Bevy UI Build macros

This crate won't receive any update and won't be compatible with newer versions of bevy.

Prefer either:

• bevy_ui_dsl
• cuicui_dsl

A collection of macros to speed up the process of defining UIs in bevy.

Bevy version

We do not specify the bevy version we depend on. The reason is mostly that I rely on a personal fork of bevy, and it's a complete hassle to fork every bevy library to make them work with my own fork of bevy.

Since this does nothing else than define macros, there is no compiled code in this crate. the only requirements for the macro to work is that the few bevy symbols we rely on are in scope where the macros are called. The bevy symbols we explicity use are:

• bevy::ecs::system::Insert
• bevy::math::{Rect::{self, all}, Size::new}
• bevy::prelude::Parent
• bevy::ui::{entity::NodeBundle, Style, Val::{Percent, Px}}

Macros

The macros are nothing more than wrappers around the struct commonly used when defining bevy UIs.

// unit! -- UNIT --
unit!(10 px); unit!(100 pct); 
// Equivalent to
Val::Px(10.0); Val::Percent(100.0);

// style! -- STYLE --
style! {
  flex_wrap: FlexWrap::Wrap,
  flex_basis: unit!(90 pct),
};
// Equivalent to
Style {
   flex_wrap: FlexWrap::Wrap,
   flex_basis: unit!(90 pct),
   ..Default::default()
};

// size! -- SIZE --
size!(100 pct, 90 pct); size!(90 px, 40 px);
// Equivalent to
Size::new(Val::Percent(100.0), Val::Percent(90.0));
Size::new(Val::Px(90.0), Val::Px(40.0));

// rect! -- RECT --
rect!(10 px); rect!(5 px, 0 px); rect!(100 pct, 10 pct, 50 pct, 0 pct);
// Equivalent to
Rect::all(Val::Px(10.0));
Rect {
    left: Val::Px(5.0),
    right: Val::Px(5.0),
    top: Val::Px(0.0),
    bottom: Val::Px(0.0),
};
Rect {
    left: Val::Percent(100.0),
    top: Val::Percent(10.0),
    right: Val::Percent(50.0),
    bottom: Val::Percent(0.0),
};

// build_ui! -- BUILD_UI --
build_ui! {
     #[cmd(commands)]
     vertical{size:size!(100 pct, 100 pct)}(
         horizontal{justify_content: FlexStart, flex_basis: unit!(10 pct)}(
             tab_square[;focus], tab_square[;focus], tab_square[;focus]
         ),
         column_box(
             column[;red](
                 vertical(select_square, select_square),
                 horizontal{flex_wrap: Wrap}[gray](
                     square[;focus], square[;focus], square[;focus], square[;focus],
                     square[;focus], square[;focus], square[;focus], square[;focus],
                     square[;focus], square[;focus], square[;focus], square[;focus]
                 ),
                 horizontal{flex_wrap: Wrap}[gray](
                     square[;focus], square[;focus], square[;focus], square[;focus],
                     square[;focus], square[;focus], square[;focus], square[;focus]
                 )
             )
         )
     )
}
// Equivalent to
commands.spawn_bundle(NodeBundle {
    style: Style { size: size!(100 pct, 100 pct), .. vertical.style },
    .. vertical
})
  .with_children(|cmds| {
    cmds.spawn_bundle(NodeBundle {
        style: Style {justify_content: FlexStart, flex_basis: unit!(10 pct), .. horizontal.style },
        .. horizontal
    })
      .with_children(|cmds| {
        cmds.spawn_bundle(tab_square).insert(focus);
        cmds.spawn_bundle(tab_square).insert(focus);
        cmds.spawn_bundle(tab_square).insert(focus);
      });
    cmds.spawn_bundle(column_box)
      .with_children(|cmds| {
        cmds.spawn_bundle(column).insert(red)
          .with_children(|cmds| {
            vertical.with_children(|cmds| {
              cmds.spawn_bundle(select_square);
              cmds.spawn_bundle(select_square);
            });
            cmds.spawn_bundle(NodeBundle {
                style: Style {flex_wrap: Wrap, ..horizontal.style},
                .. horizontal
            }).insert(gray)
              .with_children(|cmds| {
                for _ in 0..12 {
                  cmds.spawn_bundle(square).insert(focus);
                }
              });
            cmds.spawn_bundle(NodeBundle {
                style: Style {flex_wrap: Wrap, ..horizontal.style},
                .. horizontal
            }).insert(gray)
              .with_children(|cmds| {
                for _ in 0..8 {
                  cmds.spawn_bundle(square).insert(focus);
                }
              });
          });
      });
  });

Changelog

• 0.6.1: (non-breaking) Add deprecation banner.
• 0.6.0: (non-breaking) Make the terminal comma in the four argument rect! variant optional.
• 0.5.0: Bevy 0.9 support
• 0.4.0: Bevy 0.8 support, use bevy::ui::Size and bevy::ui::UiRect over math::Size and math::Rect
• 0.3.0
  • Now it's possible in build_ui to end the children list with a comma
  • Added conditional children. Just wrap the children you want to only add conditionally in a if, you can add as many if in a children list. This also support if else. Important: you need to put your predicate between parenthesis if (predicate) { ... } due to a limitation of rust macros.
• 0.2.1
  • Added undefined and auto arguments to unit!, this also applies to unit-style arguments to size! and rect!
• 0.2.0

  • Breaking: The build_ui! macro now uses [bundle;comp] instead of just a list of components between square brackets. This makes it possible to specify a list of components. This however requires having the semicolon at the beginning of the square brackets if you only want to specify additional components. [;like, this]

License

This is weird. Since this code literally cannot produce distributable binary code, I don't think any of the mainstream license apply. On top of that, I usually license small libraries under the WTFPL. But I'll be a good community player and dual license under MIT or Apache 2.0 at your leisure.

Copyright © Nicola Papale, see LICENSE file for licensing details.