notedeck

commit 15eea931def41515c8ef5bf350094b5365237351
parent 0a2935a31064bac26cf9e6da87cea4f4bae41919
Author: kernelkind <kernelkind@gmail.com>
Date:   Tue, 16 Dec 2025 14:23:33 -0500

feat(notedeck-ui): HorizontalHeader

Signed-off-by: kernelkind <kernelkind@gmail.com>

Diffstat:
M
crates/notedeck_ui/src/header.rs
 | 
151
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-

1 file changed, 150 insertions(+), 1 deletion(-)
diff --git a/crates/notedeck_ui/src/header.rs b/crates/notedeck_ui/src/header.rs
@@ -1,4 +1,5 @@
-use egui::Stroke;
+use egui::{Frame, Layout, Margin, Stroke, UiBuilder};
+use egui_extras::{Size, StripBuilder};
 
 pub fn chevron(
     ui: &mut egui::Ui,
@@ -21,3 +22,151 @@ pub fn chevron(
 
     r
 }
+
+/// Generic UI Widget to render widgets horizontally where each is aligned vertically
+pub struct HorizontalHeader {
+    height: f32,
+    margin: Margin,
+    layout: Layout,
+}
+
+impl HorizontalHeader {
+    pub fn new(height: f32) -> Self {
+        Self {
+            height,
+            margin: Margin::same(8),
+            layout: Layout::left_to_right(egui::Align::Center),
+        }
+    }
+
+    pub fn with_margin(mut self, margin: Margin) -> Self {
+        self.margin = margin;
+        self
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    pub fn ui(
+        self,
+        ui: &mut egui::Ui,
+        left_priority: i8, // lower the value, higher the priority
+        center_priority: i8,
+        right_priority: i8,
+        left_aligned: impl FnMut(&mut egui::Ui),
+        centered: impl FnMut(&mut egui::Ui),
+        right_aligned: impl FnMut(&mut egui::Ui),
+    ) {
+        let prev_spacing = ui.spacing().item_spacing.y;
+        ui.spacing_mut().item_spacing.y = 0.0;
+        Frame::new().inner_margin(self.margin).show(ui, |ui| {
+            let mut rect = ui.available_rect_before_wrap();
+            rect.set_height(self.height);
+
+            let mut child_ui = ui.new_child(UiBuilder::new().max_rect(rect));
+
+            horizontal_header_inner(
+                &mut child_ui,
+                self.layout,
+                left_priority,
+                center_priority,
+                right_priority,
+                left_aligned,
+                centered,
+                right_aligned,
+            );
+            ui.advance_cursor_after_rect(rect);
+        });
+        ui.spacing_mut().item_spacing.y = prev_spacing;
+    }
+}
+
+#[allow(clippy::too_many_arguments)]
+fn horizontal_header_inner(
+    ui: &mut egui::Ui,
+    layout: Layout,
+    left_priority: i8, // lower the value, higher the priority
+    center_priority: i8,
+    right_priority: i8,
+    left_aligned: impl FnMut(&mut egui::Ui),
+    centered: impl FnMut(&mut egui::Ui),
+    right_aligned: impl FnMut(&mut egui::Ui),
+) {
+    let item_spacing = 6.0 * ui.spacing().item_spacing.x;
+    let max_width = ui.available_width() - item_spacing;
+
+    let (left_width, left_aligned) = measure_width(ui, left_aligned);
+    let (center_width, centered) = measure_width(ui, centered);
+    let (right_width, right_aligned) = measure_width(ui, right_aligned);
+
+    let half_max = max_width / 2.0;
+    let half_center = center_width / 2.0;
+    let left_spacing = half_max - left_width - half_center;
+    let right_spacing = half_max - right_width - half_center;
+
+    let mut left_center = half_center;
+    let left_cell = if left_spacing > 0.0 || left_priority < center_priority {
+        Size::exact(left_width)
+    } else {
+        Size::remainder()
+    };
+    let mut left_gap = Size::exact(left_spacing.max(0.0));
+
+    if left_spacing <= 0.0 {
+        left_gap = Size::exact(0.0);
+        if left_priority < center_priority {
+            left_center = (half_center + left_spacing).max(0.0);
+        }
+    }
+
+    let mut center_cell = Size::exact((left_center + half_center).max(0.0));
+    let mut right_gap = Size::exact(right_spacing.max(0.0));
+    let mut right_cell = Size::exact(right_width);
+
+    if right_spacing <= 0.0 {
+        right_gap = Size::exact(0.0);
+        if center_priority < right_priority {
+            right_cell = Size::remainder();
+        } else {
+            center_cell = Size::remainder();
+        }
+    }
+
+    let sizes = [left_cell, left_gap, center_cell, right_gap, right_cell];
+
+    let mut builder = StripBuilder::new(ui);
+    for size in sizes {
+        builder = builder.size(size);
+    }
+
+    builder.cell_layout(layout).horizontal(|mut strip| {
+        strip.cell(left_aligned);
+        strip.empty();
+        strip.cell(centered);
+        strip.empty();
+        strip.cell(right_aligned);
+    });
+}
+
+/// Inspired by VirtualList::ui_custom_layout
+fn measure_width(
+    ui: &mut egui::Ui,
+    mut render: impl FnMut(&mut egui::Ui),
+) -> (f32, impl FnMut(&mut egui::Ui)) {
+    let mut measure_ui = ui.new_child(
+        UiBuilder::new()
+            .max_rect(ui.max_rect())
+            .layout(Layout::left_to_right(egui::Align::Min)),
+    );
+    measure_ui.set_invisible();
+
+    let start_width = measure_ui.next_widget_position();
+    let res = measure_ui.scope_builder(UiBuilder::new().id_salt(ui.id().with("measure")), |ui| {
+        render(ui);
+        render
+    });
+    let end_width = measure_ui.next_widget_position();
+
+    (
+        (end_width.x - start_width.x + ui.spacing().item_spacing.x).max(0.0),
+        res.inner,
+    )
+}