This patch mainly consists of two parts, one for resolving and the other
for reordering.
In the resolving part, the added code stores the lowest embedding level
of all bidi formatting characters precede a frame to the bidi data of
that frame when necessary.
In the reordering part, virtual frame is restored from the information
stored above before asking the bidi engine to reorder frames
Collapsing a run of continuous virtual formatting characters into one
virtual character with the lowest embedding level among them should work
because a character with a higher embedding level than either of its
neighbors should not affect the reordering result of any other part of
the sequence. (No formal proof of this theorem, though)
MozReview-Commit-ID: LQjRu0mWsZP
This patch is mainly based on smontagu's wip patch. Some non-trivial differences:
* BidiParagraphData.mIsolateCount and related code are not added in this patch.
I investigated uses of this field in the wip patch, and it seems to me none of
them makes sense:
1. in the fast path of nsBidiPresUtils::ResolveParagraph, if there would be
any isolate character in the surrounding text, there must exist more than
one runs, which indicates the isolate count condition is redundant.
2. in handle of br frame in nsBidiPresUtils::TraverseFrames, based on my
understanding of "CSS Writing Modes Level 3" section "2.4.4. Paragraph
Breaks Within Embeddings and Isolates", the resolving should happen
unconditionally.
* {control,override}Char in nsBidiPresUtils::TraverseFrames are assigned
unconditionally when in a bidi inline container, so that we can properly
handle it when there are continuations. I suspect this was the reason of
regressions in dynamic reftests from the wip patch mentioned in comment 1.
MozReview-Commit-ID: LUdBAapA48e
Masayuki suggests GetCharcterRectsInRange instead of first idea's API by part 2 implementation.
IME wants to need the width per character. Now nsTextFrame/nsIFrmae has only API to get point of string. So I want to add this method to calculate simply by comment #3.
If no text frame, I would like to return error due to no character. (Caller shouldn't call this API on non-text frame.)
MozReview-Commit-ID: LQHUTzhnGn
Before this change, SetupJustificationSpacing calls ComputeJustification
to compute how justification gaps are assigned to characters, and store
them in the PropertyProvider instance. When GetSpacing is called, those
information would be used to compute actual spacings from justification
before/after each character.
The bug is that, GetSpacing did not take gaps before the given range
into account when computing the spacing, which leads to unstable results
when range varies because of ignorance of accumulated error.
This patch changes it to eagerly computing the actual spacings inside
SetupJustificationSpacing, so that GetSpacing just queries the result
from mJustificationSpacings.
MozReview-Commit-ID: HoWqeOhD85w
This patch defines two constants kSelectionTypeCount and kPresentSelectionTypeCount. The former is same as nsISelectionController::NUM_SELECTIONTYPES. The latter is kSelectionTypeCount - 1 for excluding SELECTION_NONE. The latter is useful in some loops which handle all selection types except SELECTION_NONE.
Note that this patch fixes a bug of nsFrameSelection. That doesn't treat SELECTION_NONE as a selection (see the definition of index), however, it defines redundant item and doesn't use it actually. Additionally, it computes invalid selection type in each loop. Therefore, without this patch, debug build hits MOZ_ASSERT() in ToSelectionType(RawSelectionType).
Note that these constants are defined as anonymous enum because we cannot define as const (or static) even with extern. If we'd try to do it, it caused link error or not available in nsFrameSelection.cpp as constant value since they were not initialized if they were initialized in nsSelection.cpp. Therefore, these constants are defined as enum items but using "k" prefix.
MozReview-Commit-ID: H6sH7NBEXlE
This patch defines mozilla::SelectionType as an enum class. This is safer than nsISelectionController::SELECTION_* since setting illegal value to its variable is checked at build time. So, as far as possible, this should be used everywhere (but of course, this isn't available in scriptable interfaces).
And also this implements some useful methods for managing SelectionType and RawSelectionType which are implemented in layout/nsSelection.cpp because nsISelectionController is implemented by both PresShell and nsTextEditorState. Therefore, implementing one of them may make hard to find them. On the other hand, nsSelection.cpp is a better file name to look for them.
Note that this patch creates mozilla::Selection::RawType() for binding. Native code should keep using Selection::Type() but the binding code needs to use RawType() due to impossible to convert from SelectionType to RawSelectionType without explicit cast.
MozReview-Commit-ID: 81vX7A0hHQN
mozilla::SelectionType will be an enum class. Therefore, we need to rename SelectionType with a word "raw" since it's a type for raw nsISelectionController::SELECTION_*.
MozReview-Commit-ID: K8SO0bbpv0Y
Unlike when returning an nsCOMPtr in a ternary operator or passing to a
function, I used .get() here, since the operation is actually unsafe and
deserves to be marked explicitly.
