Implementation of CSS3 nav-up/down/left/right properties from CSS3 UI.

Source/core/page/FocusController.cpp

 /*
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nuanti Ltd.
+ * Copyright (C) 2013, 2014 Opera Software ASA. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
@@ skipping 36 matching lines @@
 #include "core/html/HTMLTextFormControlElement.h"
 #include "core/page/Chrome.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/EventHandler.h"
 #include "core/page/FrameTree.h"
 #include "core/page/Page.h"
 #include "core/frame/Settings.h"
 #include "core/page/SpatialNavigation.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/RenderLayer.h"
+#include "core/rendering/RenderObject.h"
+#include "core/rendering/style/StyleNavigationValue.h"
 #include <limits>
 
 namespace blink {
 
 using namespace HTMLNames;
 
 static inline bool isShadowInsertionPointFocusScopeOwner(Node& node)
 {
     return isActiveShadowInsertionPoint(node) && toHTMLShadowElement(node).olderShadowRoot();
 }
@@ skipping 854 matching lines @@
 
     return consumed;
 }
 
 void FocusController::trace(Visitor* visitor)
 {
     visitor->trace(m_page);
     visitor->trace(m_focusedFrame);
 }
 
+bool FocusController::handleCSSFocusNavigation(FocusType type)
+{
+    ASSERT(focusedOrMainFrame());
+    if (!focusedOrMainFrame()->isLocalFrame())
+        return false;
+
+    LocalFrame* currentFrame = toLocalFrame(focusedOrMainFrame());
+    Document* focusedDocument = currentFrame->document();
+    if (!focusedDocument)
+        return false;
+
+    Element* focused = focusedDocument->focusedElement();
+    RenderObject* renderer = focused ? focused->renderer() : 0;
+    if (!renderer)
+        return false;
+
+    StyleNavigationValue value;
+
+    switch (type) {
+    case FocusTypeForward:
+    case FocusTypeBackward:
+        return false;
+    case FocusTypeUp:
+        value = renderer->style()->navUp();
+        break;
+    case FocusTypeDown:
+        value = renderer->style()->navDown();
+        break;
+    case FocusTypeLeft:
+        value = renderer->style()->navLeft();
+        break;
+    case FocusTypeRight:
+        value = renderer->style()->navRight();
+        break;
+    case FocusTypeNone:
+    default:
+        ASSERT_NOT_REACHED();
+        break;
+    }
+
+    if (value.isAuto())
+        return false;
+
+    // If we were in the autoscroll/panScroll mode we want to stop it.
+    currentFrame->eventHandler().stopAutoscroll();
+
+    ENavigationTarget navigationTarget = value.navigationTarget();
+    Frame* targetFrame = 0;
+    if (navigationTarget == Current)
+        targetFrame = currentFrame;
+    else if (navigationTarget == Root)
+        targetFrame = currentFrame->tree().top();
+    else
+        targetFrame = currentFrame->tree().find(value.targetName());
+
+    if (!targetFrame || !targetFrame->isLocalFrame())
+        return false;
+
+    Element* targetElement = toLocalFrame(targetFrame)->document()->getElementById(value.id());
+
+    if (!targetElement)
+        return false;
+
+    // If it's the same as the current focused, it should be considered a valid navigation,
+    // but there is no need to change focus.
+    if (focused == targetElement)
+        return true;
+
+    return setFocusedElement(targetElement, targetFrame);
+}
+
 } // namespace blink