Shape Detection: Add Text Detection in Chrome Android

third_party/WebKit/Source/modules/shapedetection/TextDetector.cpp

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "modules/shapedetection/TextDetector.h"
+
+#include "core/dom/DOMException.h"
+#include "core/dom/DOMRect.h"
+#include "core/frame/LocalFrame.h"
+#include "core/html/canvas/CanvasImageSource.h"
+#include "modules/shapedetection/DetectedText.h"
+#include "public/platform/InterfaceProvider.h"
+
+namespace blink {
+
+TextDetector* TextDetector::create(Document& document) {
+  return new TextDetector(*document.frame());
+}
+
+TextDetector::TextDetector(LocalFrame& frame) : ShapeDetector(frame) {
+  frame.interfaceProvider()->getInterface(mojo::MakeRequest(&m_textService));
+  m_textService.set_connection_error_handler(convertToBaseCallback(WTF::bind(
+      &TextDetector::onTextServiceConnectionError, wrapWeakPersistent(this))));
+}
+
+ScriptPromise TextDetector::doDetect(
+    ScriptPromiseResolver* resolver,
+    mojo::ScopedSharedBufferHandle sharedBufferHandle,
+    int imageWidth,
+    int imageHeight) {
+  ScriptPromise promise = resolver->promise();
+  if (!m_textService) {
+    resolver->reject(DOMException::create(
+        NotSupportedError, "Text detection service unavailable."));
+    return promise;
+  }
+  m_textServiceRequests.add(resolver);
+  m_textService->Detect(std::move(sharedBufferHandle), imageWidth, imageHeight,
+                        convertToBaseCallback(WTF::bind(
+                            &TextDetector::onDetectText, wrapPersistent(this),
+                            wrapPersistent(resolver))));
+  return promise;
+}
+
+void TextDetector::onDetectText(
+    ScriptPromiseResolver* resolver,
+    Vector<mojom::blink::TextDetectionResultPtr> textDetectionResults) {
+  DCHECK(m_textServiceRequests.contains(resolver));
+  m_textServiceRequests.remove(resolver);
+
+  HeapVector<Member<DetectedText>> detectedText;
+  for (const auto& text : textDetectionResults) {
+    detectedText.append(DetectedText::create(
+        text->raw_value,
+        DOMRect::create(text->bounding_box->x, text->bounding_box->y,
+                        text->bounding_box->width,
+                        text->bounding_box->height)));
+  }
+
+  resolver->resolve(detectedText);
+}
+
+void TextDetector::onTextServiceConnectionError() {
+  for (const auto& request : m_textServiceRequests) {
+    request->reject(DOMException::create(NotSupportedError,
+                                         "Text Detection not implemented."));
+  }
+  m_textServiceRequests.clear();
+  m_textService.reset();
+}
+
+DEFINE_TRACE(TextDetector) {
+  ShapeDetector::trace(visitor);
+  visitor->trace(m_textServiceRequests);
+}
+
+}  // namespace blink