feat(custom): add halign and valign options to box widget (#988)

docs/modules/Custom.md

@@ -47,6 +47,8 @@ A container to place nested widgets inside.
 |---------------|------------------------------------------------------------|----------------|-------------------------------------------------------------------|
 | `orientation` | `'horizontal'` or `'vertical'` (shorthand: `'h'` or `'v'`) | `'horizontal'` | Whether child widgets should be horizontally or vertically added. |
 | `widgets`     | `(Module or Widget)[]`                                     | `[]`           | List of modules/widgets to add to this box.                       |
+| `halign`      | `'start'` or `'center'` or `'end'` or `'fill'`             | `'fill'`       | The horizontal alignment of the box within its parent container.   |
+| `valign`      | `'start'` or `'center'` or `'end'` or `'fill'`             | `'fill'`       | The vertical alignment of the box within its parent container.     |
 
 #### Label
 

src/modules/custom/box.rs

@@ -5,6 +5,31 @@ use crate::modules::custom::WidgetConfig;
 use gtk::prelude::*;
 use serde::Deserialize;
 
+#[derive(Debug, Deserialize, Clone)]
+#[serde(rename_all = "lowercase")]
+#[cfg_attr(feature = "schema", derive(schemars::JsonSchema))]
+pub enum ModuleAlignment {
+    /// Align widget to the start (left for horizontal, top for vertical).
+    Start,
+    /// Align widget to the center.
+    Center,
+    /// Align widget to the end (right for horizontal, bottom for vertical).
+    End,
+    /// Stretch widget to fill available space.
+    Fill,
+}
+
+impl From<ModuleAlignment> for gtk::Align {
+    fn from(align: ModuleAlignment) -> Self {
+        match align {
+            ModuleAlignment::Start => gtk::Align::Start,
+            ModuleAlignment::Center => gtk::Align::Center,
+            ModuleAlignment::End => gtk::Align::End,
+            ModuleAlignment::Fill => gtk::Align::Fill,
+        }
+    }
+}
+
 #[derive(Debug, Deserialize, Clone)]
 #[cfg_attr(feature = "schema", derive(schemars::JsonSchema))]
 pub struct BoxWidget {
@@ -21,10 +46,21 @@ pub struct BoxWidget {
     /// Whether child widgets should be horizontally or vertically added.
     ///
     /// **Valid options**: `horizontal`, `vertical`, `h`, `v`
-    /// <br />
     /// **Default**: `horizontal`
     orientation: Option<ModuleOrientation>,
 
+    /// Horizontal alignment of the box relative to its parent.
+    ///
+    /// **Valid options**: `start`, `center`, `end`, `fill`
+    /// **Default**: `fill`
+    halign: Option<ModuleAlignment>,
+
+    /// Vertical alignment of the box relative to its parent.
+    ///
+    /// **Valid options**: `start`, `center`, `end`, `fill`
+    /// **Default**: `fill`
+    valign: Option<ModuleAlignment>,
+
     /// Modules and widgets to add to this box.
     ///
     /// **Default**: `null`
@@ -47,6 +83,12 @@ impl CustomWidget for BoxWidget {
             }
         }
 
+        let horizontal_alignment = self.halign.unwrap_or(ModuleAlignment::Fill);
+        let vertical_alignment = self.valign.unwrap_or(ModuleAlignment::Fill);
+
+        container.set_halign(horizontal_alignment.into());
+        container.set_valign(vertical_alignment.into());
+
         container
     }
 }