Add current_candidate_index and total_candidates to candidate_window

These fields are added as requested by ChromeVox's team to tell
ChromeVox user the true number of candidates and the current selection's
index.

Bug: 1074158
Change-Id: I697f96fe955fd5dc151543d47b26c605060f0a37
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2162501
Commit-Queue: My Nguyen <myy@chromium.org>
Reviewed-by: Keith Lee <keithlee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#762794}

chrome/browser/chromeos/input_method/input_method_engine.cc

@@ -67,6 +67,8 @@ InputMethodEngine::CandidateWindowProperty::CandidateWindowProperty()
 
 InputMethodEngine::CandidateWindowProperty::~CandidateWindowProperty() =
     default;
+InputMethodEngine::CandidateWindowProperty::CandidateWindowProperty(
+    const CandidateWindowProperty& other) = default;
 
 InputMethodEngine::InputMethodEngine() = default;
 
@@ -128,6 +130,8 @@ void InputMethodEngine::SetCandidateWindowProperty(
       candidate_window_.GetProperty().cursor_position;
   dest_property.auxiliary_text = property.auxiliary_text;
   dest_property.is_auxiliary_text_visible = property.is_auxiliary_text_visible;
+  dest_property.current_candidate_index = property.current_candidate_index;
+  dest_property.total_candidates = property.total_candidates;
 
   candidate_window_.SetProperty(dest_property);
   candidate_window_property_ = property;

chrome/browser/chromeos/input_method/input_method_engine.h

@@ -74,6 +74,7 @@ class InputMethodEngine : public ::input_method::InputMethodEngineBase,
   struct CandidateWindowProperty {
     CandidateWindowProperty();
     virtual ~CandidateWindowProperty();
+    CandidateWindowProperty(const CandidateWindowProperty& other);
     int page_size;
     bool is_cursor_visible;
     bool is_vertical;
@@ -83,6 +84,11 @@ class InputMethodEngine : public ::input_method::InputMethodEngineBase,
     // window.
     std::string auxiliary_text;
     bool is_auxiliary_text_visible;
+
+    // The index of the current chosen candidate out of total candidates.
+    // value is -1 if there is no current chosen candidate.
+    int current_candidate_index = -1;
+    int total_candidates = 0;
   };
 
   InputMethodEngine();

chrome/browser/chromeos/input_method/input_method_engine_browsertests.cc

@@ -798,6 +798,46 @@ IN_PROC_BROWSER_TEST_P(InputMethodEngineBrowserTest,
     EXPECT_TRUE(table.is_auxiliary_text_visible());
     EXPECT_EQ("AUXILIARY_TEXT", table.auxiliary_text());
   }
+  {
+    SCOPED_TRACE("setCandidateWindowProperties:currentCandidateIndex test");
+    mock_input_context->Reset();
+    mock_candidate_window->Reset();
+
+    const char set_candidate_window_properties_test_script[] =
+        "chrome.input.ime.setCandidateWindowProperties({"
+        "  engineID: engineBridge.getActiveEngineID(),"
+        "  properties: {"
+        "    currentCandidateIndex: 1"
+        "  }"
+        "});";
+    ASSERT_TRUE(content::ExecuteScript(
+        host->host_contents(), set_candidate_window_properties_test_script));
+    EXPECT_EQ(1, mock_candidate_window->update_lookup_table_call_count());
+
+    const ui::CandidateWindow& table =
+        mock_candidate_window->last_update_lookup_table_arg().lookup_table;
+    EXPECT_EQ(1, table.current_candidate_index());
+  }
+  {
+    SCOPED_TRACE("setCandidateWindowProperties:totalCandidates test");
+    mock_input_context->Reset();
+    mock_candidate_window->Reset();
+
+    const char set_candidate_window_properties_test_script[] =
+        "chrome.input.ime.setCandidateWindowProperties({"
+        "  engineID: engineBridge.getActiveEngineID(),"
+        "  properties: {"
+        "    totalCandidates: 100"
+        "  }"
+        "});";
+    ASSERT_TRUE(content::ExecuteScript(
+        host->host_contents(), set_candidate_window_properties_test_script));
+    EXPECT_EQ(1, mock_candidate_window->update_lookup_table_call_count());
+
+    const ui::CandidateWindow& table =
+        mock_candidate_window->last_update_lookup_table_arg().lookup_table;
+    EXPECT_EQ(100, table.total_candidates());
+  }
   {
     SCOPED_TRACE("setCandidates test");
     mock_input_context->Reset();

chrome/browser/extensions/api/input_ime/input_ime_api_chromeos.cc

@@ -651,6 +651,17 @@ InputImeSetCandidateWindowPropertiesFunction::Run() {
     modified = true;
   }
 
+  if (properties.current_candidate_index) {
+    properties_out.current_candidate_index =
+        *properties.current_candidate_index;
+    modified = true;
+  }
+
+  if (properties.total_candidates) {
+    properties_out.total_candidates = *properties.total_candidates;
+    modified = true;
+  }
+
   if (modified) {
     engine->SetCandidateWindowProperty(properties_out);
   }

chrome/common/extensions/api/input_ime.json

@@ -355,6 +355,16 @@
                     "optional": true,
                     "description": "True to display the auxiliary text, false to hide it."
                   },
+                  "totalCandidates": {
+                    "type": "integer",
+                    "optional": true,
+                    "description": "The total number of candidates for the candidate window."
+                  },
+                  "currentCandidateIndex": {
+                    "type": "integer",
+                    "optional": true,
+                    "description": "The index of the current chosen candidate out of total candidates."
+                  },
                   "windowPosition": {
                     "$ref": "WindowPosition",
                     "description": "Where to display the candidate window.",

ui/base/ime/candidate_window.h

@@ -38,6 +38,10 @@ class COMPONENT_EXPORT(UI_BASE_IME_TYPES) CandidateWindow {
     // window.
     std::string auxiliary_text;
     bool is_auxiliary_text_visible;
+
+    // The index of the current chosen candidate out of total candidates
+    int current_candidate_index;
+    int total_candidates;
   };
 
   // Represents a candidate entry.
@@ -113,6 +117,12 @@ class COMPONENT_EXPORT(UI_BASE_IME_TYPES) CandidateWindow {
     property_->auxiliary_text = auxiliary_text;
   }
 
+  const int& current_candidate_index() const {
+    return property_->current_candidate_index;
+  }
+
+  const int& total_candidates() const { return property_->total_candidates; }
+
   const std::vector<Entry>& candidates() const { return candidates_; }
   std::vector<Entry>* mutable_candidates() { return &candidates_; }