gecko-dev/dom/grid/GridLines.cpp

265 строки
8.7 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/. */
#include "GridLines.h"
#include "GridDimension.h"
#include "GridLine.h"
#include "mozilla/dom/GridBinding.h"
#include "nsGridContainerFrame.h"
namespace mozilla {
namespace dom {
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(GridLines, mParent, mLines)
NS_IMPL_CYCLE_COLLECTING_ADDREF(GridLines)
NS_IMPL_CYCLE_COLLECTING_RELEASE(GridLines)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(GridLines)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
GridLines::GridLines(GridDimension* aParent)
: mParent(aParent)
{
MOZ_ASSERT(aParent,
"Should never be instantiated with a null GridDimension");
}
GridLines::~GridLines()
{
}
JSObject*
GridLines::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
return GridLinesBinding::Wrap(aCx, this, aGivenProto);
}
uint32_t
GridLines::Length() const
{
return mLines.Length();
}
GridLine*
GridLines::Item(uint32_t aIndex)
{
return mLines.SafeElementAt(aIndex);
}
GridLine*
GridLines::IndexedGetter(uint32_t aIndex,
bool& aFound)
{
aFound = aIndex < mLines.Length();
if (!aFound) {
return nullptr;
}
return mLines[aIndex];
}
void
GridLines::SetLineInfo(const ComputedGridTrackInfo* aTrackInfo,
const ComputedGridLineInfo* aLineInfo,
const nsTArray<RefPtr<GridArea>>& aAreas,
bool aIsRow)
{
MOZ_ASSERT(aLineInfo);
mLines.Clear();
if (!aTrackInfo) {
return;
}
uint32_t trackCount = aTrackInfo->mEndFragmentTrack -
aTrackInfo->mStartFragmentTrack;
// If there is at least one track, line count is one more
// than the number of tracks.
if (trackCount > 0) {
nscoord lastTrackEdge = 0;
nscoord startOfNextTrack;
uint32_t repeatIndex = 0;
uint32_t numRepeatTracks = aTrackInfo->mRemovedRepeatTracks.Length();
uint32_t numAddedLines = 0;
for (uint32_t i = aTrackInfo->mStartFragmentTrack;
i < aTrackInfo->mEndFragmentTrack + 1;
i++) {
// Since line indexes are 1-based, calculate a 1-based value
// for this track to simplify some calculations.
const uint32_t line1Index = i + 1;
startOfNextTrack = (i < aTrackInfo->mEndFragmentTrack) ?
aTrackInfo->mPositions[i] :
lastTrackEdge;
nsTArray<nsString> lineNames;
lineNames = aLineInfo->mNames.SafeElementAt(i, nsTArray<nsString>());
// Add in names from grid areas where this line is used as a boundary.
for (auto area : aAreas) {
bool haveNameToAdd = false;
nsAutoString nameToAdd;
area->GetName(nameToAdd);
if (aIsRow) {
if (area->RowStart() == line1Index) {
haveNameToAdd = true;
nameToAdd.AppendLiteral("-start");
} else if (area->RowEnd() == line1Index) {
haveNameToAdd = true;
nameToAdd.AppendLiteral("-end");
}
} else {
if (area->ColumnStart() == line1Index) {
haveNameToAdd = true;
nameToAdd.AppendLiteral("-start");
} else if (area->ColumnEnd() == line1Index) {
haveNameToAdd = true;
nameToAdd.AppendLiteral("-end");
}
}
if (haveNameToAdd && !lineNames.Contains(nameToAdd)) {
lineNames.AppendElement(nameToAdd);
}
}
if (i >= aTrackInfo->mRepeatFirstTrack &&
repeatIndex < numRepeatTracks) {
numAddedLines += AppendRemovedAutoFits(aTrackInfo,
aLineInfo,
lastTrackEdge,
repeatIndex,
numRepeatTracks,
lineNames);
}
RefPtr<GridLine> line = new GridLine(this);
mLines.AppendElement(line);
MOZ_ASSERT(line1Index > 0, "line1Index must be positive.");
bool isBeforeFirstExplicit =
(line1Index <= aTrackInfo->mNumLeadingImplicitTracks);
// Calculate an actionable line number for this line, that could be used
// in a css grid property to align a grid item or area at that line.
// For implicit lines that appear before line 1, report a number of 0.
// We can't report negative indexes, because those have a different
// meaning in the css grid spec (negative indexes are negative-1-based
// from the end of the grid decreasing towards the front).
uint32_t lineNumber = isBeforeFirstExplicit ? 0 :
(line1Index - aTrackInfo->mNumLeadingImplicitTracks + numAddedLines);
GridDeclaration lineType =
(isBeforeFirstExplicit ||
line1Index > (aTrackInfo->mNumLeadingImplicitTracks +
aTrackInfo->mNumExplicitTracks + 1))
? GridDeclaration::Implicit
: GridDeclaration::Explicit;
line->SetLineValues(
lineNames,
nsPresContext::AppUnitsToDoubleCSSPixels(lastTrackEdge),
nsPresContext::AppUnitsToDoubleCSSPixels(startOfNextTrack -
lastTrackEdge),
lineNumber,
lineType
);
if (i < aTrackInfo->mEndFragmentTrack) {
lastTrackEdge = aTrackInfo->mPositions[i] + aTrackInfo->mSizes[i];
}
}
}
}
uint32_t
GridLines::AppendRemovedAutoFits(const ComputedGridTrackInfo* aTrackInfo,
const ComputedGridLineInfo* aLineInfo,
nscoord aLastTrackEdge,
uint32_t& aRepeatIndex,
uint32_t aNumRepeatTracks,
nsTArray<nsString>& aLineNames)
{
// Check to see if lineNames contains ALL of the before line names.
bool alreadyHasBeforeLineNames = true;
for (const auto& beforeName : aLineInfo->mNamesBefore) {
if (!aLineNames.Contains(beforeName)) {
alreadyHasBeforeLineNames = false;
break;
}
}
bool extractedExplicitLineNames = false;
nsTArray<nsString> explicitLineNames;
uint32_t linesAdded = 0;
while (aRepeatIndex < aNumRepeatTracks &&
aTrackInfo->mRemovedRepeatTracks[aRepeatIndex]) {
// If this is not the very first call to this function, and if we
// haven't already added a line this call, pull all the explicit
// names to pass along to the next line that will be added after
// this function completes.
if (aRepeatIndex > 0 &&
linesAdded == 0) {
// Find the names that didn't match the before or after names,
// and extract them.
for (const auto& name : aLineNames) {
if (!aLineInfo->mNamesBefore.Contains(name) &&
!aLineInfo->mNamesAfter.Contains(name)) {
explicitLineNames.AppendElement(name);
}
}
for (const auto& extractedName : explicitLineNames) {
aLineNames.RemoveElement(extractedName);
}
extractedExplicitLineNames = true;
}
// If this is the second or later time through, or didn't already
// have before names, add them.
if (linesAdded > 0 || !alreadyHasBeforeLineNames) {
aLineNames.AppendElements(aLineInfo->mNamesBefore);
}
RefPtr<GridLine> line = new GridLine(this);
mLines.AppendElement(line);
MOZ_ASSERT(aTrackInfo->mRepeatFirstTrack >=
aTrackInfo->mNumLeadingImplicitTracks,
"We shouldn't have a repeat track within the implicit tracks.");
uint32_t lineNumber = aTrackInfo->mRepeatFirstTrack -
aTrackInfo->mNumLeadingImplicitTracks + aRepeatIndex + 1;
line->SetLineValues(
aLineNames,
nsPresContext::AppUnitsToDoubleCSSPixels(aLastTrackEdge),
nsPresContext::AppUnitsToDoubleCSSPixels(0),
lineNumber,
GridDeclaration::Explicit
);
// No matter what, the next line should have the after names associated
// with it. If we go through the loop again, the before names will also
// be added.
aLineNames = aLineInfo->mNamesAfter;
aRepeatIndex++;
linesAdded++;
}
aRepeatIndex++;
if (extractedExplicitLineNames) {
// Pass on the explicit names we saved to the next explicit line.
aLineNames.AppendElements(explicitLineNames);
}
if (alreadyHasBeforeLineNames && linesAdded > 0) {
// If we started with before names, pass them on to the next explicit
// line.
aLineNames.AppendElements(aLineInfo->mNamesBefore);
}
return linesAdded;
}
} // namespace dom
} // namespace mozilla