Moving flexbox behind a feature flag (#414)

* Moving flexbox behind a feature flag

* More stuff behind feature flag

* Enabling flexbox by default

* Fixing double definition of default

* Update workflow

* Adding default const to Display when no features are enabled

* Comment out more stuff from the prelude

* Ensure only one default

* Putting stuff behind feature flags

* formatting

* adding std to feature testing

* Uncomment temp commented code

* Fix missing comma

* Update Ci job keys

* Cleanup and documentatnion

* Gating alignement properties behind flexbox or grid

* Rename job key back to original value

* Gate justify_items and justify_self behind the grid feature

* Reinstate alloc job name

* Fix github actions job name

---------

Co-authored-by: Nico Burns <[email protected]>

Author: Weibye

.github/workflows/ci.yml

@@ -9,6 +9,7 @@ on:
 name: Continuous integration
 
 jobs:
+  # None
   test-features-none:
     name: "Test Suite [Features: None]"
     runs-on: ubuntu-latest
@@ -19,6 +20,7 @@ jobs:
       - run: cargo build --no-default-features
       - run: cargo test --no-default-features
 
+  # Default
   test-features-default:
     name: "Test Suite [Features: Default]"
     runs-on: ubuntu-latest
@@ -37,17 +39,46 @@ jobs:
       - run: cargo build --features serde
       - run: cargo test --features serde
 
-  test-features-alloc:
-    name: "Test Suite [Features: alloc]"
+  test-features-no-grid-nor-flexbox:
+    name: "Test Suite [Features: std (no grid or flexbox)]"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: dtolnay/rust-toolchain@stable
+      - run: cargo build --no-default-features --features std
+      - run: cargo test --no-default-features --features std
+
+  # Flexbox
+  test-features-flexbox:
+    name: "Test Suite [Features: flexbox + std]"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: dtolnay/rust-toolchain@stable
+      - run: cargo build --no-default-features --features flexbox,std
+      - run: cargo test --no-default-features --features flexbox,std
+
+  # Grid
+  test-features-grid:
+    name: "Test Suite [Features: grid + std]"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: dtolnay/rust-toolchain@stable
+      - run: cargo build --no-default-features --features grid,std
+      - run: cargo test --no-default-features --features grid,std
+
+  test-features-grid-with-alloc:
+    name: "Test Suite [Features: grid + alloc]"
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
       - run: cargo build --no-default-features --features alloc,grid
       - run: cargo test --no-default-features --features alloc,grid
 
-  test-features-alloc-no-grid:
-    name: "Test Suite [Features: alloc (no grid)]"
+  test-features-alloc:
+    name: "Test Suite [Features: alloc]"
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3

Cargo.toml

@@ -22,7 +22,8 @@ slotmap = "1.0.6"
 grid = { version = "0.9.0", optional = true }
 
 [features]
-default = ["std", "grid"]
+default = ["std", "flexbox", "grid" ]
+flexbox = []
 grid = ["alloc", "dep:grid"]
 alloc = []
 std = ["num-traits/std"]

RELEASES.md

@@ -1,5 +1,12 @@
 # Release Notes
 
+## Unreleased
+
+### Changes
+
+- The Flexbox algorithm has now been moved behind the `flexbox` feature. The `flexbox` feature is enabled by default.
+- The `justify_self` property has been moved behind the `grid` feature.
+
 ## 0.3.11
 
 ### Fixes

src/compute/mod.rs

@@ -1,9 +1,11 @@
 //! The layout algorithms themselves
 
 pub(crate) mod common;
-pub(crate) mod flexbox;
 pub(crate) mod leaf;
 
+#[cfg(feature = "flexbox")]
+pub(crate) mod flexbox;
+
 #[cfg(feature = "grid")]
 pub(crate) mod grid;
 
@@ -16,7 +18,9 @@ use crate::style::{AvailableSpace, Display};
 use crate::sys::round;
 use crate::tree::LayoutTree;
 
+#[cfg(feature = "flexbox")]
 use self::flexbox::FlexboxAlgorithm;
+
 #[cfg(feature = "grid")]
 use self::grid::CssGridAlgorithm;
 use self::leaf::LeafAlgorithm;
@@ -189,6 +193,7 @@ fn compute_node_layout(
             run_mode,
             sizing_mode,
         ),
+        #[cfg(feature = "flexbox")]
         (Display::Flex, true) => perform_computations::<FlexboxAlgorithm>(
             tree,
             node,

src/debug.rs

@@ -21,6 +21,7 @@ fn print_node(tree: &impl LayoutTree, node: Node, has_sibling: bool, lines_strin
     let display = match (num_children, style.display) {
         (_, style::Display::None) => "NONE",
         (0, _) => "LEAF",
+        #[cfg(feature = "flexbox")]
         (_, style::Display::Flex) => "FLEX",
         #[cfg(feature = "grid")]
         (_, style::Display::Grid) => "GRID",

src/geometry.rs

@@ -1,9 +1,12 @@
 //! Geometric primitives useful for layout
 
-use crate::style::{Dimension, FlexDirection};
+use crate::style::Dimension;
 use crate::sys::f32_max;
 use core::ops::Add;
 
+#[cfg(feature = "flexbox")]
+use crate::style::FlexDirection;
+
 #[cfg(feature = "grid")]
 use crate::axis::AbstractAxis;
 
@@ -61,6 +64,7 @@ impl<T> Rect<T> {
     /// When applied to the left and right sides, the width is used
     /// as the second parameter of `f`.
     /// When applied to the top or bottom sides, the height is used instead.
+    #[cfg(feature = "flexbox")]
     pub(crate) fn zip_size<R, F, U>(self, size: Size<U>, f: F) -> Rect<R>
     where
         F: Fn(T, U) -> R,
@@ -134,6 +138,7 @@ where
     ///
     /// If the [`FlexDirection`] is [`FlexDirection::Row`] or [`FlexDirection::RowReverse`], this is [`Rect::horizontal`].
     /// Otherwise, this is [`Rect::vertical`].
+    #[cfg(feature = "flexbox")]
     pub(crate) fn main_axis_sum(&self, direction: FlexDirection) -> U {
         if direction.is_row() {
             self.horizontal_axis_sum()
@@ -146,6 +151,7 @@ where
     ///
     /// If the [`FlexDirection`] is [`FlexDirection::Row`] or [`FlexDirection::RowReverse`], this is [`Rect::vertical`].
     /// Otherwise, this is [`Rect::horizontal`].
+    #[cfg(feature = "flexbox")]
     pub(crate) fn cross_axis_sum(&self, direction: FlexDirection) -> U {
         if direction.is_row() {
             self.vertical_axis_sum()
@@ -160,6 +166,7 @@ where
     T: Copy + Clone,
 {
     /// The `start` or `top` value of the [`Rect`], from the perspective of the main layout axis
+    #[cfg(feature = "flexbox")]
     pub(crate) fn main_start(&self, direction: FlexDirection) -> T {
         if direction.is_row() {
             self.left
@@ -169,6 +176,7 @@ where
     }
 
     /// The `end` or `bottom` value of the [`Rect`], from the perspective of the main layout axis
+    #[cfg(feature = "flexbox")]
     pub(crate) fn main_end(&self, direction: FlexDirection) -> T {
         if direction.is_row() {
             self.right
@@ -178,6 +186,7 @@ where
     }
 
     /// The `start` or `top` value of the [`Rect`], from the perspective of the cross layout axis
+    #[cfg(feature = "flexbox")]
     pub(crate) fn cross_start(&self, direction: FlexDirection) -> T {
         if direction.is_row() {
             self.top
@@ -187,6 +196,7 @@ where
     }
 
     /// The `end` or `bottom` value of the [`Rect`], from the perspective of the main layout axis
+    #[cfg(feature = "flexbox")]
     pub(crate) fn cross_end(&self, direction: FlexDirection) -> T {
         if direction.is_row() {
             self.bottom
@@ -301,6 +311,7 @@ impl<T> Size<T> {
     /// Sets the extent of the main layout axis
     ///
     /// Whether this is the width or height depends on the `direction` provided
+    #[cfg(feature = "flexbox")]
     pub(crate) fn set_main(&mut self, direction: FlexDirection, value: T) {
         if direction.is_row() {
             self.width = value
@@ -312,6 +323,7 @@ impl<T> Size<T> {
     /// Sets the extent of the cross layout axis
     ///
     /// Whether this is the width or height depends on the `direction` provided
+    #[cfg(feature = "flexbox")]
     pub(crate) fn set_cross(&mut self, direction: FlexDirection, value: T) {
         if direction.is_row() {
             self.height = value
@@ -324,6 +336,7 @@ impl<T> Size<T> {
     ///
     /// Whether this is the width or height depends on the `direction` provided
     #[allow(dead_code)]
+    #[cfg(feature = "flexbox")]
     pub(crate) fn with_main(self, direction: FlexDirection, value: T) -> Self {
         let mut new = self;
         if direction.is_row() {
@@ -337,6 +350,7 @@ impl<T> Size<T> {
     /// Creates a new value of type Self with the cross axis set to value provided
     ///
     /// Whether this is the width or height depends on the `direction` provided
+    #[cfg(feature = "flexbox")]
     pub(crate) fn with_cross(self, direction: FlexDirection, value: T) -> Self {
         let mut new = self;
         if direction.is_row() {
@@ -350,6 +364,7 @@ impl<T> Size<T> {
     /// Gets the extent of the main layout axis
     ///
     /// Whether this is the width or height depends on the `direction` provided
+    #[cfg(feature = "flexbox")]
     pub(crate) fn main(self, direction: FlexDirection) -> T {
         if direction.is_row() {
             self.width
@@ -361,6 +376,7 @@ impl<T> Size<T> {
     /// Gets the extent of the cross layout axis
     ///
     /// Whether this is the width or height depends on the `direction` provided
+    #[cfg(feature = "flexbox")]
     pub(crate) fn cross(self, direction: FlexDirection) -> T {
         if direction.is_row() {
             self.height

src/prelude.rs

@@ -1,9 +1,13 @@
 //! Commonly used types
 
-use crate::compute::LayoutAlgorithm;
-use crate::layout::{SizeAndBaselines, SizingMode};
+#[cfg(feature = "flexbox")]
+use crate::{
+    compute::LayoutAlgorithm,
+    layout::{SizeAndBaselines, SizingMode},
+};
 
 /// Apply the flexbox algorithm and recursively layout the specified node
+#[cfg(feature = "flexbox")]
 #[inline(always)]
 pub fn layout_flexbox(
     tree: &mut impl LayoutTree,
@@ -28,8 +32,8 @@ pub use crate::{
     layout::Layout,
     node::{Node, Taffy},
     style::{
-        AlignContent, AlignItems, AlignSelf, AvailableSpace, Dimension, Display, FlexDirection, FlexWrap,
-        JustifyContent, JustifyItems, JustifySelf, LengthPercentage, LengthPercentageAuto, Position, Style,
+        AlignContent, AlignItems, AlignSelf, AvailableSpace, Dimension, Display, JustifyContent, JustifyItems,
+        JustifySelf, LengthPercentage, LengthPercentageAuto, Position, Style,
     },
     style_helpers::{
         auto, fit_content, max_content, min_content, percent, points, zero, FromFlex, FromPercent, FromPoints,
@@ -38,6 +42,9 @@ pub use crate::{
     tree::LayoutTree,
 };
 
+#[cfg(feature = "flexbox")]
+pub use crate::style::{FlexDirection, FlexWrap};
+
 #[cfg(feature = "grid")]
 pub use crate::style::{
     GridAutoFlow, GridPlacement, GridTrackRepetition, MaxTrackSizingFunction, MinTrackSizingFunction,