Masonry 是一个 Rust GUI 框架。

Masonry 提供了用于创建窗口的平台（使用 Glazier 作为后端），每个窗口都包含一个 Widget 树。它还提供了用于在 runtime 检测 Widget 树的工具，可编写单元测试，方便开发者调试和维护应用程序。

基于 Masonry，开发者可实现即时模式 (immediate-mode) GUI、Elm 架构、函数式响应 GUI 等。

示例代码

use masonry::widget::{
    Button, CrossAxisAlignment, Flex, Label, Portal, SizedBox, TextBox, WidgetMut,
};
use masonry::{
    Action, AppDelegate, AppLauncher, Color, DelegateCtx, Env, WidgetId, WindowDescription,
    WindowId,
};

struct Delegate {
    next_task: String,
}

impl AppDelegate for Delegate {
    fn on_action(
        &mut self,
        ctx: &mut DelegateCtx,
        action: Action,
    ) {
        match action {
            Action::ButtonPressed | Action::TextEntered(_) => {
                let mut root: WidgetMut<Portal<Flex>> = ctx.get_root();
                if self.next_task != "" {
                    let mut flex = root.child_mut();
                    flex.add_child(Label::new(self.next_task.clone()));
                }
            }
            Action::TextChanged(new_text) => {
                self.next_task = new_text.clone();
            }
            _ => {}
        }
    }
}

fn main() {
    // The main button and text box with some space below,
    // all inside a scrollable area.
    let root_widget = Portal::new(
        Flex::column()
            .with_child(
                Flex::row()
                    .with_child(TextBox::new(""))
                    .with_child(Button::new("Add task")),
            )
            .with_spacer(VERTICAL_WIDGET_SPACING),
    )
    .constrain_horizontal(true);

    let main_window = WindowDescription::new(root_widget)
        .title("To-do list")
        .window_size((400.0, 400.0));

    AppLauncher::with_window(main_window)
        .with_delegate(Delegate {
            next_task: String::new(),
        })
        .launch()
        .expect("Failed to launch application");
}