react-native/ReactCommon/fabric/components/image/ImageShadowNode.cpp

92 lines
2.5 KiB
C++

/**
* Copyright (c) 2015-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#include <cstdlib>
#include <fabric/components/image/ImageShadowNode.h>
#include <fabric/components/image/ImageLocalData.h>
#include <fabric/core/LayoutContext.h>
namespace facebook {
namespace react {
ComponentName ImageShadowNode::getComponentName() const {
return ComponentName("Image");
}
void ImageShadowNode::setImageManager(const SharedImageManager &imageManager) {
ensureUnsealed();
imageManager_ = imageManager;
}
void ImageShadowNode::updateLocalData() {
const auto &imageSource = getImageSource();
const auto &currentLocalData = getLocalData();
if (currentLocalData) {
assert(std::dynamic_pointer_cast<const ImageLocalData>(currentLocalData));
auto currentImageLocalData = std::static_pointer_cast<const ImageLocalData>(currentLocalData);
if (currentImageLocalData->getImageSource() == imageSource) {
// Same `imageSource` is already in `localData`,
// no need to (re)request an image resource.
return;
}
}
// Now we are about to mutate the Shadow Node.
ensureUnsealed();
auto imageRequest = imageManager_->requestImage(imageSource);
auto imageLocalData = std::make_shared<ImageLocalData>(imageSource, std::move(imageRequest));
setLocalData(imageLocalData);
}
ImageSource ImageShadowNode::getImageSource() const {
auto sources = getProps()->sources;
if (sources.size() == 0) {
return {.type = ImageSource::Type::Invalid};
}
if (sources.size() == 1) {
return sources[0];
}
auto layoutMetrics = getLayoutMetrics();
auto size = layoutMetrics.getContentFrame().size;
auto scale = layoutMetrics.pointScaleFactor;
auto targetImageArea = size.width * size.height * scale * scale;
auto bestFit = kFloatMax;
ImageSource bestSource;
for (const auto &source : sources) {
auto sourceSize = source.size;
auto sourceScale = source.scale == 0 ? scale : source.scale;
auto sourceArea =
sourceSize.width * sourceSize.height * sourceScale * sourceScale;
auto fit = std::abs(1 - (sourceArea / targetImageArea));
if (fit < bestFit) {
bestFit = fit;
bestSource = source;
}
}
return bestSource;
}
#pragma mark - LayoutableShadowNode
void ImageShadowNode::layout(LayoutContext layoutContext) {
updateLocalData();
ConcreteViewShadowNode::layout(layoutContext);
}
} // namespace react
} // namespace facebook