ui: Add widgets::Label.

all-is-cubes-ui/src/vui/widgets/text.rs

@@ -1,17 +1,18 @@
 use alloc::sync::Arc;
 
 use all_is_cubes::arcstr::ArcStr;
+use all_is_cubes::block::text::{self, Text as BlockText};
 use all_is_cubes::drawing::embedded_graphics::{
     mono_font::{MonoFont, MonoTextStyle},
     prelude::{Dimensions, Point},
-    text::{Text, TextStyle},
+    text::{Text as EgText, TextStyle},
     Drawable,
 };
 use all_is_cubes::drawing::{rectangle_to_aab, VoxelBrush};
 use all_is_cubes::math::{GridAab, Gridgid};
 use all_is_cubes::space::SpaceTransaction;
 
-use crate::vui::{widgets, LayoutGrant, LayoutRequest, Layoutable, Widget, WidgetController};
+use crate::vui::{self, widgets, LayoutGrant, LayoutRequest, Layoutable, Widget, WidgetController};
 
 /// Widget which draws text using a block per font pixel.
 ///
@@ -33,8 +34,8 @@ pub struct LargeText {
 }
 
 impl LargeText {
-    fn drawable(&self) -> Text<'_, MonoTextStyle<'_, &VoxelBrush<'_>>> {
-        Text::with_text_style(
+    fn drawable(&self) -> EgText<'_, MonoTextStyle<'_, &VoxelBrush<'_>>> {
+        EgText::with_text_style(
             &self.text,
             Point::new(0, 0),
             MonoTextStyle::new((self.font)(), &self.brush),
@@ -83,15 +84,90 @@ impl Widget for LargeText {
     }
 }
 
+/// Widget which draws a static [`Text`](BlockText) for use as a text label in UI.
+///
+/// This cannot be used for dynamic text.
+#[derive(Clone, Debug)]
+pub struct Label {
+    text: ArcStr,
+    font: text::Font,
+}
+
+impl Label {
+    /// Constructs a [`Label`] that draws the given text.
+    pub fn new(text: ArcStr) -> Self {
+        Self {
+            text,
+            font: text::Font::System16,
+        }
+    }
+}
+
+impl Layoutable for Label {
+    fn requirements(&self) -> LayoutRequest {
+        // TODO: memoize
+        LayoutRequest {
+            minimum: text_for_widget(
+                self.text.clone(),
+                self.font.clone(),
+                vui::Gravity::splat(vui::Align::Center),
+            )
+            .bounding_blocks()
+            .size(),
+        }
+    }
+}
+
+impl Widget for Label {
+    fn controller(self: Arc<Self>, grant: &LayoutGrant) -> Box<dyn WidgetController> {
+        // TODO: memoize `Text` construction for slightly more efficient reuse of widget
+        // (this will only matter once `Text` memoizes glyph layout)
+
+        widgets::OneshotController::new(draw_text_txn(
+            &text_for_widget(self.text.clone(), self.font.clone(), grant.gravity),
+            grant,
+        ))
+    }
+}
+
+fn text_for_widget(text: ArcStr, font: text::Font, gravity: vui::Gravity) -> text::Text {
+    text::Text::new(
+        text,
+        font,
+        text::Positioning {
+            x: match gravity.x {
+                vui::Align::Low => text::PositioningX::Left,
+                vui::Align::Center => text::PositioningX::Center,
+                vui::Align::High => text::PositioningX::Right,
+            },
+            // TODO: need to be able to set the anchor to produce middle-of-block
+            line_y: text::PositioningY::BodyBottom,
+            z: 0,
+        },
+    )
+}
+
+fn draw_text_txn(text: &BlockText, grant: &LayoutGrant) -> SpaceTransaction {
+    let text_aabb = text.bounding_blocks();
+    let grant = grant.shrink_to(text_aabb.size(), true);
+    text.installation(
+        Gridgid::from_translation(grant.bounds.lower_bounds() - text_aabb.lower_bounds()),
+        core::convert::identity,
+    )
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::vui;
+    use all_is_cubes::arcstr::literal;
     use all_is_cubes::block::Block;
     use all_is_cubes::drawing::embedded_graphics::mono_font::iso_8859_1::FONT_9X15_BOLD;
     use all_is_cubes::math::{GridVector, Rgba};
+    use all_is_cubes::space::{SpaceBuilder, SpacePhysics};
 
     #[test]
-    fn text_size() {
+    fn large_text_size() {
         let text = "abc";
         let widget = LargeText {
             text: text.into(),
@@ -106,4 +182,16 @@ mod tests {
             }
         );
     }
+
+    #[test]
+    fn label_layout() {
+        let tree: vui::WidgetTree = vui::LayoutTree::leaf(Arc::new(Label::new(literal!("hi"))));
+
+        // to_space() serves as a transaction sanity check. TODO: make a proper tester
+        tree.to_space(
+            SpaceBuilder::default().physics(SpacePhysics::DEFAULT_FOR_BLOCK),
+            vui::Gravity::new(vui::Align::Center, vui::Align::Center, vui::Align::Low),
+        )
+        .unwrap();
+    }
 }