1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/base/ActiveLayerTracker.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,86 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +#ifndef ACTIVELAYERTRACKER_H_
1.9 +#define ACTIVELAYERTRACKER_H_
1.10 +
1.11 +#include "nsCSSProperty.h"
1.12 +
1.13 +class nsIFrame;
1.14 +
1.15 +namespace mozilla {
1.16 +
1.17 +/**
1.18 + * This class receives various notifications about style changes and content
1.19 + * changes that affect layerization decisions, and implements the heuristics
1.20 + * that drive those decisions. It manages per-frame state to support those
1.21 + * heuristics.
1.22 + */
1.23 +class ActiveLayerTracker {
1.24 +public:
1.25 + static void Shutdown();
1.26 +
1.27 + /*
1.28 + * We track style changes to selected styles:
1.29 + * eCSSProperty_transform
1.30 + * eCSSProperty_opacity
1.31 + * eCSSProperty_left, eCSSProperty_top, eCSSProperty_right, eCSSProperty_bottom
1.32 + * and use that information to guess whether style changes are animated.
1.33 + */
1.34 +
1.35 + /**
1.36 + * Notify aFrame's style property as having changed due to a restyle,
1.37 + * and therefore possibly wanting an active layer to render that style.
1.38 + * Any such marking will time out after a short period.
1.39 + * @param aProperty the property that has changed
1.40 + */
1.41 + static void NotifyRestyle(nsIFrame* aFrame, nsCSSProperty aProperty);
1.42 + /**
1.43 + * Notify aFrame's left/top/right/bottom properties as having (maybe)
1.44 + * changed due to a restyle, and therefore possibly wanting an active layer
1.45 + * to render that style. Any such marking will time out after a short period.
1.46 + */
1.47 + static void NotifyOffsetRestyle(nsIFrame* aFrame);
1.48 + /**
1.49 + * Mark aFrame as being known to have an animation of aProperty.
1.50 + * Any such marking will time out after a short period.
1.51 + */
1.52 + static void NotifyAnimated(nsIFrame* aFrame, nsCSSProperty aProperty);
1.53 + /**
1.54 + * Notify that a property in the inline style rule of aFrame's element
1.55 + * has been modified.
1.56 + * This notification is incomplete --- not all modifications to inline
1.57 + * style will trigger this.
1.58 + */
1.59 + static void NotifyInlineStyleRuleModified(nsIFrame* aFrame, nsCSSProperty aProperty);
1.60 + /**
1.61 + * Return true if aFrame's aProperty style should be considered as being animated
1.62 + * for constructing active layers.
1.63 + */
1.64 + static bool IsStyleAnimated(nsIFrame* aFrame, nsCSSProperty aProperty);
1.65 + /**
1.66 + * Return true if any of aFrame's offset property styles should be considered
1.67 + * as being animated for constructing active layers.
1.68 + */
1.69 + static bool IsOffsetOrMarginStyleAnimated(nsIFrame* aFrame);
1.70 +
1.71 + /*
1.72 + * We track modifications to the content of certain frames (i.e. canvas frames)
1.73 + * and use that to make layering decisions.
1.74 + */
1.75 +
1.76 + /**
1.77 + * Mark aFrame's content as being active. This marking will time out after
1.78 + * a short period.
1.79 + */
1.80 + static void NotifyContentChange(nsIFrame* aFrame);
1.81 + /**
1.82 + * Return true if this frame's content is still marked as active.
1.83 + */
1.84 + static bool IsContentActive(nsIFrame* aFrame);
1.85 +};
1.86 +
1.87 +}
1.88 +
1.89 +#endif /* ACTIVELAYERTRACKER_H_ */
