Actually the workaround that is used to show parenthesis in the right direction
is not needed any more, since this is part of the unicode bidi writing algorithm.
This fixes at the same time the use of [] or as delimiters in arabic, which was wrong on screen.
Note that there is a problem with hebrew, but this will require a fileformat change.
The use of RLO/LRO overrides to force text orientation was really hackish and the way it was done caused dropped letters in Mac OS X (for some unknown reasons).
This new approach is much cleaner, except that it relies on features not advertised in documentation
but present at least from Qt 4.5 to Qt 5.3:
* TextFlag enum values TextForceLeftToRight and TextForceRightToLeft, which are strong versions
of QPainter::setLayoutDirection; they are passed as a parameter of QPainter::drawText.
* QTextLayout::setFlags method, which is required to pass the above flags to QTextLayout.
The unicode override method is still used to draw strings Mac OS X because, for some reason, the direction was not really enforced in this case.
This can only be done where splitting of string is identical in row breaking and display. It will be possible to reintroduce this when row painting uses the tokenized row information.
This variable was introduced to guard against any bad consequence of the then-new right-to-left
languages support. Let's be bold and get rid of it altogether!
Now right to left support is always enabled.
This commits (tries to) reintroduce properly the code that was reverted at the beginning of this branch. This had to be done because these patches interefered with the big refactoring of TextMetrics.cpp.
This commit reintroduces the changes to TextMetrics.cpp contained in c668ebf6, c85dbfea9 and 061509bf.
This is handled by Qt now.
Note that a small optimization (do not draw text that is to the left
of WorkArea) is removed because it cannot be guaranteed to be exact
anymore. It was probably not very useful anyway, and would become
useless once the RowPainter is rewritten to use Row information.
Update 00README_STR_METRICS_BRANCH.
The display of partially-selected word is now done in a new Painter::text method
which displays the string twice with different clip settings. This allows to
catter for the case where Color_selectiontext is not black.
Morover, the code that uses unicode override characters to force the
direction of a string is moved to lstrings.h.
Fixes: #9116
Moreover, breaks row at insets when there is no suitable separator.
Also make the code of Row::shorten_if_needed somewhat simpler by using
iterators and factoring the code.
Fixes: #9120
The old implementation of Row::Element::pos2x and x2pos did not work
correctly with Arabic text, because characters can have shapes that
depend on context.
This new implementation leverages QTextLayout in a simplified way,
since only one word is added to the layout.
This allows to make Row::Element::x2pos more readable.
Fixes: #9115.
Do not cut strings at separators in RowPainter when text is not
justified. This speeds-up painting by reducing the number of strings
to draw.
Do also a modest cleanup of paintChar (remove dubious optimization).
Instead of relying on character range (Hebrew or Arabic) or character
direction, use RLO unicode character (Right-to-Left override) to force
painting in the direction indicated by the current font. This should
be as close as we can to the old LyX behavior (and requires less
code).
If this code works as intended, it will be possible to remove a lot of
code from Encodings.cpp.
We rely on Qt built-in unicode support for handling Arabic and Hebrew
compose characters. This allows to avoid to use our homegrown
machinery.
This should provide a nice speedup at a low cost and
will eventually allow us to get rid of:
* most of our Arabic/Hebrew machinery in Encodings.cpp,
* Paragraph::transformChar,
* and probably more.
All these problems are related to what happens at the extreme points of rows
* since VIRTUAL elements have a width but no contents, they have to
be treated specially at some places. It would have been better to
avoid testing for them explicitly, but I did not find a way.
* Improve and cleanup the code in breakRow and fix in passing a crash
when clicking on the right of an incomplete MARGIN_MANUAL
paragraph.
* improve the computation of row width in TextMetrics::computeRowMetrics.
* handle properly the case where a position if not found on the row
in both cursorX and getPosNearX (actually, this happens when
selecting).
* Some code cleanup and comments.
The fact that the bug was still present in the features/str-metrics
branch comes from a goof in the initial implementation of 'virtual'
row elements (completion and end-of-par markers). Now that this is
corrected, everything works as it should.
The fact that the bug is present in master is due to some other reason
that is not useful to investigate now.
* fix handling of boundary situations in Row::Elements::x2pos;
* fix handling of boundary situations in TextMetrics::getColumnNearX;
* make sure to always use Font::isVisibleRightToLeft instead of Font::isRightToLeft;
* Improve debug messages.
The horizontal position of the inset was not taken in account.
The rounding is not always the same as with the old code, but this
is not really important.
Additional changes:
* improve debug output of rows
* remove Bidi& argument of the RowPainter constructor, since it is always
an empty Bifi that is passed. This means that the Bidi class is not
used at all any more in TextMetrics.cpp. The only remaining user is
RowPainter.
Break words longer than the screen width. The code is more complicated
than I would like, but I have no better idea right now.
Implement properly the notion of a row broken by a display inset. This is useful in different places.
Also fix a bug with last line of a paragraph spotted by Kornel.
Use proper font everywhere for end-of-par marker
Fix getColumnNearX for RTL text and for centered/right-justified paragraphs.
Let computeRowMetrics update the row width.
* convert cursorX to new scheme; old computation is still there for the sake of comparison.
* use Row to compute separator width in computeRowMetrics; again, the old code is retained for now.
* Get rid of rowWidth()
* Row now contains a vector of Elements
* replace Row::dump by a proper << operator
* the width is updated as elements are added
* breakRow is reimplmented to use this infrastructure
Collect properly all strings to compute string metrics
Some changes with respect to existing code
- end of paragraph font is now the one of the text
- words longer than a line are not broken anymore. I think this is not useful if we have horizontal scrollbar
Other than that, the code is still compatible with rowWidth and friends.
The configuration time suffers mostly on checking, which of the export tests
is to be reverted.
1.) There is a new configuration flag now, "LYX_ENABLE_EXOPRT_TESTS.
If not set (default) no export tests are created.
2.) If set, then the optimization halves the time needed for creation of tests.
The effect on my side:
a.) Until now the time was: ~ 26 seconds
b.) The optimized time is now: ~ 16 seconds
c.) With not enabled export tests: ~ 5 seconds
