feat(core/rust): First shot at Paragraphs API

core/embed/rust/src/ui/component/text/mod.rs

@@ -1,2 +1,3 @@
 pub mod formatted;
 pub mod layout;
+pub mod paragraphs;

core/embed/rust/src/ui/component/text/paragraphs.rs

@@ -0,0 +1,131 @@
+use heapless::Vec;
+
+use crate::ui::{
+    component::{Component, Event, EventCtx, Never},
+    display::Font,
+    geometry::{Dimensions, LinearLayout, Offset, Rect},
+};
+
+use super::layout::{DefaultTextTheme, TextLayout, TextNoop, TextRenderer};
+
+pub const MAX_PARAGRAPHS: usize = 6;
+
+pub struct Paragraphs<T> {
+    area: Rect,
+    list: Vec<Paragraph<T>, MAX_PARAGRAPHS>,
+    layout: LinearLayout,
+}
+
+impl<T> Paragraphs<T>
+where
+    T: AsRef<[u8]>,
+{
+    pub fn new(area: Rect) -> Self {
+        Self {
+            area,
+            list: Vec::new(),
+            layout: LinearLayout::vertical().align_at_center().with_spacing(10),
+        }
+    }
+
+    pub fn with_layout(mut self, layout: LinearLayout) -> Self {
+        self.layout = layout;
+        self
+    }
+
+    pub fn add<D: DefaultTextTheme>(mut self, text_font: Font, content: T) -> Self {
+        let paragraph = Paragraph::new(
+            content,
+            TextLayout {
+                text_font,
+                ..TextLayout::new::<D>(self.area)
+            },
+        );
+        if self.list.push(paragraph).is_err() {
+            #[cfg(feature = "ui_debug")]
+            panic!("paragraph list is full");
+        }
+        self
+    }
+
+    pub fn arrange(mut self) -> Self {
+        self.layout.arrange(self.area, &mut self.list);
+        self
+    }
+}
+
+impl<T> Component for Paragraphs<T>
+where
+    T: AsRef<[u8]>,
+{
+    type Msg = Never;
+
+    fn event(&mut self, _ctx: &mut EventCtx, _event: Event) -> Option<Self::Msg> {
+        None
+    }
+
+    fn paint(&mut self) {
+        for paragraph in &mut self.list {
+            paragraph.paint();
+        }
+    }
+}
+
+pub struct Paragraph<T> {
+    content: T,
+    layout: TextLayout,
+    size: Offset,
+}
+
+impl<T> Paragraph<T>
+where
+    T: AsRef<[u8]>,
+{
+    pub fn new(content: T, layout: TextLayout) -> Self {
+        Self {
+            size: Self::measure(&content, layout),
+            content,
+            layout,
+        }
+    }
+
+    fn measure(content: &T, layout: TextLayout) -> Offset {
+        let mut cursor = layout.initial_cursor();
+        layout.layout_text(content.as_ref(), &mut cursor, &mut TextNoop);
+        let width = layout.bounds.width();
+        let height = cursor.y - layout.initial_cursor().y;
+        Offset::new(width, height)
+    }
+}
+
+impl<T> Dimensions for Paragraph<T>
+where
+    T: AsRef<[u8]>,
+{
+    fn get_size(&mut self) -> Offset {
+        self.size
+    }
+
+    fn set_area(&mut self, area: Rect) {
+        self.layout.bounds = area;
+    }
+}
+
+impl<T> Component for Paragraph<T>
+where
+    T: AsRef<[u8]>,
+{
+    type Msg = Never;
+
+    fn event(&mut self, _ctx: &mut EventCtx, _event: Event) -> Option<Self::Msg> {
+        None
+    }
+
+    fn paint(&mut self) {
+        self.layout.layout_text(
+            self.content.as_ref(),
+            &mut self.layout.initial_cursor(),
+            &mut TextRenderer,
+        );
+    }
+}