blob: 62be25f377f007f243fb0b8270388a8a197ae5c9 [file] [log] [blame]
* Copyright (C) 1999 Lars Knoll (
* 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
* 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.
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/layout/layout_box.h"
namespace blink {
struct IntrinsicSizingInfo;
// 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."
// Blink consider that replaced elements have an intrinsic sizes (e.g. the
// natural size of an image or a video). The intrinsic size is stored by
// m_intrinsicSize.
// The computation sometimes ask for the intrinsic ratio, defined as follow:
// intrinsicWidth
// intrinsicRatio = -------------------
// intrinsicHeight
// The intrinsic ratio is used to keep the same proportion as the intrinsic
// size (thus avoiding visual distortions if width / height doesn't match
// the intrinsic value).
class CORE_EXPORT LayoutReplaced : public LayoutBox {
LayoutReplaced(Element*, const LayoutSize& intrinsic_size);
~LayoutReplaced() override;
LayoutUnit ComputeReplacedLogicalWidth(
ShouldComputePreferred = kComputeActual) const override;
LayoutUnit ComputeReplacedLogicalHeight(
LayoutUnit estimated_used_width = LayoutUnit()) const override;
bool HasReplacedLogicalHeight() const;
// This function returns the local rect of the replaced content.
virtual LayoutRect ReplacedContentRect() 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 LayoutRect PreSnappedRectForPersistentSizing(LayoutRect);
bool NeedsPreferredWidthsRecalculation() const override;
// These values are specified to be 300 and 150 pixels in the CSS 2.1 spec.
static const int kDefaultWidth;
static const int kDefaultHeight;
bool CanHaveChildren() const override { return false; }
virtual void PaintReplaced(const PaintInfo&,
const LayoutPoint& paint_offset) const {}
LayoutRect LocalSelectionRect() const final;
bool HasObjectFit() const {
return StyleRef().GetObjectFit() !=
void Paint(const PaintInfo&) const override;
// Replaced objects often have contents to paint.
bool PaintedOutputOfObjectHasNoEffectRegardlessOfSize() const override {
return false;
// This function is public only so we can call it when computing
// intrinsic size in LayoutNG.
virtual void ComputeIntrinsicSizingInfo(IntrinsicSizingInfo&) const;
void WillBeDestroyed() override;
void UpdateLayout() override;
LayoutSize IntrinsicSize() const final { return intrinsic_size_; }
void ComputePositionedLogicalWidth(
LogicalExtentComputedValues&) const override;
void ComputePositionedLogicalHeight(
LogicalExtentComputedValues&) const override;
void ComputeIntrinsicLogicalWidths(LayoutUnit& min_logical_width,
LayoutUnit& max_logical_width) const final;
// This function calculates the placement of the replaced contents. It takes
// intrinsic size of the replaced contents, stretch to fit CSS content box
// according to object-fit.
LayoutRect ComputeObjectFit(
const LayoutSize* overridden_intrinsic_size = nullptr) const;
LayoutUnit IntrinsicContentLogicalHeight() const override {
return IntrinsicLogicalHeight();
virtual LayoutUnit MinimumReplacedHeight() const { return LayoutUnit(); }
void StyleDidChange(StyleDifference, const ComputedStyle* old_style) override;
void SetIntrinsicSize(const LayoutSize& intrinsic_size) {
intrinsic_size_ = intrinsic_size;
// This callback is invoked whenever the intrinsic size changed.
// The intrinsic size can change due to the network (from the default
// intrinsic size [see above] to the actual intrinsic size) or to some
// CSS properties like 'zoom' or 'image-orientation'.
virtual void IntrinsicSizeChanged();
PositionWithAffinity PositionForPoint(const LayoutPoint&) const override;
bool IsOfType(LayoutObjectType type) const override {
return type == kLayoutObjectLayoutReplaced || LayoutBox::IsOfType(type);
void ComputePreferredLogicalWidths() final;
void ComputeIntrinsicSizingInfoForReplacedContent(IntrinsicSizingInfo&) const;
FloatSize ConstrainIntrinsicSizeToMinMax(const IntrinsicSizingInfo&) const;
LayoutUnit ComputeConstrainedLogicalWidth(ShouldComputePreferred) const;
mutable LayoutSize intrinsic_size_;
DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutReplaced, IsLayoutReplaced());
} // namespace blink