layout/flexbox/
mod.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5use geom::{FlexAxis, MainStartCrossStart};
6use malloc_size_of_derive::MallocSizeOf;
7use script::layout_dom::ServoThreadSafeLayoutNode;
8use servo_arc::Arc as ServoArc;
9use style::context::SharedStyleContext;
10use style::logical_geometry::WritingMode;
11use style::properties::ComputedValues;
12use style::properties::longhands::align_items::computed_value::T as AlignItems;
13use style::properties::longhands::flex_direction::computed_value::T as FlexDirection;
14use style::properties::longhands::flex_wrap::computed_value::T as FlexWrap;
15use style::values::computed::{AlignContent, JustifyContent};
16use style::values::specified::align::AlignFlags;
17
18use crate::PropagatedBoxTreeData;
19use crate::cell::ArcRefCell;
20use crate::construct_modern::{ModernContainerBuilder, ModernItemKind};
21use crate::context::LayoutContext;
22use crate::dom::LayoutBox;
23use crate::dom_traversal::{NodeAndStyleInfo, NonReplacedContents};
24use crate::formatting_contexts::IndependentFormattingContext;
25use crate::fragment_tree::BaseFragmentInfo;
26use crate::layout_box_base::LayoutBoxBase;
27use crate::positioned::AbsolutelyPositionedBox;
28
29mod geom;
30mod layout;
31
32/// A structure to hold the configuration of a flex container for use during layout
33/// and preferred width calculation.
34#[derive(Clone, Debug, MallocSizeOf)]
35pub(crate) struct FlexContainerConfig {
36    container_is_single_line: bool,
37    writing_mode: WritingMode,
38    flex_axis: FlexAxis,
39    flex_direction: FlexDirection,
40    flex_direction_is_reversed: bool,
41    flex_wrap: FlexWrap,
42    flex_wrap_is_reversed: bool,
43    main_start_cross_start_sides_are: MainStartCrossStart,
44    align_content: AlignContent,
45    align_items: AlignItems,
46    justify_content: JustifyContent,
47}
48
49impl FlexContainerConfig {
50    fn new(container_style: &ComputedValues) -> FlexContainerConfig {
51        let flex_direction = container_style.clone_flex_direction();
52        let flex_axis = FlexAxis::from(flex_direction);
53        let flex_wrap = container_style.get_position().flex_wrap;
54        let container_is_single_line = match flex_wrap {
55            FlexWrap::Nowrap => true,
56            FlexWrap::Wrap | FlexWrap::WrapReverse => false,
57        };
58        let flex_direction_is_reversed = match flex_direction {
59            FlexDirection::Row | FlexDirection::Column => false,
60            FlexDirection::RowReverse | FlexDirection::ColumnReverse => true,
61        };
62        let flex_wrap_reverse = match flex_wrap {
63            FlexWrap::Nowrap | FlexWrap::Wrap => false,
64            FlexWrap::WrapReverse => true,
65        };
66
67        let align_content = container_style.clone_align_content();
68        let align_items = AlignItems(match container_style.clone_align_items().0 {
69            AlignFlags::AUTO | AlignFlags::NORMAL => AlignFlags::STRETCH,
70            align => align,
71        });
72        let justify_content = container_style.clone_justify_content();
73        let main_start_cross_start_sides_are =
74            MainStartCrossStart::from(flex_direction, flex_wrap_reverse);
75
76        FlexContainerConfig {
77            container_is_single_line,
78            writing_mode: container_style.writing_mode,
79            flex_axis,
80            flex_direction,
81            flex_direction_is_reversed,
82            flex_wrap,
83            flex_wrap_is_reversed: flex_wrap_reverse,
84            main_start_cross_start_sides_are,
85            align_content,
86            align_items,
87            justify_content,
88        }
89    }
90}
91
92#[derive(Debug, MallocSizeOf)]
93pub(crate) struct FlexContainer {
94    children: Vec<ArcRefCell<FlexLevelBox>>,
95
96    style: ServoArc<ComputedValues>,
97
98    /// The configuration of this [`FlexContainer`].
99    config: FlexContainerConfig,
100}
101
102impl FlexContainer {
103    pub fn construct(
104        context: &LayoutContext,
105        info: &NodeAndStyleInfo<'_>,
106        contents: NonReplacedContents,
107        propagated_data: PropagatedBoxTreeData,
108    ) -> Self {
109        let mut builder = ModernContainerBuilder::new(context, info, propagated_data);
110        contents.traverse(context, info, &mut builder);
111        let items = builder.finish();
112
113        let children = items
114            .into_iter()
115            .map(|item| {
116                let box_ = match item.kind {
117                    ModernItemKind::InFlow(independent_formatting_context) => ArcRefCell::new(
118                        FlexLevelBox::FlexItem(FlexItemBox::new(independent_formatting_context)),
119                    ),
120                    ModernItemKind::OutOfFlow(independent_formatting_context) => {
121                        let abs_pos_box = ArcRefCell::new(AbsolutelyPositionedBox::new(
122                            independent_formatting_context,
123                        ));
124                        ArcRefCell::new(FlexLevelBox::OutOfFlowAbsolutelyPositionedBox(abs_pos_box))
125                    },
126                    ModernItemKind::ReusedBox(layout_box) => match layout_box {
127                        LayoutBox::FlexLevel(flex_level_box) => flex_level_box,
128                        _ => unreachable!(
129                            "Undamaged flex level element should be associated with flex level box"
130                        ),
131                    },
132                };
133
134                if let Some(box_slot) = item.box_slot {
135                    box_slot.set(LayoutBox::FlexLevel(box_.clone()));
136                }
137
138                box_
139            })
140            .collect();
141
142        Self {
143            children,
144            style: info.style.clone(),
145            config: FlexContainerConfig::new(&info.style),
146        }
147    }
148
149    pub(crate) fn repair_style(&mut self, new_style: &ServoArc<ComputedValues>) {
150        self.config = FlexContainerConfig::new(new_style);
151        self.style = new_style.clone();
152    }
153}
154
155#[allow(clippy::large_enum_variant)]
156#[derive(Debug, MallocSizeOf)]
157pub(crate) enum FlexLevelBox {
158    FlexItem(FlexItemBox),
159    OutOfFlowAbsolutelyPositionedBox(ArcRefCell<AbsolutelyPositionedBox>),
160}
161
162impl FlexLevelBox {
163    pub(crate) fn repair_style(
164        &mut self,
165        context: &SharedStyleContext,
166        node: &ServoThreadSafeLayoutNode,
167        new_style: &ServoArc<ComputedValues>,
168    ) {
169        match self {
170            FlexLevelBox::FlexItem(flex_item_box) => flex_item_box
171                .independent_formatting_context
172                .repair_style(context, node, new_style),
173            FlexLevelBox::OutOfFlowAbsolutelyPositionedBox(positioned_box) => positioned_box
174                .borrow_mut()
175                .context
176                .repair_style(context, node, new_style),
177        }
178    }
179
180    pub(crate) fn clear_fragment_layout_cache(&self) {
181        match self {
182            FlexLevelBox::FlexItem(flex_item_box) => flex_item_box
183                .independent_formatting_context
184                .base
185                .clear_fragment_layout_cache(),
186            FlexLevelBox::OutOfFlowAbsolutelyPositionedBox(positioned_box) => positioned_box
187                .borrow()
188                .context
189                .base
190                .clear_fragment_layout_cache(),
191        }
192    }
193
194    pub(crate) fn with_base<T>(&self, callback: impl FnOnce(&LayoutBoxBase) -> T) -> T {
195        match self {
196            FlexLevelBox::FlexItem(flex_item_box) => {
197                callback(&flex_item_box.independent_formatting_context.base)
198            },
199            FlexLevelBox::OutOfFlowAbsolutelyPositionedBox(positioned_box) => {
200                callback(&positioned_box.borrow().context.base)
201            },
202        }
203    }
204
205    pub(crate) fn with_base_mut<T>(&mut self, callback: impl Fn(&mut LayoutBoxBase) -> T) -> T {
206        match self {
207            FlexLevelBox::FlexItem(flex_item_box) => {
208                callback(&mut flex_item_box.independent_formatting_context.base)
209            },
210            FlexLevelBox::OutOfFlowAbsolutelyPositionedBox(positioned_box) => {
211                callback(&mut positioned_box.borrow_mut().context.base)
212            },
213        }
214    }
215}
216
217#[derive(MallocSizeOf)]
218pub(crate) struct FlexItemBox {
219    independent_formatting_context: IndependentFormattingContext,
220}
221
222impl std::fmt::Debug for FlexItemBox {
223    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
224        f.write_str("FlexItemBox")
225    }
226}
227
228impl FlexItemBox {
229    fn new(independent_formatting_context: IndependentFormattingContext) -> Self {
230        Self {
231            independent_formatting_context,
232        }
233    }
234
235    fn style(&self) -> &ServoArc<ComputedValues> {
236        self.independent_formatting_context.style()
237    }
238
239    fn base_fragment_info(&self) -> BaseFragmentInfo {
240        self.independent_formatting_context.base_fragment_info()
241    }
242}
layout/flexbox/mod.rs

layout/flexbox/
mod.rs
