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

third_party/WebKit/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.
+ * Copyright (C) 2016 Samsung Electronics. 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 11 matching lines @@
  */
 
 #include "core/page/FocusController.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/AXObjectCache.h"
 #include "core/dom/ContainerNode.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/ElementTraversal.h"
+#include "core/dom/NodeComputedStyle.h"
 #include "core/dom/Range.h"
 #include "core/dom/shadow/ElementShadow.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/dom/shadow/SlotScopedTraversal.h"
 #include "core/editing/EditingUtilities.h" // For firstPositionInOrBeforeNode
 #include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
 #include "core/events/Event.h"
 #include "core/frame/FrameClient.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/RemoteFrame.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLAreaElement.h"
 #include "core/html/HTMLImageElement.h"
 #include "core/html/HTMLPlugInElement.h"
 #include "core/html/HTMLShadowElement.h"
 #include "core/html/HTMLSlotElement.h"
 #include "core/html/HTMLTextFormControlElement.h"
 #include "core/input/EventHandler.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/FrameTree.h"
 #include "core/page/Page.h"
 #include "core/layout/HitTestResult.h"
 #include "core/page/SpatialNavigation.h"
+#include "core/style/StyleNavigationValue.h"
 #include <limits>
 
 namespace blink {
 
 using namespace HTMLNames;
 
 namespace {
 
 inline bool isShadowInsertionPointFocusScopeOwner(Element& element)
 {
@@ skipping 1237 matching lines @@
 
     return consumed;
 }
 
 DEFINE_TRACE(FocusController)
 {
     visitor->trace(m_page);
     visitor->trace(m_focusedFrame);
 }
 
+bool FocusController::advanceCSSNavigationFocus(WebFocusType type)

[fs, 2016/05/18 15:55:05]

Could this be refactored into something that advanceFocusDirectionally(...)
could call? (And do away with most of the entry-checks...)

+{
+    ASSERT(focusedOrMainFrame());
+    if (!focusedOrMainFrame()->isLocalFrame())
+        return false;
+
+    LocalFrame* currentFrame = toLocalFrame(focusedOrMainFrame());
+    Document* focusedDocument = currentFrame->document();
+    if (!focusedDocument)
+        return false;
+
+    Element* focused = focusedDocument->focusedElement();
+    const ComputedStyle* style = focused ? focused->computedStyle() : 0;
+    if (!style)
+        return false;
+
+    StyleNavigationValue value;
+
+    switch (type) {
+    case WebFocusTypeForward:
+    case WebFocusTypeBackward:

[fs, 2016/05/18 15:55:05]

We should never see these in this code-path IIRC, so these could go with
WebFocusTypeNone below.

+        return false;
+    case WebFocusTypeUp:
+        value = style->navUp();
+        break;
+    case WebFocusTypeDown:
+        value = style->navDown();
+        break;
+    case WebFocusTypeLeft:
+        value = style->navLeft();
+        break;
+    case WebFocusTypeRight:
+        value = style->navRight();
+        break;
+    case WebFocusTypeNone:
+    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;

[fs, 2016/05/18 15:55:05]

nullptr

+    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;
+
+    targetElement->focus(FocusParams(SelectionBehaviorOnFocus::Reset, type, nullptr));
+    return true;
+//    return setFocusedElement(targetElement, targetFrame);

[fs, 2016/05/18 15:55:05]

Remove.

+}
+
 } // namespace blink