gecko-dev/layout/generic/WritingModes.h

2048 строки
67 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/. */
#ifndef WritingModes_h_
#define WritingModes_h_
#include "mozilla/ComputedStyle.h"
#include "mozilla/ComputedStyleInlines.h"
#include "nsRect.h"
#include "nsBidiUtils.h"
// It is the caller's responsibility to operate on logical-coordinate objects
// with matched writing modes. Failure to do so will be a runtime bug; the
// compiler can't catch it, but in debug mode, we'll throw an assertion.
// NOTE that in non-debug builds, a writing mode mismatch error will NOT be
// detected, yet the results will be nonsense (and may lead to further layout
// failures). Therefore, it is important to test (and fuzz-test) writing-mode
// support using debug builds.
// Methods in logical-coordinate classes that take another logical-coordinate
// object as a parameter should call CHECK_WRITING_MODE on it to verify that
// the writing modes match.
// (In some cases, there are internal (private) methods that don't do this;
// such methods should only be used by other methods that have already checked
// the writing modes.)
// The check ignores the eSidewaysMask bit of writing mode, because this does
// not affect the interpretation of logical coordinates.
#define CHECK_WRITING_MODE(param) \
NS_ASSERTION(param.IgnoreSideways() == GetWritingMode().IgnoreSideways(), \
"writing-mode mismatch")
namespace mozilla {
namespace widget {
struct IMENotification;
} // namespace widget
// Physical axis constants.
enum PhysicalAxis { eAxisVertical = 0x0, eAxisHorizontal = 0x1 };
inline LogicalAxis GetOrthogonalAxis(LogicalAxis aAxis) {
return aAxis == eLogicalAxisBlock ? eLogicalAxisInline : eLogicalAxisBlock;
}
inline bool IsInline(LogicalSide aSide) { return aSide & 0x2; }
inline bool IsBlock(LogicalSide aSide) { return !IsInline(aSide); }
inline bool IsEnd(LogicalSide aSide) { return aSide & 0x1; }
inline bool IsStart(LogicalSide aSide) { return !IsEnd(aSide); }
inline LogicalAxis GetAxis(LogicalSide aSide) {
return IsInline(aSide) ? eLogicalAxisInline : eLogicalAxisBlock;
}
inline LogicalEdge GetEdge(LogicalSide aSide) {
return IsEnd(aSide) ? eLogicalEdgeEnd : eLogicalEdgeStart;
}
inline LogicalEdge GetOppositeEdge(LogicalEdge aEdge) {
// This relies on the only two LogicalEdge enum values being 0 and 1.
return LogicalEdge(1 - aEdge);
}
inline LogicalSide MakeLogicalSide(LogicalAxis aAxis, LogicalEdge aEdge) {
return LogicalSide((aAxis << 1) | aEdge);
}
inline LogicalSide GetOppositeSide(LogicalSide aSide) {
return MakeLogicalSide(GetAxis(aSide), GetOppositeEdge(GetEdge(aSide)));
}
enum LogicalSideBits {
eLogicalSideBitsNone = 0,
eLogicalSideBitsBStart = 1 << eLogicalSideBStart,
eLogicalSideBitsBEnd = 1 << eLogicalSideBEnd,
eLogicalSideBitsIEnd = 1 << eLogicalSideIEnd,
eLogicalSideBitsIStart = 1 << eLogicalSideIStart,
eLogicalSideBitsBBoth = eLogicalSideBitsBStart | eLogicalSideBitsBEnd,
eLogicalSideBitsIBoth = eLogicalSideBitsIStart | eLogicalSideBitsIEnd,
eLogicalSideBitsAll = eLogicalSideBitsBBoth | eLogicalSideBitsIBoth
};
enum LineRelativeDir {
eLineRelativeDirOver = eLogicalSideBStart,
eLineRelativeDirUnder = eLogicalSideBEnd,
eLineRelativeDirLeft = eLogicalSideIStart,
eLineRelativeDirRight = eLogicalSideIEnd
};
/**
* LogicalSides represents a set of logical sides.
*/
struct LogicalSides final {
LogicalSides() : mBits(0) {}
explicit LogicalSides(LogicalSideBits aSideBits) {
MOZ_ASSERT((aSideBits & ~eLogicalSideBitsAll) == 0, "illegal side bits");
mBits = aSideBits;
}
bool IsEmpty() const { return mBits == 0; }
bool BStart() const { return mBits & eLogicalSideBitsBStart; }
bool BEnd() const { return mBits & eLogicalSideBitsBEnd; }
bool IStart() const { return mBits & eLogicalSideBitsIStart; }
bool IEnd() const { return mBits & eLogicalSideBitsIEnd; }
bool Contains(LogicalSideBits aSideBits) const {
MOZ_ASSERT((aSideBits & ~eLogicalSideBitsAll) == 0, "illegal side bits");
return (mBits & aSideBits) == aSideBits;
}
LogicalSides operator|(LogicalSides aOther) const {
return LogicalSides(LogicalSideBits(mBits | aOther.mBits));
}
LogicalSides operator|(LogicalSideBits aSideBits) const {
return *this | LogicalSides(aSideBits);
}
LogicalSides& operator|=(LogicalSides aOther) {
mBits |= aOther.mBits;
return *this;
}
LogicalSides& operator|=(LogicalSideBits aSideBits) {
return *this |= LogicalSides(aSideBits);
}
bool operator==(LogicalSides aOther) const { return mBits == aOther.mBits; }
bool operator!=(LogicalSides aOther) const { return !(*this == aOther); }
private:
uint8_t mBits;
};
/**
* mozilla::WritingMode is an immutable class representing a
* writing mode.
*
* It efficiently stores the writing mode and can rapidly compute
* interesting things about it for use in layout.
*
* Writing modes are computed from the CSS 'direction',
* 'writing-mode', and 'text-orientation' properties.
* See CSS3 Writing Modes for more information
* http://www.w3.org/TR/css3-writing-modes/
*/
class WritingMode {
public:
/**
* Absolute inline flow direction
*/
enum InlineDir {
eInlineLTR = 0x00, // text flows horizontally left to right
eInlineRTL = 0x02, // text flows horizontally right to left
eInlineTTB = 0x01, // text flows vertically top to bottom
eInlineBTT = 0x03, // text flows vertically bottom to top
};
/**
* Absolute block flow direction
*/
enum BlockDir {
eBlockTB = 0x00, // horizontal lines stack top to bottom
eBlockRL = 0x01, // vertical lines stack right to left
eBlockLR = 0x05, // vertical lines stack left to right
};
/**
* Line-relative (bidi-relative) inline flow direction
*/
enum BidiDir {
eBidiLTR = 0x00, // inline flow matches bidi LTR text
eBidiRTL = 0x10, // inline flow matches bidi RTL text
};
/**
* Unknown writing mode (should never actually be stored or used anywhere).
*/
enum { eUnknownWritingMode = 0xff };
/**
* Return the absolute inline flow direction as an InlineDir
*/
InlineDir GetInlineDir() const {
return InlineDir(mWritingMode & eInlineMask);
}
/**
* Return the absolute block flow direction as a BlockDir
*/
BlockDir GetBlockDir() const { return BlockDir(mWritingMode & eBlockMask); }
/**
* Return the line-relative inline flow direction as a BidiDir
*/
BidiDir GetBidiDir() const { return BidiDir(mWritingMode & eBidiMask); }
/**
* Return true if the inline flow direction is against physical direction
* (i.e. right-to-left or bottom-to-top).
* This occurs when writing-mode is sideways-lr OR direction is rtl (but not
* if both of those are true).
*/
bool IsInlineReversed() const { return !!(mWritingMode & eInlineFlowMask); }
/**
* Return true if bidi direction is LTR. (Convenience method)
*/
bool IsBidiLTR() const { return eBidiLTR == GetBidiDir(); }
/**
* True if vertical-mode block direction is LR (convenience method).
*/
bool IsVerticalLR() const { return eBlockLR == GetBlockDir(); }
/**
* True if vertical-mode block direction is RL (convenience method).
*/
bool IsVerticalRL() const { return eBlockRL == GetBlockDir(); }
/**
* True if vertical writing mode, i.e. when
* writing-mode: vertical-lr | vertical-rl.
*/
bool IsVertical() const { return !!(mWritingMode & eOrientationMask); }
/**
* True if line-over/line-under are inverted from block-start/block-end.
* This is true only when writing-mode is vertical-lr.
*/
bool IsLineInverted() const { return !!(mWritingMode & eLineOrientMask); }
/**
* Block-axis flow-relative to line-relative factor.
* May be used as a multiplication factor for block-axis coordinates
* to convert between flow- and line-relative coordinate systems (e.g.
* positioning an over- or under-line decoration).
*/
int FlowRelativeToLineRelativeFactor() const {
return IsLineInverted() ? -1 : 1;
}
/**
* True if the text-orientation will force all text to be rendered sideways
* in vertical lines, in which case we should prefer an alphabetic baseline;
* otherwise, the default is centered.
* Note that some glyph runs may be rendered sideways even if this is false,
* due to text-orientation:mixed resolution, but in that case the dominant
* baseline remains centered.
*/
bool IsSideways() const { return !!(mWritingMode & eSidewaysMask); }
#ifdef DEBUG // Used by CHECK_WRITING_MODE to compare modes without regard
// for the eSidewaysMask flag.
WritingMode IgnoreSideways() const {
return WritingMode(mWritingMode & ~eSidewaysMask);
}
#endif
/**
* Return true if boxes with this writing mode should use central baselines.
*/
bool IsCentralBaseline() const { return IsVertical() && !IsSideways(); }
/**
* Return true if boxes with this writing mode should use alphabetical
* baselines.
*/
bool IsAlphabeticalBaseline() const { return !IsCentralBaseline(); }
static mozilla::PhysicalAxis PhysicalAxisForLogicalAxis(
uint8_t aWritingModeValue, LogicalAxis aAxis) {
// This relies on bit 0 of a writing-value mode indicating vertical
// orientation and bit 0 of a LogicalAxis value indicating the inline axis,
// so that it can correctly form mozilla::PhysicalAxis values using bit
// manipulation.
static_assert(NS_STYLE_WRITING_MODE_HORIZONTAL_TB == 0 &&
NS_STYLE_WRITING_MODE_VERTICAL_RL == 1 &&
NS_STYLE_WRITING_MODE_VERTICAL_LR == 3 &&
eLogicalAxisBlock == 0 && eLogicalAxisInline == 1 &&
eAxisVertical == 0 && eAxisHorizontal == 1,
"unexpected writing-mode, logical axis or physical axis "
"constant values");
return mozilla::PhysicalAxis((aWritingModeValue ^ aAxis) & 0x1);
}
mozilla::PhysicalAxis PhysicalAxis(LogicalAxis aAxis) const {
// This will set wm to either NS_STYLE_WRITING_MODE_HORIZONTAL_TB or
// NS_STYLE_WRITING_MODE_VERTICAL_RL, and not the other two (real
// and hypothetical) values. But this is fine; we only need to
// distinguish between vertical and horizontal in
// PhysicalAxisForLogicalAxis.
const auto wm = static_cast<uint8_t>(mWritingMode & eOrientationMask);
return PhysicalAxisForLogicalAxis(wm, aAxis);
}
static mozilla::Side PhysicalSideForBlockAxis(uint8_t aWritingModeValue,
LogicalEdge aEdge) {
// indexes are NS_STYLE_WRITING_MODE_* values, which are the same as these
// two-bit values:
// bit 0 = the eOrientationMask value
// bit 1 = the eBlockFlowMask value
static const mozilla::Side kLogicalBlockSides[][2] = {
{eSideTop, eSideBottom}, // horizontal-tb
{eSideRight, eSideLeft}, // vertical-rl
{eSideBottom, eSideTop}, // (horizontal-bt)
{eSideLeft, eSideRight}, // vertical-lr
};
// Ignore the SIDEWAYS_MASK bit of the writing-mode value, as this has no
// effect on the side mappings.
aWritingModeValue &= ~NS_STYLE_WRITING_MODE_SIDEWAYS_MASK;
// What's left of the writing-mode should be in the range 0-3:
NS_ASSERTION(aWritingModeValue < 4, "invalid aWritingModeValue value");
return kLogicalBlockSides[aWritingModeValue][aEdge];
}
mozilla::Side PhysicalSideForInlineAxis(LogicalEdge aEdge) const {
// indexes are four-bit values:
// bit 0 = the eOrientationMask value
// bit 1 = the eInlineFlowMask value
// bit 2 = the eBlockFlowMask value
// bit 3 = the eLineOrientMask value
// Not all of these combinations can actually be specified via CSS: there
// is no horizontal-bt writing-mode, and no text-orientation value that
// produces "inverted" text. (The former 'sideways-left' value, no longer
// in the spec, would have produced this in vertical-rl mode.)
static const mozilla::Side kLogicalInlineSides[][2] = {
{eSideLeft, eSideRight}, // horizontal-tb ltr
{eSideTop, eSideBottom}, // vertical-rl ltr
{eSideRight, eSideLeft}, // horizontal-tb rtl
{eSideBottom, eSideTop}, // vertical-rl rtl
{eSideRight, eSideLeft}, // (horizontal-bt) (inverted) ltr
{eSideTop, eSideBottom}, // sideways-lr rtl
{eSideLeft, eSideRight}, // (horizontal-bt) (inverted) rtl
{eSideBottom, eSideTop}, // sideways-lr ltr
{eSideLeft, eSideRight}, // horizontal-tb (inverted) rtl
{eSideTop, eSideBottom}, // vertical-rl (inverted) rtl
{eSideRight, eSideLeft}, // horizontal-tb (inverted) ltr
{eSideBottom, eSideTop}, // vertical-rl (inverted) ltr
{eSideLeft, eSideRight}, // (horizontal-bt) ltr
{eSideTop, eSideBottom}, // vertical-lr ltr
{eSideRight, eSideLeft}, // (horizontal-bt) rtl
{eSideBottom, eSideTop}, // vertical-lr rtl
};
// Inline axis sides depend on all three of writing-mode, text-orientation
// and direction, which are encoded in the eOrientationMask,
// eInlineFlowMask, eBlockFlowMask and eLineOrientMask bits. Use these four
// bits to index into kLogicalInlineSides.
static_assert(eOrientationMask == 0x01 && eInlineFlowMask == 0x02 &&
eBlockFlowMask == 0x04 && eLineOrientMask == 0x08,
"unexpected mask values");
int index = mWritingMode & 0x0F;
return kLogicalInlineSides[index][aEdge];
}
/**
* Returns the physical side corresponding to the specified logical side,
* given the current writing mode.
*/
mozilla::Side PhysicalSide(LogicalSide aSide) const {
if (IsBlock(aSide)) {
static_assert(eOrientationMask == 0x01 && eBlockFlowMask == 0x04,
"unexpected mask values");
const auto wm =
static_cast<uint8_t>(((mWritingMode & eBlockFlowMask) >> 1) |
(mWritingMode & eOrientationMask));
return PhysicalSideForBlockAxis(wm, GetEdge(aSide));
}
return PhysicalSideForInlineAxis(GetEdge(aSide));
}
/**
* Returns the logical side corresponding to the specified physical side,
* given the current writing mode.
* (This is the inverse of the PhysicalSide() method above.)
*/
LogicalSide LogicalSideForPhysicalSide(mozilla::Side aSide) const {
// clang-format off
// indexes are four-bit values:
// bit 0 = the eOrientationMask value
// bit 1 = the eInlineFlowMask value
// bit 2 = the eBlockFlowMask value
// bit 3 = the eLineOrientMask value
static const LogicalSide kPhysicalToLogicalSides[][4] = {
// top right
// bottom left
{ eLogicalSideBStart, eLogicalSideIEnd,
eLogicalSideBEnd, eLogicalSideIStart }, // horizontal-tb ltr
{ eLogicalSideIStart, eLogicalSideBStart,
eLogicalSideIEnd, eLogicalSideBEnd }, // vertical-rl ltr
{ eLogicalSideBStart, eLogicalSideIStart,
eLogicalSideBEnd, eLogicalSideIEnd }, // horizontal-tb rtl
{ eLogicalSideIEnd, eLogicalSideBStart,
eLogicalSideIStart, eLogicalSideBEnd }, // vertical-rl rtl
{ eLogicalSideBEnd, eLogicalSideIStart,
eLogicalSideBStart, eLogicalSideIEnd }, // (horizontal-bt) (inv) ltr
{ eLogicalSideIStart, eLogicalSideBEnd,
eLogicalSideIEnd, eLogicalSideBStart }, // vertical-lr sw-left rtl
{ eLogicalSideBEnd, eLogicalSideIEnd,
eLogicalSideBStart, eLogicalSideIStart }, // (horizontal-bt) (inv) rtl
{ eLogicalSideIEnd, eLogicalSideBEnd,
eLogicalSideIStart, eLogicalSideBStart }, // vertical-lr sw-left ltr
{ eLogicalSideBStart, eLogicalSideIEnd,
eLogicalSideBEnd, eLogicalSideIStart }, // horizontal-tb (inv) rtl
{ eLogicalSideIStart, eLogicalSideBStart,
eLogicalSideIEnd, eLogicalSideBEnd }, // vertical-rl sw-left rtl
{ eLogicalSideBStart, eLogicalSideIStart,
eLogicalSideBEnd, eLogicalSideIEnd }, // horizontal-tb (inv) ltr
{ eLogicalSideIEnd, eLogicalSideBStart,
eLogicalSideIStart, eLogicalSideBEnd }, // vertical-rl sw-left ltr
{ eLogicalSideBEnd, eLogicalSideIEnd,
eLogicalSideBStart, eLogicalSideIStart }, // (horizontal-bt) ltr
{ eLogicalSideIStart, eLogicalSideBEnd,
eLogicalSideIEnd, eLogicalSideBStart }, // vertical-lr ltr
{ eLogicalSideBEnd, eLogicalSideIStart,
eLogicalSideBStart, eLogicalSideIEnd }, // (horizontal-bt) rtl
{ eLogicalSideIEnd, eLogicalSideBEnd,
eLogicalSideIStart, eLogicalSideBStart }, // vertical-lr rtl
};
// clang-format on
static_assert(eOrientationMask == 0x01 && eInlineFlowMask == 0x02 &&
eBlockFlowMask == 0x04 && eLineOrientMask == 0x08,
"unexpected mask values");
int index = mWritingMode & 0x0F;
return kPhysicalToLogicalSides[index][aSide];
}
/**
* Returns the logical side corresponding to the specified
* line-relative direction, given the current writing mode.
*/
LogicalSide LogicalSideForLineRelativeDir(LineRelativeDir aDir) const {
auto side = static_cast<LogicalSide>(aDir);
if (IsInline(side)) {
return IsBidiLTR() ? side : GetOppositeSide(side);
}
return !IsLineInverted() ? side : GetOppositeSide(side);
}
/**
* Default constructor gives us a horizontal, LTR writing mode.
* XXX We will probably eliminate this and require explicit initialization
* in all cases once transition is complete.
*/
WritingMode() : mWritingMode(0) {}
/**
* Construct writing mode based on a ComputedStyle.
*/
explicit WritingMode(ComputedStyle* aComputedStyle) {
NS_ASSERTION(aComputedStyle, "we need an ComputedStyle here");
InitFromStyleVisibility(aComputedStyle->StyleVisibility());
}
explicit WritingMode(const nsStyleVisibility* aStyleVisibility) {
NS_ASSERTION(aStyleVisibility, "we need an nsStyleVisibility here");
InitFromStyleVisibility(aStyleVisibility);
}
private:
void InitFromStyleVisibility(const nsStyleVisibility* aStyleVisibility) {
switch (aStyleVisibility->mWritingMode) {
case NS_STYLE_WRITING_MODE_HORIZONTAL_TB:
mWritingMode = 0;
break;
case NS_STYLE_WRITING_MODE_VERTICAL_LR: {
mWritingMode = eBlockFlowMask | eLineOrientMask | eOrientationMask;
uint8_t textOrientation = aStyleVisibility->mTextOrientation;
if (textOrientation == NS_STYLE_TEXT_ORIENTATION_SIDEWAYS) {
mWritingMode |= eSidewaysMask;
}
break;
}
case NS_STYLE_WRITING_MODE_VERTICAL_RL: {
mWritingMode = eOrientationMask;
uint8_t textOrientation = aStyleVisibility->mTextOrientation;
if (textOrientation == NS_STYLE_TEXT_ORIENTATION_SIDEWAYS) {
mWritingMode |= eSidewaysMask;
}
break;
}
case NS_STYLE_WRITING_MODE_SIDEWAYS_LR:
mWritingMode =
eBlockFlowMask | eInlineFlowMask | eOrientationMask | eSidewaysMask;
break;
case NS_STYLE_WRITING_MODE_SIDEWAYS_RL:
mWritingMode = eOrientationMask | eSidewaysMask;
break;
default:
MOZ_ASSERT_UNREACHABLE("unknown writing mode!");
mWritingMode = 0;
break;
}
if (NS_STYLE_DIRECTION_RTL == aStyleVisibility->mDirection) {
mWritingMode ^= eInlineFlowMask | eBidiMask;
}
}
public:
/**
* This function performs fixup for elements with 'unicode-bidi: plaintext',
* where inline directionality is derived from the Unicode bidi categories
* of the element's content, and not the CSS 'direction' property.
*
* The WritingMode constructor will have already incorporated the 'direction'
* property into our flag bits, so such elements need to use this method
* (after resolving the bidi level of their content) to update the direction
* bits as needed.
*
* If it turns out that our bidi direction already matches what plaintext
* resolution determined, there's nothing to do here. If it didn't (i.e. if
* the rtl-ness doesn't match), then we correct the direction by flipping the
* same bits that get flipped in the constructor's CSS 'direction'-based
* chunk.
*
* XXX change uint8_t to UBiDiLevel after bug 924851
*/
void SetDirectionFromBidiLevel(uint8_t level) {
if (IS_LEVEL_RTL(level) == IsBidiLTR()) {
mWritingMode ^= eBidiMask | eInlineFlowMask;
}
}
/**
* Compare two WritingModes for equality.
*/
bool operator==(const WritingMode& aOther) const {
return mWritingMode == aOther.mWritingMode;
}
bool operator!=(const WritingMode& aOther) const {
return mWritingMode != aOther.mWritingMode;
}
/**
* Check whether two modes are orthogonal to each other.
*/
bool IsOrthogonalTo(const WritingMode& aOther) const {
return IsVertical() != aOther.IsVertical();
}
/**
* Returns true if this WritingMode's aLogicalAxis has the same physical
* start side as the parallel axis of WritingMode |aOther|.
*
* @param aLogicalAxis The axis to compare from this WritingMode.
* @param aOther The other WritingMode (from which we'll choose the axis
* that's parallel to this WritingMode's aLogicalAxis, for
* comparison).
*/
bool ParallelAxisStartsOnSameSide(LogicalAxis aLogicalAxis,
const WritingMode& aOther) const {
mozilla::Side myStartSide =
this->PhysicalSide(MakeLogicalSide(aLogicalAxis, eLogicalEdgeStart));
// Figure out which of aOther's axes is parallel to |this| WritingMode's
// aLogicalAxis, and get its physical start side as well.
LogicalAxis otherWMAxis = aOther.IsOrthogonalTo(*this)
? GetOrthogonalAxis(aLogicalAxis)
: aLogicalAxis;
mozilla::Side otherWMStartSide =
aOther.PhysicalSide(MakeLogicalSide(otherWMAxis, eLogicalEdgeStart));
NS_ASSERTION(myStartSide % 2 == otherWMStartSide % 2,
"Should end up with sides in the same physical axis");
return myStartSide == otherWMStartSide;
}
uint8_t GetBits() const { return mWritingMode; }
const char* DebugString() const {
return IsVertical()
? IsVerticalLR()
? IsBidiLTR() ? IsSideways() ? "sw-lr-ltr" : "v-lr-ltr"
: IsSideways() ? "sw-lr-rtl" : "v-lr-rtl"
: IsBidiLTR() ? IsSideways() ? "sw-rl-ltr" : "v-rl-ltr"
: IsSideways() ? "sw-rl-rtl" : "v-rl-rtl"
: IsBidiLTR() ? "h-ltr" : "h-rtl";
}
private:
friend class LogicalPoint;
friend class LogicalSize;
friend class LogicalMargin;
friend class LogicalRect;
friend struct IPC::ParamTraits<WritingMode>;
// IMENotification cannot store this class directly since this has some
// constructors. Therefore, it stores mWritingMode and recreate the
// instance from it.
friend struct widget::IMENotification;
/**
* Return a WritingMode representing an unknown value.
*/
static inline WritingMode Unknown() {
return WritingMode(eUnknownWritingMode);
}
/**
* Constructing a WritingMode with an arbitrary value is a private operation
* currently only used by the Unknown() static method.
*/
explicit WritingMode(uint8_t aValue) : mWritingMode(aValue) {}
uint8_t mWritingMode;
enum Masks {
// Masks for our bits; true chosen as opposite of commonest case
eOrientationMask = 0x01, // true means vertical text
eInlineFlowMask = 0x02, // true means absolute RTL/BTT (against physical
// coords)
eBlockFlowMask = 0x04, // true means vertical-LR (or horizontal-BT if
// added)
eLineOrientMask = 0x08, // true means over != block-start
eBidiMask = 0x10, // true means line-relative RTL (bidi RTL)
// Note: We have one excess bit of info; WritingMode can pack into 4 bits.
// But since we have space, we're caching interesting things for fast
// access.
eSidewaysMask = 0x20, // true means text is being rendered vertically
// using rotated glyphs (i.e. writing-mode is
// sideways-*, or writing-mode is vertical-* AND
// text-orientation is sideways),
// which means we'll use alphabetic instead of
// centered default baseline for vertical text
// Masks for output enums
eInlineMask = 0x03,
eBlockMask = 0x05
};
};
/**
* Logical-coordinate classes:
*
* There are three sets of coordinate space:
* - physical (top, left, bottom, right)
* relative to graphics coord system
* - flow-relative (block-start, inline-start, block-end, inline-end)
* relative to block/inline flow directions
* - line-relative (line-over, line-left, line-under, line-right)
* relative to glyph orientation / inline bidi directions
* See CSS3 Writing Modes for more information
* http://www.w3.org/TR/css3-writing-modes/#abstract-box
*
* For shorthand, B represents the block-axis
* I represents the inline-axis
*
* The flow-relative geometric classes store coords in flow-relative space.
* They use a private ns{Point,Size,Rect,Margin} member to store the actual
* coordinate values, but reinterpret them as logical instead of physical.
* This allows us to easily perform calculations in logical space (provided
* writing modes of the operands match), by simply mapping to nsPoint (etc)
* methods.
*
* Physical-coordinate accessors/setters are responsible to translate these
* internal logical values as necessary.
*
* In DEBUG builds, the logical types store their WritingMode and check
* that the same WritingMode is passed whenever callers ask them to do a
* writing-mode-dependent operation. Non-DEBUG builds do NOT check this,
* to avoid the overhead of storing WritingMode fields.
*
* Open question: do we need a different set optimized for line-relative
* math, for use in nsLineLayout and the like? Or is multiplying values
* by FlowRelativeToLineRelativeFactor() enough?
*/
/**
* Flow-relative point
*/
class LogicalPoint {
public:
explicit LogicalPoint(WritingMode aWritingMode)
:
#ifdef DEBUG
mWritingMode(aWritingMode),
#endif
mPoint(0, 0) {
}
// Construct from a writing mode and individual coordinates (which MUST be
// values in that writing mode, NOT physical coordinates!)
LogicalPoint(WritingMode aWritingMode, nscoord aI, nscoord aB)
:
#ifdef DEBUG
mWritingMode(aWritingMode),
#endif
mPoint(aI, aB) {
}
// Construct from a writing mode and a physical point, within a given
// containing rectangle's size (defining the conversion between LTR
// and RTL coordinates, and between TTB and BTT coordinates).
LogicalPoint(WritingMode aWritingMode, const nsPoint& aPoint,
const nsSize& aContainerSize)
#ifdef DEBUG
: mWritingMode(aWritingMode)
#endif
{
if (aWritingMode.IsVertical()) {
I() = aWritingMode.IsInlineReversed() ? aContainerSize.height - aPoint.y
: aPoint.y;
B() = aWritingMode.IsVerticalLR() ? aPoint.x
: aContainerSize.width - aPoint.x;
} else {
I() = aWritingMode.IsInlineReversed() ? aContainerSize.width - aPoint.x
: aPoint.x;
B() = aPoint.y;
}
}
/**
* Read-only (const) access to the logical coordinates.
*/
nscoord I(WritingMode aWritingMode) const // inline-axis
{
CHECK_WRITING_MODE(aWritingMode);
return mPoint.x;
}
nscoord B(WritingMode aWritingMode) const // block-axis
{
CHECK_WRITING_MODE(aWritingMode);
return mPoint.y;
}
nscoord LineRelative(WritingMode aWritingMode,
const nsSize& aContainerSize) const // line-axis
{
CHECK_WRITING_MODE(aWritingMode);
if (aWritingMode.IsBidiLTR()) {
return I();
}
return (aWritingMode.IsVertical() ? aContainerSize.height
: aContainerSize.width) -
I();
}
/**
* These non-const accessors return a reference (lvalue) that can be
* assigned to by callers.
*/
nscoord& I(WritingMode aWritingMode) // inline-axis
{
CHECK_WRITING_MODE(aWritingMode);
return mPoint.x;
}
nscoord& B(WritingMode aWritingMode) // block-axis
{
CHECK_WRITING_MODE(aWritingMode);
return mPoint.y;
}
/**
* Return a physical point corresponding to our logical coordinates,
* converted according to our writing mode.
*/
nsPoint GetPhysicalPoint(WritingMode aWritingMode,
const nsSize& aContainerSize) const {
CHECK_WRITING_MODE(aWritingMode);
if (aWritingMode.IsVertical()) {
return nsPoint(
aWritingMode.IsVerticalLR() ? B() : aContainerSize.width - B(),
aWritingMode.IsInlineReversed() ? aContainerSize.height - I() : I());
} else {
return nsPoint(
aWritingMode.IsInlineReversed() ? aContainerSize.width - I() : I(),
B());
}
}
/**
* Return the equivalent point in a different writing mode.
*/
LogicalPoint ConvertTo(WritingMode aToMode, WritingMode aFromMode,
const nsSize& aContainerSize) const {
CHECK_WRITING_MODE(aFromMode);
return aToMode == aFromMode
? *this
: LogicalPoint(aToMode,
GetPhysicalPoint(aFromMode, aContainerSize),
aContainerSize);
}
bool operator==(const LogicalPoint& aOther) const {
CHECK_WRITING_MODE(aOther.GetWritingMode());
return mPoint == aOther.mPoint;
}
bool operator!=(const LogicalPoint& aOther) const {
CHECK_WRITING_MODE(aOther.GetWritingMode());
return mPoint != aOther.mPoint;
}
LogicalPoint operator+(const LogicalPoint& aOther) const {
CHECK_WRITING_MODE(aOther.GetWritingMode());
// In non-debug builds, LogicalPoint does not store the WritingMode,
// so the first parameter here (which will always be eUnknownWritingMode)
// is ignored.
return LogicalPoint(GetWritingMode(), mPoint.x + aOther.mPoint.x,
mPoint.y + aOther.mPoint.y);
}
LogicalPoint& operator+=(const LogicalPoint& aOther) {
CHECK_WRITING_MODE(aOther.GetWritingMode());
I() += aOther.I();
B() += aOther.B();
return *this;
}
LogicalPoint operator-(const LogicalPoint& aOther) const {
CHECK_WRITING_MODE(aOther.GetWritingMode());
// In non-debug builds, LogicalPoint does not store the WritingMode,
// so the first parameter here (which will always be eUnknownWritingMode)
// is ignored.
return LogicalPoint(GetWritingMode(), mPoint.x - aOther.mPoint.x,
mPoint.y - aOther.mPoint.y);
}
LogicalPoint& operator-=(const LogicalPoint& aOther) {
CHECK_WRITING_MODE(aOther.GetWritingMode());
I() -= aOther.I();
B() -= aOther.B();
return *this;
}
private:
friend class LogicalRect;
/**
* NOTE that in non-DEBUG builds, GetWritingMode() always returns
* eUnknownWritingMode, as the current mode is not stored in the logical-
* geometry classes. Therefore, this method is private; it is used ONLY
* by the DEBUG-mode checking macros in this class and its friends;
* other code is not allowed to ask a logical point for its writing mode,
* as this info will simply not be available in non-DEBUG builds.
*
* Also, in non-DEBUG builds, CHECK_WRITING_MODE does nothing, and the
* WritingMode parameter to logical methods will generally be optimized
* away altogether.
*/
#ifdef DEBUG
WritingMode GetWritingMode() const { return mWritingMode; }
#else
WritingMode GetWritingMode() const { return WritingMode::Unknown(); }
#endif
// We don't allow construction of a LogicalPoint with no writing mode.
LogicalPoint() = delete;
// Accessors that don't take or check a WritingMode value.
// These are for internal use only; they are called by methods that have
// themselves already checked the WritingMode passed by the caller.
nscoord I() const // inline-axis
{
return mPoint.x;
}
nscoord B() const // block-axis
{
return mPoint.y;
}
nscoord& I() // inline-axis
{
return mPoint.x;
}
nscoord& B() // block-axis
{
return mPoint.y;
}
#ifdef DEBUG
WritingMode mWritingMode;
#endif
// We use an nsPoint to hold the coordinates, but reinterpret its .x and .y
// fields as the inline and block directions. Hence, this is not exposed
// directly, but only through accessors that will map them according to the
// writing mode.
nsPoint mPoint;
};
/**
* Flow-relative size
*/
class LogicalSize {
public:
explicit LogicalSize(WritingMode aWritingMode)
:
#ifdef DEBUG
mWritingMode(aWritingMode),
#endif
mSize(0, 0) {
}
LogicalSize(WritingMode aWritingMode, nscoord aISize, nscoord aBSize)
:
#ifdef DEBUG
mWritingMode(aWritingMode),
#endif
mSize(aISize, aBSize) {
}
LogicalSize(WritingMode aWritingMode, const nsSize& aPhysicalSize)
#ifdef DEBUG
: mWritingMode(aWritingMode)
#endif
{
if (aWritingMode.IsVertical()) {
ISize() = aPhysicalSize.height;
BSize() = aPhysicalSize.width;
} else {
ISize() = aPhysicalSize.width;
BSize() = aPhysicalSize.height;
}
}
void SizeTo(WritingMode aWritingMode, nscoord aISize, nscoord aBSize) {
CHECK_WRITING_MODE(aWritingMode);
mSize.SizeTo(aISize, aBSize);
}
/**
* Dimensions in logical and physical terms
*/
nscoord ISize(WritingMode aWritingMode) const // inline-size
{
CHECK_WRITING_MODE(aWritingMode);
return mSize.width;
}
nscoord BSize(WritingMode aWritingMode) const // block-size
{
CHECK_WRITING_MODE(aWritingMode);
return mSize.height;
}
nscoord Size(LogicalAxis aAxis, WritingMode aWM) const {
return aAxis == eLogicalAxisInline ? ISize(aWM) : BSize(aWM);
}
nscoord Width(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical() ? BSize() : ISize();
}
nscoord Height(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical() ? ISize() : BSize();
}
/**
* Writable references to the logical dimensions
*/
nscoord& ISize(WritingMode aWritingMode) // inline-size
{
CHECK_WRITING_MODE(aWritingMode);
return mSize.width;
}
nscoord& BSize(WritingMode aWritingMode) // block-size
{
CHECK_WRITING_MODE(aWritingMode);
return mSize.height;
}
nscoord& Size(LogicalAxis aAxis, WritingMode aWM) {
return aAxis == eLogicalAxisInline ? ISize(aWM) : BSize(aWM);
}
/**
* Return an nsSize containing our physical dimensions
*/
nsSize GetPhysicalSize(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical() ? nsSize(BSize(), ISize())
: nsSize(ISize(), BSize());
}
/**
* Return a LogicalSize representing this size in a different writing mode
*/
LogicalSize ConvertTo(WritingMode aToMode, WritingMode aFromMode) const {
#ifdef DEBUG
// In DEBUG builds make sure to return a LogicalSize with the
// expected writing mode
CHECK_WRITING_MODE(aFromMode);
return aToMode == aFromMode
? *this
: LogicalSize(aToMode, GetPhysicalSize(aFromMode));
#else
// optimization for non-DEBUG builds where LogicalSize doesn't store
// the writing mode
return (aToMode == aFromMode || !aToMode.IsOrthogonalTo(aFromMode))
? *this
: LogicalSize(aToMode, BSize(), ISize());
#endif
}
/**
* Test if a size is (0, 0).
*/
bool IsAllZero() const { return ISize() == 0 && BSize() == 0; }
/**
* Various binary operators on LogicalSize. These are valid ONLY for operands
* that share the same writing mode.
*/
bool operator==(const LogicalSize& aOther) const {
CHECK_WRITING_MODE(aOther.GetWritingMode());
return mSize == aOther.mSize;
}
bool operator!=(const LogicalSize& aOther) const {
CHECK_WRITING_MODE(aOther.GetWritingMode());
return mSize != aOther.mSize;
}
LogicalSize operator+(const LogicalSize& aOther) const {
CHECK_WRITING_MODE(aOther.GetWritingMode());
return LogicalSize(GetWritingMode(), ISize() + aOther.ISize(),
BSize() + aOther.BSize());
}
LogicalSize& operator+=(const LogicalSize& aOther) {
CHECK_WRITING_MODE(aOther.GetWritingMode());
ISize() += aOther.ISize();
BSize() += aOther.BSize();
return *this;
}
LogicalSize operator-(const LogicalSize& aOther) const {
CHECK_WRITING_MODE(aOther.GetWritingMode());
return LogicalSize(GetWritingMode(), ISize() - aOther.ISize(),
BSize() - aOther.BSize());
}
LogicalSize& operator-=(const LogicalSize& aOther) {
CHECK_WRITING_MODE(aOther.GetWritingMode());
ISize() -= aOther.ISize();
BSize() -= aOther.BSize();
return *this;
}
private:
friend class LogicalRect;
LogicalSize() = delete;
#ifdef DEBUG
WritingMode GetWritingMode() const { return mWritingMode; }
#else
WritingMode GetWritingMode() const { return WritingMode::Unknown(); }
#endif
nscoord ISize() const // inline-size
{
return mSize.width;
}
nscoord BSize() const // block-size
{
return mSize.height;
}
nscoord& ISize() // inline-size
{
return mSize.width;
}
nscoord& BSize() // block-size
{
return mSize.height;
}
#ifdef DEBUG
WritingMode mWritingMode;
#endif
nsSize mSize;
};
/**
* Flow-relative margin
*/
class LogicalMargin {
public:
explicit LogicalMargin(WritingMode aWritingMode)
:
#ifdef DEBUG
mWritingMode(aWritingMode),
#endif
mMargin(0, 0, 0, 0) {
}
LogicalMargin(WritingMode aWritingMode, nscoord aBStart, nscoord aIEnd,
nscoord aBEnd, nscoord aIStart)
:
#ifdef DEBUG
mWritingMode(aWritingMode),
#endif
mMargin(aBStart, aIEnd, aBEnd, aIStart) {
}
LogicalMargin(WritingMode aWritingMode, const nsMargin& aPhysicalMargin)
#ifdef DEBUG
: mWritingMode(aWritingMode)
#endif
{
if (aWritingMode.IsVertical()) {
if (aWritingMode.IsVerticalLR()) {
mMargin.top = aPhysicalMargin.left;
mMargin.bottom = aPhysicalMargin.right;
} else {
mMargin.top = aPhysicalMargin.right;
mMargin.bottom = aPhysicalMargin.left;
}
if (aWritingMode.IsInlineReversed()) {
mMargin.left = aPhysicalMargin.bottom;
mMargin.right = aPhysicalMargin.top;
} else {
mMargin.left = aPhysicalMargin.top;
mMargin.right = aPhysicalMargin.bottom;
}
} else {
mMargin.top = aPhysicalMargin.top;
mMargin.bottom = aPhysicalMargin.bottom;
if (aWritingMode.IsInlineReversed()) {
mMargin.left = aPhysicalMargin.right;
mMargin.right = aPhysicalMargin.left;
} else {
mMargin.left = aPhysicalMargin.left;
mMargin.right = aPhysicalMargin.right;
}
}
}
nscoord IStart(WritingMode aWritingMode) const // inline-start margin
{
CHECK_WRITING_MODE(aWritingMode);
return mMargin.left;
}
nscoord IEnd(WritingMode aWritingMode) const // inline-end margin
{
CHECK_WRITING_MODE(aWritingMode);
return mMargin.right;
}
nscoord BStart(WritingMode aWritingMode) const // block-start margin
{
CHECK_WRITING_MODE(aWritingMode);
return mMargin.top;
}
nscoord BEnd(WritingMode aWritingMode) const // block-end margin
{
CHECK_WRITING_MODE(aWritingMode);
return mMargin.bottom;
}
nscoord Start(LogicalAxis aAxis, WritingMode aWM) const {
return aAxis == eLogicalAxisInline ? IStart(aWM) : BStart(aWM);
}
nscoord End(LogicalAxis aAxis, WritingMode aWM) const {
return aAxis == eLogicalAxisInline ? IEnd(aWM) : BEnd(aWM);
}
nscoord& IStart(WritingMode aWritingMode) // inline-start margin
{
CHECK_WRITING_MODE(aWritingMode);
return mMargin.left;
}
nscoord& IEnd(WritingMode aWritingMode) // inline-end margin
{
CHECK_WRITING_MODE(aWritingMode);
return mMargin.right;
}
nscoord& BStart(WritingMode aWritingMode) // block-start margin
{
CHECK_WRITING_MODE(aWritingMode);
return mMargin.top;
}
nscoord& BEnd(WritingMode aWritingMode) // block-end margin
{
CHECK_WRITING_MODE(aWritingMode);
return mMargin.bottom;
}
nscoord& Start(LogicalAxis aAxis, WritingMode aWM) {
return aAxis == eLogicalAxisInline ? IStart(aWM) : BStart(aWM);
}
nscoord& End(LogicalAxis aAxis, WritingMode aWM) {
return aAxis == eLogicalAxisInline ? IEnd(aWM) : BEnd(aWM);
}
nscoord IStartEnd(WritingMode aWritingMode) const // inline margins
{
CHECK_WRITING_MODE(aWritingMode);
return mMargin.LeftRight();
}
nscoord BStartEnd(WritingMode aWritingMode) const // block margins
{
CHECK_WRITING_MODE(aWritingMode);
return mMargin.TopBottom();
}
nscoord StartEnd(LogicalAxis aAxis, WritingMode aWM) const {
return aAxis == eLogicalAxisInline ? IStartEnd(aWM) : BStartEnd(aWM);
}
/*
* Return margin values for line-relative sides, as defined in
* http://www.w3.org/TR/css-writing-modes-3/#line-directions:
*
* line-left
* Nominally the side from which LTR text would start.
* line-right
* Nominally the side from which RTL text would start. (Opposite of
* line-left.)
*/
nscoord LineLeft(WritingMode aWritingMode) const {
// We don't need to CHECK_WRITING_MODE here because the IStart or IEnd
// accessor that we call will do it.
return aWritingMode.IsBidiLTR() ? IStart(aWritingMode) : IEnd(aWritingMode);
}
nscoord LineRight(WritingMode aWritingMode) const {
return aWritingMode.IsBidiLTR() ? IEnd(aWritingMode) : IStart(aWritingMode);
}
/**
* Return a LogicalSize representing the total size of the inline-
* and block-dimension margins.
*/
LogicalSize Size(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return LogicalSize(aWritingMode, IStartEnd(), BStartEnd());
}
/**
* Accessors for physical margins, using our writing mode to convert from
* logical values.
*/
nscoord Top(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical()
? (aWritingMode.IsInlineReversed() ? IEnd() : IStart())
: BStart();
}
nscoord Bottom(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical()
? (aWritingMode.IsInlineReversed() ? IStart() : IEnd())
: BEnd();
}
nscoord Left(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical()
? (aWritingMode.IsVerticalLR() ? BStart() : BEnd())
: (aWritingMode.IsInlineReversed() ? IEnd() : IStart());
}
nscoord Right(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical()
? (aWritingMode.IsVerticalLR() ? BEnd() : BStart())
: (aWritingMode.IsInlineReversed() ? IStart() : IEnd());
}
nscoord LeftRight(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical() ? BStartEnd() : IStartEnd();
}
nscoord TopBottom(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical() ? IStartEnd() : BStartEnd();
}
void SizeTo(WritingMode aWritingMode, nscoord aBStart, nscoord aIEnd,
nscoord aBEnd, nscoord aIStart) {
CHECK_WRITING_MODE(aWritingMode);
mMargin.SizeTo(aBStart, aIEnd, aBEnd, aIStart);
}
/**
* Return an nsMargin containing our physical coordinates
*/
nsMargin GetPhysicalMargin(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical()
? (aWritingMode.IsVerticalLR()
? (aWritingMode.IsInlineReversed()
? nsMargin(IEnd(), BEnd(), IStart(), BStart())
: nsMargin(IStart(), BEnd(), IEnd(), BStart()))
: (aWritingMode.IsInlineReversed()
? nsMargin(IEnd(), BStart(), IStart(), BEnd())
: nsMargin(IStart(), BStart(), IEnd(), BEnd())))
: (aWritingMode.IsInlineReversed()
? nsMargin(BStart(), IStart(), BEnd(), IEnd())
: nsMargin(BStart(), IEnd(), BEnd(), IStart()));
}
/**
* Return a LogicalMargin representing this margin in a different
* writing mode
*/
LogicalMargin ConvertTo(WritingMode aToMode, WritingMode aFromMode) const {
CHECK_WRITING_MODE(aFromMode);
return aToMode == aFromMode
? *this
: LogicalMargin(aToMode, GetPhysicalMargin(aFromMode));
}
void ApplySkipSides(LogicalSides aSkipSides) {
if (aSkipSides.BStart()) {
BStart() = 0;
}
if (aSkipSides.BEnd()) {
BEnd() = 0;
}
if (aSkipSides.IStart()) {
IStart() = 0;
}
if (aSkipSides.IEnd()) {
IEnd() = 0;
}
}
bool IsAllZero() const {
return (mMargin.left == 0 && mMargin.top == 0 && mMargin.right == 0 &&
mMargin.bottom == 0);
}
LogicalMargin operator+(const LogicalMargin& aMargin) const {
CHECK_WRITING_MODE(aMargin.GetWritingMode());
return LogicalMargin(GetWritingMode(), BStart() + aMargin.BStart(),
IEnd() + aMargin.IEnd(), BEnd() + aMargin.BEnd(),
IStart() + aMargin.IStart());
}
LogicalMargin operator+=(const LogicalMargin& aMargin) {
CHECK_WRITING_MODE(aMargin.GetWritingMode());
mMargin += aMargin.mMargin;
return *this;
}
LogicalMargin operator-(const LogicalMargin& aMargin) const {
CHECK_WRITING_MODE(aMargin.GetWritingMode());
return LogicalMargin(GetWritingMode(), BStart() - aMargin.BStart(),
IEnd() - aMargin.IEnd(), BEnd() - aMargin.BEnd(),
IStart() - aMargin.IStart());
}
private:
friend class LogicalRect;
LogicalMargin() = delete;
#ifdef DEBUG
WritingMode GetWritingMode() const { return mWritingMode; }
#else
WritingMode GetWritingMode() const { return WritingMode::Unknown(); }
#endif
nscoord IStart() const // inline-start margin
{
return mMargin.left;
}
nscoord IEnd() const // inline-end margin
{
return mMargin.right;
}
nscoord BStart() const // block-start margin
{
return mMargin.top;
}
nscoord BEnd() const // block-end margin
{
return mMargin.bottom;
}
nscoord& IStart() // inline-start margin
{
return mMargin.left;
}
nscoord& IEnd() // inline-end margin
{
return mMargin.right;
}
nscoord& BStart() // block-start margin
{
return mMargin.top;
}
nscoord& BEnd() // block-end margin
{
return mMargin.bottom;
}
nscoord IStartEnd() const // inline margins
{
return mMargin.LeftRight();
}
nscoord BStartEnd() const // block margins
{
return mMargin.TopBottom();
}
#ifdef DEBUG
WritingMode mWritingMode;
#endif
nsMargin mMargin;
};
/**
* Flow-relative rectangle
*/
class LogicalRect {
public:
explicit LogicalRect(WritingMode aWritingMode)
:
#ifdef DEBUG
mWritingMode(aWritingMode),
#endif
mIStart(0),
mBStart(0),
mISize(0),
mBSize(0) {
}
LogicalRect(WritingMode aWritingMode, nscoord aIStart, nscoord aBStart,
nscoord aISize, nscoord aBSize)
:
#ifdef DEBUG
mWritingMode(aWritingMode),
#endif
mIStart(aIStart),
mBStart(aBStart),
mISize(aISize),
mBSize(aBSize) {
}
LogicalRect(WritingMode aWritingMode, const LogicalPoint& aOrigin,
const LogicalSize& aSize)
:
#ifdef DEBUG
mWritingMode(aWritingMode),
#endif
mIStart(aOrigin.mPoint.x),
mBStart(aOrigin.mPoint.y),
mISize(aSize.mSize.width),
mBSize(aSize.mSize.height) {
CHECK_WRITING_MODE(aOrigin.GetWritingMode());
CHECK_WRITING_MODE(aSize.GetWritingMode());
}
LogicalRect(WritingMode aWritingMode, const nsRect& aRect,
const nsSize& aContainerSize)
#ifdef DEBUG
: mWritingMode(aWritingMode)
#endif
{
if (aWritingMode.IsVertical()) {
mBStart = aWritingMode.IsVerticalLR()
? aRect.X()
: aContainerSize.width - aRect.XMost();
mIStart = aWritingMode.IsInlineReversed()
? aContainerSize.height - aRect.YMost()
: aRect.Y();
mBSize = aRect.Width();
mISize = aRect.Height();
} else {
mIStart = aWritingMode.IsInlineReversed()
? aContainerSize.width - aRect.XMost()
: aRect.X();
mBStart = aRect.Y();
mISize = aRect.Width();
mBSize = aRect.Height();
}
}
/**
* Inline- and block-dimension geometry.
*/
nscoord IStart(WritingMode aWritingMode) const // inline-start edge
{
CHECK_WRITING_MODE(aWritingMode);
return mIStart;
}
nscoord IEnd(WritingMode aWritingMode) const // inline-end edge
{
CHECK_WRITING_MODE(aWritingMode);
return mIStart + mISize;
}
nscoord ISize(WritingMode aWritingMode) const // inline-size
{
CHECK_WRITING_MODE(aWritingMode);
return mISize;
}
nscoord BStart(WritingMode aWritingMode) const // block-start edge
{
CHECK_WRITING_MODE(aWritingMode);
return mBStart;
}
nscoord BEnd(WritingMode aWritingMode) const // block-end edge
{
CHECK_WRITING_MODE(aWritingMode);
return mBStart + mBSize;
}
nscoord BSize(WritingMode aWritingMode) const // block-size
{
CHECK_WRITING_MODE(aWritingMode);
return mBSize;
}
/**
* Writable (reference) accessors are only available for the basic logical
* fields (Start and Size), not derivatives like End.
*/
nscoord& IStart(WritingMode aWritingMode) // inline-start edge
{
CHECK_WRITING_MODE(aWritingMode);
return mIStart;
}
nscoord& ISize(WritingMode aWritingMode) // inline-size
{
CHECK_WRITING_MODE(aWritingMode);
return mISize;
}
nscoord& BStart(WritingMode aWritingMode) // block-start edge
{
CHECK_WRITING_MODE(aWritingMode);
return mBStart;
}
nscoord& BSize(WritingMode aWritingMode) // block-size
{
CHECK_WRITING_MODE(aWritingMode);
return mBSize;
}
/**
* Accessors for line-relative coordinates
*/
nscoord LineLeft(WritingMode aWritingMode,
const nsSize& aContainerSize) const {
CHECK_WRITING_MODE(aWritingMode);
if (aWritingMode.IsBidiLTR()) {
return IStart();
}
nscoord containerISize = aWritingMode.IsVertical() ? aContainerSize.height
: aContainerSize.width;
return containerISize - IEnd();
}
nscoord LineRight(WritingMode aWritingMode,
const nsSize& aContainerSize) const {
CHECK_WRITING_MODE(aWritingMode);
if (aWritingMode.IsBidiLTR()) {
return IEnd();
}
nscoord containerISize = aWritingMode.IsVertical() ? aContainerSize.height
: aContainerSize.width;
return containerISize - IStart();
}
/**
* Physical coordinates of the rect.
*/
nscoord X(WritingMode aWritingMode, nscoord aContainerWidth) const {
CHECK_WRITING_MODE(aWritingMode);
if (aWritingMode.IsVertical()) {
return aWritingMode.IsVerticalLR() ? mBStart : aContainerWidth - BEnd();
}
return aWritingMode.IsInlineReversed() ? aContainerWidth - IEnd() : mIStart;
}
nscoord Y(WritingMode aWritingMode, nscoord aContainerHeight) const {
CHECK_WRITING_MODE(aWritingMode);
if (aWritingMode.IsVertical()) {
return aWritingMode.IsInlineReversed() ? aContainerHeight - IEnd()
: mIStart;
}
return mBStart;
}
nscoord Width(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical() ? mBSize : mISize;
}
nscoord Height(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return aWritingMode.IsVertical() ? mISize : mBSize;
}
nscoord XMost(WritingMode aWritingMode, nscoord aContainerWidth) const {
CHECK_WRITING_MODE(aWritingMode);
if (aWritingMode.IsVertical()) {
return aWritingMode.IsVerticalLR() ? BEnd() : aContainerWidth - mBStart;
}
return aWritingMode.IsInlineReversed() ? aContainerWidth - mIStart : IEnd();
}
nscoord YMost(WritingMode aWritingMode, nscoord aContainerHeight) const {
CHECK_WRITING_MODE(aWritingMode);
if (aWritingMode.IsVertical()) {
return aWritingMode.IsInlineReversed() ? aContainerHeight - mIStart
: IEnd();
}
return BEnd();
}
bool IsEmpty() const { return mISize <= 0 || mBSize <= 0; }
bool IsAllZero() const {
return (mIStart == 0 && mBStart == 0 && mISize == 0 && mBSize == 0);
}
bool IsZeroSize() const { return (mISize == 0 && mBSize == 0); }
void SetEmpty() { mISize = mBSize = 0; }
bool IsEqualEdges(const LogicalRect aOther) const {
CHECK_WRITING_MODE(aOther.GetWritingMode());
bool result = mIStart == aOther.mIStart && mBStart == aOther.mBStart &&
mISize == aOther.mISize && mBSize == aOther.mBSize;
// We want the same result as nsRect, so assert we get it.
MOZ_ASSERT(result ==
nsRect(mIStart, mBStart, mISize, mBSize)
.IsEqualEdges(nsRect(aOther.mIStart, aOther.mBStart,
aOther.mISize, aOther.mBSize)));
return result;
}
LogicalPoint Origin(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return LogicalPoint(aWritingMode, IStart(), BStart());
}
void SetOrigin(WritingMode aWritingMode, const LogicalPoint& aPoint) {
IStart(aWritingMode) = aPoint.I(aWritingMode);
BStart(aWritingMode) = aPoint.B(aWritingMode);
}
LogicalSize Size(WritingMode aWritingMode) const {
CHECK_WRITING_MODE(aWritingMode);
return LogicalSize(aWritingMode, ISize(), BSize());
}
LogicalRect operator+(const LogicalPoint& aPoint) const {
CHECK_WRITING_MODE(aPoint.GetWritingMode());
return LogicalRect(GetWritingMode(), IStart() + aPoint.I(),
BStart() + aPoint.B(), ISize(), BSize());
}
LogicalRect& operator+=(const LogicalPoint& aPoint) {
CHECK_WRITING_MODE(aPoint.GetWritingMode());
mIStart += aPoint.mPoint.x;
mBStart += aPoint.mPoint.y;
return *this;
}
LogicalRect operator-(const LogicalPoint& aPoint) const {
CHECK_WRITING_MODE(aPoint.GetWritingMode());
return LogicalRect(GetWritingMode(), IStart() - aPoint.I(),
BStart() - aPoint.B(), ISize(), BSize());
}
LogicalRect& operator-=(const LogicalPoint& aPoint) {
CHECK_WRITING_MODE(aPoint.GetWritingMode());
mIStart -= aPoint.mPoint.x;
mBStart -= aPoint.mPoint.y;
return *this;
}
void MoveBy(WritingMode aWritingMode, const LogicalPoint& aDelta) {
CHECK_WRITING_MODE(aWritingMode);
CHECK_WRITING_MODE(aDelta.GetWritingMode());
IStart() += aDelta.I();
BStart() += aDelta.B();
}
void Inflate(nscoord aD) {
#ifdef DEBUG
// Compute using nsRect and assert the results match
nsRect rectDebug(mIStart, mBStart, mISize, mBSize);
rectDebug.Inflate(aD);
#endif
mIStart -= aD;
mBStart -= aD;
mISize += 2 * aD;
mBSize += 2 * aD;
MOZ_ASSERT(
rectDebug.IsEqualEdges(nsRect(mIStart, mBStart, mISize, mBSize)));
}
void Inflate(nscoord aDI, nscoord aDB) {
#ifdef DEBUG
// Compute using nsRect and assert the results match
nsRect rectDebug(mIStart, mBStart, mISize, mBSize);
rectDebug.Inflate(aDI, aDB);
#endif
mIStart -= aDI;
mBStart -= aDB;
mISize += 2 * aDI;
mBSize += 2 * aDB;
MOZ_ASSERT(
rectDebug.IsEqualEdges(nsRect(mIStart, mBStart, mISize, mBSize)));
}
void Inflate(WritingMode aWritingMode, const LogicalMargin& aMargin) {
CHECK_WRITING_MODE(aWritingMode);
CHECK_WRITING_MODE(aMargin.GetWritingMode());
#ifdef DEBUG
// Compute using nsRect and assert the results match
nsRect rectDebug(mIStart, mBStart, mISize, mBSize);
rectDebug.Inflate(aMargin.mMargin);
#endif
mIStart -= aMargin.mMargin.left;
mBStart -= aMargin.mMargin.top;
mISize += aMargin.mMargin.LeftRight();
mBSize += aMargin.mMargin.TopBottom();
MOZ_ASSERT(
rectDebug.IsEqualEdges(nsRect(mIStart, mBStart, mISize, mBSize)));
}
void Deflate(nscoord aD) {
#ifdef DEBUG
// Compute using nsRect and assert the results match
nsRect rectDebug(mIStart, mBStart, mISize, mBSize);
rectDebug.Deflate(aD);
#endif
mIStart += aD;
mBStart += aD;
mISize = std::max(0, mISize - 2 * aD);
mBSize = std::max(0, mBSize - 2 * aD);
MOZ_ASSERT(
rectDebug.IsEqualEdges(nsRect(mIStart, mBStart, mISize, mBSize)));
}
void Deflate(nscoord aDI, nscoord aDB) {
#ifdef DEBUG
// Compute using nsRect and assert the results match
nsRect rectDebug(mIStart, mBStart, mISize, mBSize);
rectDebug.Deflate(aDI, aDB);
#endif
mIStart += aDI;
mBStart += aDB;
mISize = std::max(0, mISize - 2 * aDI);
mBSize = std::max(0, mBSize - 2 * aDB);
MOZ_ASSERT(
rectDebug.IsEqualEdges(nsRect(mIStart, mBStart, mISize, mBSize)));
}
void Deflate(WritingMode aWritingMode, const LogicalMargin& aMargin) {
CHECK_WRITING_MODE(aWritingMode);
CHECK_WRITING_MODE(aMargin.GetWritingMode());
#ifdef DEBUG
// Compute using nsRect and assert the results match
nsRect rectDebug(mIStart, mBStart, mISize, mBSize);
rectDebug.Deflate(aMargin.mMargin);
#endif
mIStart += aMargin.mMargin.left;
mBStart += aMargin.mMargin.top;
mISize = std::max(0, mISize - aMargin.mMargin.LeftRight());
mBSize = std::max(0, mBSize - aMargin.mMargin.TopBottom());
MOZ_ASSERT(
rectDebug.IsEqualEdges(nsRect(mIStart, mBStart, mISize, mBSize)));
}
/**
* Return an nsRect containing our physical coordinates within the given
* container size.
*/
nsRect GetPhysicalRect(WritingMode aWritingMode,
const nsSize& aContainerSize) const {
CHECK_WRITING_MODE(aWritingMode);
if (aWritingMode.IsVertical()) {
return nsRect(aWritingMode.IsVerticalLR() ? BStart()
: aContainerSize.width - BEnd(),
aWritingMode.IsInlineReversed()
? aContainerSize.height - IEnd()
: IStart(),
BSize(), ISize());
} else {
return nsRect(aWritingMode.IsInlineReversed()
? aContainerSize.width - IEnd()
: IStart(),
BStart(), ISize(), BSize());
}
}
/**
* Return a LogicalRect representing this rect in a different writing mode
*/
LogicalRect ConvertTo(WritingMode aToMode, WritingMode aFromMode,
const nsSize& aContainerSize) const {
CHECK_WRITING_MODE(aFromMode);
return aToMode == aFromMode
? *this
: LogicalRect(aToMode,
GetPhysicalRect(aFromMode, aContainerSize),
aContainerSize);
}
/**
* Set *this to be the rectangle containing the intersection of aRect1
* and aRect2, return whether the intersection is non-empty.
*/
bool IntersectRect(const LogicalRect& aRect1, const LogicalRect& aRect2) {
CHECK_WRITING_MODE(aRect1.mWritingMode);
CHECK_WRITING_MODE(aRect2.mWritingMode);
#ifdef DEBUG
// Compute using nsRect and assert the results match
nsRect rectDebug;
rectDebug.IntersectRect(
nsRect(aRect1.mIStart, aRect1.mBStart, aRect1.mISize, aRect1.mBSize),
nsRect(aRect2.mIStart, aRect2.mBStart, aRect2.mISize, aRect2.mBSize));
#endif
nscoord iEnd = std::min(aRect1.IEnd(), aRect2.IEnd());
mIStart = std::max(aRect1.mIStart, aRect2.mIStart);
mISize = iEnd - mIStart;
nscoord bEnd = std::min(aRect1.BEnd(), aRect2.BEnd());
mBStart = std::max(aRect1.mBStart, aRect2.mBStart);
mBSize = bEnd - mBStart;
if (mISize < 0 || mBSize < 0) {
mISize = 0;
mBSize = 0;
}
MOZ_ASSERT(
(rectDebug.IsEmpty() && (mISize == 0 || mBSize == 0)) ||
rectDebug.IsEqualEdges(nsRect(mIStart, mBStart, mISize, mBSize)));
return mISize > 0 && mBSize > 0;
}
private:
LogicalRect() = delete;
#ifdef DEBUG
WritingMode GetWritingMode() const { return mWritingMode; }
#else
WritingMode GetWritingMode() const { return WritingMode::Unknown(); }
#endif
nscoord IStart() const // inline-start edge
{
return mIStart;
}
nscoord IEnd() const // inline-end edge
{
return mIStart + mISize;
}
nscoord ISize() const // inline-size
{
return mISize;
}
nscoord BStart() const // block-start edge
{
return mBStart;
}
nscoord BEnd() const // block-end edge
{
return mBStart + mBSize;
}
nscoord BSize() const // block-size
{
return mBSize;
}
nscoord& IStart() // inline-start edge
{
return mIStart;
}
nscoord& ISize() // inline-size
{
return mISize;
}
nscoord& BStart() // block-start edge
{
return mBStart;
}
nscoord& BSize() // block-size
{
return mBSize;
}
#ifdef DEBUG
WritingMode mWritingMode;
#endif
// Inline- and block-geometry dimension
nscoord mIStart; // inline-start edge
nscoord mBStart; // block-start edge
nscoord mISize; // inline-size
nscoord mBSize; // block-size
};
template <typename T>
const T& StyleRect<T>::Get(mozilla::WritingMode aWM,
mozilla::LogicalSide aSide) const {
return Get(aWM.PhysicalSide(aSide));
}
template <typename T>
const T& StyleRect<T>::GetIStart(mozilla::WritingMode aWM) const {
return Get(aWM, mozilla::eLogicalSideIStart);
}
template <typename T>
const T& StyleRect<T>::GetBStart(mozilla::WritingMode aWM) const {
return Get(aWM, mozilla::eLogicalSideBStart);
}
template <typename T>
const T& StyleRect<T>::GetIEnd(mozilla::WritingMode aWM) const {
return Get(aWM, mozilla::eLogicalSideIEnd);
}
template <typename T>
const T& StyleRect<T>::GetBEnd(mozilla::WritingMode aWM) const {
return Get(aWM, mozilla::eLogicalSideBEnd);
}
} // namespace mozilla
// Definitions of inline methods for nsStyleSides, declared in nsStyleCoord.h
// but not defined there because they need WritingMode.
inline nsStyleUnit nsStyleSides::GetUnit(mozilla::WritingMode aWM,
mozilla::LogicalSide aSide) const {
return GetUnit(aWM.PhysicalSide(aSide));
}
inline nsStyleUnit nsStyleSides::GetIStartUnit(mozilla::WritingMode aWM) const {
return GetUnit(aWM, mozilla::eLogicalSideIStart);
}
inline nsStyleUnit nsStyleSides::GetBStartUnit(mozilla::WritingMode aWM) const {
return GetUnit(aWM, mozilla::eLogicalSideBStart);
}
inline nsStyleUnit nsStyleSides::GetIEndUnit(mozilla::WritingMode aWM) const {
return GetUnit(aWM, mozilla::eLogicalSideIEnd);
}
inline nsStyleUnit nsStyleSides::GetBEndUnit(mozilla::WritingMode aWM) const {
return GetUnit(aWM, mozilla::eLogicalSideBEnd);
}
inline bool nsStyleSides::HasBlockAxisAuto(mozilla::WritingMode aWM) const {
return GetBStartUnit(aWM) == eStyleUnit_Auto ||
GetBEndUnit(aWM) == eStyleUnit_Auto;
}
inline bool nsStyleSides::HasInlineAxisAuto(mozilla::WritingMode aWM) const {
return GetIStartUnit(aWM) == eStyleUnit_Auto ||
GetIEndUnit(aWM) == eStyleUnit_Auto;
}
inline nsStyleCoord nsStyleSides::Get(mozilla::WritingMode aWM,
mozilla::LogicalSide aSide) const {
return Get(aWM.PhysicalSide(aSide));
}
inline nsStyleCoord nsStyleSides::GetIStart(mozilla::WritingMode aWM) const {
return Get(aWM, mozilla::eLogicalSideIStart);
}
inline nsStyleCoord nsStyleSides::GetBStart(mozilla::WritingMode aWM) const {
return Get(aWM, mozilla::eLogicalSideBStart);
}
inline nsStyleCoord nsStyleSides::GetIEnd(mozilla::WritingMode aWM) const {
return Get(aWM, mozilla::eLogicalSideIEnd);
}
inline nsStyleCoord nsStyleSides::GetBEnd(mozilla::WritingMode aWM) const {
return Get(aWM, mozilla::eLogicalSideBEnd);
}
// Definitions of inline methods for nsStylePosition, declared in
// nsStyleStruct.h but not defined there because they need WritingMode.
inline const mozilla::StyleSize& nsStylePosition::ISize(WritingMode aWM) const {
return aWM.IsVertical() ? mHeight : mWidth;
}
inline const mozilla::StyleSize& nsStylePosition::MinISize(
WritingMode aWM) const {
return aWM.IsVertical() ? mMinHeight : mMinWidth;
}
inline const mozilla::StyleMaxSize& nsStylePosition::MaxISize(
WritingMode aWM) const {
return aWM.IsVertical() ? mMaxHeight : mMaxWidth;
}
inline const mozilla::StyleSize& nsStylePosition::BSize(WritingMode aWM) const {
return aWM.IsVertical() ? mWidth : mHeight;
}
inline const mozilla::StyleSize& nsStylePosition::MinBSize(
WritingMode aWM) const {
return aWM.IsVertical() ? mMinWidth : mMinHeight;
}
inline const mozilla::StyleMaxSize& nsStylePosition::MaxBSize(
WritingMode aWM) const {
return aWM.IsVertical() ? mMaxWidth : mMaxHeight;
}
inline bool nsStylePosition::ISizeDependsOnContainer(WritingMode aWM) const {
const auto& iSize = ISize(aWM);
return iSize.IsAuto() || ISizeCoordDependsOnContainer(iSize);
}
inline bool nsStylePosition::MinISizeDependsOnContainer(WritingMode aWM) const {
// NOTE: For a flex item, "min-inline-size:auto" is supposed to behave like
// "min-content", which does depend on the container, so you might think we'd
// need a special case for "flex item && min-inline-size:auto" here. However,
// we don't actually need that special-case code, because flex items are
// explicitly supposed to *ignore* their min-inline-size (i.e. behave like
// it's 0) until the flex container explicitly considers it. So -- since the
// flex container doesn't rely on this method, we don't need to worry about
// special behavior for flex items' "min-inline-size:auto" values here.
return ISizeCoordDependsOnContainer(MinISize(aWM));
}
inline bool nsStylePosition::MaxISizeDependsOnContainer(WritingMode aWM) const {
// NOTE: The comment above MinISizeDependsOnContainer about flex items
// applies here, too.
return ISizeCoordDependsOnContainer(MaxISize(aWM));
}
// Note that these functions count `auto` as depending on the container
// since that's the case for absolutely positioned elements.
// However, some callers do not care about this case and should check
// for it, since it is the most common case.
// FIXME: We should probably change the assumption to be the other way
// around.
inline bool nsStylePosition::BSizeDependsOnContainer(WritingMode aWM) const {
const auto& bSize = BSize(aWM);
return bSize.BehavesLikeInitialValueOnBlockAxis() ||
BSizeCoordDependsOnContainer(bSize);
}
inline bool nsStylePosition::MinBSizeDependsOnContainer(WritingMode aWM) const {
return BSizeCoordDependsOnContainer(MinBSize(aWM));
}
inline bool nsStylePosition::MaxBSizeDependsOnContainer(WritingMode aWM) const {
return BSizeCoordDependsOnContainer(MaxBSize(aWM));
}
inline bool nsStyleMargin::HasBlockAxisAuto(mozilla::WritingMode aWM) const {
return mMargin.GetBStart(aWM).IsAuto() || mMargin.GetBEnd(aWM).IsAuto();
}
inline bool nsStyleMargin::HasInlineAxisAuto(mozilla::WritingMode aWM) const {
return mMargin.GetIStart(aWM).IsAuto() || mMargin.GetIEnd(aWM).IsAuto();
}
#endif // WritingModes_h_