This propagates the non-inherited (in the nsChangeHint sense, not the
CSS inheritance sense) parts of the parent's change hint through
ReResolveStyleContext so that we can use them in
nsStyleContext::CalcDifference. In the cases where we don't know the
parent's hint, we assume the worst, that all the non-inherited hints
were present in the parent's style change.
This should be a significant performance improvement handling simple
style changes (such as a style attribute change setting a non-inherited
property) on elements with large numbers of descendants that have data
in ForceCompare structs that can't be stored in the rule tree (for
example, margins or widths in em or rem units).
This is in preparation for adding an additional caller.
nsChangeHint_NonInherited_Hints will be reintroduced in patch 6, but as
the maximum set of such hints rather than the minimal set, and with the
less confusing name nsChangeHint_Hints_NotHandledForDescendants.
This generation number will be incremented every time that the frame
tree for a presshell changes. Callers need to deal with the case where
this value overflows. We use this to avoid a bunch of Android
screenshotting.
* * *
Bug 539356 - Part 9a - Add new display list invalidation API to nsDisplayItem and implement it. r=roc
* * *
Bug 539356 - Part 9b - Add new frame invalidation API. r=roc
* * *
Bug 539356 - Part 9c - Remove old invalidation code. r=bz
* * *
Bug 539356 - Part 9d - Make SVG support the new invalidation model. r=jwatt
* * *
Bug 539356 - Part 9e - FrameLayerBuilder changes for display list invalidation. r=roc
* * *
Bug 539356 - Part 9f - Compute the invalid area of the layer tree and pass this to the widget. r=roc
* * *
Bug 539356 - Part 9g - Modify MozAfterPaint code to work with the new invalidation model. r=roc
This patch adds a change hint to signal that one of the offsets on a
frame has been changed. When processing the hint, we do one of the
following things based on the position property of the frame.
* For static frames, we ignore the offset changes completely, as they
will not change the layout.
* For relative positioned frames, this patch refactors the
nsHTMLReflowState::ComputeRelativeOffsets function so that it can be
used from other callers, and it uses that to compute the new relative
offsets, and uses the offsets computed previously to compute the new
position of the frame.
* For absolute positioned frames, we set up a fake parent reflow state
object, and then we create a new reflow state object for the frame in
question. This setup is similar to what nsFrame::BoxReflow does.
Once we have the new reflow state object, we use it to compute the
absolute offsets, and then we use the computed offsets to set the new
position of the frame. The offset computation is similar to what
nsAbsoluteContainingBlock::ReflowAbsoluteFrame does. In some cases
where it is possible for the dimensions of the frame to change based
on the offset changes, we fall back to a full reflow.
