[SVG2] Add tabindex handling in svg.

Source/core/svg/SVGElement.cpp

Index: Source/core/svg/SVGElement.cpp
diff --git a/Source/core/svg/SVGElement.cpp b/Source/core/svg/SVGElement.cpp
index ca015d3ee51e2cd407a6d61be7d794ee9b1140b7..57c94f3244be0e1e40dde71f52dd03c12ae8fcd6 100644
--- a/Source/core/svg/SVGElement.cpp
+++ b/Source/core/svg/SVGElement.cpp
@@ -36,7 +36,9 @@
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/events/Event.h"
+#include "core/frame/Settings.h"
 #include "core/html/HTMLElement.h"
+#include "core/html/parser/HTMLParserIdioms.h"
 #include "core/rendering/RenderObject.h"
 #include "core/rendering/svg/RenderSVGResourceContainer.h"
 #include "core/svg/SVGCursorElement.h"
@@ -630,6 +632,54 @@ void SVGElement::setCorrespondingElement(SVGElement* correspondingElement)
     ensureSVGRareData()->setCorrespondingElement(correspondingElement);
 }
 
+short SVGElement::tabIndex() const
+{
+    if (supportsFocus())
+        return Element::tabIndex();
+    return -1;
+}
+
+void SVGElement::setTabIndex(int value)
+{
+    setIntegralAttribute(tabindexAttr, value);
+}
+
+bool SVGElement::rendererIsFocusable() const
+{
+    return inDocument() && supportsFocus() && !isInert() && Element::tabIndex() >= 0;

[fs, 2014/03/14 16:05:12]

IIUC, they way this is called the the first three will always be true? Also,
should 'visibility' be considered (call to tjhe base-class implementation)?

[Erik Dahlström (inactive), 2014/03/17 14:45:29]

Hmm, true. I'll remove this.

visibility:hidden on a div means not focusable, even if tabindex > 0 is
specified, I think we want the same in svg too.

+}
+
+bool SVGElement::supportsFocus() const
+{
+    // FIXME: supportsFocus() can be called when layout is not up to date.
+    // Logic that deals with the renderer should be moved to rendererIsFocusable().
+    // 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())
+        || supportsSpatialNavigationFocus();
+}
+
+bool SVGElement::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;
+    return hasEventListeners(EventTypeNames::click)
+        || hasEventListeners(EventTypeNames::keydown)
+        || hasEventListeners(EventTypeNames::keypress)
+        || hasEventListeners(EventTypeNames::keyup)
+        || hasEventListeners(EventTypeNames::focus)
+        || hasEventListeners(EventTypeNames::blur)
+        || hasEventListeners(EventTypeNames::focusin)
+        || hasEventListeners(EventTypeNames::focusout);
+}
+
 void SVGElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
 {
     if (name == HTMLNames::classAttr) {
@@ -641,6 +691,19 @@ void SVGElement::parseAttribute(const QualifiedName& name, const AtomicString& v
         m_className->setBaseValueAsString(value, parseError);
         reportAttributeParsingError(parseError, name, value);
     } else if (name.matches(XMLNames::langAttr) || name.matches(XMLNames::spaceAttr)) {
+    } else if (name == tabindexAttr) {
+        int tabindex = 0;
+        if (value.isEmpty()) {
+            clearTabIndexExplicitlyIfNeeded();
+            if (treeScope().adjustedFocusedElement() == this) {
+                // We might want to call blur(), but it's dangerous to dispatch
+                // events here.
+                document().setNeedsFocusedElementCheck();
+            }
+        } else if (parseHTMLInteger(value, tabindex)) {
+            // Clamp tabindex to the range of 'short' to match Firefox's behavior.
+            setTabIndexExplicitly(max(static_cast<int>(std::numeric_limits<short>::min()), std::min(tabindex, static_cast<int>(std::numeric_limits<short>::max()))));
+        }
     } else {
         // standard events
         const AtomicString& eventName = HTMLElement::eventNameForAttributeName(name);
@@ -1025,12 +1088,8 @@ RenderStyle* SVGElement::computedStyle(PseudoId pseudoElementSpecifier)
 
 bool SVGElement::hasFocusEventListeners() const
 {
-    return hasEventListeners(EventTypeNames::focusin) || hasEventListeners(EventTypeNames::focusout);
-}
-
-bool SVGElement::isKeyboardFocusable() const
-{
-    return isFocusable();
+    return hasEventListeners(EventTypeNames::focusin) || hasEventListeners(EventTypeNames::focusout)
+        || hasEventListeners(EventTypeNames::focus) || hasEventListeners(EventTypeNames::blur);
 }
 
 #ifndef NDEBUG