css/quick-settings: Update icon-button styles

- add an entire	flat style to button drawing function
- clean	up the icon button css in quick	settings
- adjust padding in QS sliders
- fixes #5918

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2510>

data/theme/gnome-shell-sass/_common.scss

@@ -105,24 +105,15 @@ stage {
   &:insensitive { @include button(insensitive);}
   &:active { @include button(active);}
   &: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; }
+  &.flat {
+    @include button(normal, $flat:true);
+    &:focus { @include button(focus, $flat:true);}
+    &:hover { @include button(hover, $flat:true);}
+    &:insensitive { @include button(insensitive, $flat:true);}
+    &:active { @include button(active, $flat:true);}
+    &:checked { @include button(checked, $flat:true);}
+  }
 }
 
 // buttons in dialogs/notifications

data/theme/gnome-shell-sass/_drawing.scss

@@ -143,7 +143,7 @@
 //
 // since buttons are all flat an borderless now the mixin is simpler
 
-@mixin button($t, $tc:$fg_color, $c:$bg_color) {
+@mixin button($t, $tc:$fg_color, $c:$bg_color, $flat: false) {
 
   $button_bg_color: mix($tc, $c, $button_mix_factor);
   transition-duration: 100ms;
@@ -152,6 +152,9 @@
   @if $t==normal {
     color: $tc;
     background-color: $button_bg_color;
+    @if $flat {
+      background-color: transparent;
+    }
     @if $is_highcontrast == "true" {
       box-shadow: inset 0 0 0 1px $button_inset_color;
     }

data/theme/gnome-shell-sass/widgets/_buttons.scss

@@ -6,5 +6,14 @@
 }
 
 .icon-button {
-  @extend %icon_button; // that's it
+  @extend .button; // same style as buttons
+
+  border-radius: 99px;
+  padding: $base_padding*2;
+  min-height: 16px;
+
+  StIcon {
+    icon-size: $base_icon_size;
+    -st-icon-style: symbolic;
+  }
 }

data/theme/gnome-shell-sass/widgets/_quick-settings.scss

@@ -48,8 +48,6 @@
 }
 
 .quick-slider {
-  padding: 0 $base_padding;
-
   & > StBoxLayout { spacing: $base_padding; }
 
   .slider-bin {
@@ -58,8 +56,12 @@
     padding: $base_padding;
     border-radius: 99px;
   }
-  .quick-toggle-icon { icon-size: $base_icon_size; }
-  .icon-button { background-color: transparent; }
+  .quick-toggle-icon {
+    icon-size: $base_icon_size;
+
+    &:ltr { margin-left: $base_padding; }
+    &:rtl { margin-right: $base_padding; }
+  }
 }
 
 .quick-toggle-menu {
@@ -100,8 +102,6 @@
 .quick-settings-system-item {
   & > StBoxLayout { spacing: 2 * $base_padding; }
 
-  .icon-button > StIcon { -st-icon-style: symbolic; }
-
   & .power-item {
     min-height: 0;
     min-width: 0;

js/ui/quickSettings.js

@@ -198,7 +198,7 @@ var QuickSlider = GObject.registerClass({
 
         this._menuButton = new St.Button({
             child: new St.Icon({icon_name: 'go-next-symbolic'}),
-            style_class: 'icon-button',
+            style_class: 'icon-button flat',
             can_focus: true,
             x_expand: false,
             y_expand: true,