[gnome-shell-sass] style: Add generic .icon-button class

[Florian Müllner <fmuellner src gnome org>]

commit 8b3bfc8c6aabd1aac145c84f44b0fd1c96810727
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Aug 2 19:26:53 2022 +0200

    style: Add generic .icon-button class
    
    The class is meant for buttons that only contain an icon, as
    found in many GTK apps.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2397>

 _common.scss          | 18 ++++++++++++++++++
 widgets/_buttons.scss |  4 ++++
 2 files changed, 22 insertions(+)
---
diff --git a/_common.scss b/_common.scss
index 0b89700..6372af4 100644
--- a/_common.scss
+++ b/_common.scss
@@ -102,6 +102,24 @@ stage {
   &:checked { @include button(checked);}
 }
 
+// normal icon-only button
+%icon_button {
+  border-radius: 99px;
+  border-style: solid;
+  border-width: 1px;
+  font-weight: bold;
+  padding: $base_padding*2;
+
+  @include button(normal);
+  &:focus { @include button(focus);}
+  &:hover { @include button(hover);}
+  &:insensitive { @include button(insensitive);}
+  &:active { @include button(active);}
+  &:checked { @include button(checked);}
+
+  & > StIcon { icon-size: $base_icon_size; }
+}
+
 // buttons in dialogs/notifications
 // lighter in color and have a greater radius
 
diff --git a/widgets/_buttons.scss b/widgets/_buttons.scss
index 6a72c07..df99524 100644
--- a/widgets/_buttons.scss
+++ b/widgets/_buttons.scss
@@ -4,3 +4,7 @@
   @extend %button; // that's it
   min-height: 22px;
 }
+
+.icon-button {
+  @extend %icon_button; // that's it
+}