T00 foundation: theme, motion, assets, icon, buttons, gallery

Theme tokens in light and dark with high contrast, a palette cross-fade,
motion curves and a damped spring, embedded Lucide icons with Inter and
JetBrains Mono, Icon, Button, IconButton, and a gallery that captures
its own window. Reviewed by codex gpt-6-astra (max): PASS in round 3.

src/buttons/icon_button.rs

@@ -0,0 +1,89 @@
+use gpui::{
+    App, ClickEvent, ElementId, IntoElement, MouseButton, RenderOnce, Window, div, prelude::*,
+};
+
+use super::button::{ButtonVariant, ClickHandler, label_size, tone};
+use crate::{
+    primitives::{Icon, IconName},
+    theme::{ActiveTheme, ControlSize, Radius},
+};
+
+/// Square button holding one icon.
+#[derive(IntoElement)]
+pub struct IconButton {
+    id: ElementId,
+    icon: IconName,
+    variant: ButtonVariant,
+    size: ControlSize,
+    disabled: bool,
+    on_click: Option<ClickHandler>,
+}
+
+impl IconButton {
+    pub fn new(id: impl Into<ElementId>, icon: IconName) -> Self {
+        Self {
+            id: id.into(),
+            icon,
+            variant: ButtonVariant::Ghost,
+            size: ControlSize::default(),
+            disabled: false,
+            on_click: None,
+        }
+    }
+
+    pub fn variant(mut self, variant: ButtonVariant) -> Self {
+        self.variant = variant;
+        self
+    }
+
+    pub fn size(mut self, size: ControlSize) -> Self {
+        self.size = size;
+        self
+    }
+
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.disabled = disabled;
+        self
+    }
+
+    pub fn on_click(
+        mut self,
+        handler: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_click = Some(Box::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for IconButton {
+    fn render(self, _: &mut Window, cx: &mut App) -> impl IntoElement {
+        let theme = cx.theme();
+        let tone = tone(self.variant, &theme.colors);
+        let (_, icon_size) = label_size(self.size);
+        let side = theme.control_height(self.size);
+
+        div()
+            .id(self.id)
+            .flex()
+            .flex_none()
+            .items_center()
+            .justify_center()
+            .size(side)
+            .rounded(theme.radius(Radius::Md))
+            .bg(tone.bg)
+            .when_some(tone.border, |el, border| el.border_1().border_color(border))
+            .child(Icon::new(self.icon).size(icon_size).color(tone.fg))
+            .map(|el| {
+                if self.disabled {
+                    return el.opacity(0.45).cursor_not_allowed();
+                }
+                el.cursor_pointer()
+                    .tab_index(0)
+                    .hover(|style| style.bg(tone.hover))
+                    .active(|style| style.bg(tone.pressed))
+                    .focus(|style| style.shadow(theme.focus_ring()))
+                    .on_mouse_down(MouseButton::Left, |_, window, _| window.prevent_default())
+                    .when_some(self.on_click, |el, handler| el.on_click(handler))
+            })
+    }
+}