); |
| if (_spacing == value) |
| return; |
| _spacing = value; |
| markNeedsLayout(); |
| } |
| |
| /// How the runs themselves should be placed in the cross axis. |
| /// |
| /// For example, if [runAlignment] is [WrapAlignment.center], the runs are |
| /// grouped together in the center of the overall [RenderWrap] in the cross |
| /// axis. |
| /// |
| /// Defaults to [WrapAlignment.start]. |
| /// |
| /// See also: |
| /// |
| /// * [alignment], which controls how the children within each run are placed |
| /// relative to each other in the main axis. |
| /// * [crossAxisAlignment], which controls how the children within each run |
| /// are placed relative to each other in the cross axis. |
| WrapAlignment get runAlignment => _runAlignment; |
| WrapAlignment _runAlignment; |
| set runAlignment (WrapAlignment value) { |
| assert(value != null); |
| if (_runAlignment == value) |
| return; |
| _runAlignment = value; |
| markNeedsLayout(); |
| } |
| |
| /// How much space to place between the runs themselves in the cross axis. |
| /// |
| /// For example, if [runSpacing] is 10.0, the runs will be spaced at least |
| /// 10.0 logical pixels apart in the cross axis. |
| /// |
| /// If there is additional free space in the overall [RenderWrap] (e.g., |
| /// because the wrap has a minimum size that is not filled), the additional |
| /// free space will be allocated according to the [runAlignment]. |
| /// |
| /// Defaults to 0.0. |
| double get runSpacing => _runSpacing; |
| double _runSpacing; |
| set runSpacing (double value) { |
| assert(value != null); |
| if (_runSpacing == value) |
| return; |
| _runSpacing = value; |
| markNeedsLayout(); |
| } |
| |
| /// How the children within a run should be aligned relative to each other in |
| /// the cross axis. |
| /// |
| /// For example, if this is set to [WrapCrossAlignment.end], and the |
| /// [direction] is [Axis.horizontal], then the children within each |
| /// run will have their bottom edges aligned to the bottom edge of the run. |
| /// |
| /// Defaults to [WrapCrossAlignment.start]. |
| /// |
| /// See also: |
| /// |
| /// * [alignment], which controls how the children within each run are placed |
| /// relative to each other in the main axis. |
| /// * [runAlignment], which controls how the runs are placed relative to each |
| /// other in the cross axis. |
| WrapCrossAlignment get crossAxisAlignment => _crossAxisAlignment; |
| WrapCrossAlignment _crossAxisAlignment; |
| set crossAxisAlignment (WrapCrossAlignment value) { |
| assert(value != null); |
| if (_crossAxisAlignment == value) |
| return; |
| _crossAxisAlignment = value; |
| markNeedsLayout(); |
| } |
| |
| /// Determines the order to lay children out horizontally and how to interpret |
| /// `start` and `end` in the horizontal direction. |
| /// |
| /// If the [direction] is [Axis.horizontal], this controls the order in which |
| /// children are positioned (left-to-right or right-to-left), and the meaning |
| /// of the [alignment] property's [WrapAlignment.start] and |
| /// [WrapAlignment.end] values. |
| /// |
| /// If the [direction] is [Axis.horizontal], and either the |
| /// [alignment] is either [WrapAlignment.start] or [WrapAlignment.end], or |
| /// there's more than one child, then the [textDirection] must not be null. |
| /// |
| /// If the [direction] is [Axis.vertical], this controls the order in |
| /// which runs are positioned, the meaning of the [runAlignment] property's |
| /// [WrapAlignment.start] and [WrapAlignment.end] values, as well as the |
| /// [crossAxisAlignment] property's [WrapCrossAlignment.start] and |
| /// [WrapCrossAlignment.end] values. |
| /// |
| /// If the [direction] is [Axis.vertical], and either the |
| /// [runAlignment] is either [WrapAlignment.start] or [WrapAlignment.end], the |
| /// [crossAxisAlignment] is either [WrapCrossAlignment.start] or |
| /// [WrapCrossAlignment.end], or there's more than one child, then the |
| /// [textDirection] must not be null. |
| TextDirection? get textDirection => _textDirection; |
| TextDirection? _textDirection; |
| set textDirection(TextDirection? value) { |
| if (_textDirection != value) { |
| _textDirection = value; |
| markNeedsLayout(); |
| } |
| } |
| |
| /// Determines the order to lay children out vertically and how to interpret |
| /// `start` and `end` in the vertical direction. |
| /// |
| /// If the [direction] is [Axis.vertical], this controls which order children |
| /// are painted in (down or up), the meaning of the [alignment] property's |
| /// [WrapAlignment.start] and [WrapAlignment.end] values. |
| /// |
| /// If the [direction] is [Axis.vertical], and either the [alignment] |
| /// is either [WrapAlignment.start] or [WrapAlignment.end], or there's |
| /// more than one child, then the [verticalDirection] must not be null. |
| /// |
| /// If the [direction] is [Axis.horizontal], this controls the order in which |
| /// runs are positioned, the meaning of the [runAlignment] property's |
| /// [WrapAlignment.start] and [WrapAlignment.end] values, as well as the |
| /// [crossAxisAlignment] property's [WrapCrossAlignment.start] and |
| /// [WrapCrossAlignment.end] values. |
| /// |
| /// If the [direction] is [Axis.horizontal], and either the |
| /// [runAlignment] is either [WrapAlignment.start] or [WrapAlignment.end], the |
| /// [crossAxisAlignment] is either [WrapCrossAlignment.start] or |
| /// [WrapCrossAlignment.end], or there's more than one child, then the |
| /// [verticalDirection] must not be null. |
| VerticalDirection get verticalDirection => _verticalDirection; |
| VerticalDirection _verticalDirection; |
| set verticalDirection(VerticalDirection value) { |
| if (_verticalDirection != value) { |
| _verticalDirection = value; |
| markNeedsLayout(); |
| } |
| } |
| |
| /// {@macro flutter.material.Material.clipBehavior} |
| /// |
| /// Defaults to [Clip.none], and must not be null. |
| Clip get clipBehavior => _clipBehavior; |
| Clip _clipBehavior = Clip.none; |
| set clipBehavior(Clip value) { |
| assert(value != null); |
| if (value != _clipBehavior) { |
| _clipBehavior = value; |
| markNeedsPaint(); |
| markNeedsSemanticsUpdate(); |
| } |
| } |
| |
| bool get _debugHasNecessaryDirections { |
| assert(direction != null); |
| assert(alignment != null); |
| assert(runAlignment != null); |
| assert(crossAxisAlignment != null); |
| if (firstChild != null && lastChild != firstChild) { |
| // i.e. there's more than one child |
| switch (direction) { |
| case Axis.horizontal: |
| assert(textDirection != null, 'Horizontal $runtimeType with multiple children has a null textDirection, so the layout order is undefined.'); |
| break; |
| case Axis.vertical: |
| assert(verticalDirection != null, 'Vertical $runtimeType with multiple children has a null verticalDirection, so the layout order is undefined.'); |
| break; |
| } |
| } |
| if (alignment == WrapAlignment.start || alignment == WrapAlignment.end) { |
| switch (direction) { |
| case Axis.horizontal: |
| assert(textDirection != null, 'Horizontal $runtimeType with alignment $alignment has a null textDirection, so the alignment cannot be resolved.'); |
| break; |
| case Axis.vertical: |
| assert(verticalDirection != null, 'Vertical $runtimeType with alignment $alignment has a null verticalDirection, so the alignment cannot be resolved.'); |
| break; |
| } |
| } |
| if (runAlignment == WrapAlignment.start || runAlignment == WrapAlignment.end) { |
| switch (direction) { |
| case Axis.horizontal: |
| assert(verticalDirection != null, 'Horizontal $runtimeType with runAlignment $runAlignment has a null verticalDirection, so the alignment cannot be resolved.'); |
| break; |
| case Axis.vertical: |
| assert(textDirection != null, 'Vertical $runtimeType with runAlignment $runAlignment has a null textDirection, so the alignment cannot be resolved.'); |
| break; |
| } |
| } |
| if (crossAxisAlignment == WrapCrossAlignment.start || crossAxisAlignment == WrapCrossAlignment.end) { |
| switch (direction) { |
| case Axis.horizontal: |
| assert(verticalDirection != null, 'Horizontal $runtimeType with crossAxisAlignment $crossAxisAlignment has a null verticalDirection, so the alignment cannot be resolved.'); |
| break; |
| case Axis.vertical: |
| assert(textDirection != null, 'Vertical $runtimeType with crossAxisAlignment $crossAxisAlignment has a null textDirection, so the alignment cannot be resolved.'); |
| break; |
| } |
| } |
| return true; |
| } |
| |
| @override |
| void setupParentData(RenderBox child) { |
| if (child.parentData is! WrapParentData) |
| child.parentData = WrapParentData(); |
| } |
| |
| @override |
| double computeMinIntrinsicWidth(double height) { |
| switch (direction) { |
| case Axis.horizontal: |
| double width = 0.0; |
| RenderBox? child = firstChild; |
| while (child != null) { |
| width = math.max(width, child.getMinIntrinsicWidth(double.infinity)); |
| child = childAfter(child); |
| } |
| return width; |
| case Axis.vertical: |
| return computeDryLayout(BoxConstraints(maxHeight: height)).width; |
| } |
| } |
| |
| @override |
| double computeMaxIntrinsicWidth(double height) { |
| switch (direction) { |
| case Axis.horizontal: |
| double width = 0.0; |
| RenderBox? child = firstChild; |
| while (child != null) { |
| width += child.getMaxIntrinsicWidth(double.infinity); |
| child = childAfter(child); |
| } |
| return width; |
| case Axis.vertical: |
| return computeDryLayout(BoxConstraints(maxHeight: height)).width; |
| } |
| } |
| |
| @override |
| double computeMinIntrinsicHeight(double width) { |
| switch (direction) { |
| case Axis.horizontal: |
| return computeDryLayout(BoxConstraints(maxWidth: width)).height; |
| case Axis.vertical: |
| double height = 0.0; |
| RenderBox? child = firstChild; |
| while (child != null) { |
| height = math.max(height, child.getMinIntrinsicHeight(double.infinity)); |
| child = childAfter(child); |
| } |
| return height; |
| } |
| } |
| |
| @override |
| double computeMaxIntrinsicHeight(double width) { |
| switch (direction) { |
| case Axis.horizontal: |
| return computeDryLayout(BoxConstraints(maxWidth: width)).height; |
| case Axis.vertical: |
| double height = 0.0; |
| RenderBox? child = firstChild; |
| while (child != null) { |
| height += child.getMaxIntrinsicHeight(double.infinity); |
| child = childAfter(child); |
| } |
| return height; |
| } |
| } |
| |
| @override |
| double? computeDistanceToActualBaseline(TextBaseline baseline) { |
| return defaultComputeDistanceToHighestActualBaseline(baseline); |
| } |
| |
| double _getMainAxisExtent(Size childSize) { |
| switch (direction) { |
| case Axis.horizontal: |
| return childSize.width; |
| case Axis.vertical: |
| return childSize.height; |
| } |
| } |
| |
| double _getCrossAxisExtent(Size childSize) { |
| switch (direction) { |
| case Axis.horizontal: |
| return childSize.height; |
| case Axis.vertical: |
| return childSize.width; |
| } |
| } |
| |
| Offset _getOffset(double mainAxisOffset, double crossAxisOffset) { |
| switch (direction) { |
| case Axis.horizontal: |
| return Offset(mainAxisOffset, crossAxisOffset); |
| case Axis.vertical: |
| return Offset(crossAxisOffset, mainAxisOffset); |
| } |
| } |
| |
| double _getChildCrossAxisOffset(bool flipCrossAxis, double runCrossAxisExtent, double childCrossAxisExtent) { |
| final double freeSpace = runCrossAxisExtent - childCrossAxisExtent; |
| switch (crossAxisAlignment) { |
| case WrapCrossAlignment.start: |
| return flipCrossAxis ? freeSpace : 0.0; |
| case WrapCrossAlignment.end: |
| return flipCrossAxis ? 0.0 : freeSpace; |
| case WrapCrossAlignment.center: |
| return freeSpace / 2.0; |
| } |
| } |
| |
| bool _hasVisualOverflow = false; |
| |
| @override |
| Size computeDryLayout(BoxConstraints constraints) { |
| return _computeDryLayout(constraints); |
| } |
| |
| Size _computeDryLayout(BoxConstraints constraints, [ChildLayouter layoutChild = ChildLayoutHelper.dryLayoutChild]) { |
| final BoxConstraints childConstraints; |
| double mainAxisLimit = 0.0; |
| switch (direction) { |
| case Axis.horizontal: |
| childConstraints = BoxConstraints(maxWidth: constraints.maxWidth); |
| mainAxisLimit = constraints.maxWidth; |
| break; |
| case Axis.vertical: |
| childConstraints = BoxConstraints(maxHeight: constraints.maxHeight); |
| mainAxisLimit = constraints.maxHeight; |
| break; |
| } |
| |
| double mainAxisExtent = 0.0; |
| double crossAxisExtent = 0.0; |
| double runMainAxisExtent = 0.0; |
| double runCrossAxisExtent = 0.0; |
| int childCount = 0; |
| RenderBox? child = firstChild; |
| while (child != null) { |
| final Size childSize = layoutChild(child, childConstraints); |
| final double childMainAxisExtent = _getMainAxisExtent(childSize); |
| final double childCrossAxisExtent = _getCrossAxisExtent(childSize); |
| // There must be at least one child before we move on to the next run. |
| if (childCount > 0 && runMainAxisExtent + childMainAxisExtent + spacing > mainAxisLimit) { |
| mainAxisExtent = math.max(mainAxisExtent, runMainAxisExtent); |
| crossAxisExtent += runCrossAxisExtent + runSpacing; |
| runMainAxisExtent = 0.0; |
| runCrossAxisExtent = 0.0; |
| childCount = 0; |
| } |
| runMainAxisExtent += childMainAxisExtent; |
| runCrossAxisExtent = math.max(runCrossAxisExtent, childCrossAxisExtent); |
| if (childCount > 0) |
| runMainAxisExtent += spacing; |
| childCount += 1; |
| child = childAfter(child); |
| } |
| crossAxisExtent += runCrossAxisExtent; |
| mainAxisExtent = math.max(mainAxisExtent, runMainAxisExtent); |
| |
| switch (direction) { |
| case Axis.horizontal: |
| return constraints.constrain(Size(mainAxisExtent, crossAxisExtent)); |
| case Axis.vertical: |
| return constraints.constrain(Size(crossAxisExtent, mainAxisExtent)); |
| } |
| } |
| |
| @override |
| void performLayout() { |
| final BoxConstraints constraints = this.constraints; |
| assert(_debugHasNecessaryDirections); |
| _hasVisualOverflow = false; |
| RenderBox? child = firstChild; |
| if (child == null) { |
| size = constraints.smallest; |
| return; |
| } |
| final BoxConstraints childConstraints; |
| double mainAxisLimit = 0.0; |
| bool flipMainAxis = false; |
| bool flipCrossAxis = false; |
| switch (direction) { |
| case Axis.horizontal: |
| childConstraints = BoxConstraints(maxWidth: constraints.maxWidth); |
| mainAxisLimit = constraints.maxWidth; |
| if (textDirection == TextDirection.rtl) |
| flipMainAxis = true; |
| if (verticalDirection == VerticalDirection.up) |
| flipCrossAxis = true; |
| break; |
| case Axis.vertical: |
| childConstraints = BoxConstraints(maxHeight: constraints.maxHeight); |
| mainAxisLimit = constraints.maxHeight; |
| if (verticalDirection == VerticalDirection.up) |
| flipMainAxis = true; |
| if (textDirection == TextDirection.rtl) |
| flipCrossAxis = true; |
| break; |
| } |
| assert(childConstraints != null); |
| assert(mainAxisLimit != null); |
| final double spacing = this.spacing; |
| final double runSpacing = this.runSpacing; |
| final List<_RunMetrics> runMetrics = <_RunMetrics>[]; |
| double mainAxisExtent = 0.0; |
| double crossAxisExtent = 0.0; |
| double runMainAxisExtent = 0.0; |
| double runCrossAxisExtent = 0.0; |
| int childCount = 0; |
| while (child != null) { |
| child.layout(childConstraints, parentUsesSize: true); |
| final double childMainAxisExtent = _getMainAxisExtent(child.size); |
| final double childCrossAxisExtent = _getCrossAxisExtent(child.size); |
| if (childCount > 0 && runMainAxisExtent + spacing + childMainAxisExtent > mainAxisLimit) { |
| mainAxisExtent = math.max(mainAxisExtent, runMainAxisExtent); |
| crossAxisExtent += runCrossAxisExtent; |
| if (runMetrics.isNotEmpty) |
| crossAxisExtent += runSpacing; |
| runMetrics.add(_RunMetrics(runMainAxisExtent, runCrossAxisExtent, childCount)); |
| runMainAxisExtent = 0.0; |
| runCrossAxisExtent = 0.0; |
| childCount = 0; |
| } |
| runMainAxisExtent += childMainAxisExtent; |
| if (childCount > 0) |
| runMainAxisExtent += spacing; |
| runCrossAxisExtent = math.max(runCrossAxisExtent, childCrossAxisExtent); |
| childCount += 1; |
| final WrapParentData childParentData = child.parentData! as WrapParentData; |
| childParentData._runIndex = runMetrics.length; |
| child = childParentData.nextSibling; |
| } |
| if (childCount > 0) { |
| mainAxisExtent = math.max(mainAxisExtent, runMainAxisExtent); |
| crossAxisExtent += runCrossAxisExtent; |
| if (runMetrics.isNotEmpty) |
| crossAxisExtent += runSpacing; |
| runMetrics.add(_RunMetrics(runMainAxisExtent, runCrossAxisExtent, childCount)); |
| } |
| |
| final int runCount = runMetrics.length; |
| assert(runCount > 0); |
| |
| double containerMainAxisExtent = 0.0; |
| double containerCrossAxisExtent = 0.0; |
| |
| switch (direction) { |
| case Axis.horizontal: |
| size = constraints.constrain(Size(mainAxisExtent, crossAxisExtent)); |
| containerMainAxisExtent = size.width; |
| containerCrossAxisExtent = size.height; |
| break; |
| case Axis.vertical: |
| size = constraints.constrain(Size(crossAxisExtent, mainAxisExtent)); |
| containerMainAxisExtent = size.height; |
| containerCrossAxisExtent = size.width; |
| break; |
| } |
| |
| _hasVisualOverflow = containerMainAxisExtent < mainAxisExtent || containerCrossAxisExtent < crossAxisExtent; |
| |
| final double crossAxisFreeSpace = math.max(0.0, containerCrossAxisExtent - crossAxisExtent); |
| double runLeadingSpace = 0.0; |
| double runBetweenSpace = 0.0; |
| switch (runAlignment) { |
| case WrapAlignment.start: |
| break; |
| case WrapAlignment.end: |
| runLeadingSpace = crossAxisFreeSpace; |
| break; |
| case WrapAlignment.center: |
| runLeadingSpace = crossAxisFreeSpace / 2.0; |
| break; |
| case WrapAlignment.spaceBetween: |
| runBetweenSpace = runCount > 1 ? crossAxisFreeSpace / (runCount - 1) : 0.0; |
| break; |
| case WrapAlignment.spaceAround: |
| runBetweenSpace = crossAxisFreeSpace / runCount; |
| runLeadingSpace = runBetweenSpace / 2.0; |
| break; |
| case WrapAlignment.spaceEvenly: |
| runBetweenSpace = crossAxisFreeSpace / (runCount + 1); |
| runLeadingSpace = runBetweenSpace; |
| break; |
| } |
| |
| runBetweenSpace += runSpacing; |
| double crossAxisOffset = flipCrossAxis ? containerCrossAxisExtent - runLeadingSpace : runLeadingSpace; |
| |
| child = firstChild; |
| for (int i = 0; i < runCount; ++i) { |
| final _RunMetrics metrics = runMetrics[i]; |
| final double runMainAxisExtent = metrics.mainAxisExtent; |
| final double runCrossAxisExtent = metrics.crossAxisExtent; |
| final int childCount = metrics.childCount; |
| |
| final double mainAxisFreeSpace = math.max(0.0, containerMainAxisExtent - runMainAxisExtent); |
| double childLeadingSpace = 0.0; |
| double childBetweenSpace = 0.0; |
| |
| switch (alignment) { |
| case WrapAlignment.start: |
| break; |
| case WrapAlignment.end: |
| childLeadingSpace = mainAxisFreeSpace; |
| break; |
| case WrapAlignment.center: |
| childLeadingSpace = mainAxisFreeSpace / 2.0; |
| break; |
| case WrapAlignment.spaceBetween: |
| childBetweenSpace = childCount > 1 ? mainAxisFreeSpace / (childCount - 1) : 0.0; |
| break; |
| case WrapAlignment.spaceAround: |
| childBetweenSpace = mainAxisFreeSpace / childCount; |
| childLeadingSpace = childBetweenSpace / 2.0; |
| break; |
| case WrapAlignment.spaceEvenly: |
| childBetweenSpace = mainAxisFreeSpace / (childCount + 1); |
| childLeadingSpace = childBetweenSpace; |
| break; |
| } |
| |
| childBetweenSpace += spacing; |
| double childMainPosition = flipMainAxis ? containerMainAxisExtent - childLeadingSpace : childLeadingSpace; |
| |
| if (flipCrossAxis) |
| crossAxisOffset -= runCrossAxisExtent; |
| |
| while (child != null) { |
| final WrapParentData childParentData = child.parentData! as WrapParentData; |
| if (childParentData._runIndex != i) |
| break; |
| final double childMainAxisExtent = _getMainAxisExtent(child.size); |
| final double childCrossAxisExtent = _getCrossAxisExtent(child.size); |
| final double childCrossAxisOffset = _getChildCrossAxisOffset(flipCrossAxis, runCrossAxisExtent, childCrossAxisExtent); |
| if (flipMainAxis) |
| childMainPosition -= childMainAxisExtent; |
| childParentData.offset = _getOffset(childMainPosition, crossAxisOffset + childCrossAxisOffset); |
| if (flipMainAxis) |
| childMainPosition -= childBetweenSpace; |
| else |
| childMainPosition += childMainAxisExtent + childBetweenSpace; |
| child = childParentData.nextSibling; |
| } |
| |
| if (flipCrossAxis) |
| crossAxisOffset -= runBetweenSpace; |
| else |
| crossAxisOffset += runCrossAxisExtent + runBetweenSpace; |
| } |
| } |
| |
| @override |
| bool hitTestChildren(BoxHitTestResult result, { required Offset position }) { |
| return defaultHitTestChildren(result, position: position); |
| } |
| |
| @override |
| void paint(PaintingContext context, Offset offset) { |
| // TODO(ianh): move the debug flex overflow paint logic somewhere common so |
| // it can be reused here |
| if (_hasVisualOverflow && clipBehavior != Clip.none) { |
| _clipRectLayer = context.pushClipRect( |
| needsCompositing, |
| offset, |
| Offset.zero & size, |
| defaultPaint, |
| clipBehavior: clipBehavior, |
| oldLayer: _clipRectLayer, |
| ); |
| } else { |
| _clipRectLayer = null; |
| defaultPaint(context, offset); |
| } |
| } |
| |
| ClipRectLayer? _clipRectLayer; |
| |
| @override |
| void debugFillProperties(DiagnosticPropertiesBuilder properties) { |
| super.debugFillProperties(properties); |
| properties.add(EnumProperty<Axis>('direction', direction)); |
| properties.add(EnumProperty<WrapAlignment>('alignment', alignment)); |
| properties.add(DoubleProperty('spacing', spacing)); |
| properties.add(EnumProperty<WrapAlignment>('runAlignment', runAlignment)); |
| properties.add(DoubleProperty('runSpacing', runSpacing)); |
| properties.add(DoubleProperty('crossAxisAlignment', runSpacing)); |
| properties.add(EnumProperty<TextDirection>('textDirection', textDirection, defaultValue: null)); |
| properties.add(EnumProperty<VerticalDirection>('verticalDirection', verticalDirection, defaultValue: VerticalDirection.down)); |
| } |
| } |
