lv_tui/widgets/
stack.rs

1use crate::component::{Component, EventCx, LayoutCx, MeasureCx};
2use crate::event::Event;
3use crate::geom::{Rect, Size};
4use crate::layout::Constraint;
5use crate::node::Node;
6use crate::render::RenderCx;
7use crate::style::{Layout, Style};
8
9/// 层叠容器 widget——子组件共享同一区域，按添加顺序自底向上渲染
10pub struct Stack {
11    children: Vec<Node>,
12    style: Style,
13}
14
15impl Stack {
16    pub fn new() -> Self {
17        Self {
18            children: Vec::new(),
19            style: Style::default().layout(Layout::Horizontal),
20        }
21    }
22
23    pub fn child(mut self, component: impl Component + 'static) -> Self {
24        self.children.push(Node::new(component));
25        self
26    }
27
28    pub fn padding(mut self, value: u16) -> Self {
29        self.style = self.style.padding(value);
30        self
31    }
32}
33
34impl Component for Stack {
35    fn render(&self, cx: &mut RenderCx) {
36        for child in &self.children {
37            child.render_with_parent(cx.buffer, cx.focused_id, cx.clip_rect, cx.wrap, cx.truncate, cx.align, Some(&cx.style));
38        }
39    }
40
41    fn for_each_child(&self, f: &mut dyn FnMut(&Node)) {
42        for child in &self.children {
43            f(child);
44        }
45    }
46
47    fn for_each_child_mut(&mut self, f: &mut dyn FnMut(&mut Node)) {
48        for child in &mut self.children {
49            f(child);
50        }
51    }
52
53    fn measure(&self, constraint: Constraint, _cx: &mut MeasureCx) -> Size {
54        let mut max_w: u16 = 0;
55        let mut max_h: u16 = 0;
56        for child in &self.children {
57            let s = child.measure(constraint);
58            max_w = max_w.max(s.width);
59            max_h = max_h.max(s.height);
60        }
61        Size {
62            width: max_w.saturating_add(self.style.padding.left).saturating_add(self.style.padding.right),
63            height: max_h.saturating_add(self.style.padding.top).saturating_add(self.style.padding.bottom),
64        }
65    }
66
67    fn focusable(&self) -> bool {
68        false
69    }
70
71
72    fn event(&mut self, event: &Event, cx: &mut EventCx) {
73        if matches!(event, Event::Focus | Event::Blur | Event::Tick) {
74            return;
75        }
76
77        // 从上到下分发（后添加的在上层，优先处理）
78        for child in self.children.iter_mut().rev() {
79            let mut child_cx =
80                EventCx::with_task_sender(&mut child.dirty, cx.global_dirty, cx.quit, cx.phase, cx.propagation_stopped, cx.task_sender.clone());
81            child.component.event(event, &mut child_cx);
82        }
83    }
84
85    fn layout(&mut self, rect: Rect, _cx: &mut LayoutCx) {
86        let inner = rect.inner(self.style.padding);
87        for child in &mut self.children {
88            child.layout(inner);
89        }
90    }
91
92    fn style(&self) -> Style {
93        self.style.clone()
94    }
95}
lv_tui/widgets/stack.rs

lv_tui/widgets/
stack.rs
