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/* -*- 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 */
#include "nsCSSPropertyID.h"
class nsIFrame;
class nsIContent;
class nsCSSPropertyIDSet;
class nsDOMCSSDeclaration;
namespace mozilla {
class nsDisplayListBuilder;
* This class receives various notifications about style changes and content
* changes that affect layerization decisions, and implements the heuristics
* that drive those decisions. It manages per-frame state to support those
* heuristics.
class ActiveLayerTracker {
static void Shutdown();
* We track style changes to selected styles:
* eCSSProperty_transform, eCSSProperty_translate,
* eCSSProperty_rotate, eCSSProperty_scale
* eCSSProperty_offset_path, eCSSProperty_offset_distance,
* eCSSProperty_offset_rotate, eCSSProperty_offset_anchor,
* eCSSProperty_offset_position, eCSSProperty_opacity
* and use that information to guess whether style changes are animated.
* Notify aFrame's style property as having changed due to a restyle,
* and therefore possibly wanting an active layer to render that style.
* Any such marking will time out after a short period.
* @param aProperty the property that has changed
static void NotifyRestyle(nsIFrame* aFrame, nsCSSPropertyID aProperty);
* Notify that a property in the inline style rule of aFrame's element
* has been modified.
static void NotifyInlineStyleRuleModified(nsIFrame* aFrame,
nsCSSPropertyID aProperty);
* Notify that a frame needs to be repainted. This is important for layering
* decisions where, say, aFrame's transform is updated from JS, but we need
* to repaint aFrame anyway, so we get no benefit from giving it its own
* layer.
static void NotifyNeedsRepaint(nsIFrame* aFrame);
* Return true if aFrame's property style in |aPropertySet| should be
* considered as being animated for constructing active layers.
static bool IsStyleAnimated(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsCSSPropertyIDSet& aPropertySet);
* Return true if aFrame's transform-like property,
* i.e. transform/translate/rotate/scale, is animated.
static bool IsTransformAnimated(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame);
* Return true if aFrame's transform style should be considered as being
* animated for pre-rendering.
static bool IsTransformMaybeAnimated(nsIFrame* aFrame);
* Return true if aFrame either has an animated scale now, or is likely to
* have one in the future because it has a CSS animation or transition
* (which may not be playing right now) that affects its scale.
static bool IsScaleSubjectToAnimation(nsIFrame* aFrame);
* Transfer the LayerActivity property to the frame's content node when the
* frame is about to be destroyed so that layer activity can be tracked
* throughout reframes of an element. Only call this when aFrame is the
* primary frame of aContent.
static void TransferActivityToContent(nsIFrame* aFrame, nsIContent* aContent);
* Transfer the LayerActivity property back to the content node's primary
* frame after the frame has been created.
static void TransferActivityToFrame(nsIContent* aContent, nsIFrame* aFrame);
} // namespace mozilla