[libadwaita/wip/exalm/menu-split-buttons: 19/19] stylesheet: Make any arrow buttons and split buttons flat as well

[Alexander Mikhaylenko <alexm src gnome org>]

commit 20242125a9f29765ab14426652278954e5f440d6
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Fri Sep 10 19:20:14 2021 +0500

    stylesheet: Make any arrow buttons and split buttons flat as well
    
    The arrow there is already an icon, so there's no ambiguity.
    
    Update the migration guide as well.

 doc/migrating-libhandy-1-4-to-libadwaita.md |  4 ++--
 src/stylesheet/widgets/_toolbars.scss       | 35 +++++++++++++++++------------
 2 files changed, 23 insertions(+), 16 deletions(-)
---
diff --git a/doc/migrating-libhandy-1-4-to-libadwaita.md b/doc/migrating-libhandy-1-4-to-libadwaita.md
index 77a09505..d30a77b1 100644
--- a/doc/migrating-libhandy-1-4-to-libadwaita.md
+++ b/doc/migrating-libhandy-1-4-to-libadwaita.md
@@ -318,8 +318,8 @@ The following buttons get flat appearance:
 
 * Icon-only buttons;
 * Buttons with an icon and a label (using [class@Adw.ButtonContent]);
-* Menu buttons containing an arrow and either an icon or [class@Adw.ButtonContent];
-* [class@Adw.SplitButton] containing either an icon or [class@Adw.ButtonContent];
+* Menu buttons containing an arrow;
+* [class@Adw.SplitButton];
 * Any other button with the `.flat` style class.
 
 The following buttons keep default appearance:
diff --git a/src/stylesheet/widgets/_toolbars.scss b/src/stylesheet/widgets/_toolbars.scss
index 07c0e193..f308dd03 100644
--- a/src/stylesheet/widgets/_toolbars.scss
+++ b/src/stylesheet/widgets/_toolbars.scss
@@ -1,19 +1,24 @@
 %toolbar {
-  button.image-button:not(.raised):not(.suggested-action):not(.destructive-action),
-  button.image-text-button:not(.raised):not(.suggested-action):not(.destructive-action) {
-    @extend %button_basic_flat;
+  button:not(.raised):not(.suggested-action):not(.destructive-action) {
+    &.arrow-button,
+    &.image-button,
+    &.image-text-button {
+      @extend %button_basic_flat;
+    }
   }
 
-  .linked button {
-    &.image-button:not(.raised):not(.suggested-action):not(.destructive-action),
-    &.image-text-button:not(.raised):not(.suggested-action):not(.destructive-action) {
+  .linked button:not(.raised):not(.suggested-action):not(.destructive-action) {
+    &.arrow-button,
+    &.image-button,
+    &.image-text-button {
       @extend %button_basic_raised;
     }
   }
 
-  menubutton.raised {
-    > button.image-button,
-    > button.image-text-button {
+  menubutton.raised > button {
+    &.arrow-button,
+    &.image-button,
+    &.image-text-button {
       @extend %button_basic_raised;
     }
   }
@@ -25,8 +30,7 @@
       margin-bottom: 6px;
     }
 
-    &.image-button:not(.raised):not(.suggested-action):not(.destructive-action),
-    &.image-text-button:not(.raised):not(.suggested-action):not(.destructive-action) {
+    &:not(.raised):not(.suggested-action):not(.destructive-action) {
       @extend %flat_split_button;
     }
   }
@@ -58,9 +62,12 @@
 
   // Reset styles for popovers
   popover {
-    button.image-button:not(.raised):not(.suggested-action):not(.destructive-action),
-    button.image-text-button:not(.raised):not(.suggested-action):not(.destructive-action) {
-      @extend %button_basic_raised;
+    button:not(.raised):not(.suggested-action):not(.destructive-action) {
+      &.arrow-button,
+      &.image-button,
+      &.image-text-button {
+        @extend %button_basic_raised;
+      }
     }
 
     entry,