Update scroll_area.rs

crates/egui/src/containers/scroll_area.rs

@@ -960,19 +960,32 @@ impl Prepared {
             let main_range = Rangef::new(inner_rect.min[d], inner_rect.max[d]);
 
             // Margin on either side of the scroll bar:
-            let inner_margin = show_factor * scroll_style.bar_inner_margin;
             let outer_margin = show_factor * scroll_style.bar_outer_margin;
 
+            let mut max_cross = outer_rect.max[1 - d] - outer_margin;
+            if ui.clip_rect().max[1 - d] < max_cross + outer_margin {
+                // Move the scrollbar so it is visible. This is needed in some cases.
+                // For instance:
+                // * When we have a vertical-only scroll area in a top level panel,
+                //   and that panel is not wide enough for the contents.
+                // * When one ScrollArea is nested inside another, and the outer
+                //   is scrolled so that the scroll-bars of the inner ScrollArea (us)
+                //   is outside the clip rectangle.
+                // Really this should use the tighter clip_rect that ignores clip_rect_margin, but we don't store that.
+                // clip_rect_margin is quite a hack. It would be nice to get rid of it.
+                max_cross = ui.clip_rect().max[1 - d] - outer_margin;
+            }
+
             // top/bottom of a horizontal scroll (d==0).
             // left/rigth of a vertical scroll (d==1).
-            let mut cross = if scroll_style.floating {
+            let cross = if scroll_style.floating {
                 let max_bar_rect = if d == 0 {
-                    outer_rect.with_min_y(outer_rect.max.y - scroll_style.allocated_width())
+                    outer_rect.with_min_y(max_cross - scroll_style.bar_width)
                 } else {
-                    outer_rect.with_min_x(outer_rect.max.x - scroll_style.allocated_width())
+                    outer_rect.with_min_x(max_cross - scroll_style.bar_width)
                 };
-                let is_hovering_bar_area = is_hovering_outer_rect
-                    && ui.rect_contains_pointer(max_bar_rect)
+                let is_hovering_bar_area = (is_hovering_outer_rect
+                    && ui.rect_contains_pointer(max_bar_rect))
                     || state.scroll_bar_interaction[d];
                 let is_hovering_bar_area_t = ui
                     .ctx()
@@ -983,30 +996,13 @@ impl Prepared {
                         is_hovering_bar_area_t,
                     );
 
-                let max_cross = outer_rect.max[1 - d] - outer_margin;
                 let min_cross = max_cross - width;
                 Rangef::new(min_cross, max_cross)
             } else {
-                let min_cross = inner_rect.max[1 - d] + inner_margin;
-                let max_cross = outer_rect.max[1 - d] - outer_margin;
+                let min_cross = max_cross - scroll_style.bar_width;
                 Rangef::new(min_cross, max_cross)
             };
 
-            if ui.clip_rect().max[1 - d] < cross.max + outer_margin {
-                // Move the scrollbar so it is visible. This is needed in some cases.
-                // For instance:
-                // * When we have a vertical-only scroll area in a top level panel,
-                //   and that panel is not wide enough for the contents.
-                // * When one ScrollArea is nested inside another, and the outer
-                //   is scrolled so that the scroll-bars of the inner ScrollArea (us)
-                //   is outside the clip rectangle.
-                // Really this should use the tighter clip_rect that ignores clip_rect_margin, but we don't store that.
-                // clip_rect_margin is quite a hack. It would be nice to get rid of it.
-                let width = cross.max - cross.min;
-                cross.max = ui.clip_rect().max[1 - d] - outer_margin;
-                cross.min = cross.max - width;
-            }
-
             let outer_scroll_rect = if d == 0 {
                 Rect::from_min_max(
                     pos2(inner_rect.left(), cross.min),