third_party/WebKit/Source/core/paint/RoundedInnerRectClipper.cpp

// Copyright 2015 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 "core/paint/RoundedInnerRectClipper.h"

#include "core/layout/LayoutObject.h"
#include "core/paint/PaintInfo.h"
#include "platform/graphics/paint/ClipDisplayItem.h"
#include "platform/graphics/paint/PaintController.h"

namespace blink {

RoundedInnerRectClipper::RoundedInnerRectClipper(
    const LayoutObject& layoutObject,
    const PaintInfo& paintInfo,
    const LayoutRect& rect,
    const FloatRoundedRect& clipRect,
    RoundedInnerRectClipperBehavior behavior)
    : m_layoutObject(layoutObject),
      m_paintInfo(paintInfo),
      m_usePaintController(behavior == ApplyToDisplayList),
      m_clipType(m_usePaintController ? m_paintInfo.displayItemTypeForClipping()
                                      : DisplayItem::kClipBoxPaintPhaseFirst) {
  Vector<FloatRoundedRect> roundedRectClips;
  if (clipRect.isRenderable()) {
    roundedRectClips.append(clipRect);
  } else {
    // We create a rounded rect for each of the corners and clip it, while
    // making sure we clip opposing corners together.
    if (!clipRect.getRadii().topLeft().isEmpty() ||
        !clipRect.getRadii().bottomRight().isEmpty()) {
      FloatRect topCorner(clipRect.rect().x(), clipRect.rect().y(),
                          rect.maxX() - clipRect.rect().x(),
                          rect.maxY() - clipRect.rect().y());
      FloatRoundedRect::Radii topCornerRadii;
      topCornerRadii.setTopLeft(clipRect.getRadii().topLeft());
      roundedRectClips.append(FloatRoundedRect(topCorner, topCornerRadii));

      FloatRect bottomCorner(rect.x().toFloat(), rect.y().toFloat(),
                             clipRect.rect().maxX() - rect.x().toFloat(),
                             clipRect.rect().maxY() - rect.y().toFloat());
      FloatRoundedRect::Radii bottomCornerRadii;
      bottomCornerRadii.setBottomRight(clipRect.getRadii().bottomRight());
      roundedRectClips.append(
          FloatRoundedRect(bottomCorner, bottomCornerRadii));
    }

    if (!clipRect.getRadii().topRight().isEmpty() ||
        !clipRect.getRadii().bottomLeft().isEmpty()) {
      FloatRect topCorner(rect.x().toFloat(), clipRect.rect().y(),
                          clipRect.rect().maxX() - rect.x().toFloat(),
                          rect.maxY() - clipRect.rect().y());
      FloatRoundedRect::Radii topCornerRadii;
      topCornerRadii.setTopRight(clipRect.getRadii().topRight());
      roundedRectClips.append(FloatRoundedRect(topCorner, topCornerRadii));

      FloatRect bottomCorner(clipRect.rect().x(), rect.y().toFloat(),
                             rect.maxX() - clipRect.rect().x(),
                             clipRect.rect().maxY() - rect.y().toFloat());
      FloatRoundedRect::Radii bottomCornerRadii;
      bottomCornerRadii.setBottomLeft(clipRect.getRadii().bottomLeft());
      roundedRectClips.append(
          FloatRoundedRect(bottomCorner, bottomCornerRadii));
    }
  }

  if (m_usePaintController) {
    m_paintInfo.context.getPaintController().createAndAppend<ClipDisplayItem>(
        layoutObject, m_clipType, LayoutRect::infiniteIntRect(),
        roundedRectClips);
  } else {
    ClipDisplayItem clipDisplayItem(layoutObject, m_clipType,
                                    LayoutRect::infiniteIntRect(),
                                    roundedRectClips);
    clipDisplayItem.replay(paintInfo.context);
  }
}

RoundedInnerRectClipper::~RoundedInnerRectClipper() {
  DisplayItem::Type endType = DisplayItem::clipTypeToEndClipType(m_clipType);
  if (m_usePaintController) {
    m_paintInfo.context.getPaintController().endItem<EndClipDisplayItem>(
        m_layoutObject, endType);
  } else {
    EndClipDisplayItem endClipDisplayItem(m_layoutObject, endType);
    endClipDisplayItem.replay(m_paintInfo.context);
  }
}

}  // namespace blink