This means that, when a string contains high-plane Unicode characters,
the length of a docstring and the corresponding QString will be
different: Qt will encode these characters using several 16bit
characters.
We have additionally to take into account QTBUG-25536, which implies
that sometimes qstring_to_ucs4(toqstr(s)) !=s. It is not clear whether
this bug can be a problem in other places.
Fixes bug #10443.
This fixes two particular problems
* with Qt5, it seems that QFontMetrics::width does not return the
correct value for some Arabic text; this patch uses QTextLayout
instead to compute a string width
* Likewise, the undocumented layout flags TextForceRightToLeft and
TextForceLeftToRight do not work with Arabic text; this patch uses
unicode override characters instead.
It might be that the two issues are related. In any case, they do not
happen with latin text where right-to-left direction is enforced. And
they do not happen with Qt4.
Additionally, remove some dead code in GuiFontMetrics::pos2x().
Fixes bug #10436.
This should avoid performance problems related to the window update machinery.
Moreover this fixes a crash introduced by 82808fea when closing a file.
Note that GuiWorkArea::Private already had a read_only_ member, but it
was unused.
Also rename LyXVC::vcname() to LyXVC::vcstatus() since it now contains
directly the UI string to be shown.
Now that there is a signal to inform the controller when the buffer view has
changed, it is no longer necessary to store a perishable pointer to a buffer
view in the dialog view. (Indeed, it was only really useful for checking whether
the new buffer view pointer was different from the old one.)
TODO: other dialogs should be audited for similar hazards.
The limit of 10% is used in both getStatus() and dispatch() to set a
minimum zoom level. Having it centralized makes the code more
readable and makes changing the minimum less error-prone.
A better solution would be to entirely get rid of this borrowed pointer with
unclear lifetime, but this requires to introduce a new signal for when the
buffer view attached to the GuiView has changed.
The title is changed to "LaTeX (pdflatex) Preview", etc. depending on the
format. The actual default format is computed.
The menu name "Source Pane" is replaced by "Code Preview Pane" to better reflect
its purpose.
The window title is built from the current file name and its
mofidication state. We use our own code instead of the automatic title
bar provided when windowFileName() is set because
1/ Qt does not keep the full path name
2/ Qt does not yield a nice application name
The "read only" and "version control" status are shown in the status bar:
* for read only we use the tab read only emblem (with the right size)
* for version control, we show the name of the backend (using a new
vcname() method of the backend).
The iconText() of the view is not updated anymore, since this is
deprecated in Qt5.
