gecko-dev/dom/grid/Grid.cpp
Brad Werth 4a8b9977c8 Bug 1815140 Part 1: Make Grid dom object an idempotent property of its frame. r=emilio
This ensures that repeated calls to Element::GetGridFragments will return
an array of idempotent Grid objects for each fragment. This is
accomplished by making the Grid object hold a WeakFrame back to its
originating frame, and updating a property on construction and
destruction.

Differential Revision: https://phabricator.services.mozilla.com/D169724
2023-02-23 01:07:34 +00:00

120 lines
4.2 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 "Grid.h"
#include "GridArea.h"
#include "GridDimension.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/GridBinding.h"
#include "nsGridContainerFrame.h"
#include "nsTHashSet.h"
namespace mozilla::dom {
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(Grid)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(Grid)
tmp->ForgetFrame();
NS_IMPL_CYCLE_COLLECTION_UNLINK(mParent, mRows, mCols, mAreas)
NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(Grid)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParent, mRows, mCols, mAreas)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTING_ADDREF(Grid)
NS_IMPL_CYCLE_COLLECTING_RELEASE(Grid)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(Grid)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
Grid::Grid(nsISupports* aParent, nsGridContainerFrame* aFrame)
: mParent(do_QueryInterface(aParent)),
mFrame(aFrame),
mRows(new GridDimension(this)),
mCols(new GridDimension(this)) {
MOZ_ASSERT(aFrame,
"Should never be instantiated with a null nsGridContainerFrame");
aFrame->SetProperty(nsGridContainerFrame::GridFragmentInfo(), this);
// Construct areas first, because lines may need to reference them
// to extract additional names for boundary lines.
// Add implicit areas first. Track the names that we add here, because
// we will ignore future explicit areas with the same name.
nsTHashSet<RefPtr<nsAtom>> namesSeen;
nsGridContainerFrame::ImplicitNamedAreas* implicitAreas =
aFrame->GetImplicitNamedAreas();
if (implicitAreas) {
for (auto iter = implicitAreas->iter(); !iter.done(); iter.next()) {
auto& areaInfo = iter.get().value();
namesSeen.Insert(areaInfo.name.AsAtom());
GridArea* area =
new GridArea(this, areaInfo.name.AsAtom(), GridDeclaration::Implicit,
areaInfo.rows.start, areaInfo.rows.end,
areaInfo.columns.start, areaInfo.columns.end);
mAreas.AppendElement(area);
}
}
// Add explicit areas next, as long as they don't have the same name
// as the implicit areas, because the implicit values override what was
// initially available in the explicit areas.
if (auto* explicitAreas = aFrame->GetExplicitNamedAreas()) {
for (auto& areaInfo : explicitAreas->AsSpan()) {
if (!namesSeen.Contains(areaInfo.name.AsAtom())) {
GridArea* area = new GridArea(
this, areaInfo.name.AsAtom(), GridDeclaration::Explicit,
areaInfo.rows.start, areaInfo.rows.end, areaInfo.columns.start,
areaInfo.columns.end);
mAreas.AppendElement(area);
}
}
}
// Now construct the tracks and lines.
const ComputedGridTrackInfo* rowTrackInfo = aFrame->GetComputedTemplateRows();
const ComputedGridLineInfo* rowLineInfo =
aFrame->GetComputedTemplateRowLines();
mRows->SetTrackInfo(rowTrackInfo);
mRows->SetLineInfo(rowTrackInfo, rowLineInfo, mAreas, true);
const ComputedGridTrackInfo* columnTrackInfo =
aFrame->GetComputedTemplateColumns();
const ComputedGridLineInfo* columnLineInfo =
aFrame->GetComputedTemplateColumnLines();
mCols->SetTrackInfo(columnTrackInfo);
mCols->SetLineInfo(columnTrackInfo, columnLineInfo, mAreas, false);
}
Grid::~Grid() = default;
JSObject* Grid::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
return Grid_Binding::Wrap(aCx, this, aGivenProto);
}
void Grid::ForgetFrame() {
if (mFrame.IsAlive()) {
mFrame->RemoveProperty(nsGridContainerFrame::GridFragmentInfo());
mFrame.Clear(mFrame->PresContext()->GetPresShell());
}
}
GridDimension* Grid::Rows() const { return mRows; }
GridDimension* Grid::Cols() const { return mCols; }
void Grid::GetAreas(nsTArray<RefPtr<GridArea>>& aAreas) const {
aAreas = mAreas.Clone();
}
} // namespace mozilla::dom