editor: add a timeout for text insertion

This CL adds a timeout timer of 1s which starts when a text insertion
request is sent.

To reduce user confusion, the text is only inserted if the input field
is re-focused within 1s from the moment when the user hits
Insert/Replace.

Bug: b:317143117
Change-Id: I79a77eeeec0aeddd250cc86158ea0b3acd1a5a23
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5138576
Reviewed-by: Curtis McMullan <curtismcmullan@chromium.org>
Reviewed-by: Darren Shen <shend@chromium.org>
Commit-Queue: Chuong Ho <hdchuong@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1243915}

chrome/browser/ash/input_method/editor_mediator.cc

@@ -202,7 +202,7 @@ void EditorMediator::CacheContext() {
   }
 }
 
-void EditorMediator::OnTextInserted() {
+void EditorMediator::OnTextInsertionRequested() {
   // After queuing the text to be inserted, closing the mako web ui should
   // return the focus back to the original input.
   mako_bubble_coordinator_.CloseUI();

chrome/browser/ash/input_method/editor_mediator.h

@@ -77,7 +77,7 @@ class EditorMediator : public EditorEventSink,
   void OnDisplayTabletStateChanged(display::TabletState state) override;
 
   // EditorTextActuator::Delegate overrides
-  void OnTextInserted() override;
+  void OnTextInsertionRequested() override;
   void ProcessConsentAction(ConsentAction consent_action) override;
   void ShowUI() override;
   void CloseUI() override;

chrome/browser/ash/input_method/editor_text_actuator.cc

@@ -39,7 +39,7 @@ void EditorTextActuator::InsertText(const std::string& text) {
   // We queue the text to be inserted here rather then insert it directly into
   // the input.
   inserter_.InsertTextOnNextFocus(text);
-  delegate_->OnTextInserted();
+  delegate_->OnTextInsertionRequested();
 }
 
 void EditorTextActuator::ApproveConsent() {

chrome/browser/ash/input_method/editor_text_actuator.h

@@ -22,7 +22,7 @@ class EditorTextActuator : public orca::mojom::TextActuator {
   class Delegate {
    public:
     virtual ~Delegate() = default;
-    virtual void OnTextInserted() = 0;
+    virtual void OnTextInsertionRequested() = 0;
     virtual void ProcessConsentAction(ConsentAction consent_action) = 0;
     virtual void ShowUI() = 0;
     virtual void CloseUI() = 0;

chrome/browser/ash/input_method/editor_text_inserter.cc

@@ -13,6 +13,8 @@ namespace ash {
 namespace input_method {
 namespace {
 
+constexpr base::TimeDelta kInsertionTimeout = base::Seconds(1);
+
 void InsertText(std::string_view text) {
   TextInputTarget* input = IMEBridge::Get()->GetInputContextHandler();
   if (!input) {
@@ -30,6 +32,13 @@ EditorTextInserter::~EditorTextInserter() = default;
 
 void EditorTextInserter::InsertTextOnNextFocus(std::string_view text) {
   pending_text_insert_ = PendingTextInsert{std::string(text)};
+
+  // Starts the timer and if the text field is not re-focused after the timer
+  // expires, do not insert the text.
+  text_insertion_timer_.Start(
+      FROM_HERE, kInsertionTimeout,
+      base::BindOnce(&EditorTextInserter::CancelTextInsertion,
+                     weak_ptr_factory_.GetWeakPtr()));
 }
 
 void EditorTextInserter::OnFocus(int context_id) {
@@ -40,12 +49,17 @@ void EditorTextInserter::OnFocus(int context_id) {
   if (pending_text_insert_) {
     InsertText(pending_text_insert_->text);
     pending_text_insert_ = absl::nullopt;
+    text_insertion_timer_.Reset();
   }
 }
 
 void EditorTextInserter::OnBlur() {
   focused_client_ = absl::nullopt;
 }
 
+void EditorTextInserter::CancelTextInsertion() {
+  pending_text_insert_ = absl::nullopt;
+}
+
 }  // namespace input_method
 }  // namespace ash

chrome/browser/ash/input_method/editor_text_inserter.h

@@ -7,6 +7,9 @@
 
 #include <string>
 
+#include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
 #include "third_party/abseil-cpp/absl/types/optional.h"
 
 namespace ash {
@@ -35,12 +38,18 @@ class EditorTextInserter {
     std::string text;
   };
 
+  void CancelTextInsertion();
+
   // Holds any pending text insertions. It is assumed that only one text
   // insertion will be requested at any given time.
   absl::optional<PendingTextInsert> pending_text_insert_;
 
   // Holds the context of a focused text client.
   absl::optional<TextClientContext> focused_client_;
+
+  base::OneShotTimer text_insertion_timer_;
+
+  base::WeakPtrFactory<EditorTextInserter> weak_ptr_factory_{this};
 };
 
 }  // namespace input_method