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/*
* Copyright (C) 1999 Lars Knoll (knoll@kde.org)
* Copyright (C) 2004, 2005, 2006, 2007, 2009 Apple Inc. All rights reserved.
*
* 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 THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_REPLACED_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_REPLACED_H_
#include <optional>
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/layout/geometry/physical_rect.h"
#include "third_party/blink/renderer/core/layout/layout_box.h"
#include "third_party/blink/renderer/core/layout/layout_object.h"
#include "ui/gfx/geometry/size_f.h"
namespace blink {
struct PhysicalNaturalSizingInfo;
// LayoutReplaced is the base class for a replaced element as defined by CSS:
//
// "An element whose content is outside the scope of the CSS formatting model,
// such as an image, embedded document, or applet."
// http://www.w3.org/TR/CSS2/conform.html#defs
//
// Blink consider that replaced elements have natural dimensions (e.g. the
// natural size of an image or a video). The natural dimensions are provided by
// an implementation of `GetNaturalDimensions()`.
class CORE_EXPORT LayoutReplaced : public LayoutBox {
public:
explicit LayoutReplaced(Element*);
~LayoutReplaced() override;
// This function returns the local rect of the replaced content. The rectangle
// is in the coordinate space of the element's physical border-box and assumes
// no clipping.
PhysicalRect ReplacedContentRect() const;
virtual PhysicalRect ReplacedContentRectFrom(
const PhysicalRect& base_content_rect) const;
// This is used by a few special elements, e.g. <video>, <iframe> to ensure
// a persistent sizing under different subpixel offset, because these
// elements have a high cost to resize. The drawback is that we may overflow
// or underflow the final content box by 1px.
static PhysicalRect PreSnappedRectForPersistentSizing(const PhysicalRect&);
void AddVisualEffectOverflow();
void RecalcVisualOverflow() override;
// These values are specified to be 300 and 150 pixels in the CSS 2.1 spec.
// http://www.w3.org/TR/CSS2/visudet.html#inline-replaced-width
static const int kDefaultWidth;
static const int kDefaultHeight;
bool CanHaveChildren() const override {
NOT_DESTROYED();
return false;
}
virtual bool DrawsBackgroundOntoContentLayer() const {
NOT_DESTROYED();
return false;
}
virtual void PaintReplaced(const PaintInfo&,
const PhysicalOffset& paint_offset) const {
NOT_DESTROYED();
}
PhysicalRect LocalSelectionVisualRect() const final;
bool HasObjectFit() const {
NOT_DESTROYED();
return StyleRef().GetObjectFit() !=
ComputedStyleInitialValues::InitialObjectFit();
}
void Paint(const PaintInfo&) const override;
// Compute the natural dimensions of the replaced content. Should not apply
// any additional transformations (like 'object-view-box'). The natural size
// returned should be in "zoomed CSS pixels" (i.e
// `ComputedStyle::EffectiveZoom()` should be applied). The natural aspect
// ratio needn't be zoomed (but can be).
virtual PhysicalNaturalSizingInfo GetNaturalDimensions() const = 0;
// Returns the natural dimensions of the replaced content with any additional
// transformations - such as 'object-view-box' - applied.
// This function is public only so we can call it when computing
// intrinsic size in LayoutNG.
PhysicalNaturalSizingInfo ComputeNaturalSizingInfo() const;
// This callback must be invoked whenever the underlying natural dimensions
// has changed.
//
// The natural dimensions can change due to the network (from the default
// natural size [see above] to the actual natural dimensions) or to some CSS
// properties like 'zoom' or 'image-orientation'.
virtual void NaturalSizeChanged();
bool RespectsCSSOverflow() const override;
// Returns true if the content is guarenteed to be clipped to the element's
// content box.
bool ClipsToContentBox() const;
protected:
virtual bool ShouldApplyObjectViewBox() const {
NOT_DESTROYED();
return true;
}
bool IsInSelfHitTestingPhase(HitTestPhase phase) const override {
NOT_DESTROYED();
if (LayoutBox::IsInSelfHitTestingPhase(phase))
return true;
auto* element = DynamicTo<Element>(GetNode());
return element && element->IsReplacedElementRespectingCSSOverflow() &&
phase == HitTestPhase::kSelfBlockBackground;
}
void WillBeDestroyed() override;
// This function calculates the placement of the replaced contents. It takes
// natural dimensions of the replaced contents, stretch to fit CSS content
// box according to object-fit, object-position and object-view-box.
PhysicalRect ComputeReplacedContentRect(
const PhysicalRect& base_content_rect,
const PhysicalNaturalSizingInfo& sizing_info) const;
void StyleDidChange(StyleDifference, const ComputedStyle* old_style) override;
PositionWithAffinity PositionForPoint(const PhysicalOffset&) const override;
bool IsLayoutReplaced() const final {
NOT_DESTROYED();
return true;
}
// ReplacedPainter doesn't support CompositeBackgroundAttachmentFixed yet.
bool ComputeCanCompositeBackgroundAttachmentFixed() const override {
NOT_DESTROYED();
return false;
}
// ImageResourceObserver
gfx::Size ComputeSpeculativeDecodeSize() const override;
private:
// Computes a rect, relative to the element's content's natural size, that
// should be used as the content source when rendering this element. This
// value is used as the input for object-fit/object-position during painting.
std::optional<PhysicalRect> ComputeObjectViewBoxRect(
const PhysicalNaturalSizingInfo& sizing_info) const;
PhysicalRect ComputeObjectFitAndPositionRect(
const PhysicalRect& base_content_rect,
const PhysicalNaturalSizingInfo& sizing_info) const;
};
template <>
struct DowncastTraits<LayoutReplaced> {
static bool AllowFrom(const LayoutObject& object) {
return object.IsLayoutReplaced();
}
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_REPLACED_H_
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