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

Source/core/page/FocusController.cpp

Index: Source/core/page/FocusController.cpp
diff --git a/Source/core/page/FocusController.cpp b/Source/core/page/FocusController.cpp
index f9cb3d95a7062afb608644e7ab992efb0939656f..52af0c4a5a9d4639c67d3e32fc70e1bc6ff0106e 100644
--- a/Source/core/page/FocusController.cpp
+++ b/Source/core/page/FocusController.cpp
@@ -1,6 +1,7 @@
 /*
  * 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
@@ -57,6 +58,8 @@
 #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 {
@@ -931,4 +934,75 @@ void FocusController::trace(Visitor* visitor)
     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