The method horizontalAdvance() replaces width() starting with Qt 5.11.
To handle this, all direct calls to QFontMetrics::width() are replaced
by calls to GuiFontMetrics::width(), and the code for
GuiFontMetrics::width(QChar) uses horizontalAdvance on newer Qt
versions.
Without this patch, there would be errors like these (warnings turned into errors):
D:\LyX\lyx-unstable\src\frontends\qt\GuiView.cpp(2413): error C4101: 'e': unreferenced local variable
D:\LyX\lyx-unstable\src\frontends\qt\GuiView.cpp(4879): error C4101: 'ex': unreferenced local variable
Intended changes:
* code is shorter and cleaner
* caret scales better with zoom when cursor_width=0: completion
indicator, l-shaped cursor...
Details:
* Rename BufferView::getPosAndHeight to getPosAndDim because ascent is
needed too and width could in the future be set depending on font.
* Get rid of rect_ in CaretWidget and record a Dimension (and y value) instead.
Remove also caret_width_ and slant_, replace rtl_ with dir.
* Make CaretWidget members public and lose the trailing _.
* change CaretWidget::update to read its parameters from current bufferview.
This can lead to mistakes. If no buffer is required at the beginning,
it is better to pass 'nullptr' explicitly.
Fix a case of missing parameter in GuiCompleter (introduced at
f3656600). This avoids some spurious "There is no group open (creating
one)" messages.
Fixes for bug #11428. Emphasis is used regularly and it is helpful to
see whether the next text will be written emphasized directly from the
cursor.
This is also implemented in MS Word and Google docs but not in
LibreWriter.
Also fixes the caret for RTL languages whose width was previously
extended into the wrong direction.
Instead of working around crashes in update of caret geometry, only
request it as needed. The actual computation will take place just
before painting the caret.
It might be that this is overkill and that caret geometry should be
updated unconditionally. One would have to to some timing while idle to
ascertain that.
Fixes bug #11912.
The rules for typesetting math differ from the rules for typesetting
text. For example, two italic 'f' chars have to be typeset more closely
than two 'o' chars in text mode, but not in math mode. Qt provides a
method that returns the distance appropriate for drawing a subsequent
character in text mode, but nothing for math mode. Typically, the
distance appropriate for drawing the next character in math mode is
the actual width span by the character, corrected by the rules of
an appendix in the TeXbook. Recently, those rules are followed more
closely in LyX but not exactly, and we have to find a way to adapt to them.
Some symbols may need more spacing around them than the width they span.
So, we use the distance suggested by Qt, unless it is less than the
width of the rectangle bounding the symbol. Before Qt 5.11 the used method
was QFontMetrics::width(), but since then it has been declared obsolete
in favor of QFontMetrics::horizontalAdvance(), whose name conveys better
its meaning.
Instead of working around crashes in update of caret geometry, only
request it as needed. The actual computaiton will take place just
before painting the caret.
It might be that this is overkill and that caret geometry should be
updated unconditionally. One would have to to some timing while idle to
ascertain that.
Fixes bug #11912.
When the fonts distributed with texlive with same family name
as ours are also managed by fontconfig, Qt is not able to
discriminate ours by the style only. In order to be sure Qt
will load our fonts, we change the foundry name from 'PfEd'
to 'LyEd' and augment the font family name with this foundry
name. This only works on *nix, because adding a foundry name
seemingly breaks things on Windows. However, this is a *nix
only problem, seemingly.
