Make SearchBoxView Search Box have the functionality to autocomplete user queries.

Current iteration:
1. Autocomplete queries will only autocomplete if it is confident in a
   url or text query (no apps or answer cards).
2. Autocomplete is based off of the first result view in the
   SearchResultPageView.
3. Up/Down/Left/Right/Tab keys all trigger autocomplete.

Bug: 865543
Change-Id: I579a6f1fb4cdc2af5e7a43577a73a843663e5e8c
Reviewed-on: https://chromium-review.googlesource.com/1161014Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Daniel Zhang <oxyflush@google.com>
Cr-Commit-Position: refs/heads/master@{#580258}

ash/app_list/views/app_list_view_unittest.cc

@@ -591,8 +591,7 @@ TEST_P(AppListViewFocusTest, LinearFocusTraversalInHalfState) {
   forward_view_list.push_back(contents_view()
                                   ->search_result_answer_card_view_for_test()
                                   ->GetSearchAnswerContainerViewForTest());
-  SearchResultListView* list_view =
-      contents_view()->search_result_list_view_for_test();
+  SearchResultListView* list_view = contents_view()->search_result_list_view();
   for (int i = 0; i < kListResults; ++i)
     forward_view_list.push_back(list_view->GetResultViewAt(i));
   forward_view_list.push_back(search_box_view()->search_box());
@@ -744,8 +743,7 @@ TEST_F(AppListViewFocusTest, VerticalFocusTraversalInHalfState) {
   forward_view_list.push_back(contents_view()
                                   ->search_result_answer_card_view_for_test()
                                   ->GetSearchAnswerContainerViewForTest());
-  SearchResultListView* list_view =
-      contents_view()->search_result_list_view_for_test();
+  SearchResultListView* list_view = contents_view()->search_result_list_view();
   for (int i = 0; i < kListResults; ++i)
     forward_view_list.push_back(list_view->GetResultViewAt(i));
   forward_view_list.push_back(search_box_view()->search_box());
@@ -1031,8 +1029,7 @@ TEST_F(AppListViewFocusTest, FirstResultSelectedAfterSearchResultsUpdated) {
   search_box_view()->search_box()->InsertText(base::ASCIIToUTF16("test"));
   const int kListResults = 2;
   SetUpSearchResults(0, kListResults, false);
-  SearchResultListView* list_view =
-      contents_view()->search_result_list_view_for_test();
+  SearchResultListView* list_view = contents_view()->search_result_list_view();
   EXPECT_EQ(search_box_view()->search_box(), focused_view());
   EXPECT_EQ(list_view->GetResultViewAt(0),
             contents_view()->search_results_page_view()->first_result_view());
@@ -1075,8 +1072,7 @@ TEST_F(AppListViewFocusTest, FirstResultNotSelectedAfterQuicklyHittingTab) {
   search_box_view()->search_box()->InsertText(base::ASCIIToUTF16("test1"));
   const int kListResults = 2;
   SetUpSearchResults(0, kListResults, false);
-  SearchResultListView* list_view =
-      contents_view()->search_result_list_view_for_test();
+  SearchResultListView* list_view = contents_view()->search_result_list_view();
   SearchResultBaseView* first_result_view =
       contents_view()->search_results_page_view()->first_result_view();
   EXPECT_EQ(search_box_view()->search_box(), focused_view());

ash/app_list/views/contents_view.h

@@ -108,7 +108,7 @@ class APP_LIST_EXPORT ContentsView : public views::View,
       const {
     return search_result_tile_item_list_view_;
   }
-  SearchResultListView* search_result_list_view_for_test() const {
+  SearchResultListView* search_result_list_view() const {
     return search_result_list_view_;
   }
   HorizontalPageContainer* horizontal_page_container() const {

ash/app_list/views/search_box_view.cc

@@ -298,6 +298,43 @@ void SearchBoxView::ShowZeroStateSuggestions() {
   ContentsChanged(search_box(), empty_query);
 }
 
+void SearchBoxView::OnWallpaperColorsChanged() {
+  GetWallpaperProminentColors(
+      base::BindOnce(&SearchBoxView::OnWallpaperProminentColorsReceived,
+                     weak_ptr_factory_.GetWeakPtr()));
+}
+
+void SearchBoxView::ProcessAutocomplete(bool is_search_result_list_view_first) {
+  if (!is_search_result_list_view_first || last_key_pressed_ == ui::VKEY_BACK ||
+      search_model_->results()->item_count() == 0) {
+    // No first result exists, backspace was pressed, or no results exist.
+    ClearAutocompleteText();
+    return;
+  }
+
+  const base::string16& current_text = search_box()->text();
+  const base::string16& details =
+      search_model_->results()->GetItemAt(0)->details();
+  const base::string16& search_text =
+      search_model_->results()->GetItemAt(0)->title();
+  if (base::StartsWith(details, current_text,
+                       base::CompareCase::INSENSITIVE_ASCII)) {
+    // Current text in the search_box matches the first result's url.
+    SetAutocompleteText(details);
+    return;
+  }
+  if (base::StartsWith(search_text, current_text,
+                       base::CompareCase::INSENSITIVE_ASCII)) {
+    // Current text in the search_box matches the first result's search result
+    // text.
+    SetAutocompleteText(search_text);
+    return;
+  }
+  // Current text in the search_box does not match the first result's url or
+  // search result text.
+  ClearAutocompleteText();
+}
+
 void SearchBoxView::GetWallpaperProminentColors(
     AppListViewDelegate::GetWallpaperProminentColorsCallback callback) {
   view_delegate_->GetWallpaperProminentColors(std::move(callback));
@@ -322,15 +359,86 @@ void SearchBoxView::OnWallpaperProminentColorsReceived(
   SchedulePaint();
 }
 
+void SearchBoxView::AcceptAutocompleteText() {
+  if (highlight_range_.start() != search_box()->text().length())
+    ContentsChanged(search_box(), search_box()->text());
+}
+
+void SearchBoxView::AcceptOneCharInAutocompleteText() {
+  highlight_range_.set_start(highlight_range_.start() + 1);
+  highlight_range_.set_end(search_box()->text().length());
+  const base::string16 original_text = search_box()->text();
+  search_box()->SetText(
+      search_box()->text().substr(0, highlight_range_.start()));
+  ContentsChanged(search_box(), search_box()->text());
+  search_box()->SetText(original_text);
+  search_box()->SetSelectionRange(highlight_range_);
+}
+
+void SearchBoxView::ClearAutocompleteText() {
+  search_box()->SetText(
+      search_box()->text().substr(0, highlight_range_.start()));
+}
+
 void SearchBoxView::ContentsChanged(views::Textfield* sender,
                                     const base::string16& new_contents) {
+  // Update autocomplete text highlight range to track user typed text.
+  highlight_range_.set_start(search_box()->text().length());
   search_box::SearchBoxViewBase::ContentsChanged(sender, new_contents);
   app_list_view_->SetStateFromSearchBoxView(
       IsSearchBoxTrimmedQueryEmpty(), true /*triggered_by_contents_change*/);
 }
 
+void SearchBoxView::SetAutocompleteText(
+    const base::string16& autocomplete_text) {
+  const base::string16& current_text = search_box()->text();
+  // Currrent text is a prefix of autocomplete text.
+  DCHECK(base::StartsWith(autocomplete_text, current_text,
+                          base::CompareCase::INSENSITIVE_ASCII));
+  // Don't set autocomplete text if it's the same as current search box text.
+  if (autocomplete_text.length() == current_text.length())
+    return;
+
+  search_box()->SetText(autocomplete_text);
+  highlight_range_.set_end(autocomplete_text.length());
+  search_box()->SelectRange(highlight_range_);
+}
+
+void SearchBoxView::UpdateAutocompleteSelectionRange(uint32_t start,
+                                                     uint32_t end) {
+  highlight_range_.set_start(start);
+  highlight_range_.set_end(end);
+}
+
 bool SearchBoxView::HandleKeyEvent(views::Textfield* sender,
                                    const ui::KeyEvent& key_event) {
+  if (search_box()->HasFocus() && is_search_box_active() &&
+      !search_box()->text().empty()) {
+    // If the search box has no text in it currently, autocomplete should not
+    // work.
+    last_key_pressed_ = key_event.key_code();
+    if (key_event.type() == ui::ET_KEY_PRESSED &&
+        key_event.key_code() != ui::VKEY_BACK) {
+      if (key_event.key_code() == ui::VKEY_RIGHT ||
+          key_event.key_code() == ui::VKEY_LEFT ||
+          key_event.key_code() == ui::VKEY_DOWN ||
+          key_event.key_code() == ui::VKEY_UP ||
+          key_event.key_code() == ui::VKEY_TAB) {
+        AcceptAutocompleteText();
+      } else {
+        const base::string16 pending_text = search_box()->GetSelectedText();
+        // Hitting the next key in the autocompete suggestion continues
+        // autocomplete suggestion. If the selected range doesn't match the
+        // recorded highlight range, the selection should be overwritten.
+        if (!pending_text.empty() &&
+            key_event.GetCharacter() == pending_text[0] &&
+            pending_text.length() == highlight_range_.length()) {
+          AcceptOneCharInAutocompleteText();
+          return true;
+        }
+      }
+    }
+  }
   if (key_event.type() == ui::ET_KEY_PRESSED &&
       key_event.key_code() == ui::VKEY_RETURN) {
     if (!IsSearchBoxTrimmedQueryEmpty()) {
@@ -401,10 +509,4 @@ void SearchBoxView::SearchEngineChanged() {
   UpdateSearchIcon();
 }
 
-void SearchBoxView::OnWallpaperColorsChanged() {
-  GetWallpaperProminentColors(
-      base::BindOnce(&SearchBoxView::OnWallpaperProminentColorsReceived,
-                     weak_ptr_factory_.GetWeakPtr()));
-}
-
 }  // namespace app_list

ash/app_list/views/search_box_view.h

@@ -80,6 +80,9 @@ class APP_LIST_EXPORT SearchBoxView : public search_box::SearchBoxViewBase,
   // Called when the wallpaper colors change.
   void OnWallpaperColorsChanged();
 
+  // Sets the autocomplete text if autocomplete conditions are met.
+  void ProcessAutocomplete(bool is_search_result_list_view_first);
+
  private:
   // Gets the wallpaper prominent colors.
   void GetWallpaperProminentColors(
@@ -90,6 +93,21 @@ class APP_LIST_EXPORT SearchBoxView : public search_box::SearchBoxViewBase,
   void OnWallpaperProminentColorsReceived(
       const std::vector<SkColor>& prominent_colors);
 
+  // Notifies SearchBoxViewDelegate that the autocomplete text is valid.
+  void AcceptAutocompleteText();
+
+  // Accepts one character in the autocomplete text and fires query.
+  void AcceptOneCharInAutocompleteText();
+
+  // Removes all autocomplete text.
+  void ClearAutocompleteText();
+
+  // After verifying autocomplete text is valid, sets the current searchbox
+  // text to the autocomplete text and sets the text highlight.
+  void SetAutocompleteText(const base::string16& autocomplete_text);
+
+  void UpdateAutocompleteSelectionRange(uint32_t start, uint32_t end);
+
   // Overridden from views::TextfieldController:
   void ContentsChanged(views::Textfield* sender,
                        const base::string16& new_contents) override;
@@ -104,6 +122,12 @@ class APP_LIST_EXPORT SearchBoxView : public search_box::SearchBoxViewBase,
   void Update() override;
   void SearchEngineChanged() override;
 
+  // The range of highlighted text for autocomplete.
+  gfx::Range highlight_range_;
+
+  // The key most recently pressed.
+  ui::KeyboardCode last_key_pressed_ = ui::VKEY_UNKNOWN;
+
   AppListViewDelegate* view_delegate_;   // Not owned.
   SearchModel* search_model_ = nullptr;  // Owned by the profile-keyed service.
 

ash/app_list/views/search_result_page_view.cc

@@ -278,6 +278,14 @@ void SearchResultPageView::OnSearchResultContainerResultsChanged() {
 
   first_result_view_ = result_container_views_[0]->GetFirstResultView();
 
+  // Update SearchBoxView search box autocomplete as necessary based on new
+  // first result view.
+  if (first_result_view_) {
+    AppListPage::contents_view()->GetSearchBoxView()->ProcessAutocomplete(
+        result_container_views_[0] ==
+        AppListPage::contents_view()->search_result_list_view());
+  }
+
   // If one of the search result is focused, do not highlight the first search
   // result.
   if (Contains(focused_view))

ash/app_list/views/search_result_page_view_unittest.cc

@@ -78,7 +78,7 @@ class SearchResultPageViewTest
     view_ = contents_view->search_results_page_view();
     tile_list_view_ =
         contents_view->search_result_tile_item_list_view_for_test();
-    list_view_ = contents_view->search_result_list_view_for_test();
+    list_view_ = contents_view->search_result_list_view();
   }
   void TearDown() override {
     app_list_view_->GetWidget()->Close();