Transfer Searchify state to PDF Viewer WebUI.

To measure PDF Searchify's success in increasing user interaction with
PDFs and to show Searchify progress (see go/pdf-ocr-design, page 8), the
following two states are passed to the PDF Viewer WebUI:
 - PDF has searchify text.
 - Searchify is in progress.

The former will be used to record the new metrics and the latter will be
used to show Searchify progress indicator.

Bug: 360803943
Change-Id: I08bc59813b0ec1718df3475dc1a6ad8b1519b34c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6001955
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1380199}

chrome/browser/resources/pdf/pdf_viewer.ts

@@ -912,6 +912,12 @@ export class PdfViewerElement extends PdfViewerBaseElement {
         // Editing mode can only be entered once, and cannot be exited.
         this.hasEdits_ = true;
         return;
+      case 'setHasSearchifyText':
+        // TODO(crbug.com/360803943): Add separate metrics for searchified PDFs.
+        return;
+      case 'showSearchifyInProgress':
+        // TODO(crbug.com/360803943): Trigger showing/hiding searchify progress.
+        return;
       case 'startedFindInPage':
         record(UserAction.FIND_IN_PAGE);
         return;

pdf/pdf_view_web_plugin.cc

@@ -1418,8 +1418,54 @@ bool PdfViewWebPlugin::IsInAnnotationMode() const {
 #if BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
 void PdfViewWebPlugin::OnSearchifyStateChange(bool busy) {
   pdf_host_->OnSearchifyStateChange(busy);
+
+  if (busy && show_searchify_in_progress_) {
+    return;
+  }
+
+  if (busy) {
+    // The UI is asked to show the progress indicator with 1s delay, so that if
+    // the task finishes in less than 1s, the indicator would not be shown.
+    show_searchify_in_progress_ = true;
+    base::SingleThreadTaskRunner::GetCurrentDefault()->PostDelayedTask(
+        FROM_HERE,
+        base::BindOnce(&PdfViewWebPlugin::SetShowSearchifyInProgress,
+                       weak_factory_.GetWeakPtr(), /*show=*/true),
+        base::Seconds(1));
+    return;
+  }
+
+  if (show_searchify_in_progress_) {
+    show_searchify_in_progress_ = false;
+    SetShowSearchifyInProgress(false);
+  }
 }
-#endif
+
+void PdfViewWebPlugin::SetShowSearchifyInProgress(bool show) {
+  // Searchify tasks are expected to be quite fast most of the times, and if so,
+  // showing progress indicator is not needed.
+  // `SetShowSearchifyInProgress` is posted with delay to allow discarding the
+  // the request to show the progress indicator in such cases.
+  // A true `show` and a false `show_searchify_in_progress_` means that the task
+  // finished before the indicator is shown and UI element is not needed.
+  if (show && !show_searchify_in_progress_) {
+    return;
+  }
+
+  // TODO(crbug.com/360803943): Add test.
+  base::Value::Dict message;
+  message.Set("type", "showSearchifyInProgress");
+  message.Set("show", show);
+  client_->PostMessage(std::move(message));
+}
+
+void PdfViewWebPlugin::OnHasSearchifyText() {
+  // TODO(crbug.com/360803943): Add test.
+  base::Value::Dict message;
+  message.Set("type", "setHasSearchifyText");
+  client_->PostMessage(std::move(message));
+}
+#endif  // BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
 
 void PdfViewWebPlugin::SetCaretPosition(const gfx::PointF& position) {
   engine_->SetCaretPosition(FrameToPdfCoordinates(position));

pdf/pdf_view_web_plugin.h

@@ -385,6 +385,7 @@ class PdfViewWebPlugin final : public PDFiumEngineClient,
 #endif  // BUILDFLAG(ENABLE_PDF_INK2)
 #if BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
   void OnSearchifyStateChange(bool busy) override;
+  void OnHasSearchifyText() override;
 #endif
 
   // pdf::mojom::PdfListener:
@@ -694,6 +695,11 @@ class PdfViewWebPlugin final : public PDFiumEngineClient,
   // Starts loading accessibility information.
   void LoadAccessibility();
 
+#if BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
+  // Triggered to show/hide Searchify progress indicator.
+  void SetShowSearchifyInProgress(bool show);
+#endif
+
   bool initialized_ = false;
 
   blink::WebString selected_text_;
@@ -914,6 +920,10 @@ class PdfViewWebPlugin final : public PDFiumEngineClient,
   // Queue of available preview pages to load next.
   base::queue<PreviewPageInfo> preview_pages_info_;
 
+#if BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
+  bool show_searchify_in_progress_ = false;
+#endif
+
   base::WeakPtrFactory<PdfViewWebPlugin> weak_factory_{this};
 };
 

pdf/pdfium/pdfium_engine.cc

@@ -4292,6 +4292,13 @@ void PDFiumEngine::CancelPendingSearchify(int page_index) {
 void PDFiumEngine::OnSearchifyStateChange(bool busy) {
   client_->OnSearchifyStateChange(busy);
 }
+
+void PDFiumEngine::OnHasSearchifyText() {
+  if (!has_searchify_text_) {
+    has_searchify_text_ = true;
+    client_->OnHasSearchifyText();
+  }
+}
 #endif  // BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
 
 void PDFiumEngine::UpdateLinkUnderCursor(const std::string& target_url) {

pdf/pdfium/pdfium_engine.h

@@ -391,6 +391,9 @@ class PDFiumEngine : public DocumentLoader::Client, public IFSDK_PAUSE {
   // See the comment for `OnSearchifyStateChange` in pdf/pdf.mojom.
   void OnSearchifyStateChange(bool busy);
 
+  // Called when searchify text is added.
+  void OnHasSearchifyText();
+
   PDFiumOnDemandSearchifier* GetSearchifierForTesting() {
     return searchifier_.get();
   }
@@ -870,6 +873,9 @@ class PDFiumEngine : public DocumentLoader::Client, public IFSDK_PAUSE {
   // Keeps track of the indices of pages for which "PDF.PageHasText" metric is
   // reported.
   std::set<int> page_has_text_metric_reported_;
+
+  // Records if at least one page has searchify text.
+  bool has_searchify_text_ = false;
 #endif
 
   std::unique_ptr<PDFiumDocument> document_;

pdf/pdfium/pdfium_engine_client.h

@@ -207,6 +207,9 @@ class PDFiumEngineClient {
 #if BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
   // See the comment for `OnSearchifyStateChange` in pdf/pdf.mojom.
   virtual void OnSearchifyStateChange(bool busy) = 0;
+
+  // Notifies that at least one page is searchified.
+  virtual void OnHasSearchifyText() = 0;
 #endif
 };
 

pdf/pdfium/pdfium_on_demand_searchifier.cc

@@ -168,12 +168,17 @@ void PDFiumOnDemandSearchifier::SearchifyNextImage() {
     // It is expected that the page would be still loaded.
     FPDF_PAGE page = current_page_->page();
     CHECK(page);
+    bool added_text = false;
     for (auto& result : current_page_ocr_results_) {
       FPDF_PAGEOBJECT image = FPDFPage_GetObject(page, result.image_index);
       std::vector<FPDF_PAGEOBJECT> added_text_objects =
           AddTextOnImage(engine_->doc(), page, font_.get(), image,
                          std::move(result.annotation), result.image_size);
       current_page_->OnSearchifyGotOcrResult(added_text_objects);
+      added_text |= !added_text_objects.empty();
+    }
+    if (added_text) {
+      engine_->OnHasSearchifyText();
     }
     current_page_ocr_results_.clear();
 

pdf/preview_mode_client.cc

@@ -179,7 +179,13 @@ bool PreviewModeClient::IsInAnnotationMode() const {
 #endif  // BUILDFLAG(ENABLE_PDF_INK2)
 
 #if BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
-void PreviewModeClient::OnSearchifyStateChange(bool busy) {}
+void PreviewModeClient::OnSearchifyStateChange(bool busy) {
+  NOTREACHED();
+}
+
+void PreviewModeClient::OnHasSearchifyText() {
+  NOTREACHED();
+}
 #endif
 
 }  // namespace chrome_pdf

pdf/preview_mode_client.h

@@ -80,6 +80,7 @@ class PreviewModeClient : public PDFiumEngineClient {
 #endif  // BUILDFLAG(ENABLE_PDF_INK2)
 #if BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
   void OnSearchifyStateChange(bool busy) override;
+  void OnHasSearchifyText() override;
 #endif
 
  private:

pdf/test/test_client.cc

@@ -80,6 +80,8 @@ bool TestClient::IsInAnnotationMode() const {
 
 #if BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
 void TestClient::OnSearchifyStateChange(bool busy) {}
+
+void TestClient::OnHasSearchifyText() {}
 #endif
 
 }  // namespace chrome_pdf

pdf/test/test_client.h

@@ -50,6 +50,7 @@ class TestClient : public PDFiumEngineClient {
 #endif  // BUILDFLAG(ENABLE_PDF_INK2)
 #if BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
   void OnSearchifyStateChange(bool busy) override;
+  void OnHasSearchifyText() override;
 #endif
 
  private: