third_party/WebKit/Source/core/style/FillLayer.h

/*
 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
 *           (C) 2000 Antti Koivisto (koivisto@kde.org)
 *           (C) 2000 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2003, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef FillLayer_h
#define FillLayer_h

#include "core/CoreExport.h"
#include "core/style/ComputedStyleConstants.h"
#include "core/style/StyleImage.h"
#include "platform/Length.h"
#include "platform/LengthSize.h"
#include "platform/graphics/GraphicsTypes.h"
#include "wtf/Allocator.h"
#include "wtf/RefPtr.h"

namespace blink {

struct FillSize {
  DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
  FillSize() : type(SizeLength) {}

  FillSize(EFillSizeType t, const LengthSize& l) : type(t), size(l) {}

  bool operator==(const FillSize& o) const {
    return type == o.type && size == o.size;
  }
  bool operator!=(const FillSize& o) const { return !(*this == o); }

  EFillSizeType type;
  LengthSize size;
};

// FIXME(Oilpan): Move FillLayer to Oilpan's heap.
class CORE_EXPORT FillLayer {
  USING_FAST_MALLOC(FillLayer);

 public:
  FillLayer(EFillLayerType, bool useInitialValues = false);
  ~FillLayer();

  StyleImage* image() const { return m_image.get(); }
  const Length& xPosition() const { return m_xPosition; }
  const Length& yPosition() const { return m_yPosition; }
  BackgroundEdgeOrigin backgroundXOrigin() const {
    return static_cast<BackgroundEdgeOrigin>(m_backgroundXOrigin);
  }
  BackgroundEdgeOrigin backgroundYOrigin() const {
    return static_cast<BackgroundEdgeOrigin>(m_backgroundYOrigin);
  }
  EFillAttachment attachment() const {
    return static_cast<EFillAttachment>(m_attachment);
  }
  EFillBox clip() const { return static_cast<EFillBox>(m_clip); }
  EFillBox origin() const { return static_cast<EFillBox>(m_origin); }
  EFillRepeat repeatX() const { return static_cast<EFillRepeat>(m_repeatX); }
  EFillRepeat repeatY() const { return static_cast<EFillRepeat>(m_repeatY); }
  CompositeOperator composite() const {
    return static_cast<CompositeOperator>(m_composite);
  }
  WebBlendMode blendMode() const {
    return static_cast<WebBlendMode>(m_blendMode);
  }
  const LengthSize& sizeLength() const { return m_sizeLength; }
  EFillSizeType sizeType() const {
    return static_cast<EFillSizeType>(m_sizeType);
  }
  FillSize size() const {
    return FillSize(static_cast<EFillSizeType>(m_sizeType), m_sizeLength);
  }
  EMaskSourceType maskSourceType() const {
    return static_cast<EMaskSourceType>(m_maskSourceType);
  }

  const FillLayer* next() const { return m_next; }
  FillLayer* next() { return m_next; }
  FillLayer* ensureNext() {
    if (!m_next)
      m_next = new FillLayer(type());
    return m_next;
  }

  bool isImageSet() const { return m_imageSet; }
  bool isXPositionSet() const { return m_xPosSet; }
  bool isYPositionSet() const { return m_yPosSet; }
  bool isBackgroundXOriginSet() const { return m_backgroundXOriginSet; }
  bool isBackgroundYOriginSet() const { return m_backgroundYOriginSet; }
  bool isAttachmentSet() const { return m_attachmentSet; }
  bool isClipSet() const { return m_clipSet; }
  bool isOriginSet() const { return m_originSet; }
  bool isRepeatXSet() const { return m_repeatXSet; }
  bool isRepeatYSet() const { return m_repeatYSet; }
  bool isCompositeSet() const { return m_compositeSet; }
  bool isBlendModeSet() const { return m_blendModeSet; }
  bool isSizeSet() const { return m_sizeType != SizeNone; }
  bool isMaskSourceTypeSet() const { return m_maskSourceTypeSet; }

  void setImage(StyleImage* i) {
    m_image = i;
    m_imageSet = true;
  }
  void setXPosition(const Length& position) {
    m_xPosition = position;
    m_xPosSet = true;
    m_backgroundXOriginSet = false;
    m_backgroundXOrigin = LeftEdge;
  }
  void setYPosition(const Length& position) {
    m_yPosition = position;
    m_yPosSet = true;
    m_backgroundYOriginSet = false;
    m_backgroundYOrigin = TopEdge;
  }
  void setBackgroundXOrigin(BackgroundEdgeOrigin origin) {
    m_backgroundXOrigin = origin;
    m_backgroundXOriginSet = true;
  }
  void setBackgroundYOrigin(BackgroundEdgeOrigin origin) {
    m_backgroundYOrigin = origin;
    m_backgroundYOriginSet = true;
  }
  void setAttachment(EFillAttachment attachment) {
    ASSERT(!m_cachedPropertiesComputed);
    m_attachment = attachment;
    m_attachmentSet = true;
  }
  void setClip(EFillBox b) {
    ASSERT(!m_cachedPropertiesComputed);
    m_clip = b;
    m_clipSet = true;
  }
  void setOrigin(EFillBox b) {
    ASSERT(!m_cachedPropertiesComputed);
    m_origin = b;
    m_originSet = true;
  }
  void setRepeatX(EFillRepeat r) {
    m_repeatX = r;
    m_repeatXSet = true;
  }
  void setRepeatY(EFillRepeat r) {
    m_repeatY = r;
    m_repeatYSet = true;
  }
  void setComposite(CompositeOperator c) {
    m_composite = c;
    m_compositeSet = true;
  }
  void setBlendMode(WebBlendMode b) {
    m_blendMode = b;
    m_blendModeSet = true;
  }
  void setSizeType(EFillSizeType b) { m_sizeType = b; }
  void setSizeLength(const LengthSize& length) { m_sizeLength = length; }
  void setSize(const FillSize& f) {
    m_sizeType = f.type;
    m_sizeLength = f.size;
  }
  void setMaskSourceType(EMaskSourceType m) {
    m_maskSourceType = m;
    m_maskSourceTypeSet = true;
  }

  void clearImage() {
    m_image.clear();
    m_imageSet = false;
  }
  void clearXPosition() {
    m_xPosSet = false;
    m_backgroundXOriginSet = false;
  }
  void clearYPosition() {
    m_yPosSet = false;
    m_backgroundYOriginSet = false;
  }

  void clearAttachment() { m_attachmentSet = false; }
  void clearClip() { m_clipSet = false; }
  void clearOrigin() { m_originSet = false; }
  void clearRepeatX() { m_repeatXSet = false; }
  void clearRepeatY() { m_repeatYSet = false; }
  void clearComposite() { m_compositeSet = false; }
  void clearBlendMode() { m_blendModeSet = false; }
  void clearSize() { m_sizeType = SizeNone; }
  void clearMaskSourceType() { m_maskSourceTypeSet = false; }

  FillLayer& operator=(const FillLayer&);
  FillLayer(const FillLayer&);

  bool operator==(const FillLayer&) const;
  bool operator!=(const FillLayer& o) const { return !(*this == o); }

  bool containsImage(StyleImage*) const;
  bool imagesAreLoaded() const;

  bool hasImage() const {
    if (m_image)
      return true;
    return m_next ? m_next->hasImage() : false;
  }

  bool hasFixedImage() const {
    if (m_image && m_attachment == FixedBackgroundAttachment)
      return true;
    return m_next ? m_next->hasFixedImage() : false;
  }

  bool imageOccludesNextLayers(const LayoutObject&) const;
  bool hasRepeatXY() const;
  bool clipOccludesNextLayers() const;

  EFillLayerType type() const { return static_cast<EFillLayerType>(m_type); }

  void fillUnsetProperties();
  void cullEmptyLayers();

  static bool imagesIdentical(const FillLayer*, const FillLayer*);

  EFillBox thisOrNextLayersClipMax() const {
    computeCachedPropertiesIfNeeded();
    return static_cast<EFillBox>(m_thisOrNextLayersClipMax);
  }
  bool thisOrNextLayersUseContentBox() const {
    computeCachedPropertiesIfNeeded();
    return m_thisOrNextLayersUseContentBox;
  }
  bool thisOrNextLayersHaveLocalAttachment() const {
    computeCachedPropertiesIfNeeded();
    return m_thisOrNextLayersHaveLocalAttachment;
  }
  void computeCachedPropertiesIfNeeded() const;

  static EFillAttachment initialFillAttachment(EFillLayerType) {
    return ScrollBackgroundAttachment;
  }
  static EFillBox initialFillClip(EFillLayerType) { return BorderFillBox; }
  static EFillBox initialFillOrigin(EFillLayerType type) {
    return type == BackgroundFillLayer ? PaddingFillBox : BorderFillBox;
  }
  static EFillRepeat initialFillRepeatX(EFillLayerType) { return RepeatFill; }
  static EFillRepeat initialFillRepeatY(EFillLayerType) { return RepeatFill; }
  static CompositeOperator initialFillComposite(EFillLayerType) {
    return CompositeSourceOver;
  }
  static WebBlendMode initialFillBlendMode(EFillLayerType) {
    return WebBlendModeNormal;
  }
  static EFillSizeType initialFillSizeType(EFillLayerType) {
    return SizeLength;
  }
  static LengthSize initialFillSizeLength(EFillLayerType) {
    return LengthSize();
  }
  static FillSize initialFillSize(EFillLayerType type) {
    return FillSize(initialFillSizeType(type), initialFillSizeLength(type));
  }
  static Length initialFillXPosition(EFillLayerType) {
    return Length(0.0, Percent);
  }
  static Length initialFillYPosition(EFillLayerType) {
    return Length(0.0, Percent);
  }
  static StyleImage* initialFillImage(EFillLayerType) { return 0; }
  static EMaskSourceType initialFillMaskSourceType(EFillLayerType) {
    return MaskAlpha;
  }

 private:
  friend class ComputedStyle;

  FillLayer() {}

  bool imageIsOpaque(const LayoutObject&) const;
  bool imageTilesLayer() const;

  FillLayer* m_next;

  Persistent<StyleImage> m_image;

  Length m_xPosition;
  Length m_yPosition;

  LengthSize m_sizeLength;

  unsigned m_attachment : 2;         // EFillAttachment
  unsigned m_clip : 2;               // EFillBox
  unsigned m_origin : 2;             // EFillBox
  unsigned m_repeatX : 3;            // EFillRepeat
  unsigned m_repeatY : 3;            // EFillRepeat
  unsigned m_composite : 4;          // CompositeOperator
  unsigned m_sizeType : 2;           // EFillSizeType
  unsigned m_blendMode : 5;          // WebBlendMode
  unsigned m_maskSourceType : 1;     // EMaskSourceType
  unsigned m_backgroundXOrigin : 2;  // BackgroundEdgeOrigin
  unsigned m_backgroundYOrigin : 2;  // BackgroundEdgeOrigin

  unsigned m_imageSet : 1;
  unsigned m_attachmentSet : 1;
  unsigned m_clipSet : 1;
  unsigned m_originSet : 1;
  unsigned m_repeatXSet : 1;
  unsigned m_repeatYSet : 1;
  unsigned m_xPosSet : 1;
  unsigned m_yPosSet : 1;
  unsigned m_backgroundXOriginSet : 1;
  unsigned m_backgroundYOriginSet : 1;
  unsigned m_compositeSet : 1;
  unsigned m_blendModeSet : 1;
  unsigned m_maskSourceTypeSet : 1;

  unsigned m_type : 1;  // EFillLayerType

  // EFillBox, maximum m_clip value from this to bottom layer
  mutable unsigned m_thisOrNextLayersClipMax : 2;
  // True if any of this or subsequent layers has content-box clip or origin.
  mutable unsigned m_thisOrNextLayersUseContentBox : 1;
  // True if any of this or subsequent layers has local attachment.
  mutable unsigned m_thisOrNextLayersHaveLocalAttachment : 1;
  // Set once any of the above is accessed. The layers will be frozen
  // thereafter.
  mutable unsigned m_cachedPropertiesComputed : 1;
};

}  // namespace blink

#endif  // FillLayer_h