Adding support for Smart GO NEXT feature in Android Chrome

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 03eff0db2ed476a19c6ff94d34c04f0d759b7efc..502a118c8eca67b50a06ec6931c1f6a10cba058b 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -37,6 +37,7 @@
 #include "core/clipboard/DataObject.h"
 #include "core/dom/Document.h"
 #include "core/dom/DocumentMarkerController.h"
+#include "core/dom/ElementTraversal.h"
 #include "core/dom/Fullscreen.h"
 #include "core/dom/LayoutTreeBuilderTraversal.h"
 #include "core/dom/Text.h"
@@ -60,6 +61,7 @@
 #include "core/frame/Settings.h"
 #include "core/frame/SmartClip.h"
 #include "core/frame/TopControls.h"
+#include "core/html/HTMLFormElement.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/html/HTMLMediaElement.h"
 #include "core/html/HTMLPlugInElement.h"
@@ -120,6 +122,7 @@
 #include "public/platform/WebCompositeAndReadbackAsyncCallback.h"
 #include "public/platform/WebDragData.h"
 #include "public/platform/WebFloatPoint.h"
+#include "public/platform/WebFocusType.h"
 #include "public/platform/WebGestureCurve.h"
 #include "public/platform/WebImage.h"
 #include "public/platform/WebLayerTreeView.h"
@@ -2505,9 +2508,76 @@ int WebViewImpl::textInputFlags()
         }
     }
 
+    if (isListeningToKeyboardEvents(element))
+        flags |= WebTextInputFlagListeningToKeyboardEvents;
+
+    if (nextFocusableElementInForm(element, WebFocusTypeForward))
+        flags |= WebTextInputFlagHaveNextFocusableElement;
+
+    if (nextFocusableElementInForm(element, WebFocusTypeBackward))
+        flags |= WebTextInputFlagHavePreviousFocusableElement;
+
     return flags;
 }
 
+Element* WebViewImpl::nextFocusableElementInForm(Element* element, WebFocusType focusType)
+{
+    if (!element->isFormControlElement() && !element->isContentEditable())
+        return nullptr;
+
+    HTMLFormElement* formOwner = nullptr;
+    if (element->isContentEditable())
+        formOwner = Traversal<HTMLFormElement>::firstAncestor(*element);
+    else
+        formOwner = toHTMLFormControlElement(element)->formOwner();
+
+    if (!formOwner)
+        return nullptr;
+
+    Node* nextNode = element;
+    while ((nextNode = page()->focusController().findFocusableElement(focusType, *nextNode))) {
+        if (nextNode->isContentEditable() && nextNode->isDescendantOf(formOwner))
+            return toElement(nextNode);
+        if (!toElement(nextNode)->isFormControlElement())
+            continue;
+        HTMLFormControlElement* formElement = toHTMLFormControlElement(nextNode);
+        if (formElement->formOwner() != formOwner)
+            continue;
+        LayoutObject* layout = nextNode->layoutObject();
+        if (layout && layout->isTextControl()) {
+            // TODO(ajith.v) Extend it for Select element, Radio button and Check boxes
+            return toElement(nextNode);
+        }
+    }
+    return nullptr;
+}
+
+bool WebViewImpl::isListeningToKeyboardEvents(Element* element)
+{
+    if (!element->isFormControlElement() && !element->isContentEditable())
+        return false;
+    Node* node = element;
+    do {
+        if (node->hasEventListeners(EventTypeNames::keydown) || node->hasEventListeners(EventTypeNames::keypress) || node->hasEventListeners(EventTypeNames::keyup))
+            return true;
+    } while ((node = node->parentNode()));
+    return false;
+}
+
+void WebViewImpl::advanceFocusInForm(WebFocusType focusType)
+{
+    Element* element = focusedElement();
+    if (!element)
+        return;
+
+    RefPtrWillBeRawPtr<Element> nextElement = nextFocusableElementInForm(element, focusType);
+    if (!nextElement)
+        return;
+
+    nextElement->scrollIntoViewIfNeeded(true /*centerIfNeeded*/);
+    nextElement->focus(false, focusType);
+}
+
 WebString WebViewImpl::inputModeOfFocusedElement()
 {
     if (!RuntimeEnabledFeatures::inputModeAttributeEnabled())