When the cursor in RTL text, icons for "depth-increment" or
"layout-toggle Enumerate" look wrong.
To fix this, the lfun "bidi" is introduced. "bidi ltr func" behaves
like "func" in LTR text, but is unknown in RTL text. "bidi rtl" does
the opposite. This allows to add two icons, but only have one icon
available. When no document is available, only LTR is assumed.
To make this work, the handling of unknown functions in toolbar has
been changed so this these functions can change dynamically their
existence.
The icon themes `default', `oxygen' and `classic' have been updated
accordingly.
Fixes bug #4451.
In particular, the directory frontends/qt4 is renamed to frontends/qt.
Many configurations file have to be updated. All mentions of qt4 in
the source have been audited, and changed to qt if necessary.
The only part that has not been updated is the CMake build system.
By default, the behavior is the same as before, except that the
language of new document is not unconditionally en_US anymore.
The new checkbox "Respect OS keyboard language" (off by default)
governs this behavior.
Update prefs format to 30.
Instead of setting language from context when moving the cursor, set
it to the OS input language. This behavior will probably need to be
controlled by a preference, since not everybody changes keyboard
mapping when changing language.
This required to move BufferView::setCursorLanguage to
Cursor::setLanguageFromInput().
This bug provides two features:
1/ when a new document is created the language is set to the current
keyboard language.
2/ when keyboard is switched at OS level, the input language of
current window is changed. The language is set preferably to one of
those of the document. Ex. if the keyboard changes to en_GB but one
is typing a document in US English and Hebrew, then US English will
be selected rather that adding UK English to the list.
The implementation depends a lot on Qt. The platform status is :
* working on Windows 10
* not working with Linux (although 1/ works with Qt4); it seems that
Qt5 supports switching through ibus, but I do not know what this
means.
* not yet tested on macOS.
This addresses bugs #6450, #6247 and somehow #10514.
