gecko/dom/smil/nsSMILCompositor.cpp
2015-05-03 15:32:37 -04:00

188 lines
5.7 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 "nsSMILCompositor.h"
#include "nsSMILCSSProperty.h"
#include "nsCSSProps.h"
#include "nsHashKeys.h"
// PLDHashEntryHdr methods
bool
nsSMILCompositor::KeyEquals(KeyTypePointer aKey) const
{
return aKey && aKey->Equals(mKey);
}
/*static*/ PLDHashNumber
nsSMILCompositor::HashKey(KeyTypePointer aKey)
{
// Combine the 3 values into one numeric value, which will be hashed.
// NOTE: We right-shift one of the pointers by 2 to get some randomness in
// its 2 lowest-order bits. (Those shifted-off bits will always be 0 since
// our pointers will be word-aligned.)
return (NS_PTR_TO_UINT32(aKey->mElement.get()) >> 2) +
NS_PTR_TO_UINT32(aKey->mAttributeName.get()) +
(aKey->mIsCSS ? 1 : 0);
}
// Cycle-collection support
void
nsSMILCompositor::Traverse(nsCycleCollectionTraversalCallback* aCallback)
{
if (!mKey.mElement)
return;
NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback, "Compositor mKey.mElement");
aCallback->NoteXPCOMChild(mKey.mElement);
}
// Other methods
void
nsSMILCompositor::AddAnimationFunction(nsSMILAnimationFunction* aFunc)
{
if (aFunc) {
mAnimationFunctions.AppendElement(aFunc);
}
}
void
nsSMILCompositor::ComposeAttribute()
{
if (!mKey.mElement)
return;
// FIRST: Get the nsISMILAttr (to grab base value from, and to eventually
// give animated value to)
nsAutoPtr<nsISMILAttr> smilAttr(CreateSMILAttr());
if (!smilAttr) {
// Target attribute not found (or, out of memory)
return;
}
if (mAnimationFunctions.IsEmpty()) {
// No active animation functions. (We can still have a nsSMILCompositor in
// that case if an animation function has *just* become inactive)
smilAttr->ClearAnimValue();
return;
}
// SECOND: Sort the animationFunctions, to prepare for compositing.
nsSMILAnimationFunction::Comparator comparator;
mAnimationFunctions.Sort(comparator);
// THIRD: Step backwards through animation functions to find out
// which ones we actually care about.
uint32_t firstFuncToCompose = GetFirstFuncToAffectSandwich();
// FOURTH: Get & cache base value
nsSMILValue sandwichResultValue;
if (!mAnimationFunctions[firstFuncToCompose]->WillReplace()) {
sandwichResultValue = smilAttr->GetBaseValue();
}
UpdateCachedBaseValue(sandwichResultValue);
if (!mForceCompositing) {
return;
}
// FIFTH: Compose animation functions
uint32_t length = mAnimationFunctions.Length();
for (uint32_t i = firstFuncToCompose; i < length; ++i) {
mAnimationFunctions[i]->ComposeResult(*smilAttr, sandwichResultValue);
}
if (sandwichResultValue.IsNull()) {
smilAttr->ClearAnimValue();
return;
}
// SIXTH: Set the animated value to the final composited result.
nsresult rv = smilAttr->SetAnimValue(sandwichResultValue);
if (NS_FAILED(rv)) {
NS_WARNING("nsISMILAttr::SetAnimValue failed");
}
}
void
nsSMILCompositor::ClearAnimationEffects()
{
if (!mKey.mElement || !mKey.mAttributeName)
return;
nsAutoPtr<nsISMILAttr> smilAttr(CreateSMILAttr());
if (!smilAttr) {
// Target attribute not found (or, out of memory)
return;
}
smilAttr->ClearAnimValue();
}
// Protected Helper Functions
// --------------------------
nsISMILAttr*
nsSMILCompositor::CreateSMILAttr()
{
if (mKey.mIsCSS) {
nsCSSProperty propId =
nsCSSProps::LookupProperty(nsDependentAtomString(mKey.mAttributeName),
nsCSSProps::eEnabledForAllContent);
if (nsSMILCSSProperty::IsPropertyAnimatable(propId)) {
return new nsSMILCSSProperty(propId, mKey.mElement.get());
}
} else {
return mKey.mElement->GetAnimatedAttr(mKey.mAttributeNamespaceID,
mKey.mAttributeName);
}
return nullptr;
}
uint32_t
nsSMILCompositor::GetFirstFuncToAffectSandwich()
{
uint32_t i;
for (i = mAnimationFunctions.Length(); i > 0; --i) {
nsSMILAnimationFunction* curAnimFunc = mAnimationFunctions[i-1];
// In the following, the lack of short-circuit behavior of |= means that we
// will ALWAYS run UpdateCachedTarget (even if mForceCompositing is true)
// but only call HasChanged and WasSkippedInPrevSample if necessary. This
// is important since we need UpdateCachedTarget to run in order to detect
// changes to the target in subsequent samples.
mForceCompositing |=
curAnimFunc->UpdateCachedTarget(mKey) ||
curAnimFunc->HasChanged() ||
curAnimFunc->WasSkippedInPrevSample();
if (curAnimFunc->WillReplace()) {
--i;
break;
}
}
// Mark remaining animation functions as having been skipped so if we later
// use them we'll know to force compositing.
// Note that we only really need to do this if something has changed
// (otherwise we would have set the flag on a previous sample) and if
// something has changed mForceCompositing will be true.
if (mForceCompositing) {
for (uint32_t j = i; j > 0; --j) {
mAnimationFunctions[j-1]->SetWasSkipped();
}
}
return i;
}
void
nsSMILCompositor::UpdateCachedBaseValue(const nsSMILValue& aBaseValue)
{
if (!mCachedBaseValue) {
// We don't have last sample's base value cached. Assume it's changed.
mCachedBaseValue = new nsSMILValue(aBaseValue);
NS_WARN_IF_FALSE(mCachedBaseValue, "failed to cache base value (OOM?)");
mForceCompositing = true;
} else if (*mCachedBaseValue != aBaseValue) {
// Base value has changed since last sample.
*mCachedBaseValue = aBaseValue;
mForceCompositing = true;
}
}