Implement ImeInstance.SetComposingRegion mojo API.

The mojo call is connected to InputConnection.setComposingRegion() in
Android side.

Bug: b:163013722
Test: components_unittests
Change-Id: I4dd9d76f8788fb76e649fd8418c84ef56c8cc6f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2352453
Commit-Queue: Yuichiro Hanada <yhanada@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#804125}

components/arc/ime/arc_ime_bridge.h

@@ -60,6 +60,7 @@ class ArcImeBridge {
   virtual void SendExtendSelectionAndDelete(size_t before, size_t after) = 0;
   virtual void SendOnKeyboardAppearanceChanging(const gfx::Rect& new_bounds,
                                                 bool is_available) = 0;
+  virtual void SendSetComposingRegion(const gfx::Range& composing_range) = 0;
 
  protected:
   ArcImeBridge() {}

components/arc/ime/arc_ime_bridge_impl.cc

@@ -118,6 +118,16 @@ void ArcImeBridgeImpl::SendOnKeyboardAppearanceChanging(
   ime_instance->OnKeyboardAppearanceChanging(new_bounds, is_available);
 }
 
+void ArcImeBridgeImpl::SendSetComposingRegion(
+    const gfx::Range& composing_range) {
+  auto* ime_instance =
+      ARC_GET_INSTANCE_FOR_METHOD(bridge_service_->ime(), SetComposingRegion);
+  if (!ime_instance)
+    return;
+
+  ime_instance->SetComposingRegion(composing_range);
+}
+
 void ArcImeBridgeImpl::OnTextInputTypeChanged(
     ui::TextInputType type,
     bool is_personalized_learning_allowed,

components/arc/ime/arc_ime_bridge_impl.h

@@ -37,6 +37,7 @@ class ArcImeBridgeImpl : public ArcImeBridge, public mojom::ImeHost {
   void SendOnKeyboardAppearanceChanging(const gfx::Rect& new_bounds,
                                         bool is_available) override;
   void SendSelectionRange(const gfx::Range& selection_range) override;
+  void SendSetComposingRegion(const gfx::Range& composing_range) override;
 
   // mojom::ImeHost overrides:
   void OnTextInputTypeChanged(ui::TextInputType type,

components/arc/ime/arc_ime_service.cc

@@ -616,41 +616,16 @@ bool ArcImeService::ShouldDoLearning() {
 bool ArcImeService::SetCompositionFromExistingText(
     const gfx::Range& range,
     const std::vector<ui::ImeTextSpan>& ui_ime_text_spans) {
-  // TODO(https://crbug.com/952757): Implement this method using
-  // Android API's |SetComposingRegion|.
-  if (!selection_range_.is_empty() || !selection_range_.IsBoundedBy(range)) {
-    return true;
-  }
+  if (!range.IsBoundedBy(text_range_))
+    return false;
 
-  // |text_in_range_| might be only a subset of the full text, so make sure that
-  // the composition range is within bounds.
-  const gfx::Range range_relative_to_text(
-      range.GetMin() - text_range_.GetMin(),
-      range.GetMax() - text_range_.GetMin());
-  if (range_relative_to_text.GetMin() < 0 ||
-      range_relative_to_text.length() > text_in_range_.length()) {
-    return true;
-  }
+  InvalidateSurroundingTextAndSelectionRange();
+  has_composition_text_ = !range.is_empty();
 
-  // Save the text to be composed since we need to recompose it later.
-  base::string16 text = text_in_range_.substr(range_relative_to_text.GetMin(),
-                                              range_relative_to_text.length());
-  const int cursor_relative_to_text =
-      selection_range_.start() - text_range_.GetMin();
-
-  // Confirm the existing composition, delete the text to be composed, and
-  // recompose it.
-  ConfirmCompositionText(/*keep_selection=*/true);
-  ExtendSelectionAndDelete(
-      /*before=*/cursor_relative_to_text - range_relative_to_text.GetMin(),
-      /*after=*/range_relative_to_text.GetMax() - cursor_relative_to_text);
-  ui::CompositionText composition;
-
-  composition.text = std::move(text);
-  composition.selection =
-      gfx::Range(cursor_relative_to_text, cursor_relative_to_text);
-  composition.ime_text_spans = ui_ime_text_spans;
-  SetCompositionText(std::move(composition));
+  // The sent |range| might be already invalid if the textfield state in Android
+  // side is changed simultaneously. It's okay because InputConnection's
+  // setComposingRegion handles invalid region correctly.
+  ime_bridge_->SendSetComposingRegion(range);
   return true;
 }
 

components/arc/ime/arc_ime_service_unittest.cc

@@ -34,9 +34,7 @@ namespace {
 class FakeArcImeBridge : public ArcImeBridge {
  public:
   FakeArcImeBridge()
-      : count_send_insert_text_(0),
-        last_keyboard_availability_(false),
-        selection_range_(gfx::Range()) {}
+      : count_send_insert_text_(0), last_keyboard_availability_(false) {}
 
   void SendSetCompositionText(const ui::CompositionText& composition) override {
   }
@@ -55,6 +53,9 @@ class FakeArcImeBridge : public ArcImeBridge {
     last_keyboard_bounds_ = new_bounds;
     last_keyboard_availability_ = is_available;
   }
+  void SendSetComposingRegion(const gfx::Range& composing_range) override {
+    composing_range_ = composing_range;
+  }
 
   int count_send_insert_text() const { return count_send_insert_text_; }
   const gfx::Rect& last_keyboard_bounds() const {
@@ -64,12 +65,14 @@ class FakeArcImeBridge : public ArcImeBridge {
     return last_keyboard_availability_;
   }
   gfx::Range selection_range() { return selection_range_; }
+  gfx::Range composing_range() { return composing_range_; }
 
  private:
   int count_send_insert_text_;
   gfx::Rect last_keyboard_bounds_;
   bool last_keyboard_availability_;
   gfx::Range selection_range_;
+  gfx::Range composing_range_;
 };
 
 class FakeInputMethod : public ui::DummyInputMethod {
@@ -512,4 +515,27 @@ TEST_F(ArcImeServiceTest, DoNothingIfArcWindowIsNotFocused) {
   EXPECT_EQ(0, fake_input_method_->count_cancel_composition());
 }
 
+TEST_F(ArcImeServiceTest, SetComposingRegion) {
+  instance_->OnWindowFocused(arc_win_.get(), nullptr);
+
+  const gfx::Range composing_range(1, 3);
+
+  // Ignore it if the range is outside of text range.
+  instance_->SetCompositionFromExistingText(composing_range, {});
+  EXPECT_EQ(gfx::Range(), fake_arc_ime_bridge_->composing_range());
+
+  instance_->OnCursorRectChangedWithSurroundingText(
+      gfx::Rect(), gfx::Range(0, 100), base::string16(100, 'a'),
+      gfx::Range(0, 0), false);
+  instance_->SetCompositionFromExistingText(composing_range, {});
+  EXPECT_EQ(composing_range, fake_arc_ime_bridge_->composing_range());
+
+  // Ignore it if the range is outside of text range.
+  instance_->OnCursorRectChangedWithSurroundingText(
+      gfx::Rect(), gfx::Range(0, 100), base::string16(100, 'a'),
+      gfx::Range(0, 0), false);
+  instance_->SetCompositionFromExistingText(gfx::Range(50, 101), {});
+  EXPECT_EQ(composing_range, fake_arc_ime_bridge_->composing_range());
+}
+
 }  // namespace arc

components/arc/mojom/ime.mojom

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Next MinVersion: 15
+// Next MinVersion: 16
 
 module arc.mojom;
 
@@ -114,7 +114,7 @@ interface ImeHost {
       => (bool is_consumed);
 };
 
-// Next method ID: 8
+// Next method ID: 9
 interface ImeInstance {
   // DEPRECATED: Please use Init@6 instead.
   InitDeprecated@0(pending_remote<ImeHost> host_remote);
@@ -145,4 +145,7 @@ interface ImeInstance {
   // Deletes current selection plus the specified number of char16 values
   // before and after selection or caret.
   [MinVersion=4] ExtendSelectionAndDelete@5(uint64 before, uint64 after);
+
+  // Sets composing region requested by the host IME.
+  [MinVersion=15] SetComposingRegion@8(Range range);
 };