Add `const` annotations to appropriate functions (#892)
1//! Style types for Flexbox layout
2use super::{AlignContent, AlignItems, AlignSelf, CoreStyle, Dimension, JustifyContent, LengthPercentage, Style};
3use crate::geometry::Size;
4
5/// The set of styles required for a Flexbox container
6pub trait FlexboxContainerStyle: CoreStyle {
7 /// Which direction does the main axis flow in?
8 #[inline(always)]
9 fn flex_direction(&self) -> FlexDirection {
10 Style::<Self::CustomIdent>::DEFAULT.flex_direction
11 }
12 /// Should elements wrap, or stay in a single line?
13 #[inline(always)]
14 fn flex_wrap(&self) -> FlexWrap {
15 Style::<Self::CustomIdent>::DEFAULT.flex_wrap
16 }
17
18 /// How large should the gaps between items in a grid or flex container be?
19 #[inline(always)]
20 fn gap(&self) -> Size<LengthPercentage> {
21 Style::<Self::CustomIdent>::DEFAULT.gap
22 }
23
24 // Alignment properties
25
26 /// How should content contained within this item be aligned in the cross/block axis
27 #[inline(always)]
28 fn align_content(&self) -> Option<AlignContent> {
29 Style::<Self::CustomIdent>::DEFAULT.align_content
30 }
31 /// How this node's children aligned in the cross/block axis?
32 #[inline(always)]
33 fn align_items(&self) -> Option<AlignItems> {
34 Style::<Self::CustomIdent>::DEFAULT.align_items
35 }
36 /// How this node's children should be aligned in the inline axis
37 #[inline(always)]
38 fn justify_content(&self) -> Option<JustifyContent> {
39 Style::<Self::CustomIdent>::DEFAULT.justify_content
40 }
41}
42
43/// The set of styles required for a Flexbox item (child of a Flexbox container)
44pub trait FlexboxItemStyle: CoreStyle {
45 /// Sets the initial main axis size of the item
46 #[inline(always)]
47 fn flex_basis(&self) -> Dimension {
48 Style::<Self::CustomIdent>::DEFAULT.flex_basis
49 }
50 /// The relative rate at which this item grows when it is expanding to fill space
51 #[inline(always)]
52 fn flex_grow(&self) -> f32 {
53 Style::<Self::CustomIdent>::DEFAULT.flex_grow
54 }
55 /// The relative rate at which this item shrinks when it is contracting to fit into space
56 #[inline(always)]
57 fn flex_shrink(&self) -> f32 {
58 Style::<Self::CustomIdent>::DEFAULT.flex_shrink
59 }
60
61 /// How this node should be aligned in the cross/block axis
62 /// Falls back to the parents [`AlignItems`] if not set
63 #[inline(always)]
64 fn align_self(&self) -> Option<AlignSelf> {
65 Style::<Self::CustomIdent>::DEFAULT.align_self
66 }
67}
68
69use crate::geometry::AbsoluteAxis;
70
71/// Controls whether flex items are forced onto one line or can wrap onto multiple lines.
72///
73/// Defaults to [`FlexWrap::NoWrap`]
74///
75/// [Specification](https://www.w3.org/TR/css-flexbox-1/#flex-wrap-property)
76#[derive(Copy, Clone, PartialEq, Eq, Debug, Default)]
77#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
78pub enum FlexWrap {
79 /// Items will not wrap and stay on a single line
80 #[default]
81 NoWrap,
82 /// Items will wrap according to this item's [`FlexDirection`]
83 Wrap,
84 /// Items will wrap in the opposite direction to this item's [`FlexDirection`]
85 WrapReverse,
86}
87
88/// The direction of the flexbox layout main axis.
89///
90/// There are always two perpendicular layout axes: main (or primary) and cross (or secondary).
91/// Adding items will cause them to be positioned adjacent to each other along the main axis.
92/// By varying this value throughout your tree, you can create complex axis-aligned layouts.
93///
94/// Items are always aligned relative to the cross axis, and justified relative to the main axis.
95///
96/// The default behavior is [`FlexDirection::Row`].
97///
98/// [Specification](https://www.w3.org/TR/css-flexbox-1/#flex-direction-property)
99#[derive(Copy, Clone, PartialEq, Eq, Debug, Default)]
100#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
101pub enum FlexDirection {
102 /// Defines +x as the main axis
103 ///
104 /// Items will be added from left to right in a row.
105 #[default]
106 Row,
107 /// Defines +y as the main axis
108 ///
109 /// Items will be added from top to bottom in a column.
110 Column,
111 /// Defines -x as the main axis
112 ///
113 /// Items will be added from right to left in a row.
114 RowReverse,
115 /// Defines -y as the main axis
116 ///
117 /// Items will be added from bottom to top in a column.
118 ColumnReverse,
119}
120
121impl FlexDirection {
122 #[inline]
123 /// Is the direction [`FlexDirection::Row`] or [`FlexDirection::RowReverse`]?
124 pub(crate) const fn is_row(self) -> bool {
125 matches!(self, Self::Row | Self::RowReverse)
126 }
127
128 #[inline]
129 /// Is the direction [`FlexDirection::Column`] or [`FlexDirection::ColumnReverse`]?
130 pub(crate) const fn is_column(self) -> bool {
131 matches!(self, Self::Column | Self::ColumnReverse)
132 }
133
134 #[inline]
135 /// Is the direction [`FlexDirection::RowReverse`] or [`FlexDirection::ColumnReverse`]?
136 pub(crate) const fn is_reverse(self) -> bool {
137 matches!(self, Self::RowReverse | Self::ColumnReverse)
138 }
139
140 #[inline]
141 /// The `AbsoluteAxis` that corresponds to the main axis
142 pub(crate) const fn main_axis(self) -> AbsoluteAxis {
143 match self {
144 Self::Row | Self::RowReverse => AbsoluteAxis::Horizontal,
145 Self::Column | Self::ColumnReverse => AbsoluteAxis::Vertical,
146 }
147 }
148
149 #[inline]
150 /// The `AbsoluteAxis` that corresponds to the cross axis
151 pub(crate) const fn cross_axis(self) -> AbsoluteAxis {
152 match self {
153 Self::Row | Self::RowReverse => AbsoluteAxis::Vertical,
154 Self::Column | Self::ColumnReverse => AbsoluteAxis::Horizontal,
155 }
156 }
157}
158
159#[cfg(test)]
160mod tests {
161 mod test_flex_direction {
162 use crate::style::*;
163
164 #[test]
165 fn flex_direction_is_row() {
166 assert!(FlexDirection::Row.is_row());
167 assert!(FlexDirection::RowReverse.is_row());
168 assert!(!FlexDirection::Column.is_row());
169 assert!(!FlexDirection::ColumnReverse.is_row());
170 }
171
172 #[test]
173 fn flex_direction_is_column() {
174 assert!(!FlexDirection::Row.is_column());
175 assert!(!FlexDirection::RowReverse.is_column());
176 assert!(FlexDirection::Column.is_column());
177 assert!(FlexDirection::ColumnReverse.is_column());
178 }
179
180 #[test]
181 fn flex_direction_is_reverse() {
182 assert!(!FlexDirection::Row.is_reverse());
183 assert!(FlexDirection::RowReverse.is_reverse());
184 assert!(!FlexDirection::Column.is_reverse());
185 assert!(FlexDirection::ColumnReverse.is_reverse());
186 }
187 }
188}