Bug 882800 - Use IndieUI inspired scroll requests. r=davidb

accessible/src/jsat/content-script.js

@@ -16,6 +16,8 @@ XPCOMUtils.defineLazyModuleGetter(this, 'Utils',
   'resource://gre/modules/accessibility/Utils.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'EventManager',
   'resource://gre/modules/accessibility/EventManager.jsm');
+XPCOMUtils.defineLazyModuleGetter(this, 'ObjectWrapper',
+  'resource://gre/modules/ObjectWrapper.jsm');
 
 Logger.debug('content-script.js');
 
@@ -182,6 +184,21 @@ function scroll(aMessage) {
     while (acc) {
       let elem = acc.DOMNode;
 
+      // This is inspired by IndieUI events. Once they are
+      // implemented, it should be easy to transition to them.
+      // https://dvcs.w3.org/hg/IndieUI/raw-file/tip/src/indie-ui-events.html#scrollrequest
+      let uiactions = elem.getAttribute ? elem.getAttribute('uiactions') : '';
+      if (uiactions && uiactions.split(' ').indexOf('scroll') >= 0) {
+        let evt = elem.ownerDocument.createEvent('CustomEvent');
+        let details = horiz ? { deltaX: page * elem.clientWidth } :
+          { deltaY: page * elem.clientHeight };
+        evt.initCustomEvent(
+          'scrollrequest', true, true,
+          ObjectWrapper.wrap(details, elem.ownerDocument.defaultView));
+        if (!elem.dispatchEvent(evt))
+          return;
+      }
+
       // We will do window scrolling next.
       if (elem == content.document)
         break;
@@ -202,25 +219,6 @@ function scroll(aMessage) {
             return true;
           }
         }
-
-        let controllers = acc.
-          getRelationByType(
-            Ci.nsIAccessibleRelation.RELATION_CONTROLLED_BY);
-        for (let i = 0; controllers.targetsCount > i; i++) {
-          let controller = controllers.getTarget(i);
-          // If the section has a controlling slider, it should be considered
-          // the page-turner.
-          if (controller.role == Ci.nsIAccessibleRole.ROLE_SLIDER) {
-            // Sliders are controlled with ctrl+right/left. I just decided :)
-            let evt = content.document.createEvent('KeyboardEvent');
-            evt.initKeyEvent(
-              'keypress', true, true, null,
-              true, false, false, false,
-              (page > 0) ? evt.DOM_VK_RIGHT : evt.DOM_VK_LEFT, 0);
-            controller.DOMNode.dispatchEvent(evt);
-            return true;
-          }
-        }
       }
       acc = acc.parent;
     }