1 files changed, 204 insertions, 0 deletions
diff --git a/dom/smil/nsSMILCompositor.cpp b/dom/smil/nsSMILCompositor.cpp
new file mode 100644
index 000000000..fe7b2c828
--- /dev/null
+++ b/dom/smil/nsSMILCompositor.cpp
@@ -0,0 +1,204 @@
+/* -*- 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 "nsCSSProps.h"
+#include "nsHashKeys.h"
+#include "nsSMILCSSProperty.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(bool& aMightHavePendingStyleUpdates)
+{
+  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();
+    // Removing the animation effect may require a style update.
+    aMightHavePendingStyleUpdates = true;
+    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
+  aMightHavePendingStyleUpdates = true;
+  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) {
+    nsCSSPropertyID propId =
+      nsCSSProps::LookupProperty(nsDependentAtomString(mKey.mAttributeName),
+                                 CSSEnabledState::eForAllContent);
+    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()
+{
+  // For performance reasons, we throttle most animations on elements in
+  // display:none subtrees. (We can't throttle animations that target the
+  // "display" property itself, though -- if we did, display:none elements
+  // could never be dynamically displayed via animations.)
+  // To determine whether we're in a display:none subtree, we will check the
+  // element's primary frame since element in display:none subtree doesn't have
+  // a primary frame. Before this process, we will construct frame when we
+  // append an element to subtree. So we will not need to worry about pending
+  // frame construction in this step.
+  bool canThrottle = mKey.mAttributeName != nsGkAtoms::display &&
+                     !mKey.mElement->GetPrimaryFrame();
+
+  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() && !canThrottle) ||
+      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_WARNING_ASSERTION(mCachedBaseValue, "failed to cache base value (OOM?)");
+    mForceCompositing = true;
+  } else if (*mCachedBaseValue != aBaseValue) {
+    // Base value has changed since last sample.
+    *mCachedBaseValue = aBaseValue;
+    mForceCompositing = true;
+  }
+}