Bug 1578140: Use nsXULElement::Click for DoAction on XULLabelAccessible so it works for labels inside buttons. r=eeejay

For labels inside buttons, The base implementation of DispatchClickEvent doesn't fire a command event on the button.
To fix this, override DispatchClickEvent to use nsXULElement::Click, which does fire a command event on the button.

Differential Revision: https://phabricator.services.mozilla.com/D44410

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

accessible/tests/mochitest/actions.js

@@ -35,6 +35,10 @@ const XUL_EVENTS = CLICK_EVENTS | COMMAND_EVENT;
  *    // used with 'events', if missing then 'ID' is used instead.
  *    get targetID() {},
  *
+ *    // [optional] true to match DOM events bubbled up to the target,
+ *    // false (default) to only match events fired directly on the target.
+ *    get allowBubbling() {},
+ *
  *    // [optional] perform checks when 'click' event is handled if 'events'
  *    // is used.
  *    checkOnClickEvent: function() {},
@@ -182,6 +186,17 @@ function checkerOfActionInvoker(aType, aTarget, aActionObj) {
     this.eventTarget = aActionObj.eventTarget;
   }
 
+  if (aActionObj && aActionObj.allowBubbling) {
+    // Normally, we add event listeners on the document. To catch bubbled
+    // events, we need to add the listener on the target itself.
+    this.eventTarget = "element";
+    // Normally, we only match an event fired directly on the target. Override
+    // this to match a bubbled event.
+    this.match = function(aEvent) {
+      return aEvent.currentTarget == aTarget;
+    };
+  }
+
   this.phase = false;
 
   this.getID = function getID() {

accessible/tests/mochitest/actions/test_general.xul

@@ -17,6 +17,10 @@
           src="../events.js" />
   <script type="application/javascript"
           src="../actions.js" />
+  <script type="application/javascript"
+          src="../role.js" />
+  <script type="application/javascript"
+          src="../states.js" />
 
   <script type="application/javascript">
   <![CDATA[
@@ -71,6 +75,19 @@
           ID: "labelWithPopup",
           actionName: "click",
           events: CLICK_EVENTS
+        },
+        {
+          ID: "toolbarbutton_label",
+          actionName: "click",
+          targetID: "toolbarbutton",
+          events: XUL_EVENTS,
+          allowBubbling: true
+        },
+        {
+          ID: "menulist_label",
+          actionName: "click",
+          targetID: "menulist",
+          events: FOCUS_EVENT
         }/*, // XXX: bug 490288
         {
           ID: "buttonmenu_item",
@@ -138,6 +155,13 @@
         <label id="name_entry_label" value="Name" control="name_entry"/>
         <textbox id="name_entry"/>
       </hbox>
+      <toolbarbutton id="toolbarbutton">
+        <label id="toolbarbutton_label">toolbarbutton</label>
+      </toolbarbutton>
+      <hbox>
+        <label id="menulist_label" control="menulist">menulist</label>
+        <menulist id="menulist"/>
+      </hbox>
     </vbox>
   </hbox>
 </window>

accessible/xul/XULElementAccessibles.cpp

@@ -24,6 +24,7 @@
 #include "nsNetUtil.h"
 #include "nsString.h"
 #include "nsTextBoxFrame.h"
+#include "nsXULElement.h"
 
 using namespace mozilla::a11y;
 
@@ -57,6 +58,16 @@ void XULLabelAccessible::Shutdown() {
   HyperTextAccessibleWrap::Shutdown();
 }
 
+void XULLabelAccessible::DispatchClickEvent(nsIContent* aContent,
+                                            uint32_t aActionIndex) const {
+  // Bug 1578140: For labels inside buttons, The base implementation of
+  // DispatchClickEvent doesn't fire a command event on the button.
+  RefPtr<nsXULElement> el = nsXULElement::FromNodeOrNull(aContent);
+  if (el) {
+    el->Click(mozilla::dom::CallerType::System);
+  }
+}
+
 ENameValueFlag XULLabelAccessible::NativeName(nsString& aName) const {
   // if the value attr doesn't exist, the screen reader must get the accessible
   // text from the accessible text interface or from the children

accessible/xul/XULElementAccessibles.h

@@ -32,6 +32,8 @@ class XULLabelAccessible : public HyperTextAccessibleWrap {
  protected:
   // Accessible
   virtual ENameValueFlag NativeName(nsString& aName) const override;
+  virtual void DispatchClickEvent(nsIContent* aContent,
+                                  uint32_t aActionIndex) const override;
 
  private:
   RefPtr<XULLabelTextLeafAccessible> mValueTextLeaf;