Bug 275519 - [Mac] Support Command+Option+Arrows for tab switching. r=mconnor, a=bsmedberg.

toolkit/content/widgets/tabbox.xml

@@ -56,6 +56,14 @@
         </getter>
       </property>
 
+      <field name="_handleMetaAltArrows" readonly="true">
+#ifdef XP_MACOSX
+        true
+#else
+        false
+#endif
+      </field>
+
       <property name="_tabs">
         <getter>
         <![CDATA[
@@ -150,6 +158,26 @@
                   event.preventDefault();
                 }
               break;
+            case event.DOM_VK_LEFT:
+              if (event.metaKey &&  event.altKey && !event.shiftKey && !event.ctrlKey)
+                if (this.tabbox._tabs && this.tabbox._handleMetaAltArrows) {
+                  var offset = window.getComputedStyle(this.tabbox, "")
+                                     .direction == "ltr" ? -1 : 1;
+                  this.tabbox._tabs.advanceSelectedTab(offset, true);
+                  event.stopPropagation();
+                  event.preventDefault();
+                }
+              break;
+            case event.DOM_VK_RIGHT:
+              if (event.metaKey &&  event.altKey && !event.shiftKey && !event.ctrlKey)
+                if (this.tabbox._tabs && this.tabbox._handleMetaAltArrows) {
+                  var offset = window.getComputedStyle(this.tabbox, "")
+                                     .direction == "ltr" ? 1 : -1;
+                  this.tabbox._tabs.advanceSelectedTab(offset, true);
+                  event.stopPropagation();
+                  event.preventDefault();
+                }
+              break;
           }
         }
       })]]>