EditContext: enable English typing

This CL enables English typing for EditContext by redirecting inserted
text in Editor::HandleEditingKeyboardEvent if EditContext is active.

A test is also added in edit-context.html.

Change-Id: I0c63371385556869ab71652d6857d18d985260d9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2626528Reviewed-by: Anupam Snigdha <snianu@microsoft.com>
Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Alex Keng <shihken@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#843605}

third_party/blink/renderer/core/editing/editor_key_bindings.cc

@@ -32,6 +32,8 @@
 #include "third_party/blink/renderer/core/editing/editing_behavior.h"
 #include "third_party/blink/renderer/core/editing/editing_utilities.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/input_method_controller.h"
 #include "third_party/blink/renderer/core/events/keyboard_event.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
 #include "third_party/blink/renderer/core/frame/local_frame_client.h"
@@ -60,7 +62,20 @@ bool Editor::HandleEditingKeyboardEvent(KeyboardEvent* evt) {
   if (command.Execute(evt))
     return true;
 
-  if (!Behavior().ShouldInsertCharacter(*evt) || !CanEdit())
+  if (!Behavior().ShouldInsertCharacter(*evt))
+    return false;
+
+  // If EditContext is active, redirect text to EditContext, otherwise, send
+  // text to the focused element.
+  auto* edit_context =
+      GetFrame().GetInputMethodController().GetActiveEditContext();
+  if (edit_context) {
+    WebString text(WTF::String(key_event->text));
+    edit_context->InsertText(text);
+    return true;
+  }
+
+  if (!CanEdit())
     return false;
 
   const Element* const focused_element =

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

@@ -457,6 +457,20 @@ bool EditContext::SetCompositionFromExistingText(
   return true;
 }
 
+bool EditContext::InsertText(const WebString& text) {
+  String update_text(text);
+  text_ = text_.Substring(0, selection_start_) + update_text +
+          text_.Substring(selection_end_);
+  uint32_t update_range_start = selection_start_;
+  uint32_t update_range_end = selection_end_;
+  selection_start_ = selection_start_ + text.length();
+  selection_end_ = selection_start_;
+
+  DispatchTextUpdateEvent(update_text, update_range_start, update_range_end,
+                          selection_start_, selection_end_);
+  return true;
+}
+
 bool EditContext::CommitText(const WebString& text,
                              const WebVector<ui::ImeTextSpan>& ime_text_spans,
                              const WebRange& replacement_range,

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

@@ -174,6 +174,9 @@ class CORE_EXPORT EditContext final : public EventTargetWithInlineData,
       int composition_end,
       const WebVector<ui::ImeTextSpan>& ime_text_spans);
 
+  // For English typing.
+  bool InsertText(const WebString& text);
+
   bool IsVirtualKeyboardPolicyManual() const override;
   bool IsEditContextActive() const override;
   // Returns whether show()/hide() API is called from virtualkeyboard or not.

third_party/blink/web_tests/editing/input/edit-context.html

@@ -28,6 +28,19 @@ test(function() {
   assert_equals(editContext.enterKeyHint, "enter");
 }, 'Testing EditContext Dictionary Init');
 
+test(function() {
+  const editContext = new EditContext();
+  assert_not_equals(editContext, null);
+  const test = document.getElementById('test');
+  test.innerHTML = "";
+  editContext.addEventListener("textupdate", e => {
+    test.innerHTML = e.updateText;
+  });
+  editContext.focus();
+  eventSender.keyDown('a');
+  assert_equals(test.innerHTML, "a");
+}, 'Testing EditContext English typing');
+
 test(function() {
   const editContext = new EditContext();
   assert_not_equals(editContext, null);