Bug 1583531 - add in-bookmarks-menu class for arrowscrollboxes to adjust padding in bookmarks submenus r=bgrins

Differential Revision: https://phabricator.services.mozilla.com/D49633

--HG--
extra : moz-landing-system : lando

browser/components/places/content/places-menupopup.js

@@ -47,6 +47,13 @@
     `;
     }
 
+    initShadowDOM() {
+      super.initShadowDOM();
+      if (this.closest("#BMB_bookmarksPopup")) {
+        this.scrollBox.classList.add("in-bookmarks-menu");
+      }
+    }
+
     connectedCallback() {
       if (this.delayConnectedCallback()) {
         return;

toolkit/content/widgets/menupopup.js

@@ -45,26 +45,27 @@
       }
     }
 
+    initShadowDOM() {
+      // Retarget events from shadow DOM arrowscrollbox to the host.
+      this.scrollBox.addEventListener("scroll", ev =>
+        this.dispatchEvent(new Event("scroll"))
+      );
+      this.scrollBox.addEventListener("overflow", ev =>
+        this.dispatchEvent(new Event("overflow"))
+      );
+      this.scrollBox.addEventListener("underflow", ev =>
+        this.dispatchEvent(new Event("underflow"))
+      );
+      this.scrollBox._scrollButtonUp.classList.add("menupopup-scrollbutton");
+      this.scrollBox._scrollButtonDown.classList.add("menupopup-scrollbutton");
+    }
+
     get shadowRoot() {
       // We generate shadow DOM lazily on popupshowing event to avoid extra load
       // on the system during browser startup.
       if (!super.shadowRoot.firstElementChild) {
         super.shadowRoot.appendChild(this.fragment);
-
-        // Retarget events from shadow DOM arrowscrollbox to the host.
-        this.scrollBox.addEventListener("scroll", ev =>
-          this.dispatchEvent(new Event("scroll"))
-        );
-        this.scrollBox.addEventListener("overflow", ev =>
-          this.dispatchEvent(new Event("overflow"))
-        );
-        this.scrollBox.addEventListener("underflow", ev =>
-          this.dispatchEvent(new Event("underflow"))
-        );
-        this.scrollBox._scrollButtonUp.classList.add("menupopup-scrollbutton");
-        this.scrollBox._scrollButtonDown.classList.add(
-          "menupopup-scrollbutton"
-        );
+        this.initShadowDOM();
       }
       return super.shadowRoot;
     }

toolkit/themes/windows/global/scrollbox.css

@@ -11,6 +11,12 @@ arrowscrollbox[notoverflowing=true]::part(scrollbutton-down) {
   visibility: collapse;
 }
 
+/* Add some space at the top because there are no headers in menupopups of
+ the bookmarks menu. */
+arrowscrollbox.in-bookmarks-menu::part(scrollbox) {
+  padding-top: 4px;
+}
+
 /*
  * Scroll arrows
  */