gecko-dev/layout/base/LayoutConstants.h
Emilio Cobos Álvarez 352d47e585 Bug 1786214 - Remove UseAutoBSize flag. r=TYLin
Use a more precise, grid-specific flag to avoid applying grid stretching
etc, and pass an unconstrained block size instead for baseline alignment
measuring, which will cause us to interpret relative sizes as auto.

This shouldn't cause any behavior change, but is a prerequisite
necessary for bug 1609403 (where we don't always want definite sizes
being ignored in measuring reflows for baseline alignment). It's also a
bit clearer, IMO.

Differential Revision: https://phabricator.services.mozilla.com/D155178
2022-08-23 09:17:38 +00:00

98 lines
3.5 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* constants used throughout the Layout module */
#ifndef LayoutConstants_h___
#define LayoutConstants_h___
#include "mozilla/EnumSet.h"
#include "nsSize.h" // for NS_MAXSIZE
#include "Units.h"
/**
* Constant used to indicate an unconstrained size.
*
* NOTE: The constants defined in this file are semantically used as symbolic
* values, so user should not depend on the underlying numeric values. If
* new specific use cases arise, define a new constant here.
*/
#define NS_UNCONSTRAINEDSIZE NS_MAXSIZE
// NS_AUTOOFFSET is assumed to have the same value as NS_UNCONSTRAINEDSIZE.
#define NS_AUTOOFFSET NS_UNCONSTRAINEDSIZE
// +1 is to avoid clamped huge margin values being processed as auto margins
#define NS_AUTOMARGIN (NS_UNCONSTRAINEDSIZE + 1)
#define NS_INTRINSIC_ISIZE_UNKNOWN nscoord_MIN
namespace mozilla {
/**
* Bit-flags to pass to various functions that compute sizes like
* nsIFrame::ComputeSize().
*/
enum class ComputeSizeFlag : uint8_t {
/**
* Set if the frame is in a context where non-replaced blocks should
* shrink-wrap (e.g., it's floating, absolutely positioned, or
* inline-block).
*/
ShrinkWrap,
/**
* Set if this is a grid measuring reflow, to prevent stretching.
*/
IsGridMeasuringReflow,
/**
* Indicates that we should clamp the margin-box min-size to the given CB
* size. This is used for implementing the grid area clamping here:
* https://drafts.csswg.org/css-grid/#min-size-auto
*/
IClampMarginBoxMinSize, // clamp in our inline axis
BClampMarginBoxMinSize, // clamp in our block axis
/**
* The frame is stretching (per CSS Box Alignment) and doesn't have an
* Automatic Minimum Size in the indicated axis.
* (may be used for both flex/grid items, but currently only used for Grid)
* https://drafts.csswg.org/css-grid/#min-size-auto
* https://drafts.csswg.org/css-align-3/#valdef-justify-self-stretch
*/
IApplyAutoMinSize, // only has an effect when eShrinkWrap is false
};
using ComputeSizeFlags = mozilla::EnumSet<ComputeSizeFlag>;
/**
* The fallback size of width is 300px and the aspect-ratio is 2:1, based on
* CSS2 section 10.3.2 and CSS Sizing Level 3 section 5.1:
* https://drafts.csswg.org/css2/visudet.html#inline-replaced-width
* https://drafts.csswg.org/css-sizing-3/#intrinsic-sizes
*/
inline constexpr CSSIntCoord kFallbackIntrinsicWidthInPixels(300);
inline constexpr CSSIntCoord kFallbackIntrinsicHeightInPixels(150);
inline constexpr CSSIntSize kFallbackIntrinsicSizeInPixels(
kFallbackIntrinsicWidthInPixels, kFallbackIntrinsicHeightInPixels);
inline constexpr nscoord kFallbackIntrinsicWidth =
kFallbackIntrinsicWidthInPixels * AppUnitsPerCSSPixel();
inline constexpr nscoord kFallbackIntrinsicHeight =
kFallbackIntrinsicHeightInPixels * AppUnitsPerCSSPixel();
inline constexpr nsSize kFallbackIntrinsicSize(kFallbackIntrinsicWidth,
kFallbackIntrinsicHeight);
/**
* This is used in some nsLayoutUtils functions.
* Declared here so that fewer files need to include nsLayoutUtils.h.
*/
enum class IntrinsicISizeType { MinISize, PrefISize };
} // namespace mozilla
#endif // LayoutConstants_h___