[SVG2] Add tabindex handling in svg.

Source/core/svg/SVGAElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 13 matching lines @@
 
 #include "core/svg/SVGAElement.h"
 
 #include "SVGNames.h"
 #include "XLinkNames.h"
 #include "core/dom/Attr.h"
 #include "core/dom/Attribute.h"
 #include "core/dom/Document.h"
 #include "core/events/KeyboardEvent.h"
 #include "core/events/MouseEvent.h"
+#include "core/frame/FrameHost.h"
 #include "core/frame/LocalFrame.h"
 #include "core/html/HTMLAnchorElement.h"
 #include "core/html/HTMLFormElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/loader/FrameLoadRequest.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/FrameLoaderTypes.h"
 #include "core/page/Chrome.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/Page.h"
@@ skipping 123 matching lines @@
             FrameLoadRequest frameRequest(&document(), ResourceRequest(document().completeURL(url)), target);
             frameRequest.setTriggeringEvent(event);
             frame->loader().load(frameRequest);
             return;
         }
     }
 
     SVGGraphicsElement::defaultEventHandler(event);
 }
 
+short SVGAElement::tabIndex() const
+{
+    // Skip the supportsFocus check in SVGElement.
+    return Element::tabIndex();
+}
+
 bool SVGAElement::supportsFocus() const
 {
     if (rendererIsEditable())
         return SVGGraphicsElement::supportsFocus();
-    return true;
+    // If not a link we should still be able to focus the element if it has tabIndex.
+    return isLink() || Element::supportsFocus();
 }
 
 bool SVGAElement::isURLAttribute(const Attribute& attribute) const
 {
     return attribute.name().localName() == hrefAttr || SVGGraphicsElement::isURLAttribute(attribute);
 }
 
 bool SVGAElement::isMouseFocusable() const
 {
-    return false;
+    // Links are focusable by default, but only allow links with tabindex or contenteditable to be mouse focusable.
+    // https://bugs.webkit.org/show_bug.cgi?id=26856
+    if (isLink())
+        return Element::supportsFocus();
+
+    return SVGElement::isMouseFocusable();
 }
 
 bool SVGAElement::isKeyboardFocusable() const
 {
-    if (!isFocusable())
-        return false;
+    if (isFocusable() && Element::supportsFocus())
+        return SVGElement::isKeyboardFocusable();
 
-    if (Page* page = document().page())
-        return page->chrome().client().tabsToLinks();
-    return false;
+    if (isLink())
+        return document().frameHost()->chrome().client().tabsToLinks();
+    return SVGElement::isKeyboardFocusable();
+}
+
+bool SVGAElement::canStartSelection() const
+{
+    if (!isLink())
+        return SVGElement::canStartSelection();
+    return rendererIsEditable();
 }
 
 bool SVGAElement::willRespondToMouseClickEvents()
 {
     return isLink() || SVGGraphicsElement::willRespondToMouseClickEvents();
 }
 
 } // namespace WebCore