[Android] Adding Smart GO/NEXT feature in Chrome

third_party/WebKit/Source/core/editing/InputMethodController.cpp

Index: third_party/WebKit/Source/core/editing/InputMethodController.cpp
diff --git a/third_party/WebKit/Source/core/editing/InputMethodController.cpp b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
index 1d880e513e4a5ed8d765678f2a04352ee79b47ec..b13181a2d83da7366b0572feec4c6240b1ec61db 100644
--- a/third_party/WebKit/Source/core/editing/InputMethodController.cpp
+++ b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
@@ -30,6 +30,7 @@
 #include "core/InputTypeNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
+#include "core/dom/ElementTraversal.h"
 #include "core/dom/Text.h"
 #include "core/editing/EditingUtilities.h"
 #include "core/editing/Editor.h"
@@ -39,12 +40,15 @@
 #include "core/editing/state_machines/ForwardCodePointStateMachine.h"
 #include "core/events/CompositionEvent.h"
 #include "core/frame/LocalFrame.h"
+#include "core/html/HTMLFormElement.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/html/HTMLTextAreaElement.h"
 #include "core/input/EventHandler.h"
 #include "core/layout/LayoutObject.h"
 #include "core/layout/LayoutTheme.h"
 #include "core/page/ChromeClient.h"
+#include "core/page/FocusController.h"
+#include "core/page/Page.h"
 
 namespace blink {
 
@@ -1143,9 +1147,77 @@ int InputMethodController::TextInputFlags() const {
     }
   }
 
+  if (IsListeningToKeyboardEvents(element))
+    flags |= kWebTextInputFlagListeningToKeyboardEvents;
+
+  if (NextFocusableElementInForm(element, kWebFocusTypeForward))
+    flags |= kWebTextInputFlagHaveNextFocusableElement;
+
+  if (NextFocusableElementInForm(element, kWebFocusTypeBackward))
+    flags |= kWebTextInputFlagHavePreviousFocusableElement;
+
   return flags;
 }
 
+bool InputMethodController::IsListeningToKeyboardEvents(

[Changwan Ryu, 2017/04/27 16:34:54]

I'm not sure if this makes much sense... There are tons of different ways to
listen to text changes, too. Also, the webpage may not be particularly listening
to these events to submit a form or send you somewhere.

I think you should remove this logic, and just show 'enter', and expect webpage
to use input mode if they want to show 'GO'.

[yosin_UTC9, 2017/04/28 03:32:11]

Agree with changewan@. This is too specific and coverage narrow.
We may want to show "Go" for simple submit button, <input type=submit>, button
w/ "click"(include tap) event handler.

[AKVT, 2017/05/03 14:35:12]

Yes I am convinced here, as it has a very narrow coverage.

As I pointed in ImeUtils.java, I have still doubt on inputMode as it's still
going as trivial assignment, without having a thought of nearby (previous or
next) elements.

+    Element* element) const {
+  if (!element->IsFormControlElement() &&
+      !ToHTMLElement(element)->isContentEditableForBinding())
+    return false;
+  for (Node* node = element; node; node = node->parentNode()) {
+    if (node->HasEventListeners(EventTypeNames::keydown) ||
+        node->HasEventListeners(EventTypeNames::keypress) ||
+        node->HasEventListeners(EventTypeNames::keyup))
+      return true;
+  }
+  return false;
+}
+
+Element* InputMethodController::NextFocusableElementInForm(

[yosin_UTC9, 2017/04/28 01:07:28]

This function should be in FocusController instead of
InputeMethodController(IMC).
IMC should be passive about focus.

[yosin_UTC9, 2017/04/28 03:32:11]

I think this function should be implemented on top of TAB move function to
respect "tabindex" attribute,
which TAB move function handled.

[AKVT, 2017/05/03 14:35:12]

Done.

[AKVT, 2017/05/03 14:35:12]

Done.

+    Element* element,
+    WebFocusType focusType) const {
+  if (!element->IsFormControlElement() &&
+      !ToHTMLElement(element)->isContentEditableForBinding())
+    return nullptr;
+
+  HTMLFormElement* formOwner = nullptr;
+  if (ToHTMLElement(element)->isContentEditableForBinding())
+    formOwner = Traversal<HTMLFormElement>::FirstAncestor(*element);
+  else
+    formOwner = ToHTMLFormControlElement(element)->formOwner();
+
+  if (!formOwner)
+    return nullptr;
+
+  Element* nextElement = element;
+  for (nextElement =
+           GetDocument().GetPage()->GetFocusController().FindFocusableElement(
+               focusType, *nextElement);
+       nextElement;
+       nextElement =
+           GetDocument().GetPage()->GetFocusController().FindFocusableElement(
+               focusType, *nextElement)) {
+    if (ToHTMLElement(nextElement)->isContentEditableForBinding() &&
+        nextElement->IsDescendantOf(formOwner))
+      return nextElement;
+    if (!nextElement->IsFormControlElement())
+      continue;
+    HTMLFormControlElement* formElement = ToHTMLFormControlElement(nextElement);
+    if (formElement->formOwner() != formOwner)
+      continue;
+    // Skip disabled or readonly editable elements.
+    if (formElement->IsDisabledOrReadOnly())
+      continue;
+    LayoutObject* layout = nextElement->GetLayoutObject();
+    if (layout && layout->IsTextControl()) {
+      // TODO(ajith.v) Extend it for Select element, Radio button and Check
+      // boxes
+      return nextElement;
+    }
+  }
+  return nullptr;
+}
+
 WebTextInputMode InputMethodController::InputModeOfFocusedElement() const {
   if (!RuntimeEnabledFeatures::inputModeAttributeEnabled())
     return kWebTextInputModeDefault;