gecko-dev/dom/svg/DOMSVGTransformList.cpp

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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 "DOMSVGTransformList.h"
#include "mozilla/dom/SVGTransform.h"
#include "mozilla/dom/SVGMatrix.h"
#include "nsSVGAnimatedTransformList.h"
#include "nsSVGElement.h"
#include "mozilla/dom/SVGTransformListBinding.h"
#include "nsError.h"
#include <algorithm>
// local helper functions
namespace {
void UpdateListIndicesFromIndex(
FallibleTArray<mozilla::dom::SVGTransform*>& aItemsArray,
uint32_t aStartingIndex)
{
uint32_t length = aItemsArray.Length();
for (uint32_t i = aStartingIndex; i < length; ++i) {
if (aItemsArray[i]) {
aItemsArray[i]->UpdateListIndex(i);
}
}
}
} // namespace
namespace mozilla {
using namespace dom;
// We could use NS_IMPL_CYCLE_COLLECTION(, except that in Unlink() we need to
// clear our SVGAnimatedTransformList's weak ref to us to be safe. (The other
// option would be to not unlink and rely on the breaking of the other edges in
// the cycle, as NS_SVG_VAL_IMPL_CYCLE_COLLECTION does.)
NS_IMPL_CYCLE_COLLECTION_CLASS(DOMSVGTransformList)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(DOMSVGTransformList)
if (tmp->mAList) {
if (tmp->IsAnimValList()) {
tmp->mAList->mAnimVal = nullptr;
} else {
tmp->mAList->mBaseVal = nullptr;
}
NS_IMPL_CYCLE_COLLECTION_UNLINK(mAList)
}
NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(DOMSVGTransformList)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAList)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(DOMSVGTransformList)
NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_CYCLE_COLLECTING_ADDREF(DOMSVGTransformList)
NS_IMPL_CYCLE_COLLECTING_RELEASE(DOMSVGTransformList)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DOMSVGTransformList)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
//----------------------------------------------------------------------
// DOMSVGTransformList methods:
JSObject*
DOMSVGTransformList::WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto)
{
return mozilla::dom::SVGTransformList_Binding::Wrap(cx, this, aGivenProto);
}
//----------------------------------------------------------------------
// Helper class: AutoChangeTransformListNotifier
// Stack-based helper class to pair calls to WillChangeTransformList and
// DidChangeTransformList.
class MOZ_RAII AutoChangeTransformListNotifier
{
public:
explicit AutoChangeTransformListNotifier(DOMSVGTransformList* aTransformList MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: mTransformList(aTransformList)
{
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
MOZ_ASSERT(mTransformList, "Expecting non-null transformList");
mEmptyOrOldValue =
mTransformList->Element()->WillChangeTransformList();
}
~AutoChangeTransformListNotifier()
{
mTransformList->Element()->DidChangeTransformList(mEmptyOrOldValue);
if (mTransformList->IsAnimating()) {
mTransformList->Element()->AnimationNeedsResample();
}
}
private:
DOMSVGTransformList* const mTransformList;
nsAttrValue mEmptyOrOldValue;
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
void
DOMSVGTransformList::InternalListLengthWillChange(uint32_t aNewLength)
{
uint32_t oldLength = mItems.Length();
if (aNewLength > SVGTransform::MaxListIndex()) {
// It's safe to get out of sync with our internal list as long as we have
// FEWER items than it does.
aNewLength = SVGTransform::MaxListIndex();
}
RefPtr<DOMSVGTransformList> kungFuDeathGrip;
if (aNewLength < oldLength) {
// RemovingFromList() might clear last reference to |this|.
// Retain a temporary reference to keep from dying before returning.
kungFuDeathGrip = this;
}
// If our length will decrease, notify the items that will be removed:
for (uint32_t i = aNewLength; i < oldLength; ++i) {
if (mItems[i]) {
mItems[i]->RemovingFromList();
}
}
if (!mItems.SetLength(aNewLength, fallible)) {
// We silently ignore SetLength OOM failure since being out of sync is safe
// so long as we have *fewer* items than our internal list.
mItems.Clear();
return;
}
// If our length has increased, null out the new pointers:
for (uint32_t i = oldLength; i < aNewLength; ++i) {
mItems[i] = nullptr;
}
}
SVGTransformList&
DOMSVGTransformList::InternalList() const
{
nsSVGAnimatedTransformList *alist = Element()->GetAnimatedTransformList();
return IsAnimValList() && alist->mAnimVal ?
*alist->mAnimVal :
alist->mBaseVal;
}
//----------------------------------------------------------------------
void
DOMSVGTransformList::Clear(ErrorResult& error)
{
if (IsAnimValList()) {
error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return;
}
if (LengthNoFlush() > 0) {
AutoChangeTransformListNotifier notifier(this);
// Notify any existing DOM items of removal *before* truncating the lists
// so that they can find their SVGTransform internal counterparts and copy
// their values. This also notifies the animVal list:
mAList->InternalBaseValListWillChangeLengthTo(0);
mItems.Clear();
InternalList().Clear();
}
}
already_AddRefed<SVGTransform>
DOMSVGTransformList::Initialize(SVGTransform& newItem, ErrorResult& error)
{
if (IsAnimValList()) {
error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return nullptr;
}
// If newItem is already in a list we should insert a clone of newItem, and
// for consistency, this should happen even if *this* is the list that
// newItem is currently in. Note that in the case of newItem being in this
// list, the Clear() call before the InsertItemBefore() call would remove it
// from this list, and so the InsertItemBefore() call would not insert a
// clone of newItem, it would actually insert newItem. To prevent that from
// happening we have to do the clone here, if necessary.
RefPtr<SVGTransform> domItem = &newItem;
if (domItem->HasOwner()) {
domItem = newItem.Clone();
}
Clear(error);
MOZ_ASSERT(!error.Failed(), "How could this fail?");
return InsertItemBefore(*domItem, 0, error);
}
already_AddRefed<SVGTransform>
DOMSVGTransformList::GetItem(uint32_t index, ErrorResult& error)
{
bool found;
RefPtr<SVGTransform> item = IndexedGetter(index, found, error);
if (!found) {
error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
}
return item.forget();
}
already_AddRefed<SVGTransform>
DOMSVGTransformList::IndexedGetter(uint32_t index, bool& found,
ErrorResult& error)
{
if (IsAnimValList()) {
Element()->FlushAnimations();
}
found = index < LengthNoFlush();
if (found) {
return GetItemAt(index);
}
return nullptr;
}
already_AddRefed<SVGTransform>
DOMSVGTransformList::InsertItemBefore(SVGTransform& newItem,
uint32_t index, ErrorResult& error)
{
if (IsAnimValList()) {
error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return nullptr;
}
index = std::min(index, LengthNoFlush());
if (index >= SVGTransform::MaxListIndex()) {
error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
RefPtr<SVGTransform> domItem = &newItem;
if (newItem.HasOwner()) {
domItem = newItem.Clone(); // must do this before changing anything!
}
// Ensure we have enough memory so we can avoid complex error handling below:
if (!mItems.SetCapacity(mItems.Length() + 1, fallible) ||
!InternalList().SetCapacity(InternalList().Length() + 1)) {
error.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
if (AnimListMirrorsBaseList()) {
if (!mAList->mAnimVal->mItems.SetCapacity(
mAList->mAnimVal->mItems.Length() + 1, fallible)) {
error.Throw(NS_ERROR_OUT_OF_MEMORY);
return nullptr;
}
}
AutoChangeTransformListNotifier notifier(this);
// Now that we know we're inserting, keep animVal list in sync as necessary.
MaybeInsertNullInAnimValListAt(index);
InternalList().InsertItem(index, domItem->ToSVGTransform());
MOZ_ALWAYS_TRUE(mItems.InsertElementAt(index, domItem.get(), fallible));
// This MUST come after the insertion into InternalList(), or else under the
// insertion into InternalList() the values read from domItem would be bad
// data from InternalList() itself!:
domItem->InsertingIntoList(this, index, IsAnimValList());
UpdateListIndicesFromIndex(mItems, index + 1);
return domItem.forget();
}
already_AddRefed<SVGTransform>
DOMSVGTransformList::ReplaceItem(SVGTransform& newItem,
uint32_t index, ErrorResult& error)
{
if (IsAnimValList()) {
error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return nullptr;
}
if (index >= LengthNoFlush()) {
error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
RefPtr<SVGTransform> domItem = &newItem;
if (newItem.HasOwner()) {
domItem = newItem.Clone(); // must do this before changing anything!
}
AutoChangeTransformListNotifier notifier(this);
if (mItems[index]) {
// Notify any existing DOM item of removal *before* modifying the lists so
// that the DOM item can copy the *old* value at its index:
mItems[index]->RemovingFromList();
}
InternalList()[index] = domItem->ToSVGTransform();
mItems[index] = domItem;
// This MUST come after the ToSVGPoint() call, otherwise that call
// would end up reading bad data from InternalList()!
domItem->InsertingIntoList(this, index, IsAnimValList());
return domItem.forget();
}
already_AddRefed<SVGTransform>
DOMSVGTransformList::RemoveItem(uint32_t index, ErrorResult& error)
{
if (IsAnimValList()) {
error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return nullptr;
}
if (index >= LengthNoFlush()) {
error.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
return nullptr;
}
AutoChangeTransformListNotifier notifier(this);
// Now that we know we're removing, keep animVal list in sync as necessary.
// Do this *before* touching InternalList() so the removed item can get its
// internal value.
MaybeRemoveItemFromAnimValListAt(index);
// We have to return the removed item, so get it, creating it if necessary:
RefPtr<SVGTransform> result = GetItemAt(index);
// Notify the DOM item of removal *before* modifying the lists so that the
// DOM item can copy its *old* value:
result->RemovingFromList();
InternalList().RemoveItem(index);
mItems.RemoveElementAt(index);
UpdateListIndicesFromIndex(mItems, index);
return result.forget();
}
already_AddRefed<SVGTransform>
DOMSVGTransformList::CreateSVGTransformFromMatrix(dom::SVGMatrix& matrix)
{
RefPtr<SVGTransform> result = new SVGTransform(matrix.GetMatrix());
return result.forget();
}
already_AddRefed<SVGTransform>
DOMSVGTransformList::Consolidate(ErrorResult& error)
{
if (IsAnimValList()) {
error.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
return nullptr;
}
if (LengthNoFlush() == 0) {
return nullptr;
}
// Note that SVG 1.1 says, "The consolidation operation creates new
// SVGTransform object as the first and only item in the list" hence, even if
// LengthNoFlush() == 1 we can't return that one item (after making it a
// matrix type). We must orphan the existing item and then make a new one.
// First calculate our matrix
gfxMatrix mx = InternalList().GetConsolidationMatrix();
// Then orphan the existing items
Clear(error);
MOZ_ASSERT(!error.Failed(), "How could this fail?");
// And append the new transform
RefPtr<SVGTransform> transform = new SVGTransform(mx);
return InsertItemBefore(*transform, LengthNoFlush(), error);
}
//----------------------------------------------------------------------
// Implementation helpers:
already_AddRefed<SVGTransform>
DOMSVGTransformList::GetItemAt(uint32_t aIndex)
{
MOZ_ASSERT(aIndex < mItems.Length());
if (!mItems[aIndex]) {
mItems[aIndex] = new SVGTransform(this, aIndex, IsAnimValList());
}
RefPtr<SVGTransform> result = mItems[aIndex];
return result.forget();
}
void
DOMSVGTransformList::MaybeInsertNullInAnimValListAt(uint32_t aIndex)
{
MOZ_ASSERT(!IsAnimValList(), "call from baseVal to animVal");
if (!AnimListMirrorsBaseList()) {
return;
}
DOMSVGTransformList* animVal = mAList->mAnimVal;
MOZ_ASSERT(animVal, "AnimListMirrorsBaseList() promised a non-null animVal");
MOZ_ASSERT(animVal->mItems.Length() == mItems.Length(),
"animVal list not in sync!");
MOZ_ALWAYS_TRUE(animVal->mItems.InsertElementAt(aIndex, nullptr, fallible));
UpdateListIndicesFromIndex(animVal->mItems, aIndex + 1);
}
void
DOMSVGTransformList::MaybeRemoveItemFromAnimValListAt(uint32_t aIndex)
{
MOZ_ASSERT(!IsAnimValList(), "call from baseVal to animVal");
if (!AnimListMirrorsBaseList()) {
return;
}
// This needs to be a strong reference; otherwise, the RemovingFromList call
// below might drop the last reference to animVal before we're done with it.
RefPtr<DOMSVGTransformList> animVal = mAList->mAnimVal;
MOZ_ASSERT(animVal, "AnimListMirrorsBaseList() promised a non-null animVal");
MOZ_ASSERT(animVal->mItems.Length() == mItems.Length(),
"animVal list not in sync!");
if (animVal->mItems[aIndex]) {
animVal->mItems[aIndex]->RemovingFromList();
}
animVal->mItems.RemoveElementAt(aIndex);
UpdateListIndicesFromIndex(animVal->mItems, aIndex);
}
} // namespace mozilla