The MOZ_DEBUG_RESTYLE_STRUCTS environment variable can be set to a comma-
separated list of style struct names. When restyle logging is enabled,
this will cause the style context tree -- showing cached style struct
pointers for those structs specified -- to be logged before each
individual restyle is processed. It will also show the struct pointer
values involved when swapping structs between style contexts.
For example, set MOZ_DEBUG_RESTYLE_STRUCTS=Font,UserInterface to show
the cached nsStyleFont and nsStyleUserInterface pointers on the style
contexts involved in the restyle process.
Set the MOZ_DEBUG_RESTYLE environment variable and every restyle will have
detailed logging printed to stderr. By default, restyles for animations are
not logged; you can include them by also setting MOZ_DEBUG_RESTYLE_ANIMATIONS.
If you wish to limit restyle logging to a particular change, you can call
nsPresContext::StartRestyleLogging() and nsPresContext::StopRestyleLogging()
at appropriate points. (You might want to add a couple of helper methods
temporarily on nsIDocument and then expose them to your page with Web IDL
to make them easier to call.) You do not need to have set MOZ_DEBUG_RESTYLE
for this to work.
Set the MOZ_DEBUG_RESTYLE environment variable and every restyle will have
detailed logging printed to stderr. By default, restyles for animations are
not logged; you can include them by also setting MOZ_DEBUG_RESTYLE_ANIMATIONS.
If you wish to limit restyle logging to a particular change, you can call
nsPresContext::StartRestyleLogging() and nsPresContext::StopRestyleLogging()
at appropriate points. (You might want to add a couple of helper methods
temporarily on nsIDocument and then expose them to your page with Web IDL
to make them easier to call.) You do not need to have set MOZ_DEBUG_RESTYLE
for this to work.
Later patches will combine the coalescing of restyling between the
miniflush performed for animations and for transitions into a single
RestyleTracker, which will coalesce the work better. This patch changes
the API exposed for doing that so that the coalescing patch will contain
only the internals.
This depends on bug 898333 in order to avoid causing:
TEST-UNEXPECTED-FAIL | chrome://mochitests/content/chrome/dom/tests/mochitest/chrome/test_focused_link_scroll.xul | Assertion count 1 is greater than expected range 0-0 assertions.
due to the assertion:
###!!! ASSERTION: Shouldn't be trying to restyle non-elements directly: '!aContent || aContent->IsElement()', file ../../../layout/base/nsStyleChangeList.cpp, line 62
The assertion count change in layout/generic/crashtests/571995.xhtml is
expected because it changes us from having 7 of:
###!!! ASSERTION: Shouldn't be trying to restyle non-elements directly: '!aContent || aContent->IsElement()', file ../../../layout/base/nsStyleChangeList.cpp, line 62
with the stack:
mozilla::ElementRestyler::CaptureChange(nsStyleContext*, nsStyleContext*, nsChangeHint) [layout/base/nsChangeHint.h:191]
mozilla::ElementRestyler::RestyleSelf(nsRestyleHint) [layout/base/RestyleManager.cpp:2304]
to only having one. This is expected since this patch changes
RestyleSelf to only call CaptureChange for the first continuation or
block-in-inline sibling.
This patch fundamentally makes three changes:
(1) Change the way RestyleSelf is used so that it is called in a loop,
over all of the same-style continuations and block-in-inline
siblings.
(I had a note here reminding myself:
TODO: Don't set hints for descendants!
but I no longer remember what it meant.)
(2) Change the traversal of children to traverse all of the children of
the items traversed in (1).
(3) When traversing children, skip children that are continuations,
since we already reached them in (1) and (2).
A later patch will change the RestyleSelf loop to copy for the later
continuations rather than repeating the work. This will mean reverting
many of the RestyleSelf changes contained here.
Some of the pieces marked temporary will be removed in bug 828312 patch
11, and the rest should hopefully be removed in bug 918064.