all: remove traditional i3 titlebars, add corner rounding

src/theme.rs

@@ -643,6 +643,95 @@ impl Into<ConfigBarPosition> for BarPosition {
     }
 }
 
+/// Per-corner radius for rounded rectangles.
+///
+/// Each field specifies the radius (in logical pixels) for one corner.
+/// A radius of 0 means a square corner.
+#[derive(Copy, Clone, Debug, Default, PartialEq)]
+pub struct CornerRadius {
+    pub top_left: f32,
+    pub top_right: f32,
+    pub bottom_right: f32,
+    pub bottom_left: f32,
+}
+
+impl From<f32> for CornerRadius {
+    fn from(value: f32) -> Self {
+        Self {
+            top_left: value,
+            top_right: value,
+            bottom_right: value,
+            bottom_left: value,
+        }
+    }
+}
+
+impl From<CornerRadius> for [f32; 4] {
+    fn from(cr: CornerRadius) -> Self {
+        [cr.top_left, cr.top_right, cr.bottom_right, cr.bottom_left]
+    }
+}
+
+impl CornerRadius {
+    /// Shrink or grow all radii by `width`. Radii that are 0 stay 0 (square
+    /// corners remain square). Negative `width` shrinks; the result is clamped
+    /// to 0.
+    pub fn expanded_by(mut self, width: f32) -> Self {
+        if self.top_left > 0.0 {
+            self.top_left = (self.top_left + width).max(0.0);
+        }
+        if self.top_right > 0.0 {
+            self.top_right = (self.top_right + width).max(0.0);
+        }
+        if self.bottom_right > 0.0 {
+            self.bottom_right = (self.bottom_right + width).max(0.0);
+        }
+        if self.bottom_left > 0.0 {
+            self.bottom_left = (self.bottom_left + width).max(0.0);
+        }
+        self
+    }
+
+    /// Scale all radii by a factor (e.g. for HiDPI).
+    pub fn scaled_by(self, scale: f32) -> Self {
+        Self {
+            top_left: self.top_left * scale,
+            top_right: self.top_right * scale,
+            bottom_right: self.bottom_right * scale,
+            bottom_left: self.bottom_left * scale,
+        }
+    }
+
+    /// Reduce all radii proportionally so that adjacent corners don't overlap,
+    /// following the CSS spec algorithm.
+    pub fn fit_to(self, width: f32, height: f32) -> Self {
+        let reduction = f32::min(
+            f32::min(
+                width / (self.top_left + self.top_right),
+                width / (self.bottom_left + self.bottom_right),
+            ),
+            f32::min(
+                height / (self.top_left + self.bottom_left),
+                height / (self.top_right + self.bottom_right),
+            ),
+        );
+        let reduction = f32::min(1.0, reduction);
+        Self {
+            top_left: self.top_left * reduction,
+            top_right: self.top_right * reduction,
+            bottom_right: self.bottom_right * reduction,
+            bottom_left: self.bottom_left * reduction,
+        }
+    }
+
+    pub fn is_zero(&self) -> bool {
+        self.top_left == 0.0
+            && self.top_right == 0.0
+            && self.bottom_right == 0.0
+            && self.bottom_left == 0.0
+    }
+}
+
 pub struct Theme {
     pub colors: ThemeColors,
     pub sizes: ThemeSizes,
@@ -650,9 +739,12 @@ pub struct Theme {
     pub bar_font: CloneCell<Option<Arc<String>>>,
     pub title_font: CloneCell<Option<Arc<String>>>,
     pub default_font: Arc<String>,
+    #[allow(dead_code)]
     pub show_titles: Cell<bool>,
+    #[allow(dead_code)]
     pub floating_titles: Cell<bool>,
     pub bar_position: Cell<BarPosition>,
+    pub corner_radius: Cell<CornerRadius>,
 }
 
 impl Default for Theme {
@@ -668,50 +760,22 @@ impl Default for Theme {
             show_titles: Cell::new(true),
             floating_titles: Cell::new(false),
             bar_position: Default::default(),
+            corner_radius: Cell::new(CornerRadius::default()),
         }
     }
 }
 
 impl Theme {
-    pub fn title_font(&self) -> Arc<String> {
-        self.title_font.get().unwrap_or_else(|| self.font.get())
-    }
-
     pub fn bar_font(&self) -> Arc<String> {
         self.bar_font.get().unwrap_or_else(|| self.font.get())
     }
 
     pub fn title_height(&self) -> i32 {
-        if self.show_titles.get() {
-            self.sizes.title_height.get()
-        } else {
-            0
-        }
-    }
-
-    pub fn title_underline_height(&self) -> i32 {
-        if self.show_titles.get() { 1 } else { 0 }
-    }
-
-    pub fn floating_title_top_margin(&self) -> i32 {
-        if self.floating_titles.get() && self.sizes.gap.get() != 0 {
-            self.sizes.border_width.get()
-        } else {
-            0
-        }
+        0
     }
 
     pub fn title_plus_underline_height(&self) -> i32 {
-        if self.show_titles.get() {
-            if self.floating_titles.get() && self.sizes.gap.get() != 0 {
-                let bw = self.sizes.border_width.get();
-                3 * bw + self.sizes.title_height.get() + self.sizes.title_gap.get()
-            } else {
-                self.sizes.title_height.get() + 1
-            }
-        } else {
-            0
-        }
+        0
     }
 }