Shapedetection module: Blink side implementation

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

 // Copyright 2016 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/FaceDetector.h"
 
-#include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMException.h"
+#include "core/dom/DOMRect.h"
+#include "core/dom/Document.h"
+#include "core/fetch/ImageResource.h"
+#include "core/frame/LocalFrame.h"
+#include "core/html/HTMLImageElement.h"
+#include "platform/graphics/Image.h"
+#include "public/platform/InterfaceProvider.h"
+#include "third_party/skia/include/core/SkImage.h"
+#include "third_party/skia/include/core/SkImageInfo.h"
 
 namespace blink {
 
-FaceDetector* FaceDetector::create()
+namespace {
+
+mojo::ScopedSharedBufferHandle getSharedBufferHandle(const HTMLImageElement* img)
 {
-    return new FaceDetector();
+    ImageResource* const imgResource = img->cachedImage();
+    if (!imgResource) {
+        DLOG(ERROR) << "Failed to convert HTMLImageElement to ImageSource.";
+        return mojo::ScopedSharedBufferHandle();
+    }
+
+    Image* const blinkImage = imgResource->getImage();
+    if (!blinkImage) {
+        DLOG(ERROR) << "Failed to convert ImageSource to blink::Image.";
+        return mojo::ScopedSharedBufferHandle();
+    }
+
+    const sk_sp<SkImage> skiaImg = blinkImage->imageForCurrentFrame();
+    DCHECK_EQ(img->naturalWidth(), skiaImg->width());
+    DCHECK_EQ(img->naturalHeight(), skiaImg->height());
+
+    if (!skiaImg) {
+        DLOG(ERROR) << "Failed to convert blink::Image to sk_sp<SkImage>.";
+        return mojo::ScopedSharedBufferHandle();
+    }
+
+    const SkImageInfo skiaInfo = SkImageInfo::MakeN32(skiaImg->width(), skiaImg->height(), skiaImg->alphaType());
+
+    const uint32_t allocationSize = skiaInfo.getSafeSize(skiaInfo.minRowBytes());
+    mojo::ScopedSharedBufferHandle sharedBufferHandle = mojo::SharedBufferHandle::Create(allocationSize);
+    const mojo::ScopedSharedBufferMapping mappingPtr = sharedBufferHandle->Map(allocationSize);

[mcasas, 2016/10/03 21:02:46]

Naming: don't use abbreviations like Img for 
img, and don't add suffixes to define a 
variable data type:

s/imgResource/imageResource/
s/skiaImg/image/
s/mappingPtr/mappedBuffer/

[xianglu, 2016/10/03 22:00:06]

Done.

+    DCHECK(mappingPtr);
+
+    const SkPixmap pixmap(skiaInfo, mappingPtr.get(), skiaInfo.minRowBytes());
+    if (!skiaImg->readPixels(pixmap, 0, 0)) {
+        DLOG(ERROR) << "Failed to read pixels from sk_sp<SkImage>.";
+        return mojo::ScopedSharedBufferHandle();
+    }
+
+    return sharedBufferHandle;
 }
 
-ScriptPromise FaceDetector::detect(ScriptState* scriptState, const HTMLImageElement* image)
+} // anonymous namespace
+
+FaceDetector* FaceDetector::create(const Document& document)
+{
+    return new FaceDetector(*document.frame());
+}
+
+FaceDetector::FaceDetector(LocalFrame& frame)
+{
+    DCHECK(!m_service.is_bound());
+    DCHECK(frame.interfaceProvider());
+    frame.interfaceProvider()->getInterface(mojo::GetProxy(&m_service));
+}
+
+ScriptPromise FaceDetector::detect(ScriptState* scriptState, const HTMLImageElement* img)
 {
     ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
-    resolver->reject(DOMException::create(NotSupportedError, "Not implemented"));
+
+    if (!m_service) {
+        resolver->reject(DOMException::create(NotFoundError, "Face detection service unavailable."));
+        return promise;
+    }
+
+    if (!img) {
+        resolver->reject(DOMException::create(SyntaxError, "The provided HTMLImageElement is empty."));
+        return promise;
+    }
+
+    // TODO(xianglu): Add security check when the spec is ready. https://crbug.com/646083
+    mojo::ScopedSharedBufferHandle sharedBufferHandle = getSharedBufferHandle(img);
+    if (!sharedBufferHandle->is_valid()) {
+        resolver->reject(DOMException::create(SyntaxError, "Failed to get sharedBufferHandle."));
+        return promise;
+    }
+
+    m_serviceRequests.add(resolver);
+    DCHECK(m_service.is_bound());
+    m_service->DetectFace(
+        std::move(sharedBufferHandle),
+        img->naturalWidth(),
+        img->naturalHeight(),
+        convertToBaseCallback(WTF::bind(&FaceDetector::onDetectFace, wrapPersistent(this), wrapPersistent(resolver)))
+        );
+    sharedBufferHandle.reset();
     return promise;
 }
 
+
+void FaceDetector::onDetectFace(ScriptPromiseResolver* resolver, mojom::blink::FaceDetectionResultPtr faceDetectionResult)
+{
+    if (!m_serviceRequests.contains(resolver))
+        return;
+
+    HeapVector<Member<DOMRect>> detectedFaces;
+    for (const auto& boundingBox : faceDetectionResult->boundingBoxes) {
+        detectedFaces.append(DOMRect::create(boundingBox->x, boundingBox->y,
+boundingBox->width, boundingBox->height));

[mcasas, 2016/10/03 21:02:46]

These two lines need clang-formatting.

Also, after the big reformatting of last Fri,
we should be using 2 space indenting, so
please rebase your patch against master
to update the indenting.

[xianglu, 2016/10/03 22:00:06]

Done.

+    }
+
+    resolver->resolve(detectedFaces);
+    m_serviceRequests.remove(resolver);
+}
+
+DEFINE_TRACE(FaceDetector)
+{
+    visitor->trace(m_serviceRequests);
+}
+
 } // namespace blink