EditContext prototype implementation

This change contains the prototype implementation of EditContext APIs.
EditContext simplifies the process of integrating a web app with advanced
text input methods such as IME, VK shape-writing, speech recognition etc.
EditContext decouples text input from the HTML DOM view.
Rather than having the web platform infer the data required to enable
sophisticated text input mechanisms from the HTML DOM, the author will
provide that data explicitly through the API surface of the EditContext.
Additionally, EditContext communicates events driven from text input UI
to JavaScript.

Explainer: https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/
           master/EditContext/explainer.md

Test: run_web_tests web_tests/editing/input/edit-context.html

Bug: 999184

Change-Id: I36f115bf37e6ea2adb64c2f42e024dc800b56480
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1868848
Commit-Queue: Anupam Snigdha <snianu@microsoft.com>
Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713160}

third_party/blink/public/web/web_input_method_controller.h

@@ -80,6 +80,13 @@ class WebInputMethodController {
   virtual bool GetCompositionCharacterBounds(WebVector<WebRect>& bounds) {
     return false;
   }
+
+  // Populate |control_bounds| and |selection_bounds| with the bounds fetched
+  // from the active EditContext
+  virtual void GetLayoutBounds(WebRect& control_bounds,
+                               WebRect& selection_bounds) = 0;
+  // Returns true if there is an active EditContext
+  virtual bool IsEditContextActive() const = 0;
 };
 
 }  // namespace blink

third_party/blink/renderer/core/core_idl_files.gni

@@ -143,6 +143,7 @@ core_idl_files =
                     "trustedtypes/trusted_type_policy.idl",
                     "trustedtypes/trusted_type_policy_factory.idl",
                     "editing/selection.idl",
+                    "editing/ime/edit_context.idl",
                     "editing/ime/text_update_event.idl",
                     "editing/ime/text_format_update_event.idl",
                     "events/animation_event.idl",
@@ -626,6 +627,7 @@ core_dictionary_idl_files =
                     "dom/events/event_init.idl",
                     "dom/events/event_listener_options.idl",
                     "dom/events/event_modifier_init.idl",
+                    "editing/ime/edit_context_init.idl",
                     "editing/ime/text_update_event_init.idl",
                     "editing/ime/text_format_update_event_init.idl",
                     "events/animation_event_init.idl",

third_party/blink/renderer/core/editing/BUILD.gn

@@ -144,6 +144,8 @@ blink_core_sources("editing") {
     "frame_selection.h",
     "granularity_strategy.cc",
     "granularity_strategy.h",
+    "ime/edit_context.cc",
+    "ime/edit_context.h",
     "ime/ime_text_span.cc",
     "ime/ime_text_span.h",
     "ime/ime_text_span_vector_builder.cc",

third_party/blink/renderer/core/editing/ime/edit_context.idl

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// The goal of the EditContext is to expose the lower-level APIs provided by
+// modern operating systems to facilitate various input modalities to unlock
+// advanced editing scenarios. For more information please refer
+// https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/master/EditContext/explainer.md
+[
+    Constructor(optional EditContextInit options),
+    ConstructorCallWith=ScriptState,
+    Exposed=Window,
+    RuntimeEnabled=EditContext
+] interface EditContext : EventTarget {
+    void focus();
+    void blur();
+    [RaisesException] void updateSelection(unsigned long start, unsigned long end);
+    void updateLayout(DOMRect controlBounds, DOMRect selectionBounds);
+    [RaisesException] void updateText(unsigned long start, unsigned long end, DOMString newText);
+
+    attribute DOMString text;
+    [RaisesException=Setter] attribute unsigned long selectionStart;
+    [RaisesException=Setter] attribute unsigned long selectionEnd;
+    attribute EditContextInputMode inputMode;
+    attribute EditContextInputPanelPolicy inputPanelPolicy;
+    attribute EditContextEnterKeyHint enterKeyHint;
+
+    // Event handler attributes
+    attribute EventHandler ontextupdate;
+    attribute EventHandler ontextformatupdate;
+    attribute EventHandler oncompositionstart;
+    attribute EventHandler oncompositionend;
+};

third_party/blink/renderer/core/editing/ime/edit_context_init.idl

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+enum EditContextInputMode { "none", "text", "decimal", "search", "email", "numeric", "tel", "url", "password" };
+enum EditContextEnterKeyHint { "enter", "done", "go", "next", "previous", "search", "send" };
+enum EditContextInputPanelPolicy { "auto", "manual" };
+
+dictionary EditContextInit {
+    DOMString text;
+    unsigned long selectionStart;
+    unsigned long selectionEnd;
+    EditContextInputMode inputMode;
+    EditContextInputPanelPolicy inputPanelPolicy;
+    EditContextEnterKeyHint enterKeyHint;
+};

third_party/blink/renderer/core/editing/ime/input_method_controller.cc

@@ -38,6 +38,7 @@
 #include "third_party/blink/renderer/core/editing/editor.h"
 #include "third_party/blink/renderer/core/editing/ephemeral_range.h"
 #include "third_party/blink/renderer/core/editing/frame_selection.h"
+#include "third_party/blink/renderer/core/editing/ime/edit_context.h"
 #include "third_party/blink/renderer/core/editing/markers/document_marker_controller.h"
 #include "third_party/blink/renderer/core/editing/markers/suggestion_marker_properties.h"
 #include "third_party/blink/renderer/core/editing/reveal_selection_scope.h"
@@ -1555,6 +1556,7 @@ void InputMethodController::WillChangeFocus() {
 void InputMethodController::Trace(Visitor* visitor) {
   visitor->Trace(frame_);
   visitor->Trace(composition_range_);
+  visitor->Trace(active_edit_context_);
   DocumentShutdownObserver::Trace(visitor);
 }
 

third_party/blink/renderer/core/editing/ime/input_method_controller.h

@@ -42,6 +42,7 @@
 namespace blink {
 
 class Editor;
+class EditContext;
 class LocalFrame;
 class Range;
 enum class TypingContinuation;
@@ -113,6 +114,12 @@ class CORE_EXPORT InputMethodController final
   // Call this when we will change focus.
   void WillChangeFocus();
 
+  // Returns the |EditContext| that is currently active
+  EditContext* GetActiveEditContext() const { return active_edit_context_; }
+  void SetActiveEditContext(EditContext* edit_context) {
+    active_edit_context_ = edit_context;
+  }
+
  private:
   friend class InputMethodControllerTest;
 
@@ -121,6 +128,7 @@ class CORE_EXPORT InputMethodController final
 
   Member<LocalFrame> frame_;
   Member<Range> composition_range_;
+  Member<EditContext> active_edit_context_;
   bool has_composition_;
 
   Editor& GetEditor() const;

third_party/blink/renderer/core/editing/ime/text_format_update_event.h

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_EVENTS_TEXT_FORMAT_UPDATE_EVENT_H_
-#define THIRD_PARTY_BLINK_RENDERER_CORE_EVENTS_TEXT_FORMAT_UPDATE_EVENT_H_
+#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_EDITING_IME_TEXT_FORMAT_UPDATE_EVENT_H_
+#define THIRD_PARTY_BLINK_RENDERER_CORE_EDITING_IME_TEXT_FORMAT_UPDATE_EVENT_H_
 
 #include "base/macros.h"
 #include "third_party/blink/renderer/core/core_export.h"
@@ -56,4 +56,4 @@ class CORE_EXPORT TextFormatUpdateEvent final : public Event {
 };
 
 }  // namespace blink
-#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_EVENTS_TEXT_FORMAT_UPDATE_EVENT_H_
+#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_EDITING_IME_TEXT_FORMAT_UPDATE_EVENT_H_

third_party/blink/renderer/core/editing/ime/text_update_event.h

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_EVENTS_TEXT_UPDATE_EVENT_H_
-#define THIRD_PARTY_BLINK_RENDERER_CORE_EVENTS_TEXT_UPDATE_EVENT_H_
+#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_EDITING_IME_TEXT_UPDATE_EVENT_H_
+#define THIRD_PARTY_BLINK_RENDERER_CORE_EDITING_IME_TEXT_UPDATE_EVENT_H_
 
 #include "base/macros.h"
 #include "third_party/blink/renderer/core/core_export.h"
@@ -59,4 +59,4 @@ class CORE_EXPORT TextUpdateEvent final : public Event {
 };
 
 }  // namespace blink
-#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_EVENTS_TEXT_UPDATE_EVENT_H_
+#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_EDITING_IME_TEXT_UPDATE_EVENT_H_

third_party/blink/renderer/core/events/event_target_names.json5

@@ -11,6 +11,7 @@
     "AccessibleNode",
     "Animation",
     "Clipboard",
+    "EditContext",
     "FontFaceSet",
     "MediaQueryList",
     "BroadcastChannel",

third_party/blink/renderer/core/exported/web_input_method_controller_impl.cc

@@ -15,6 +15,7 @@
 #include "third_party/blink/renderer/core/editing/editor.h"
 #include "third_party/blink/renderer/core/editing/ephemeral_range.h"
 #include "third_party/blink/renderer/core/editing/frame_selection.h"
+#include "third_party/blink/renderer/core/editing/ime/edit_context.h"
 #include "third_party/blink/renderer/core/editing/ime/ime_text_span_vector_builder.h"
 #include "third_party/blink/renderer/core/editing/ime/input_method_controller.h"
 #include "third_party/blink/renderer/core/editing/plain_text_range.h"
@@ -37,12 +38,22 @@ void WebInputMethodControllerImpl::Trace(blink::Visitor* visitor) {
   visitor->Trace(web_frame_);
 }
 
+bool WebInputMethodControllerImpl::IsEditContextActive() const {
+  return GetInputMethodController().GetActiveEditContext();
+}
+
 bool WebInputMethodControllerImpl::SetComposition(
     const WebString& text,
     const WebVector<WebImeTextSpan>& ime_text_spans,
     const WebRange& replacement_range,
     int selection_start,
     int selection_end) {
+  if (IsEditContextActive()) {
+    return GetInputMethodController().GetActiveEditContext()->SetComposition(
+        text, ime_text_spans, replacement_range, selection_start,
+        selection_end);
+  }
+
   if (WebPlugin* plugin = FocusedPluginIfInputMethodSupported()) {
     return plugin->SetComposition(text, ime_text_spans, replacement_range,
                                   selection_start, selection_end);
@@ -94,6 +105,12 @@ bool WebInputMethodControllerImpl::FinishComposingText(
   // in WebViewImpl::focusedLocalFrameInWidget(), we will reach here with
   // |web_frame_| not focused on page.
 
+  if (IsEditContextActive()) {
+    return GetInputMethodController()
+        .GetActiveEditContext()
+        ->FinishComposingText(selection_behavior);
+  }
+
   if (WebPlugin* plugin = FocusedPluginIfInputMethodSupported())
     return plugin->FinishComposingText(selection_behavior);
 
@@ -115,6 +132,11 @@ bool WebInputMethodControllerImpl::CommitText(
   std::unique_ptr<UserGestureIndicator> gesture_indicator =
       LocalFrame::NotifyUserActivation(GetFrame());
 
+  if (IsEditContextActive()) {
+    return GetInputMethodController().GetActiveEditContext()->CommitText(
+        text, ime_text_spans, replacement_range, relative_caret_position);
+  }
+
   if (WebPlugin* plugin = FocusedPluginIfInputMethodSupported()) {
     return plugin->CommitText(text, ime_text_spans, replacement_range,
                               relative_caret_position);
@@ -136,6 +158,9 @@ bool WebInputMethodControllerImpl::CommitText(
 }
 
 WebTextInputInfo WebInputMethodControllerImpl::TextInputInfo() {
+  if (IsEditContextActive())
+    return GetInputMethodController().GetActiveEditContext()->TextInputInfo();
+
   return GetFrame()->GetInputMethodController().TextInputInfo();
 }
 
@@ -146,10 +171,27 @@ int WebInputMethodControllerImpl::ComputeWebTextInputNextPreviousFlags() {
 }
 
 WebTextInputType WebInputMethodControllerImpl::TextInputType() {
+  if (IsEditContextActive())
+    return GetInputMethodController().GetActiveEditContext()->TextInputType();
+
   return GetFrame()->GetInputMethodController().TextInputType();
 }
 
+void WebInputMethodControllerImpl::GetLayoutBounds(WebRect& control_bounds,
+                                                   WebRect& selection_bounds) {
+  if (IsEditContextActive()) {
+    return GetInputMethodController().GetActiveEditContext()->GetLayoutBounds(
+        control_bounds, selection_bounds);
+  }
+}
+
 WebRange WebInputMethodControllerImpl::CompositionRange() {
+  if (IsEditContextActive()) {
+    return GetInputMethodController()
+        .GetActiveEditContext()
+        ->CompositionRange();
+  }
+
   EphemeralRange range =
       GetFrame()->GetInputMethodController().CompositionEphemeralRange();
 
@@ -166,6 +208,9 @@ WebRange WebInputMethodControllerImpl::CompositionRange() {
 
 bool WebInputMethodControllerImpl::GetCompositionCharacterBounds(
     WebVector<WebRect>& bounds) {
+  if (IsEditContextActive())
+    return false;
+
   WebRange range = CompositionRange();
   if (range.IsEmpty())
     return false;
@@ -187,6 +232,12 @@ bool WebInputMethodControllerImpl::GetCompositionCharacterBounds(
 }
 
 WebRange WebInputMethodControllerImpl::GetSelectionOffsets() const {
+  if (IsEditContextActive()) {
+    return GetInputMethodController()
+        .GetActiveEditContext()
+        ->GetSelectionOffsets();
+  }
+
   // TODO(editing-dev): The use of UpdateStyleAndLayout
   // needs to be audited.  See http://crbug.com/590369 for more details.
   GetFrame()->GetDocument()->UpdateStyleAndLayout();

third_party/blink/renderer/core/exported/web_input_method_controller_impl.h

@@ -49,6 +49,10 @@ class CORE_EXPORT WebInputMethodControllerImpl
 
   WebRange GetSelectionOffsets() const override;
 
+  void GetLayoutBounds(WebRect& control_bounds,
+                       WebRect& selection_bounds) override;
+  bool IsEditContextActive() const override;
+
   void Trace(blink::Visitor*);
 
  private:

third_party/blink/renderer/core/frame/web_local_frame_impl.cc

@@ -160,6 +160,7 @@
 #include "third_party/blink/renderer/core/editing/finder/find_in_page_coordinates.h"
 #include "third_party/blink/renderer/core/editing/finder/text_finder.h"
 #include "third_party/blink/renderer/core/editing/frame_selection.h"
+#include "third_party/blink/renderer/core/editing/ime/edit_context.h"
 #include "third_party/blink/renderer/core/editing/ime/ime_text_span_vector_builder.h"
 #include "third_party/blink/renderer/core/editing/ime/input_method_controller.h"
 #include "third_party/blink/renderer/core/editing/iterators/text_iterator.h"
@@ -1352,6 +1353,12 @@ bool WebLocalFrameImpl::SetCompositionFromExistingText(
     int composition_end,
     const WebVector<WebImeTextSpan>& ime_text_spans) {
   TRACE_EVENT0("blink", "WebLocalFrameImpl::setCompositionFromExistingText");
+  if (EditContext* edit_context =
+          GetFrame()->GetInputMethodController().GetActiveEditContext()) {
+    return edit_context->SetCompositionFromExistingText(
+        composition_start, composition_end, ime_text_spans);
+  }
+
   if (!GetFrame()->GetEditor().CanEdit())
     return false;
 
@@ -1371,6 +1378,12 @@ bool WebLocalFrameImpl::SetCompositionFromExistingText(
 
 void WebLocalFrameImpl::ExtendSelectionAndDelete(int before, int after) {
   TRACE_EVENT0("blink", "WebLocalFrameImpl::extendSelectionAndDelete");
+  if (EditContext* edit_context =
+          GetFrame()->GetInputMethodController().GetActiveEditContext()) {
+    edit_context->ExtendSelectionAndDelete(before, after);
+    return;
+  }
+
   if (WebPlugin* plugin = FocusedPluginIfInputMethodSupported()) {
     plugin->ExtendSelectionAndDelete(before, after);
     return;

third_party/blink/web_tests/webexposed/global-interface-listing-expected.txt

@@ -1953,6 +1953,34 @@ interface DynamicsCompressorNode : AudioNode
     getter release
     getter threshold
     method constructor
+interface EditContext : EventTarget
+    attribute @@toStringTag
+    getter enterKeyHint
+    getter inputMode
+    getter inputPanelPolicy
+    getter oncompositionend
+    getter oncompositionstart
+    getter ontextformatupdate
+    getter ontextupdate
+    getter selectionEnd
+    getter selectionStart
+    getter text
+    method blur
+    method constructor
+    method focus
+    method updateLayout
+    method updateSelection
+    method updateText
+    setter enterKeyHint
+    setter inputMode
+    setter inputPanelPolicy
+    setter oncompositionend
+    setter oncompositionstart
+    setter ontextformatupdate
+    setter ontextupdate
+    setter selectionEnd
+    setter selectionStart
+    setter text
 interface Element : Node
     attribute @@toStringTag
     attribute @@unscopables