Spatial navigation enhancements

Source/core/html/HTMLElement.cpp

Index: Source/core/html/HTMLElement.cpp
diff --git a/Source/core/html/HTMLElement.cpp b/Source/core/html/HTMLElement.cpp
index 5953c68a61aaab77335aa6b2db57edbf83173f32..645ebf1a55d9aa7aa33af5a51b14dfd416542f96 100644
--- a/Source/core/html/HTMLElement.cpp
+++ b/Source/core/html/HTMLElement.cpp
@@ -38,6 +38,7 @@
 #include "core/dom/EventListener.h"
 #include "core/dom/EventNames.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/dom/KeyboardEvent.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/Text.h"
 #include "core/editing/markup.h"
@@ -48,6 +49,7 @@
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/loader/FrameLoader.h"
 #include "core/page/Frame.h"
+#include "core/page/Settings.h"
 #include "core/rendering/RenderWordBreak.h"
 #include <wtf/StdLibExtras.h>
 #include <wtf/text/CString.h>
@@ -598,6 +600,23 @@ bool HTMLElement::hasCustomFocusLogic() const
     return false;
 }
 
+bool HTMLElement::supportsSpatialNavigationFocus() const
+{
+    // This function checks whether the element satisfies the extended criteria
+    // for the element to be focusable, introduced by spatial navigation feature,
+    // i.e. checks if click or keyboard event handler is specified.
+    // This is the way to make it possible to navigate to (focus) elements
+    // which web designer meant for being active (made them respond to click events).
+
+    if (!document()->settings() || !document()->settings()->spatialNavigationEnabled())
+        return false;
+    EventTarget* target = const_cast<HTMLElement*>(this);
+    return target->hasEventListeners(eventNames().clickEvent)
+        || target->hasEventListeners(eventNames().keydownEvent)
+        || target->hasEventListeners(eventNames().keypressEvent)
+        || target->hasEventListeners(eventNames().keyupEvent);
+}
+
 bool HTMLElement::supportsFocus() const
 {
     // FIXME: supportsFocus() can be called when layout is not up to date.
@@ -605,7 +624,8 @@ bool HTMLElement::supportsFocus() const
     // But supportsFocus must return true when the element is editable, or else
     // it won't be focusable. Furthermore, supportsFocus cannot just return true
     // always or else tabIndex() will change for all HTML elements.
-    return Element::supportsFocus() || (rendererIsEditable() && parentNode() && !parentNode()->rendererIsEditable());
+    return Element::supportsFocus() || (rendererIsEditable() && parentNode() && !parentNode()->rendererIsEditable())
+        || supportsSpatialNavigationFocus();
 }
 
 String HTMLElement::contentEditable() const
@@ -1029,6 +1049,28 @@ void HTMLElement::addHTMLColorToStyle(MutableStylePropertySet* style, CSSPropert
     style->setProperty(propertyID, cssValuePool().createColorValue(parsedColor.rgb()));
 }
 
+void HTMLElement::defaultEventHandler(Event* event)
+{
+    if (event->type() == eventNames().keypressEvent && event->isKeyboardEvent()) {
+        handleKeypressEvent(toKeyboardEvent(event));
+        if (event->defaultHandled())
+            return;
+    }
+
+    StyledElement::defaultEventHandler(event);
+}
+
+void HTMLElement::handleKeypressEvent(KeyboardEvent* event)
+{
+    if (!document()->settings() || !document()->settings()->spatialNavigationEnabled() || !supportsFocus())
+        return;
+    int charCode = event->charCode();
+    if (charCode == '\r' || charCode == ' ') {
+        dispatchSimulatedClick(event);
+        event->setDefaultHandled();
+    }
+}
+
 } // namespace WebCore
 
 #ifndef NDEBUG