Set PickerGroupBox width to largest group, center Picker

This more or less works. Scaling in increments doesn't seem to be
possible, so centering is really only possible for the group box alone,
or with a limit to width.

Author: ids1024

src/picker/group_box/mod.rs

@@ -46,11 +46,6 @@ impl ObjectImpl for PickerGroupBoxInner {
         });
         SIGNALS.as_ref()
     }
-
-    fn constructed(&self, widget: &Self::Type) {
-        self.parent_constructed(widget);
-        widget.set_halign(gtk::Align::Center);
-    }
 }
 
 impl WidgetImpl for PickerGroupBoxInner {
@@ -59,24 +54,13 @@ impl WidgetImpl for PickerGroupBoxInner {
     }
 
     fn preferred_width(&self, _widget: &Self::Type) -> (i32, i32) {
-        let minimum_width = self
+        let width = self
             .groups
             .iter()
             .map(|x| x.widget().preferred_width().1)
             .max()
             .unwrap_or(0);
-        let natural_width = self
-            .groups
-            .chunks(3)
-            .map(|row| {
-                row.iter()
-                    .map(|x| x.widget().preferred_width().1)
-                    .sum::<i32>()
-            })
-            .max()
-            .unwrap_or(0)
-            + 2 * HSPACING;
-        (minimum_width, natural_width)
+        (width, width)
     }
 
     fn preferred_height_for_width(&self, widget: &Self::Type, width: i32) -> (i32, i32) {
@@ -85,34 +69,6 @@ impl WidgetImpl for PickerGroupBoxInner {
         (height, height)
     }
 
-    fn adjust_size_allocation(
-        &self,
-        obj: &Self::Type,
-        orientation: gtk::Orientation,
-        minimum_size: &mut i32,
-        natural_size: &mut i32,
-        allocated_pos: &mut i32,
-        allocated_size: &mut i32,
-    ) {
-        // For centering to work, adjust natural width to be the portion of
-        // allocated width that will actually be used after reflowing
-        // children.
-        if orientation == gtk::Orientation::Horizontal {
-            let rows = obj.rows_for_width(*allocated_size);
-            let total_width = max_width_for_rows(&rows);
-            *natural_size = (*natural_size).min(total_width);
-        }
-
-        self.parent_adjust_size_allocation(
-            obj,
-            orientation,
-            minimum_size,
-            natural_size,
-            allocated_pos,
-            allocated_size,
-        );
-    }
-
     fn size_allocate(&self, obj: &Self::Type, allocation: &gtk::Allocation) {
         self.parent_size_allocate(obj, allocation);
 

src/picker/mod.rs

@@ -96,6 +96,7 @@ impl ObjectImpl for PickerInner {
         cascade! {
             picker;
             ..set_orientation(gtk::Orientation::Vertical);
+            ..set_halign(gtk::Align::Center);
             ..add(&stack_switcher);
             ..add(&stack);
             ..show_all();