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 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/HTMLShadowElement.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"
 
 namespace WebCore {
 
 using namespace HTMLNames;
 
 static inline bool isShadowInsertionPointFocusScopeOwner(Node& node)
 {
     return isActiveShadowInsertionPoint(node) && toHTMLShadowElement(node).olderShadowRoot();
 }
 
@@ skipping 842 matching lines @@
         consumed = advanceFocusDirectionallyInContainer(container, startingRect, type);
         startingRect = nodeRectInAbsoluteCoordinates(container, true /* ignore border */);
         container = scrollableEnclosingBoxOrParentFrameForNodeInDirection(type, container);
         if (container && container->isDocumentNode())
             toDocument(container)->updateLayoutIgnorePendingStylesheets();
     } while (!consumed && container);
 
     return consumed;
 }
 
+bool FocusController::handleCSSFocusNavigation(FocusType type)
+{
+    DEFINE_STATIC_LOCAL(AtomicString, Current, ("current"));

[fs, 2014/04/14 12:32:01]

Maybe make this 'targetCurrent' or 'frameTargetCurrent' (and similarly for
'Root') or similar (i.e. a tad more specific.)

[Krzysztof Olczyk, 2014/04/17 13:48:40]

Done.

+    DEFINE_STATIC_LOCAL(AtomicString, Root, ("root"));
+
+    if (!focusedOrMainFrame()->isLocalFrame())
+        return false;
+
+    LocalFrame* currentFrame = toLocalFrame(focusedOrMainFrame());
+    ASSERT(currentFrame);

[fs, 2014/04/14 12:32:01]

Already dereference focusedOrMainFrame() above.

[Krzysztof Olczyk, 2014/04/17 13:48:40]

Done.

+
+    Document* focusedDocument = currentFrame->document();
+    if (!focusedDocument)
+        return false;
+
+    Element* focused = focusedDocument->focusedElement();
+    RenderObject* renderer = focused ? focused->renderer() : 0;
+    if (!renderer)
+        return false;
+
+    StyleNavigationValue value;
+
+    if (StyleNavigationData* navigationData = renderer->style()->navigation()) {
+        switch (type) {
+        case FocusTypeForward:
+        case FocusTypeBackward:
+            return false;
+        case FocusTypeUp:
+            value = navigationData->up();
+            break;
+        case FocusTypeDown:
+            value = navigationData->down();
+            break;
+        case FocusTypeLeft:
+            value = navigationData->left();
+            break;
+        case FocusTypeRight:
+            value = navigationData->right();
+            break;
+        case FocusTypeNone:
+        default:
+            ASSERT_NOT_REACHED();
+            break;
+        }
+    }
+
+    if (value.id().isNull() || value.isAuto())

[fs, 2014/04/14 12:32:01]

When will id() be the nullAtom?

[Krzysztof Olczyk, 2014/04/17 13:48:40]

Done.

+        return false;
+
+    const AtomicString& target = value.target();
+    Frame* targetFrame = 0;
+
+    // If we were in the autoscroll/panScroll mode we want to stop it.
+    currentFrame->eventHandler().stopAutoscroll();
+
+    if (target == Current)
+        targetFrame = currentFrame;
+    else if (target == Root)
+        targetFrame = currentFrame->tree().top();
+    else
+        targetFrame = currentFrame->tree().find(target);
+
+    if (!targetFrame)
+        return false;
+
+    Element* targetElement = targetFrame->document()->getElementById(value.id());
+
+    if (!targetElement)
+        return false;
+    // If it's same with the current focused, it should be consumed.

[fs, 2014/04/14 12:32:01]

s/same with the current/the same as the currently/, and maybe "consumed" ->
"considered a valid navigation" or somesuch.

[Krzysztof Olczyk, 2014/04/17 13:48:40]

Done.

+    if (focused == targetElement)
+        return true;
+
+    return setFocusedElement(targetElement, targetFrame);
+}
+
 } // namespace WebCore