third_party/WebKit/Source/web/LinkHighlightImpl.cpp

/*
 * Copyright (C) 2012 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "web/LinkHighlightImpl.h"

#include "core/dom/DOMNodeIds.h"
#include "core/dom/LayoutTreeBuilderTraversal.h"
#include "core/dom/Node.h"
#include "core/frame/FrameView.h"
#include "core/frame/LocalFrame.h"
#include "core/layout/LayoutBoxModelObject.h"
#include "core/layout/LayoutObject.h"
#include "core/layout/compositing/CompositedLayerMapping.h"
#include "core/paint/PaintLayer.h"
#include "platform/RuntimeEnabledFeatures.h"
#include "platform/animation/CompositorAnimation.h"
#include "platform/animation/CompositorAnimationCurve.h"
#include "platform/animation/CompositorFloatAnimationCurve.h"
#include "platform/animation/CompositorTargetProperty.h"
#include "platform/animation/TimingFunction.h"
#include "platform/graphics/Color.h"
#include "platform/graphics/CompositorElementId.h"
#include "platform/graphics/CompositorMutableProperties.h"
#include "platform/graphics/GraphicsLayer.h"
#include "platform/graphics/paint/DrawingRecorder.h"
#include "public/platform/Platform.h"
#include "public/platform/WebCompositorSupport.h"
#include "public/platform/WebContentLayer.h"
#include "public/platform/WebDisplayItemList.h"
#include "public/platform/WebFloatPoint.h"
#include "public/platform/WebLayer.h"
#include "public/platform/WebRect.h"
#include "public/platform/WebSize.h"
#include "public/web/WebKit.h"
#include "third_party/skia/include/core/SkCanvas.h"
#include "third_party/skia/include/core/SkMatrix44.h"
#include "third_party/skia/include/core/SkPictureRecorder.h"
#include "ui/gfx/geometry/rect.h"
#include "web/WebLocalFrameImpl.h"
#include "web/WebSettingsImpl.h"
#include "web/WebViewImpl.h"
#include "wtf/CurrentTime.h"
#include "wtf/PtrUtil.h"
#include "wtf/Vector.h"
#include <memory>

namespace blink {

std::unique_ptr<LinkHighlightImpl> LinkHighlightImpl::create(
    Node* node,
    WebViewImpl* owningWebViewImpl) {
  return wrapUnique(new LinkHighlightImpl(node, owningWebViewImpl));
}

LinkHighlightImpl::LinkHighlightImpl(Node* node, WebViewImpl* owningWebViewImpl)
    : m_node(node),
      m_owningWebViewImpl(owningWebViewImpl),
      m_currentGraphicsLayer(0),
      m_isScrollingGraphicsLayer(false),
      m_geometryNeedsUpdate(false),
      m_isAnimating(false),
      m_startTime(monotonicallyIncreasingTime()) {
  DCHECK(m_node);
  DCHECK(owningWebViewImpl);
  WebCompositorSupport* compositorSupport =
      Platform::current()->compositorSupport();
  DCHECK(compositorSupport);
  m_contentLayer = wrapUnique(compositorSupport->createContentLayer(this));
  m_clipLayer = wrapUnique(compositorSupport->createLayer());
  m_clipLayer->setTransformOrigin(WebFloatPoint3D());
  m_clipLayer->addChild(m_contentLayer->layer());

  m_compositorPlayer = CompositorAnimationPlayer::create();
  DCHECK(m_compositorPlayer);
  m_compositorPlayer->setAnimationDelegate(this);
  if (m_owningWebViewImpl->linkHighlightsTimeline())
    m_owningWebViewImpl->linkHighlightsTimeline()->playerAttached(*this);

  CompositorElementId elementId = createCompositorElementId(
      DOMNodeIds::idForNode(node), CompositorSubElementId::LinkHighlight);
  m_compositorPlayer->attachElement(elementId);
  m_contentLayer->layer()->setDrawsContent(true);
  m_contentLayer->layer()->setOpacity(1);
  m_contentLayer->layer()->setElementId(elementId);
  m_geometryNeedsUpdate = true;
}

LinkHighlightImpl::~LinkHighlightImpl() {
  if (m_compositorPlayer->isElementAttached())
    m_compositorPlayer->detachElement();
  if (m_owningWebViewImpl->linkHighlightsTimeline())
    m_owningWebViewImpl->linkHighlightsTimeline()->playerDestroyed(*this);
  m_compositorPlayer->setAnimationDelegate(nullptr);
  m_compositorPlayer.reset();

  clearGraphicsLayerLinkHighlightPointer();
  releaseResources();
}

WebContentLayer* LinkHighlightImpl::contentLayer() {
  return m_contentLayer.get();
}

WebLayer* LinkHighlightImpl::clipLayer() {
  return m_clipLayer.get();
}

void LinkHighlightImpl::releaseResources() {
  m_node.clear();
}

void LinkHighlightImpl::attachLinkHighlightToCompositingLayer(
    const LayoutBoxModelObject& paintInvalidationContainer) {
  GraphicsLayer* newGraphicsLayer =
      paintInvalidationContainer.layer()->graphicsLayerBacking();
  m_isScrollingGraphicsLayer = false;
  // FIXME: There should always be a GraphicsLayer. See crbug.com/431961.
  if (paintInvalidationContainer.layer()->needsCompositedScrolling() &&
      m_node->layoutObject() != &paintInvalidationContainer) {
    newGraphicsLayer =
        paintInvalidationContainer.layer()->graphicsLayerBackingForScrolling();
    m_isScrollingGraphicsLayer = true;
  }
  if (!newGraphicsLayer)
    return;

  m_clipLayer->setTransform(SkMatrix44(SkMatrix44::kIdentity_Constructor));

  if (m_currentGraphicsLayer != newGraphicsLayer) {
    if (m_currentGraphicsLayer)
      clearGraphicsLayerLinkHighlightPointer();

    m_currentGraphicsLayer = newGraphicsLayer;
    m_currentGraphicsLayer->addLinkHighlight(this);
  }
}

static void convertTargetSpaceQuadToCompositedLayer(
    const FloatQuad& targetSpaceQuad,
    LayoutObject* targetLayoutObject,
    const LayoutBoxModelObject& paintInvalidationContainer,
    FloatQuad& compositedSpaceQuad) {
  DCHECK(targetLayoutObject);
  for (unsigned i = 0; i < 4; ++i) {
    IntPoint point;
    switch (i) {
      case 0:
        point = roundedIntPoint(targetSpaceQuad.p1());
        break;
      case 1:
        point = roundedIntPoint(targetSpaceQuad.p2());
        break;
      case 2:
        point = roundedIntPoint(targetSpaceQuad.p3());
        break;
      case 3:
        point = roundedIntPoint(targetSpaceQuad.p4());
        break;
    }

    // FIXME: this does not need to be absolute, just in the paint invalidation
    // container's space.
    point = targetLayoutObject->frame()->view()->contentsToRootFrame(point);
    point =
        paintInvalidationContainer.frame()->view()->rootFrameToContents(point);
    FloatPoint floatPoint =
        paintInvalidationContainer.absoluteToLocal(point, UseTransforms);
    PaintLayer::mapPointInPaintInvalidationContainerToBacking(
        paintInvalidationContainer, floatPoint);

    switch (i) {
      case 0:
        compositedSpaceQuad.setP1(floatPoint);
        break;
      case 1:
        compositedSpaceQuad.setP2(floatPoint);
        break;
      case 2:
        compositedSpaceQuad.setP3(floatPoint);
        break;
      case 3:
        compositedSpaceQuad.setP4(floatPoint);
        break;
    }
  }
}

static void addQuadToPath(const FloatQuad& quad, Path& path) {
  // FIXME: Make this create rounded quad-paths, just like the axis-aligned
  // case.
  path.moveTo(quad.p1());
  path.addLineTo(quad.p2());
  path.addLineTo(quad.p3());
  path.addLineTo(quad.p4());
  path.closeSubpath();
}

void LinkHighlightImpl::computeQuads(const Node& node,
                                     Vector<FloatQuad>& outQuads) const {
  if (!node.layoutObject())
    return;

  LayoutObject* layoutObject = node.layoutObject();

  // For inline elements, absoluteQuads will return a line box based on the
  // line-height and font metrics, which is technically incorrect as replaced
  // elements like images should use their intristic height and expand the
  // linebox  as needed. To get an appropriately sized highlight we descend
  // into the children and have them add their boxes.
  if (layoutObject->isLayoutInline()) {
    for (Node* child = LayoutTreeBuilderTraversal::firstChild(node); child;
         child = LayoutTreeBuilderTraversal::nextSibling(*child))
      computeQuads(*child, outQuads);
  } else {
    // FIXME: this does not need to be absolute, just in the paint invalidation
    // container's space.
    layoutObject->absoluteQuads(outQuads);
  }
}

bool LinkHighlightImpl::computeHighlightLayerPathAndPosition(
    const LayoutBoxModelObject& paintInvalidationContainer) {
  if (!m_node || !m_node->layoutObject() || !m_currentGraphicsLayer)
    return false;

  // FIXME: This is defensive code to avoid crashes such as those described in
  // crbug.com/440887. This should be cleaned up once we fix the root cause of
  // of the paint invalidation container not being composited.
  if (!paintInvalidationContainer.layer()->compositedLayerMapping() &&
      !paintInvalidationContainer.layer()->groupedMapping())
    return false;

  // Get quads for node in absolute coordinates.
  Vector<FloatQuad> quads;
  computeQuads(*m_node, quads);
  DCHECK(quads.size());
  Path newPath;

  for (size_t quadIndex = 0; quadIndex < quads.size(); ++quadIndex) {
    FloatQuad absoluteQuad = quads[quadIndex];

    // Scrolling content layers have the same offset from layout object as the
    // non-scrolling layers. Thus we need to adjust for their scroll offset.
    if (m_isScrollingGraphicsLayer) {
      DoubleSize adjustedScrollOffset = paintInvalidationContainer.layer()
                                            ->getScrollableArea()
                                            ->adjustedScrollOffset();
      absoluteQuad.move(adjustedScrollOffset.width(),
                        adjustedScrollOffset.height());
    }

    // Transform node quads in target absolute coords to local coordinates in
    // the compositor layer.
    FloatQuad transformedQuad;
    convertTargetSpaceQuadToCompositedLayer(
        absoluteQuad, m_node->layoutObject(), paintInvalidationContainer,
        transformedQuad);

    // FIXME: for now, we'll only use rounded paths if we have a single node
    // quad. The reason for this is that we may sometimes get a chain of
    // adjacent boxes (e.g. for text nodes) which end up looking like sausage
    // links: these should ideally be merged into a single rect before creating
    // the path, but that's another CL.
    if (quads.size() == 1 && transformedQuad.isRectilinear() &&
        !m_owningWebViewImpl->settingsImpl()
             ->mockGestureTapHighlightsEnabled()) {
      FloatSize rectRoundingRadii(3, 3);
      newPath.addRoundedRect(transformedQuad.boundingBox(), rectRoundingRadii);
    } else {
      addQuadToPath(transformedQuad, newPath);
    }
  }

  FloatRect boundingRect = newPath.boundingRect();
  newPath.translate(-toFloatSize(boundingRect.location()));

  bool pathHasChanged = !(newPath == m_path);
  if (pathHasChanged) {
    m_path = newPath;
    m_contentLayer->layer()->setBounds(enclosingIntRect(boundingRect).size());
  }

  m_contentLayer->layer()->setPosition(boundingRect.location());

  return pathHasChanged;
}

gfx::Rect LinkHighlightImpl::paintableRegion() {
  return gfx::Rect(0, 0, contentLayer()->layer()->bounds().width,
                   contentLayer()->layer()->bounds().height);
}

void LinkHighlightImpl::paintContents(
    WebDisplayItemList* webDisplayItemList,
    WebContentLayerClient::PaintingControlSetting paintingControl) {
  if (!m_node || !m_node->layoutObject())
    return;

  SkPictureRecorder recorder;
  gfx::Rect visualRect = paintableRegion();
  SkCanvas* canvas =
      recorder.beginRecording(visualRect.width(), visualRect.height());

  SkPaint paint;
  paint.setStyle(SkPaint::kFill_Style);
  paint.setFlags(SkPaint::kAntiAlias_Flag);
  paint.setColor(m_node->layoutObject()->style()->tapHighlightColor().rgb());
  canvas->drawPath(m_path.getSkPath(), paint);

  webDisplayItemList->appendDrawingItem(
      WebRect(visualRect.x(), visualRect.y(), visualRect.width(),
              visualRect.height()),
      recorder.finishRecordingAsPicture());
}

void LinkHighlightImpl::startHighlightAnimationIfNeeded() {
  if (m_isAnimating)
    return;

  m_isAnimating = true;
  const float startOpacity = 1;
  // FIXME: Should duration be configurable?
  const float fadeDuration = 0.1f;
  const float minPreFadeDuration = 0.1f;

  m_contentLayer->layer()->setOpacity(startOpacity);

  std::unique_ptr<CompositorFloatAnimationCurve> curve =
      CompositorFloatAnimationCurve::create();

  const auto& timingFunction = *CubicBezierTimingFunction::preset(
      CubicBezierTimingFunction::EaseType::EASE);

  curve->addKeyframe(CompositorFloatKeyframe(0, startOpacity, timingFunction));
  // Make sure we have displayed for at least minPreFadeDuration before starting
  // to fade out.
  float extraDurationRequired = std::max(
      0.f, minPreFadeDuration -
               static_cast<float>(monotonicallyIncreasingTime() - m_startTime));
  if (extraDurationRequired)
    curve->addKeyframe(CompositorFloatKeyframe(extraDurationRequired,
                                               startOpacity, timingFunction));
  // For layout tests we don't fade out.
  curve->addKeyframe(CompositorFloatKeyframe(
      fadeDuration + extraDurationRequired, layoutTestMode() ? startOpacity : 0,
      timingFunction));

  std::unique_ptr<CompositorAnimation> animation = CompositorAnimation::create(
      *curve, CompositorTargetProperty::OPACITY, 0, 0);

  m_contentLayer->layer()->setDrawsContent(true);
  m_compositorPlayer->addAnimation(std::move(animation));

  invalidate();
  m_owningWebViewImpl->mainFrameImpl()->frameWidget()->scheduleAnimation();
}

void LinkHighlightImpl::clearGraphicsLayerLinkHighlightPointer() {
  if (m_currentGraphicsLayer) {
    m_currentGraphicsLayer->removeLinkHighlight(this);
    m_currentGraphicsLayer = 0;
  }
}

void LinkHighlightImpl::notifyAnimationStarted(double, int) {}

void LinkHighlightImpl::notifyAnimationFinished(double, int) {
  // Since WebViewImpl may hang on to us for a while, make sure we
  // release resources as soon as possible.
  clearGraphicsLayerLinkHighlightPointer();
  releaseResources();
}

class LinkHighlightDisplayItemClientForTracking : public DisplayItemClient {
  String debugName() const final { return "LinkHighlight"; }
  LayoutRect visualRect() const final { return LayoutRect(); }
};

void LinkHighlightImpl::updateGeometry() {
  // To avoid unnecessary updates (e.g. other entities have requested animations
  // from our WebViewImpl), only proceed if we actually requested an update.
  if (!m_geometryNeedsUpdate)
    return;

  m_geometryNeedsUpdate = false;

  bool hasLayoutObject = m_node && m_node->layoutObject();
  if (hasLayoutObject) {
    const LayoutBoxModelObject& paintInvalidationContainer =
        m_node->layoutObject()->containerForPaintInvalidation();
    attachLinkHighlightToCompositingLayer(paintInvalidationContainer);
    if (computeHighlightLayerPathAndPosition(paintInvalidationContainer)) {
      // We only need to invalidate the layer if the highlight size has changed,
      // otherwise we can just re-position the layer without needing to
      // repaint.
      m_contentLayer->layer()->invalidate();

      if (m_currentGraphicsLayer)
        m_currentGraphicsLayer->trackPaintInvalidation(
            LinkHighlightDisplayItemClientForTracking(),
            enclosingIntRect(
                FloatRect(layer()->position().x, layer()->position().y,
                          layer()->bounds().width, layer()->bounds().height)),
            PaintInvalidationFull);
    }
  } else {
    clearGraphicsLayerLinkHighlightPointer();
    releaseResources();
  }
}

void LinkHighlightImpl::clearCurrentGraphicsLayer() {
  m_currentGraphicsLayer = 0;
  m_geometryNeedsUpdate = true;
}

void LinkHighlightImpl::invalidate() {
  // Make sure we update geometry on the next callback from
  // WebViewImpl::layout().
  m_geometryNeedsUpdate = true;
}

WebLayer* LinkHighlightImpl::layer() {
  return clipLayer();
}

CompositorAnimationPlayer* LinkHighlightImpl::compositorPlayer() const {
  return m_compositorPlayer.get();
}

}  // namespace blink